Ophthalmology Review

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September 30, 2005

Ahmed Valve Surgery for Refractory Pediatric Glaucoma: A Report of 52 Eyes

Journal of Pediatric Ophthalmology and Strabismus ,Sep/Oct, 2005

We performed a retrospective review of patients younger than 18 years of age who had Ahmed valve surgery from November 1994 to January 2003.
There were 52 eyes of 41 patients. The two most common diagnoses were congenital glaucoma and aphakic glaucoma .The mean number of glaucoma surgeries before Ahmed valve implantation was 1.7 ± 1.7. The mean age at the time of implantation was 4.9 ± 6.5 years. The mean IOP decreased from 38.1 ± 6.4 mm Hg to 20.7 ± 8.2 mm Hg at last follow-up. The final visual acuity was improved or within one Snellen line in 81.5% of the eyes. The mean postoperative follow-up period or time to failure for all patients was 2.2 ± 1.8 years (range, 3 months to 7.5 years).
CONCLUSIONS:The Ahmed valve was found to be useful in the management of refractory pediatric glaucoma. Although our success rates were similar to those observed in adults, the rates of certain postoperative complications were different.

Posted by afarahi at 11:08 PM | Comments (0)

Retroscleral Implantation Technique for Porous Polyethylene Orbital Implant After Evisceration

OPHTHALMIC SURGERY, LASERS AND IMAGING , September/October, 2005

The authors developed a technique for the retroscleral implantation of a porous polyethylene orbital implant after evisceration for the placement of an adequately large orbital implant without wound tension. The surgical results of the technique in 27 patients are reported. The technique involves the severance of the optic nerve after standard evisceration and the insertion of the orbital implant into the retroscleral and intraconal space through the side of the scleral shell. All patients received a 20-mm orbital implant. No complications such as infection, implant exposure, or worsened implant motility were observed during the average follow-up period of 22.4 months. Retroscleral implantation of the orbital implant after evisceration may be an appropriate procedure that allows placement of a large orbital implant without exposure or decreased implant motility.

Posted by afarahi at 10:45 PM | Comments (0)

The Association Between Hypermetropia and Essential Hypertension

AJO,Sep,2005
Three hundred twenty-one patients with essential hypertension and 188 age-matched and sex-matched healthy control subjects were consecutively included for the study .The mean spherical equivalent of the patients with essential hypertension was +0.88 ± 1.34 diopters (range −3.75 to +6.38 diopters), whereas the mean spherical equivalent of the control subjects was −0.26 ± 1.12 diopters (range −5.00 to +3.38 diopters) (P < .0001). Whereas 61.4% of hypertensive patients were hypermetropic, 18.1% of normotensive patients were hypermetropic (P < .0001).
Conclusions:There is a strong association of essential arterial hypertension with hypermetropia, which has not been previously reported. Given the findings of this study, we recommend that patients who have hypermetropia and have had no recent systemic examination should at least have their blood pressure checked.

Posted by afarahi at 12:28 PM | Comments (0)

September 29, 2005

Similar outcomes seen with patching, atropine

Ophthalmology Times Sep 1, 2005
In a multicenter trial, 419 children younger than 7 years with amblyopia (20/40 to 20/100 in the affected eye) were assigned to receive either patching (6 or more hours a day) or daily atropine for 6 months. Between 6 months and 2 years, treatment was at the discretion of the investigator.
Outcomes 18 months after completion of the randomized portion of the trial showed that both therapeutic approaches produced similar improvement in children who were between the ages of 3 and 7 years at enrollment.
Mean improvement in visual acuity from baseline was 3.7 lines in the patching group and 3.6 lines in the atropine group.
In both groups, the mean amblyopic eye acuity was approximately 20/32.
Six-month results, reported in 2002, had also shown that children in both groups had about the same improvement, an outcome that held up through the more recent follow-up, Dr. Repka said.
Hours of patching
In another study of moderate amblyopia, investigators compared 2 hours with 6 hours of prescribed daily patching and found similar outcomes in both groups after 4 months of treatment. And in a study of children with severe amblyopia, they compared 6 hours of daily patching with patching all waking hours. Again, results indicated that both treatment groups had similar levels of improvement.

Posted by aman at 11:29 PM | Comments (0)

High-frequency UBM helpful tool in strabismus reoperation

Ophthalmology Times Sep 1, 2005
The high-frequency ultrasound biomicroscope (UBM) can reliably estimate the distance of horizontal muscle insertion from the limbus in eyes that had previous strabismus surgery on the same muscle, according to Shuan H. Dai, MB, BS, FRANZCO, a pediatric ophthalmologist.
With this available information, surgeons can lessen the risk of potential perioperative complications such as excessive surgical manipulation, prolonged procedure time, and unnecessary scarring of the conjunctiva, said Dr. Dai, who presented a poster at the annual meeting of the American Academy of Pediatric Ophthalmology and Strabismus.
In a prospective, masked, observational study, he and his colleagues compared the measurements obtained with the UBM preoperatively and with a surgical caliper intraoperatively.
We found quite good correlations between the two methods," Dr. Dai explained. The mean distance of horizontal muscle insertion was 9.035 mm with UBM and 9.341 mm with the surgical caliper. The difference between the two methods was within 1 mm in 80.5% of the muscles measured.

Posted by aman at 11:20 PM | Comments (0)

Favorable results persist with implant

Ophthalmology Times Sep 1, 2005
Follow-up in the first 10 patients with the Artificial Silicon Retina microchip (ASR, Optobionics) implanted now ranges between 2 and 4.5 years.
"Not only has it been exciting that these patients appear to have improved vision over their baseline vision despite a variety of retinitis pigmentosa (RP) conditions, but it is notable that none has experienced any vision deterioration in the eye with the implant, although vision loss has occurred in some of the fellow eyes," said Dr. Chow, assistant professor, department of ophthalmology, Rush University Medical Center, Chicago.
In addition, visual function improvements included unexpected improvements in retinal areas distant from the implant as well as adjacent to it, supporting the prospect that the mechanism of the ASR chip might involve some neurotrophic/neuroprotective effect on the damaged retina," Dr. Chow added.
The ASR microchip is a photodiode-based device designed to stimulate contacting retinal cells electrically upon exposure to incident light.
The device measures 2 mm in diameter, is 25 µm thick, and is embedded with about 5,000 electrode-tipped, isolated microphotodiodes. The ASR microchip is implanted in the subretinal space 20° from the macula.

Posted by aman at 11:04 PM | Comments (0)

MICROSCOPE PHOTOTOXICITY

CRS TODAY Aug 2005
The first case of retinal phototoxicity undoubtedly occurred shortly after the operating microscope’s first use for cataract extraction, although it was nearly 30 more years before this complication was fully recognized.2 Light toxicity occurs in 3% to 7% of cataract cases. The duration of light exposure correlates with the risk of injury, although phototoxicity has even been reported in cases lasting just 11 minutes.3 The early finding of deep retinal whitening, with or without serous retinal detachment, resolves during the first 48 hours after surgery, and it is replaced by mottling of the retinal pigment epithelium during the next several weeks. These pigmentary changes may only be visible with fluorescein angiography as a window defect (Figure 1). Patients often complain of a paracentral scotoma but may be asymptomatic. Vision loss can be profound if the injury includes the foveola.
The most powerful tool in preventing phototoxicity is recognizing that every eye surgeon using any form of illumination may cause this complication. Although no single maneuver has proven 100% effective in avoiding light damage, limiting exposure time and intensity to that which is necessary, using some form of a light shield when possible, and properly filtering the delivered light are simple steps we should all remember.

Posted by aman at 10:44 PM | Comments (0)

Limbal Registration

CRS TODAY Aug 2005
In order to achieve true customized ablation, preoperative wavefronts must be captured and matched to the patient’s cornea, a process called registration. To have true registration, surgeons need a point on the eye that will not move.
Since its debut, the Ladarvision excimer laser (Alcon Laboratories, Inc., Fort Worth, TX) has been the only wavefront-guided laser to have the capability of registration. Alcon Laboratories, Inc., developed the system to allow for true registration, which permits surgeons to measure the patient’s corneal aberrometry preoperatively and then match these measurements against the patient’s cornea at the time of surgery to ensure that they are applying the wavefront-guided correction to the appropriate area of the patient’s eyes.
HOW IT WORKS
To achieve an optimal outcome, surgeons must register initial wavefront measurements to a fixed feature on the patient’s eye and then apply the planned ablation profile to corresponding locations on the patient’s cornea. With the Customcornea system (Alcon Laboratories, Inc.), surgeons dilate the patient’s pupil, mark the limbus, and refer to the limbus before taking wavefront measurements at the aberrometer. When the patient is ready for surgery, the surgeon matches the limbal reference with the actual limbal mark on the patient’s eye, thus ensuring accurate centration and registration. Aligning the preoperative marks prevents cyclotorsion and translation. A new advance on the Ladarvision system is automatic pupillary centration and registration, which allow automatic and speedier processing of multiple images with one-click accuracy.

Posted by aman at 10:33 PM | Comments (0)

Iris Registration

CRS TODAY Aug 2005
The latest technological development for the registration of the intended and ablated wavefront shapes is automated iris registration, which was recently approved by the FDA for use with the Visx Customvue wavefront-guided system (Visx, Incorporated, Santa Clara, CA). Iris registration relies on matching reference points in the natural iris pattern to compensate for cyclotorsion and a pupillary centroid shift between the time of wavefront capture and the ablation.
In 270 patients with preoperative BCVAs of 20/20 or better who underwent primary laser vision correction, the mean cyclotorsional movement was 2.4 ±2.0º. A comparative analysis was conducted on a subgroup of eyes with 1.50D of preoperative cylinder or greater.1 Cohort A (n=57) was treated without iris registration; cohort B (n=59) was treated with iris registration. The two groups had similar levels of cylinder preoperatively. After surgery, the iris-registration cohort had 50% less cylinder (0.20D compared with 0.40D for the non–iris-registration cohort)
Additionally, there was a statistically significant difference between the two groups in the percentage of eyes that achieved 20/20 or better UCVA postoperatively. Ninety-two percent of the iris registration cohort versus 82% of the non–iris-registration cohort saw 20/20 or better at the last postoperative visit (mean postoperative visit = 2.5 months).

Posted by aman at 10:11 PM | Comments (0)

Effect of Decentration of Wavefront-Corrected Intraocular Lenses on the Higher-Order Aberrations of the Eye

ARCHIVES Sep 2005
To evaluate the theoretical effect of decentration of aspherical intraocular lenses (IOLs) and wavefront-corrected IOLs up to the sixth order on higher-order aberrations (HOAs) (third through sixth order) of the eye.
Results Simulated implantation of the aspherical IOLs and wavefront-corrected IOLs was performed in 154 eyes of 94 patients aged 40 to 80 years. For a centered aspherical IOL and a 6-mm pupil, no eyes met the Marechal criterion, and the P10 and decreased-HOA criteria were met by 46% and 93% of eyes, respectively. For a 6-mm pupil, the required centration was 0.47 mm to meet the decreased-HOA criterion in 50% of eyes. With a wavefront-corrected IOL and a 6-mm pupil, the centrations required to meet the criteria for 90% of eyes were 0.04 mm for the Marechal criterion, 0.36 mm for P10, and 0.48 mm for the decreased-HOA criterion.
Conclusion Excellent centration is required to maximize the visual outcome of wavefront-corrected IOLs.

Posted by aman at 10:02 PM | Comments (0)

September 25, 2005

Smokers twice as likely to develop AMD

Eye,Sep,2005
A systematic review of 17 published epidemiological studies evaluated against established criteria for evidence of a causal relationship confirms a strong association between smoking and AMD. Thirteen studies found a two- to three-fold increase in AMD risk among current smokers compared with those who never smoked. Five studies found no association between smoking and AMD. There was also evidence of dose-response, a temporal relationship and reversibility of effect.

Posted by afarahi at 11:11 PM | Comments (0)

Evaluation of the Cosmetic Significance of External Dacryocystorhinostomy Scars

AJO,Sep,2005
Two hundred ninety-seven external DCRs were performed in 263 patients at the private practices of consultants who were attached to the Sydney Eye Hospital. Structured questionnaires were sent to patients, and the responses were evaluated. Patients were asked to assess the visibility of the scar and the significance of the scar to them on a scale of 1 (least) to 5 (greatest).The average age of patients was 67.9 ± 16 years, (72% female, 28% male). Ninety-six percent of the patients were caucasians of Australian/West European descent. Sixty-one of 296 scars (20.6%) were felt to be visible by patients; 31 scars (10.5%) were rated >1 on a scale of 1 to 5 and 12 scars (4%) were rated >2. The average age of patients was highest for those patients with invisible scars, and the lowest average age was for those with scars that were rated >1.
Conclusion:In view of the low percentage of patients who complained of marked scarring, scarring should not be the main ground for deciding the approach to DCR surgery, particularly in older patients. These results are valid for the population that was studied and may be different for different racial backgrounds.

Posted by afarahi at 10:41 PM | Comments (0)

The use of apraclonidine eyedrops to treat ptosis after the administration of botulinum toxin to the upper face

Dermatology Online Journal 11(1): 9- 2005
A side effect of the injection of botulinum toxin into the upper third of the face is ptosis or lid droop.The incidence of ptosis after such injections is reported to be about 5 percent, and it can happen up to 2 weeks after injections. Ptosis results from migration of the botulinum toxin to the levator palpebrae superioris muscle. The levator allows the eyelid to open properly and fully. To avoid ptosis, injections should occur at least 1 cm above the eyebrow and should not cross the midpupillary line.
A therapy recommended to treat ptosis resulting from administration of botulinum toxins A and B is Iopidine™ (apraclonidine 0.5 %) eye drops. Apraclonidine is an α2-adrenergic agonist, which causes Müller muscles to contract quickly elevating the upper eyelid 1-3 mm. The most common dosing scheme used for iopidine is one or two drops three times daily until ptosis resolves.Little published data discusses the use of apraclonidine to treat such ptosis.Research needs to be done to establish the utility and dosing of apraclonidine for botulinum toxin-induced ptosis.

Posted by afarahi at 10:08 PM | Comments (0)

September 22, 2005

The Effects of Drug Delivery Via Hydrophilic Acrylic (Hydrogel) Intraocular Lens Systems on the Epithelial Cells in Culture

OPHTHALMIC SURGERY, LASERS AND IMAGING September/October 2005

This study was designed to assess the inhibitory effects of drugs delivered via hydrophilic acrylic (hydrogel) intraocular lens (IOL) systems in vitro. Lens epithelial cells were collected from albino rabbits. The following seven groups of hydrogel IOLs were prepared: untreated IOLs and IOLs infiltrated with diclofenac sodium, tranilast, mitomycin C, colchicines, 5-fluorouracil, and ethylenediaminetetraacetic acid. The IOLs were fixed to a Cell Culture Insert; they were then bathed and incubated in minimum essential medium containing cultured lens epithelial cells. Subsequently, a comparative analysis of the cells adhering to the collagen membrane and the lens surfaces was conducted.
Adhesion of lens epithelial cells to the lens surfaces and the collagen membrane was observed in the control group. However, only slight cellular adhesion was found on the surfaces of the IOLs and on the collagen membrane in the treated IOL groups.
CONCLUSION
Use of hydrogel IOLs infiltrated with drugs was associated with inhibition of posterior subcapsular opacification in vitro.

Posted by aman at 05:51 PM | Comments (0)

Bilateral Optic Disc Edema in Patients With Severe Systemic Arterial Hypertension: Clinical Features and Visual Acuity Outcomes

OPHTHALMIC SURGERY, LASERS AND IMAGING September/October 2005

Records were reviewed of patients with bilateral optic disc edema, severe arterial hypertension, and 3 or more months of follow-up evaluated at Bascom Palmer Eye Institute between 1982 and 2003.
RESULTS
Sixteen patients (median age = 41 years; median follow-up = 31 months) were identified. Median blood pressure on initial eye examination was 220 mm Hg systolic and 126 mm Hg diastolic. Among all study eyes, median visual acuity was 20/55 on presentation. At the last follow-up examination, an acuity of 20/50 or better was achieved in 20 (63%) eyes; 12 (75%) patients achieved a final acuity of 20/50 or better in at least one eye. Posterior segment abnormalities at last follow-up included disc pallor (n = 16), macular star (n = 7), retinal pigment epithelial atrophy (n = 7), epiretinal membrane (n = 5), branch retinal vein occlusion (n = 4), and persistent disc edema (n = 2). Causes of final acuity of less than 20/50 included optic atrophy, epiretinal membrane, serous retinal detachment, macular hole, and branch retinal vein occlusion.

Posted by aman at 05:21 PM | Comments (0)

New intravitreal implant provides effective treatment for macular edema

OSN EUROPE/ASIA-PACIFIC EDITION September 2005
A new implant that gradually releases dexamethasone into the vitreous cavity is demonstrating safety and efficacy in the treatment of macular edema, according to a recent phase 2 study.
This new implant is a promising alternative to the intravitreal injection of triamcinolone acetonide. Dexamethasone is a more powerful corticosteroid, and this innovative technology of inserting it into the eye is far less invasive and allows for a long-lasting effect with fewer complications,” said Paolo Lanzetta, MD, of the University of Udine, Italy.
In the new Posurdex implant manufactured by Allergan, the active cortical steroid substance is incorporated in a biodegradable polymer matrix. Electron microscopy has shown that the polymer matrix progressively dissolves and releases the drug over a period of several months after implantation
The device was initially inserted into the vitreous cavity through a scleral incision in the pars plana, but a new method of implantation promises to be a real breakthrough for the procedure, he said.
The Posurdex is pre-loaded into a specially designed injector with a 22-gauge needle. The implant is delivered directly into the vitreous cavity through a small, self-sealing tunnel and without a conjunctival opening, he said.

Posted by aman at 05:11 PM | Comments (0)

Early multifocal ablation trials show enhanced visual acuity, surgeon says

OCULAR SURGERY NEWS 9/1/2005
Results of the U.S. clinical trial using the Visx Star S4 laser (Advanced Medical Optics) to create multifocal ablations for presbyopia correction are promising, said Colman R. Kraff, MD.
In the bilateral feasibility study for Food and Drug Administration premarket approval, the dominant eye receives a standard CustomVue treatment, and the nondominant eye receives the CustomVue treatment combined with the investigational presbyopic component, Dr. Kraff explained.
In the presbyopic correction, the central zone is steepened for near vision and the peripheral cornea is targeted for distance vision.
Early postoperative results show positive outcomes,” he said. “Uncorrected distance vision, intermediate vision and near acuity in the multifocal eye has improved in all subjects. Multifocal eyes achieved 20/40 or better uncorrected near acuity in all five subjects.”
We do what is called a pupil-size-dependent central zone,” Dr. Kraff said. “The peripheral zone, combined with the LASIK flap, produces an aspheric surface that expands the depth of focus.”
Iris registration is an important component for the presbyopic treatment because the multifocal ablation is pupil-dependent, he said.

Posted by aman at 04:49 PM | Comments (0)

An experimental study on the effect of encircling band procedure on silicone oil emulsification

BJO OCT 2005
Silicone oil is a useful tamponading material used in complex vitroretinal surgery. However, the use of silicone oil is associated with emulsification which can lead to vision threatening complications. The authors developed an experimental model to study the effect of encircling band on silicone oil emulsification.
Methods: Two identical artificial eye chambers were constructed with circumferential indentations placed at the sphere’s equator (mimicking an encircling band indentation), and filled with varying amounts of Silicone Oil 1000 centistrokes (Adato, Bausch and Lomb, UK) and balanced salt solution. The chambers were then placed on a horizontal rotating shaker, mimicking physiological saccadic eye movements, which spun the chambers at 100 Hz for 5 days at 37°C. Emulsification was then quantified by dark field microscopy, digital photography, and manual counting by a masked observer.
Conclusions:
The emulsification of silicone oil results from friction between the silicone oil and aqueous liquids. The results from this study suggest silicone oil emulsification is reduced by (1) more complete silicone oil fill and (2) indentation from an encircling band. The authors hypothesise that both these measures resulted in reduced emulsification by reducing silicone oil/aqueous movement and resulting shearing forces.

Posted by aman at 04:43 PM | Comments (0)

The relation between intraocular pressure peak in the water drinking test and visual field progression in glaucoma

BJO OCT 2005
Retrospective analysis of 76 eyes of 76 open angle glaucoma patients followed for a mean period of 26.0 (SD 13.8) months. Patients were submitted to the water drinking test at the beginning of the follow up period. Reliable achromatic automated perimetry tests performed during the studied period were used to characterise visual field progression. All subjects were under clinical therapy and had an intraocular pressure (IOP) lower than 17 mm Hg monitored by isolated measurements during the follow up period. The results of the water drinking test were compared between glaucomatous eyes with and without visual field progression.
Conclusions: Mean IOP peak and percentage of IOP variation during water drinking test were significantly higher in patients with visual field progression compared with patients who did not progress.

Posted by aman at 04:36 PM | Comments (0)

Effect of dorzolamide and timolol on ocular blood flow in patients with primary open angle glaucoma and ocular hypertension

BJO OCT 2005
One hundred and forty patients with POAG or OHT were included in a controlled, randomised, double blind study in two parallel groups; 70 were randomised to receive timolol and 70 to receive dorzolamide for a period of 6 months. Subjects whose intraocular pressure (IOP) did not respond to either of the two drugs were switched to the alternative treatment after 2 weeks. Scanning laser Doppler flowmetry was used to measure blood flow in the temporal neuroretinal rim and the cup of the optic nerve head. Pulsatile choroidal blood flow was assessed using laser interferometric measurement of fundus pulsation amplitude.
Results:
Five patients did not respond to timolol and were changed to the dorzolamide group, and 18 patients changed from dorzolamide treatment to timolol. The effects of both drugs on IOP and ocular perfusion pressure were comparable. Dorzolamide, but not timolol, increased blood flow in the temporal neuroretinal rim (8.5 (1.6)%, p<0.001 versus timolol) and the cup of the optic nerve head (13.5 (2.5)%, p<0.001 versus timolol), and fundus pulsation amplitude (8.9 (1.3)%, p<0.001 versus timolol).
Conclusions: This study indicates augmented blood flow in the optic nerve head and choroid after 6 months of treatment with dorzolamide, but not with timolol. It remains to be established whether this effect can help to reduce visual field loss in patients with glaucoma.

Posted by aman at 04:24 PM | Comments (0)

September 18, 2005

Sealed capsule irrigation: new device to prevent PCO

Ophthalmology TimesSep 10, 2005
Lisbon, Portugal – Sealed capsule irrigation (SCI) using steroids in water is a new technique being studied that may prevent posterior capsular opacification (PCO) after cataract surgery. Gerd Auffarth, MD, PhD, from Heidelberg University Eye Clinic, Heidelberg, Germany, described this approach Saturday at the European Society of Cataract and Refractive Surgeons meeting.
In a prospective randomized clinical study, Dr. Auffarth and colleagues used steroids in distilled water to influence the epithelial cells osmotically in one eye each of 17 patients; the fellow eye of each patient served as a control. The capsular bags were treated for 2 minutes and the SCI device removed. The patients were followed at 1 day and at 1, 3, and up to 12 months. To use SCI, the capsulorhexis must be smaller than 5 mm, and the pupil must be at least 6 to 7 mm.
The best-corrected visual acuity was the same between both eyes of the patients. There was also no difference between the endothelial cell counts when the eyes of each patient were compared,” Dr. Auffarth said. “When we evaluated various areas in each eye, there was no difference in PCO development in the eyes at the 3- and 6-month evaluations when SCI was used compared with the control eyes.
At the 6-month evaluation there was no difference in the treated eyes, but the control eyes began to develop more PCO,” Dr. Auffarth continued. “This trend is expected to continue and the differences to be even greater between the treated and control eyes after 2 and 3 years of follow-up.”
He said that use of more aggressive solutions is being considered, perhaps hyperosmolar solutions, to arrest the development of PCO. This is an area for future study, he added.

Posted by aman at 12:05 AM | Comments (0)

September 17, 2005

ReSTOR lens shows strong results in 12-month clinical results

Ophthalmology Times Sep 11, 2005
Lisbon, Portugal Dr. Neuhann presented 12-month clinical and visual acuity results for distance and near vision for the single-piece acrylic lens during an ESCRS free paper session on refractive surgery outcomes for presbyopia on Sunday.
The monocular and binocular distance and near visual acuity, as well as the dioptric range, of the implanted lenses in 76 eyes of 40 patients were followed in a prospective randomized trial. All patients also participated in a lifestyle and function questionnaire to judge their satisfaction as a result of the surgery.
Among the 40 patients, there were 11 males and 29 females. The mean age of the males was 63.4 and mean age for the females was 62.5. The age range was 19 to 86 years. Refractive lens exchange for presbyopia was the reason for the surgery for 54.5% of the males, and 41.4% of the females. Phacoemulsification was performed on all the patients by one physician, with no complications. Four patients had a lens exchange because of a refractive miscalculation.
In reporting his results of the ReSTOR lens, Dr. Neuhann said the mean for the uncorrected visual acuity was 20/25, with a range of 20/40 to 20/15 for all patients. Mean for uncorrected near vision acuity was J2 or better, with a range of J3 to J1+. The best-corrected visual acuity was 20/20 or better for all patients.
When distance correction was plano, intermediate vision at 60 cm for all patients averaged J5 or better 4 weeks after surgery. However, distance vision improved to J4 or better after 12 months. With distance correction of +0.75 D, intermediate vision also improved significantly.
However, he added that problems with intermediate vision for most patients have been resolved at 12 months.

Posted by aman at 11:53 PM | Comments (0)

Tissue adhesive effective in total anterior lamellar keratoplasty

Ophthalmology Times Sep 11, 2005
Lisbon, Portugal — The use of fibrin glue seems to be effective and safe in total anterior lamellar keratoplasty (TALK), a procedure that completely exposes Descemet’s membrane within the area of host corneal trephination combined with transplantation of donor cornea without Descemet’s membrane and endothelium. Thomas John, MD, explained the procedure Sunday at the European Society of Cataract and Refractive Surgeons meeting.
Ten patients (6 women, 4 men; average age, 48 years) underwent this procedure. Seven patients were diagnosed with keratoconus and three patients with corneal scarring. The symptoms included blurred vision and glare and scarring in the visual axis.
Because of the severity of the cases, the automated lamellar technique was not possible and manual TALK was performed in all cases, said Dr. John, of Loyola University at Chicago, Maywood, IL, United States.
During the procedure the fibrin glue, which comprises thrombin and fibrinogen, is applied to the entire donor/stromal interface including the visual axis.
Dr. John reported that use of the glue resulted in an even smooth adherence of the host Descemet’s membrane to the donor stroma in all cases. No folds in Descemet’s membrane were present. Postoperatively, the cornea healed uniformly without inflammation or interface scarring of the cornea.

Posted by aman at 11:46 PM | Comments (0)

Staged flap creation, ablation preferred for LASIK correction of high astigmatism post-PK

Ophthalmology Times Sep 11, 2005
Lisbon, Portugal — LASIK is an effective tool in the management of high astigmatism after penetrating keratoplasty (PK). Furthermore, a two-step technique may be preferred over a one-stage procedure because it allows for better evaluation of refractive changes induced by the keratectomy, said Ahmed Galal, MD, PhD.
Dr. Galal, VISSUM Instituto Oftalmologica de Alicante, Spain, presented the results of a prospective, consecutive observational study comparing one- and two-step LASIK procedures in a total of 22 eyes. All of the surgeries were performed at least 3 to 6 months after suture removal and only if the eye demonstrated stable topography. The same microkeratome and laser were used for all procedures. For the two-step technique, there was a 3-month delay between flap creation and the laser treatment.
Visual recovery was similar in the two groups, although there was a slight benefit for best-corrected visual acuity and uncorrected visual acuity in the two-step group. Notably, however, analysis of change in cylinder showed the mean amount of astigmatism correction was greater using the two-step versus one-step procedure, –4.4 versus –2.4 D, respectively.
Among eyes treated with the two-step technique, the flap creation itself induced a change in cylinder that ranged up to 5 D, and in one case, the LASIK ablation was not performed because the lamellar cut improved the entire astigmatic error,” Dr. Galal said.

Posted by aman at 11:38 PM | Comments (0)

Nidek receives CE Mark for excimer laser system

Ophthalmology Times Sep 12, 2005
The CE Mark is an indication that a company has met essential health, safety, and environmental protection requirements detailed in 22 European Directives covering an array of products including medical devices. The CE Mark allows products to gain access to the European market, assuring physicians and patients of the safety of the product.
The new excimer laser platform, part of the Nidek NAVEX Quest System brings together advanced hardware modules — including 200 Hz eye tracking, torsion error detection and compensation, and multipoint laser delivery — along with innovative and proprietary software algorithms such as Nidek’s OATz, CATz, and OPDCAT for customized refractive surgery. The new laser system will work alongside Nidek’s advanced diagnostic platform, the OPD-Scan, and Final-Fit Software for performing customized and personalized refractive surgery procedures.

Posted by aman at 11:33 PM | Comments (0)

IntraLase FS30 laser gets 510K approval for penetrating, lamellar corneal resections

Ophthalmology Times Sep 12, 2005
Lisbon, Portugal — IntraLase Corp., Irvine, CA, has received 510K clearance from the FDA for use of the IntraLase FS30 femtosecond laser in creating corneal resections performed in lamellar keratoplasty and penetrating keratoplasty (PK) procedures. The IntraLase FS30 laser is the first and only laser to receive clearance for use in PK, according to the manufacturer.
The company said surgeons can now use the power and precision of the laser to complete resections in a variety of corneal therapeutic applications. The new clearance allows use of the IntraLase FS30 laser to create deep corneal incisions and the full-thickness resections required for PK.
This really opens up the door for additional uses of this extremely versatile device," said Roger Steinert, MD, of the University of California, Irvine, United States. "In our initial clinical work, we found that the laser has the ability to create shaped, full-thickness corneal transplants that are much stronger than traditional PK transplants with less induction of astigmatism. In addition, transplants created with the laser may require less suturing and faster visual rehabilitation."

Posted by aman at 11:23 PM | Comments (0)

Risk factors associated with endophthalmitis after cataract surgery

Ophthalmology Times Sep 12, 2005
Lisbon, Portugal — Data on the development of endophthalmitis have been reported continuously since 1994 in Sweden, and the rate of endophthalmitis has been decreasing similar to international rates. Per Montan, MD, reported the results of a multicenter study on the risk factors that have been identified for the development of endophthalmitis Monday at the European Society of Cataract and Refractive Surgeons meeting.
The use of prophylactic antibiotics seems to be a decisive factor in preventing endophthalmitis after cataract surgery, explained Dr. Montan, from the Anterior Segment Department, St. Erik’s Hospital, Stockholm, Sweden.
The factors that were analyzed in endophthalmitis included the prophylactic regimen, preoperative complications (communication with the vitreous), the type of incision, the type of IOL implanted, and the use of an injector, Dr. Montan said.
From 2002-2004, a total of 225,471 cataract surgeries were performed and 105 cases of endophthalmitis developed, for an incidence of 0.05%. In almost all cases, prophylactic antibiotics were administered intracamerally. Temporal corneal incisions presented a slightly higher risk factor when compared with superior incisions, but the difference was no statistically significant. The use of injectors did not protect against development of endophthalmitis, and communication with the vitreous was a decisive factor.
Temporal corneal incisions presented a slightly higher risk of development of endophthalmitis. Personally, I do not think this is a major factor in my decision making when I perform phacoemulsification,” he concluded.

Posted by aman at 11:15 PM | Comments (0)

ASCRS/ESCRS survey: Dislocation, decentration top reasons for foldable IOL explantation

Ophthalmology Times Sep 12, 2005
Lisbon, Portugal — The results of the 7th annual survey on foldable IOLs indicate that dislocation and decentration are by far the most common reasons for lens explantation, with incorrect lens power the next most important factor. Nick Mamalis, MD, reported the results of the survey — conducted by (ASCRS)and(ESCRS).
The survey questionnaire considered the patient signs and symptoms; type of IOL that was removed; preoperative and postoperative visual acuity; and patient symptoms requiring removal. The IOLs considered were the one-piece plate type, one-piece IOLs with haptics, three-piece IOLs, and foldable IOLs. The IOL materials were silicone, hydrophilic, hydrophobic, and acrylic.
The most common symptoms that precipitated removal of three-piece silicone IOLs were (in descending order): dislocation, decentration, incorrect lens power, glare, and optical aberrations; for the plate silicone IOLs: dislocation and decentration; for three-piece hydrophobic acrylic IOLs: dislocation, decentration, incorrect lens power, glare, and optical aberrations; for one-piece hydrophobic acrylic IOLs with haptics: decentration, dislocation, and incorrect lens power; for hydrophilic acrylic, and one-piece IOLs: calcification; and for multifocal silicone IOLs: glare and optical aberrations, Dr. Mamalis reported. He is from the John A. Moran Eye Center, University of Utah, Salt Lake City, United States. The visual acuity levels were relatively good with all types of IOLs.
Calcification in this survey applied exclusively to hydrophobic acrylic IOLs on the surface and the substance of the lens itself. Glare and optical aberration were seen with all types of lenses,” Dr. Mamalis said.

Posted by aman at 11:03 PM | Comments (0)

Beta-blocker effective to manage regression after refractive surgery

Ophthalmology Times Sep 13, 2005
Lisbon, Portugal — Treatment with a topical beta-blocker is effective for preventing regression after LASIK to treat myopia. However, there is no way to predict which patients will respond to the therapy, according to Takayoshi Suzuki, MD, who reported his findings Tuesday at the European Society of Cataract and Refractive Surgeons meeting.
Dr. Suzuki and colleagues from the Department of Ophthalmology, Tokyo Dental College, Suidobashi Hospital, Tokyo, studied 41 eyes of 30 patients (18 women, 12 men) who had undergone LASIK for myopia. Regression occurred in all of these eyes and the patients received 0.5% topical timolol (Santen) once daily for at least 3 months. Following the treatment, the patients were divided into two groups based on the treatment response. Group 1 included patients whose vision improved by 1 line or more and Group 2 included patients who showed no improvement.
Dr. Suzuki reported that the mean preoperative manifest refraction spherical equivalent was –7 ± 0.57 D. Twenty-four eyes (58.5%) in Group 1 improved and 17 eyes in Group 2 (41.5%) either stayed the same or regressed.
We found that topical timolol was effective to prevent regression after LASIK. However, there is no way to predict which patients will respond to treatment. The patient age, the preoperative spherical equivalent, and the amount of time after surgery were not factors that affected the results,” Dr. Suzuki concluded.

Posted by aman at 10:56 PM | Comments (0)

Goblet cell dysfunction may occur after LASIK

Ophthalmology Times Sep 13, 2005
Lisbon, Portugal — Dry eye syndrome after LASIK may be the result of goblet cell dysfunction. Extended application of artificial tears may be warranted to facilitate the return to normal function, Ahmed Galal, MD, PhD, said Tuesday at the European Society of Cataract and Refractive Surgeons meeting.
After LASIK, surgeons instruct patients to use artificial tears for 1 month and then longer as needed. However, dry eye lasts longer and may require longer treatment with artificial tears,” Dr. Galal stated. He is from VISSUM Instituto Oftalmologico de Alicante and Miguel Hernandez University, Alicante, Spain.
In a prospective controlled, noncomparative study, Dr. Galal and colleagues evaluated 22 eyes of 12 patients who had undergone LASIK for myopia. The investigators performed conjunctival impression cytology in all eyes in the superior bulbar conjunctiva, the inferior temporal conjunctiva, and at the perilimbal conjunctiva using cellulose acetate filter paper before LASIK and then 1 week and 1 and months postoperatively.
Dr. Galal reported that the goblet cell density decreased from 485/mm² to 430/mm² 3 months after LASIK. All samples taken postoperatively showed a significant decrease in the goblet cell density.
When we compared the preoperative impression cytology with the postoperative impression cytology, there was a decrease in the goblet cell density. The mean decrease in the number of goblet cells per mm² was a mean of 63.5%. The goblet cell density decreased up to 6 months after LASIK. Application of artificial tears from 6 months to up to 1 year after LASIK may be needed,” Dr. Galal concluded.

Posted by aman at 10:50 PM | Comments (0)

September 16, 2005

Scleral-fixated IOL dislocation may be due to degradation of suture material over time

J Cataract Refract Surg. 2005
A recent paper sheds light on the mechanism for late dislocation of scleral-fixated intraocular lenses. In their report, they evaluated 5 consecutive instances of scleral-fixated IOL dislocation, all of which occurred 7 to 14 years after the initial implantation with 10-0 polypropylene suture. They discovered degradation of the suture where it was embedded into the sclera with microscopic analysis of one of the explanted IOLs. None of the cases demonstrated erosion of the suture through scleral tissue or untying of the suture as the mechanism for suture failure. The author recommend a larger suture diameter (9-0) and haptic placement in the ciliary sulcus in order to facilitate longer stability of scleral-fixated lenses.

Posted by kjalali at 08:41 AM | Comments (0)

Combined surgical ablation and intravitreal triamcinolone acetonide for retinal angiomatous proliferation

Eur J Ophthalmol 2005
Neovascular age-related macular degeneration (ARMD) with retinal angiomatous proliferation (RAP) has a poor natural history and the efficacy of any treatment has not yet been established. A 76-year-old woman presented with a best-corrected visual acuity (BCVA) of 20/600 and a macula with stage 3 RAP as identified by fluorescein angiography (FA), indocyanine green angiography (ICGA), and optical coherence tomography (OCT). After a standard three-port pars plana core vitrectomy (PPV), endodiathermy of the arteriolar and venous feeder vessels of each lesion was performed, intraretinal RAP feeder vessels were cut with manual vertical intraocular scissors, and 0.1 mL of triamcinolone acetonide (TAAC) was injected intravitreally. At 1 and 4 weeks and at the sixth month, the patient underwent a complete eye examination, FA, ICGA, and OCT to assess outcomes and complications. Six months later, FA and ICGA showed a complete occlusion of the RAP and absence of leakage or ischemia and OCT demonstrated decreased macular thickness with resolution of both intraretinal edema and pigment epithelium detachment, and the restoration of the normal macular profile.

Posted by kjalali at 08:37 AM | Comments (0)

Spontaneous fracture of an implanted posterior chamber intraocular lens

Eur J Ophthalmol 2005
Spontaneous fracture of an intraocular lens (IOL) haptic is a rare complication of cataract surgery. A 12-year-old patient underwent linear lens extraction, posterior capsulotomy, and anterior vitrectomy due to traumatic cataract and received a polymethyl methacrylate (PMMA) biconvex posterior chamber IOL implanted in ciliary sulcus. Five years later, IOL optic was found in anterior chamber with its haptics broken from the optic-haptic junction. The broken haptic was examined with scanning electron microscopy. The fracture site of the haptic was on the optic-haptic junction. The fractured surface had a regular appearance. Before this case, there is three reports of spontaneous fracture of an implanted posterior chamber IOL.

Posted by kjalali at 08:31 AM | Comments (0)

Prism spectacles no more effective than conventional spectacles for people with AMD

Archives of Ophthalmology, August 2005
This randomized, placebo-controlled, double-masked trial of 225 participants (median age, 81 years) finds no significant effect on any of the outcome measures, including the primary outcome, visual acuity. In addition, participants’ responses to the Manchester Low Vision Questionnaire suggest prism spectacles added to their problems.

Posted by kjalali at 08:27 AM | Comments (0)

Verteporfin PDT can successfully treat choroidal hemangioma, improve visual acuity

Retina, September 2005
During a mean follow-up of 36.6 months (range of 12 to 66 months), there was no evidence of recurrence in any of the 15 patients with circumscribed choroidal hemangioma. All patients experienced a complete and permanent regression with no signs of tumor re-growth or recurring subretinal fluid. Mean final visual acuity ranged from 20/20 to 20/400. Of the 15 patients, 13 experienced a substantial increase in visual acuity (range of two to nine lines) while vision remained stable in two patients. Chorioretinal atrophy at the previous tumor site did not enlarge over time. Re-treatments after completion of the primary treatment were unnecessary.

Posted by kjalali at 08:26 AM | Comments (0)

Scanning laser polarimetry and retinal thickness analysis before and after laser in situ keratomileusis

Eur J Ophthalmol 2005
To evaluate changes in retinal nerve fiber layer (RNFL) thickness after laser in situ keratomileusis (LASIK) using a scanning laser polarimeter with fixed corneal compensation (GDx) and the retinal thickness analyzer (RTA, thirty-eight eyes of 19 healthy subjects underwent GDx and RTA measurements before and after LASIK. Refraction: -4.0±2.75D. Measurements using GDx were followed by RTA measurements after pupil dilation. All measurements were performed the day before LASIK and 1 week postoperatively. GDx revealed a decrease in nerve fiber layer thickness measurements after LASIK, but did not reach statistical significance (p>0.05). Using RTA, mean RNFL thickness (MRNFL) and RNFL cross sectional area decreased significantly after LASIK (p=0.03 and p=0.02, respectively). Scanning laser polarimetry revealed a slight decrease in RNFL thickness measurements after LASIK. MRNFL and RNFL cross section were significantly lower after LASIK using RTA. The changes might be artifacts in a small group of myopic subjects.

Posted by kjalali at 08:18 AM | Comments (0)

High-dos e injections of triamcinolone acetonide often lead to cataract formation

European Journal of Ophthalmology, September 2005
This interventional case series of elderly patients (144 phakic eyes) who consecutively received an injection of about 20 mg intravitreal injection for diffuse diabetic macular edema (42 eyes), exudative AMD (98) and branch retinal vein occlusion (4) shows 15 percent to 20 percent developed clinically significant cataract within one year after an injection. Cataract surgery was performed in 13.9 percent of eyes about one year (median) after the first injection. Of the 20 eyes undergoing cataract surgery, 95 percent received one intravitreal injection; 5 percent, two previous injections.

Posted by kjalali at 08:14 AM | Comments (0)

September 15, 2005

Clinical factors to consider in using NSAIDs

OSN Supersite Monograph Sep 1,2005
It has been shown that topical NSAIDs decrease normal corneal sensation,7,8 hence their efficacy in decreasing postoperative pain following PRK or other surface ablation procedures. Topical NSAIDs can affect normal corneal epithelial healing,9,10 but this is a topic of controversy; other studies have shown that topical NSAIDs may not have as adverse an effect on wound healing as topical corticosteroids.
As has been demonstrated, potential problems with NSAID use exist, but can be limited if used properly. Long-term use of NSAIDs and dosing more frequently than four times daily should be avoided, and patients should be carefully evaluated for risk factors linked to corneal melting. Patients who have the following characteristics should be observed carefully during NSAID use: severe dry eye; recurrent epithelial keratopathy or persistent epithelial defect; active bacterial keratitis or neurotrophic situations from previous herpes simplex or zoster keratitis; severe ocular surface disease, such as ocular cicatricial pemphigoid or chemical burn; potential long-term use of concurrent topical steroids; and systemic disorders such as diabetes and rheumatoid arthritis. Compliance with regard to medication dosing and follow-up is important to ensure that normal wound healing occurs and corneal melting is avoided. In the setting of a corneal melt, infection should always be ruled out.

Posted by aman at 11:01 PM | Comments (0)

Corneal melting and NSAIDs

OSN Super site Sep 2005
The melting was linked to the generic formulation of diclofenac made by Falcon Pharmaceuticals, which was subsequently recalled from the market. It was hypothesized that the vitamin E solubilizer, tocophersolan, which has been shown to inhibit epithelial cell proliferation and induce apoptosis in cells, in the generic formulation induced corneal melting.
Other reports of corneal melting have occurred with the brand diclofenac, Voltaren (diclofenac sodium, Novartis), as well as with Acular (ketorolac tromethamine 0.5%, Allergan),1-4 raising the concern that other factors may contribute to corneal melting.
Matrix metalloproteinases (MMPs) are a family of proteases or collagenolytic enzymes that have multiple functions that include degradation of the extracellular matrix components, such as collagen, lamina and proteoglycans. MMPs are also involved in cell-cell and cell-matrix communication. In normal tissues, MMPs are rarely detected. MMP expression is typically seen in human tissues during rapid matrix turnover, such as tissues undergoing metastatic tumor invasion or wound healing. MMP expression has been found in corneal tissue during the wound-healing process as well.
What role can these MMPs play in NSAID-related corneal melts? Corneal melting occurs when an imbalance exists between extracellular matrix deposition and degradation. MMP expression that occurs normally in wound healing may become unregulated with NSAID use, creating an imbalance and subsequently corneal melting.

Posted by aman at 10:35 PM | Comments (0)

Genetic Risk of Rhegmatogenous Retinal Detachment

AJO Sep 2005
One hundred eighty-one patients (89.2% of those eligible) and 408 controls (88.5% of invited controls) with 1090 and 2345 relatives, respectively, were included in the analysis. Thirteen familial RRDs (1.2%) were diagnosed in 10 case probands and 9 RRDs (0.4%) in 8 control probands. Siblings and offspring of cases had a higher incidence of RRD independent of age, sex, and myopia. The cumulative lifetime risk of RRD was 7.7% for relatives of cases and 3.0% for relatives of controls, yielding a risk ratio of 2.6 (95% confidence interval, 1.1-6.2).

Posted by aman at 10:26 PM | Comments (0)

Müllerectomy for Upper Eyelid Retraction and Lagophthalmos Due to Facial Nerve Palsy

AJO Sep 2005
Thirty-four patients with chronic facial nerve palsy underwent unilateral transconjunctival removal of Müller muscle and were followed up for an average of 20 months postoperatively. Other procedures were performed to treat lower eyelid retraction, as required. Preoperative and postoperative ocular exposure symptoms, upper eyelid position, lagophthalmos, and keratopathy were compared.
Results Of the 59 preoperative symptoms, 15 (25%) resolved and 39 (66%) improved. Upper eyelid position was lowered by an average of 1.35 mm (P<.001). Lagophthalmos (P = .002) and corneal exposure (P<.001) were significantly improved. Three patients required levator aponeurosis repair, 2 for preexisting dehiscence and 1 for inadvertent aponeurosis transection.

Posted by aman at 10:17 PM | Comments (0)

A Randomized Trial Assessing Dorzolamide in Patients With Glaucoma Who Are Younger Than 6 Years

AJO Sep 2005
A 3-month, controlled, randomized, double-masked, multicenter, clinical trial. Patients were randomized to 2% dorzolamide 3 times daily or timolol maleate gel-forming solution (0.25% for patients <2 years and 0.5% for patients 2 but <6 years) once daily plus placebo twice daily. If the intraocular pressure was not controlled through monotherapy, younger patients received concomitant dorzolamide 3 times daily and 0.25% timolol gel-forming solution once daily and older patients received a fixed combination of 2% dorzolamide and 0.5% timolol twice daily. The primary safety variable was the proportion of patients who discontinued therapy for a drug-related adverse experience. Intraocular pressure reduction was a secondary measure.
Results One younger patient (1.8%) of 56 randomized to dorzolamide discontinued concomitant therapy because of bradycardia. Two older patients (3.0%) of 66 discontinued dorzolamide because of ocular adverse experiences. The most frequent ocular adverse experiences were discharge and ocular hyperemia (younger cohort) and ocular hyperemia and burning/stinging (older cohort). At week 12, the mean change in intraocular pressure for dorzolamide was statistically significant from baseline (–7.3 mm Hg [–20.6%] and –7.1 mm Hg [–23.3%]) in the younger and older cohorts, respectively; P<.001 for both.

Posted by aman at 10:03 PM | Comments (0)

Researchers ID genetic mutation linked to age-related macular degeneration

EYE WORLD Week Sep 5, 2005
Researchers at the University of Pittsburgh have identified a gene mutation that appears to significantly increase an individual's risk for age-related macular degeneration (AMD). The findings were published by the American Journal of Human Genetics and follow by a few months the discovery of the first such Уsusceptibility gene.Ф The announcement of that first gene last spring was hailed as a significant step forward in AMD research. Michael Gorin, M.D., Ph.D., who led the study, said the newly discovered gene seems to be just as strongly associated with the disease as that first gene and could increase an individual's risk as much as five times. The conclusions are based on a 15-year gene-mapping study of 612 families affected by AMD and another 323 unaffected individuals. Dr. Gorin and his colleagues found that an area of chromosome 10, where a gene called PLEKHA1 is located, was strongly associated with the disease. The study also confirmed the earlier findings by four other research groups that a variant of the gene for complement factor H, or CFH, is strongly associated with the disease. Both CFH and PLEKHA1 are involved in cellular processes related to inflammation, which could be a factor in the disease. It thus might be possible to use steroids or other anti-inflammatory agents to treat the disease at early stages, according to the study authors.

Posted by aman at 09:59 PM | Comments (0)

Heidelberg introduces glaucoma diagnosis and management product

EYE WORLD Week Sep 5, 2005
Heidelberg Engineering GmbH (Dossenheim, Germany) announced the introduction of the Heidelberg Retina Tomograph 3 (HRT3), a newly enhanced version of its flagship product for the assessment, diagnosis, and management of glaucoma. The HRT3 uses laser technology to produce a topographical image of patients' optic nerves, providing an objective analysis of the structures' cup, rim, and retinal nerve fiber layer.

Posted by aman at 09:48 PM | Comments (0)

A look at the resurgence of surface ablation

EYE WORLD Sep 2005
Richard L. Lindstrom, M.D., clinical professor of ophthalmology, University of Minnesota, Minneapolis, has also seen a rekindling of interest in surface ablation. He now does selective surface ablation in about 10% of patients.
A few years ago, he only performed LASIK.
Selecting surface patients
For most surgeons, determining which patients to offer surface ablation to is a balancing act.
“The obvious candidates are patients that have thinner corneas that are on the edge of having too little tissue remaining after a LASIK procedure” Dr. Schallhorn said. In a case where a physician chooses between using a small optical zone for treatment to preserve tissue for LASIK or going to the surface and using a standard optical zone, the latter makes sense, Dr. Schallhorn said.
He also favors surface ablation for patients that have epithelial basement membrane dystrophy, where they are more likely to have an epithelial defect as a result of a LASIK procedure, as well as for those with topographic anomalies.
“Patients would probably be better served with surface ablation if there’s an issue or question about problems that would likely arise because of LASIK,”
Dr. Lindstrom likewise uses MMC prophylactically for higher myopes.
“When I first started, I followed the…dictum of two minutes of 0.2 mg per mL with copious irrigation,” he said. “We’re now down to 12 seconds.” So far with this approach, Dr. Lindstrom has not seen any sight-threatening complications.

Posted by aman at 09:41 PM | Comments (0)

September 12, 2005

Magnetic Resonance Spectroscopy.

Journal of Neuro-Ophthalmology Sep 2005
Magnetic resonance spectroscopy (MRS) complements magnetic resonance imaging (MRI) as a non-invasive means for the characterization of tissue. While MRI uses the signal from hydrogen protons to form anatomic images, proton MRS uses this information to determine the concentration of brain metabolites such as N-acetyl aspartate (NAA), choline (Cho), creatine (Cr) and lactate in the tissue examined. The most widely used clinical application of MRS has been in the evaluation of central nervous system disorders.
MRS has its limitations and is not always specific but, with good technique and in combination with clinical information and conventional MRI, can be very helpful in diagnosing certain entities. For example, a specific pattern of metabolites can be seen in disorders such as Canavan's disease, creatine deficiency, and untreated bacterial brain abscess. MRS may also be helpful in the differentiation of high grade from low grade brain tumors, and perhaps in separating recurrent brain neoplasm from radiation injury.

Posted by aman at 11:05 PM | Comments (0)

Simultaneous Bilateral Retinal Artery Occlusions Associated with a Mitral Valve Mass.

Journal of Neuro-Ophthalmology Sep 2005
Abstract:
A 52-year-old woman with simultaneous bilateral retinal artery occlusions and normal trans-thoracic echocardiography was found to have a mitral valve lesion on trans-esophageal echocardiography. Bilateral retinal artery occlusions suggest a source of emboli at the level of the heart or aortic arch. Such cases should be evaluated not merely by trans-thoracic echocardiography, but by trans-esophageal echocardiography, which better visualizes the aortic arch and left heart cavities.

Posted by aman at 11:01 PM | Comments (0)

September 10, 2005

Bilateral Cataract and Corectopia after Laser Eyelid Epilation

AAO Sep 2005
A 27-year-old woman with a history of bilateral eyebrow laser epilation complained of oval pupils, reduced visual acuity, and photophobia immediately after laser epilation of both upper-eyelid regions. The following examinations were performed: visual acuity, slit-lamp examination, pupillary light reflex, perimetry, tonometry, gonioscopy, and funduscopy with contact lenses. The follow-up period was 9 months.
Her best baseline visual acuities were 20/25 (right) and 20/40 (left). Examination showed bilateral corectopia with superior iris atrophy, iris stroma clump at the pupillary margin, and pigment residues in the inferior chamber. A cataract developed in the anterior subcapsular regions of the lenses.
Conclusions
Laser epilation at the eyelid may result in irreversible cataract and iris atrophy.

Posted by aman at 11:47 PM | Comments (0)

Endocanalicular Laser Dacryocystorhinostomy: Analysis of 118 Consecutive Surgeries

AAO Sep 2005
One hundred eighteen consecutive ECL DCR surgeries performed on 108 patients between June 1997 and June 2003 were reviewed, excluding 6 lost to follow-up. Endocanalicular laser DCR was the initial surgical intervention for all cases except 6 that had previously undergone surgery (external or endonasal DCR) at outside hospitals. Twenty-seven of the surgeries were considered failures on the basis of recurrent epiphora or discharge, or reflux on nasolacrimal irrigation. One of the failures was permanently corrected with balloon dacryoplasty. Nine of the other failures had a repeat procedure, with 7 remaining patent after one repeat procedure and an additional one remaining patent after a third procedure. All 6 ECL DCR procedures that were performed after external or endonasal DCR at an outside institution remained patent. Among the 102 initial lacrimal surgeries in this series, there was a 73.6% success rate. The overall success, including repeat procedures, was 81.5%. The success of this technique as a repeat procedure after previous external, endonasal, or ECL DCRs was 87.5%.

Posted by aman at 11:43 PM | Comments (0)

Strabismus in Pediatric Pseudophakia

AAO Sep 2005
Charts of 94 pediatric patients who underwent cataract extraction with primary intraocular lens implantation from 1990 to 2003 at Indiana University School of Medicine were reviewed. Only those patients who had pre–cataract extraction and post–cataract extraction alignment measurements were included.
Ninety-four pediatric pseudophakia patients were identified, and 37 (39%) had strabismus. Exotropia (46%) was more common than esotropia (41%). Factors not associated with the development of strabismus included age at presentation, interval between diagnosis and cataract extraction, race, and type of cataract. Factors statistically associated with the development of strabismus include pre–cataract extraction and post–cataract extraction VA, type of strabismus, and post–cataract extraction amblyopia. The mean pre–cataract extraction deviation of the group that had strabismus surgery was 22 prism diopters, and 75% were aligned at the last examination (mean follow up, 24 months).
Conclusion
Strabismus occurs more frequently in pseudophakic pediatric patients than in the general pediatric population. Pseudophakic children should be monitored carefully for the development of strabismus, which in many cases can be successfully treated.

Posted by aman at 11:37 PM | Comments (0)

Rapid Recurrence of Geographic Atrophy after Full Macular Translocation for Nonexudative Age-Related Macular Degeneration

AAO Sep 2005
To report the recurrence of geographic atrophy (GA) in a patient with nonexudative age-related macular degeneration (AMD) after full macular translocation.
Review of the clinical, photographic, and angiographic records of a patient with GA who underwent full macular translocation.
Results
A 73-year-old man with GA secondary to nonexudative AMD underwent a macular translocation with 360 peripheral retinectomy (MT 360) in his left eye. On postoperative month 4, fundus photography showed subtle alterations of the pigment underneath the translocated foveal region. On postoperative month 9, the visual acuity worsened to preoperative levels and there was frank retinal pigment epithelium atrophy involving the new macular region.
Conclusions
The rapid recurrence and development of GA in the translocated fovea after MT 360 raise new questions regarding the pathogenesis of GA. They also raise concerns regarding the use of MT 360 in the management of nonexudative AMD.

Posted by aman at 11:30 PM | Comments (0)

Comparison of Intravitreal versus Posterior Sub–Tenon’s Capsule Injection of Triamcinolone Acetonide for Diffuse Diabetic Macular Edema

AAO Sep 2005
To compare the safety and efficacy of intravitreal versus posterior Sub–Tenon’s capsule injection of triamcinolone acetonide for diffuse diabetic macular edema.
Twelve patients (24 eyes) with bilateral diffuse diabetic macular edema.
One eye of each patient was randomly assigned to receive a single 4-mg triamcinolone acetonide intravitreal injection and the fellow eye to receive a 40-mg triamcinolone acetonide posterior Sub–Tenon’s capsule injection.
Changes in visual acuity and central macular thickness obtained using optical coherence tomography were measured during a 6-month follow-up. Potential treatment complications were monitored, including increases in intraocular pressure (IOP) and cataract progression.
Conclusions
The findings from our study neither advocate nor support the use of corticosteroids for the treatment of diabetic macular edema, but do imply that both intravitreal and Sub–Tenon’s capsule injections of triamcinolone acetonide may be equally tolerated, with short-term performance clearly favoring the intravitreal (4 mg) more than the SBT capsule (40 mg) route for the anatomic and functional aspects of improvement tested in this investigation.

Posted by aman at 11:24 PM | Comments (0)

Impact of Birth Parameters on Eye Size in a Population-Based Study of 6-Year-Old Australian Children

AJO Sep 2005
To study the effect of birth parameters, including birth weight, birth length, and birth head circumference on ocular dimensions in 6-year-old children.
A stratified random cluster sample of 6-year-old Sydney school-students (n = 1765) were participants in this study. Children had ocular dimensions measured with non-contact methods (Zeiss IOLMaster, Zeiss, Meditec-AG, Jena, Germany). Information on birth weight, height, and head circumference was derived from a questionnaire.
Results
After adjusting for cluster, age, and gender, children with birth weight <2500 g had mean axial length 22.46 mm (95% confidence interval [CI], 22.20–22.72) and mean corneal radius 7.70 mm (CI 7.61–7.79). This compared with axial length 22.80 mm (CI 22.70–22.90) and mean corneal radius 7.85 mm (CI 7.81–7.89) for children with birth weight ≥4000 g. Axial length and corneal radius were also related to birth length and head circumference. Refraction, however, was unrelated to birth size.

Posted by aman at 01:03 AM | Comments (0)

Digit Preference in Goldmann Applanation Tonometry: The Hedgehog Effect

AJO Sep 2005
Digit preference is a subconscious bias towards numbers that end in certain digits. We conducted a study to assess for digit preference in intraocular pressure measurement using the Goldmann applanation tonometer.
The study was conducted in general ophthalmic clinics in a District General Hospital in Blackpool, United Kingdom, by 6 clinical ophthalmologists. Consecutive right eye intraocular pressure measurements were collected for a 2-month period for the masked phase and were repeated for the unmasked phase. The proportion of even numbers was the main outcome measure.
Results
Six ophthalmologists completed both phases: 555 of 917 readings were even in the masked phase (P = .075), and 679 of 1056 readings were even in the unmasked phase (P = .022).
Conclusions
Our results suggest that digit preference influences measurements from the Goldmann applanation tonometer and that this persists when observers are aware of digit preference. This bias may influence both clinical decision-making and trial results.

Posted by aman at 12:55 AM | Comments (0)

Standardization of Uveitis Nomenclature for Reporting Clinical Data. Results of the First International Workshop

AJO Sep 2005
Members of an international working group were surveyed about diagnostic terminology, inflammation grading schema, and outcome measures, and the results used to develop a series of proposals to better standardize the use of these entities. Small groups employed nominal group techniques to achieve consensus on several of these issues.
Results
The group affirmed that an anatomic classification of uveitis should be used as a framework for subsequent work on diagnostic criteria for specific uveitic syndromes and that the classification of uveitis entities should be on the basis of the location of the inflammation and not on the presence of structural complications. Issues regarding the use of the terms “intermediate uveitis,” “pars planitis,” “panuveitis,” and descriptors of the onset and course of the uveitis were addressed. The following were adopted: standardized grading schema for anterior chamber cells, anterior chamber flare, and for vitreous haze; standardized methods of recording structural complications of uveitis; standardized definitions of outcomes, including “inactive” inflammation, “improvement” and “worsening” of the inflammation, and “corticosteroid sparing,” and standardized guidelines for reporting visual acuity outcomes.
Conclusions
A process of standardizing the approach to reporting clinical data in uveitis research has begun, and several terms have been standardized.

Posted by aman at 12:47 AM | Comments (0)

Fixed Dilated Pupil After Penetrating Keratoplasty for Macular Corneal Dystrophy and Keratoconus

AJO Sep 2005
A retrospective review was conducted of the charts of 195 patients who had PKP for MCD and of 1800 patients who had PKP for keratoconus at the King Khaled Eye Specialist Hospital in Riyadh, Saudi Arabia. The review included an evaluation of the preoperative and intraoperative data and the postoperative course. In addition, clinical examinations at the last visit and photographs of the cornea, pupil, iris, and lens were analyzed.
Results
Twenty-one eyes of 18 patients had fixed dilated pupil after PKP; 15 eyes of 12 patients had MCD, and six eyes of six patients had keratoconus. A rise in intraocular pressure (IOP) during the procedure was seen in five patients (23.8%). Fixed dilated pupil was documented on the first and second postoperative days and the second postoperative week in 17 (80.9%), one (4.8%), and three (14.3%) eyes, respectively. Six eyes (28.6%) of six patients had severe eye inflammation. Only one eye (4.8%) regained partial reactivity of the pupil on follow-up visits. Seven eyes (33.3%) experienced lens changes; nine eyes (42.8%) had elevated IOP on the first postoperative day, and none of the eyes had chronic glaucoma.
Conclusion
Inflammatory and multifactorial pathologic condition can cause fixed pupil after PKP. Atropine use, keratoconus, and high IOP are not constant findings in this syndrome. Awareness of the risk factors of fixed dilated pupil will help prevent against its occurrence.

Posted by aman at 12:40 AM | Comments (0)

Differences in Keratoconus as a Function of Gender

AJO Sep 2005
A total of 1209 subjects at 16 clinics. For eye-specific categorical variables, the number of eyes per subject with the characteristic was counted. For eye-specific continuous variables, the mean of both eyes was calculated. Multivariate linear (for continuous outcomes) and logistic (for categorical outcomes) regression models were created for each baseline characteristic with statistically significant (P ≤ .05) differences between men and women. Age, race, education, and corneal curvature were covariates.
Results
The women were older, more likely to report a family history of keratoconus, more likely to be nonwhite, and less likely to complete college than men. Vogt’s striae and monocular and binocular high-contrast entrance acuity were the only visual characteristics that varied between men and women in the multivariate model. Women were more likely than men to report ocular symptoms of dryness and complaints based upon a composite score of ocular symptoms. Women reported more hours per day of near work and were less likely to report the ability to wear contact lenses for enough hours to permit reading at home in the evening. Women reported more visits to their eye care practitioner during the previous 12 months. NEI-VFQ results revealed differences in self-reported difficulty with distance activities and driving.

Posted by aman at 12:35 AM | Comments (0)

Severe Fungal Keratitis Treated With Subconjunctival Fluconazole

AJO Sep 2005
This study included 13 eyes of 13 patients (mean age 49.6 years, range 28 to 75) with severe fungal keratitis that did not respond to initial therapy with topical and intravenous fluconazole plus oral itraconazole. All patients were injected with subconjunctival fluconazole 2%, up to 1.0 mL twice daily, for at least 5 days. If necessary, therapy was continued once daily for a maximum of 14 days after 5 days of injections.
Results
Six eyes were successfully treated after 5 days of subconjunctival injections of fluconazole. Seven patients required repeated injections for more than 5 days, but one of them finally underwent evisceration. The final visual acuity depended on the location of the remaining scar; in four cases, corneal transplantation was necessary. Neither local nor systemic toxic side effects were observed.
Conclusion
Subconjunctival fluconazole could be effective for treatment of severe fungal keratitis and could be very useful to avoid surgical intervention at an acute stage of this infection. Although the efficacy of the various doses cannot be determined from this series, the dose used in this study seems to be safe and effective for fungal corneal ulcer with hypopyon.

Posted by aman at 12:30 AM | Comments (0)

Prophylaxis for Second Eye Involvement in Leber Hereditary Optic Neuropathy: An Open-Labeled, Nonrandomized Multicenter Trial of Topical Brimonidine Purite

AJO Sep 2005
Nine primary mutation molecularly confirmed LHON patients with one eye vision loss for less than 6 months and normal visual function in the fellow eye were treated with brimonidine purite 0.15% (Alphagan P) 4 times daily in the unaffected eye for up to 2 years. Visual acuity was the primary efficacy outcome. Secondary measures included changes on automated perimetry and quantification of the relative afferent pupillary defect.
Conclusions
LHON may be a bilateral condition at onset more frequently than appreciated, with asymmetric severity at presentation. Topical brimonidine purite in this dosage was unsuccessful in preventing second eye involvement in recently monocularly-symptomatic LHON.

Posted by aman at 12:23 AM | Comments (0)

Long-term Results of Phototherapeutic Keratectomy With 193-nm Excimer Laser for Macular Corneal Dystrophy

AJO Sep 2005
Between October 1990 and February 2004, 10 eyes (five oculus dexter, five oculus sinister) of 6 patients (mean age, 23 ± 8 years [range, 15 to 37 years]) with superficial plaque-like opacities that were caused by macular corneal dystrophy were included. After epithelial debridement and pannus removal, PTK was performed with the 193 nm MEL 60 excimer laser. Intended laser ablation depth varied from 20 to 100 μm; the repetition rate was 20/s or 25/s, and the pulse number was 1774 ± 502 (range, 976 to 2422). Mean follow-up was 4.5 ± 3.1 years [maximum, 8.7 years]). Main outcome measures included: uncorrected visual acuity, best corrected visual acuity (BCVA), spherical equivalent, keratometric central power, keratometric astigmatism and regularity (semiquantitative classification of Zeiss keratometry; scale 0 to 3), postoperative “haze,” time interval until complete epithelial closure, recurrence rate, and necessity of subsequent penetrating keratoplasty (PK).
Results
BCVA increased from 0.3 ± 0.2 before the operation to 0.6 ± 0.1 after the operation; the mean spherical equivalent increased from −0.9 ± 1.1 diopters to −0.4 ± 1.8 diopters. Mean keratometric central power decreased from 44.5 ± 0.7 diopters to 42.5 ± 0.6 diopters. During follow-up, recurrences occurred in nine eyes (90%) after 3.4 ± 0.4 years. In six eyes, a PK was performed after an average of 5.0 years (range, 3.7 to 6.7 years). None of the transplants had a recurrence during the follow-up period.
Conclusion
In superficial opacities that are caused by macular corneal dystrophy, PTK can increase BCVA moderately for a limited period of time. Despite possible complications, primary PK still appears to be the definite therapeutic option for patients with macular corneal dystrophy.

Posted by aman at 12:17 AM | Comments (0)

Central Retinal Artery Occlusion: Visual Outcome

AJO Sep 2005
At entry, 244 consecutive patients (260 eyes) with CRAO (seen consecutively from 1973 to 2000) had a detailed ocular and medical history and ocular evaluation. CRAO eyes were classified into four categories: non-arteritic (NA) CRAO (171 eyes), NA-CRAO with cilioretinal artery sparing (35), transient NA-CRAO (41), and arteritic CRAO (13).
Results
Within 7 days of onset of CRAO, initial visual acuity differed among the four CRAO types (P < .0001). In eyes with vision of counting fingers or worse, it improved in 82% of eyes with transient NA-CRAO, 67% of eyes with NA-CRAO with cilioretinal artery sparing, and 22% of eyes with NA-CRAO. Visual acuity improved primarily within the first 7 days (P < .0001). In the central 30-degree visual field, central scotoma was most common. Central visual field improved in 39% with transient NA-CRAO, 25% with NA-CRAO with cilioretinal artery sparing, and 21% with NA-CRAO. Peripheral visual field was normal in 62.9% of eyes with transient NA-CRAO and 22.1% in those with NA-CRAO. In 51.9% of eyes with NA-CRAO, the only remaining visual field was a peripheral island. Peripheral fields improved in NA-CRAO (39%) and in transient NA-CRAO (39%).
Conclusions
Classification of CRAO is crucial for understanding differences in visual outcome. Marked improvement in visual acuity and visual field can occur without treatment and is determined by several factors. Visual field information is essential to evaluate visual disability in CRAO.

Posted by aman at 12:12 AM | Comments (0)

Macular Hole Development in Fellow Eyes of Patients With Unilateral Macular Hole

AJO Sep 2005
The fellow eyes of 201 patients with full-thickness macular holes were examined by optical coherence tomography (OCT). A subset of 58 fellow eyes with vitreofoveal attachments and perifoveal vitreous detachment was observed during follow-up, and the changes in the vitreofoveal attachment within 24 months from the initial OCT examination were investigated.
In the 58 eyes, the vitreofoveal relationship changed in 27 eyes. Among the 27 eyes, three eyes developed a full-thickness macular hole, and the other 24 eyes developed a posterior vitreous detachment only over the fovea or a complete posterior vitreous detachment without macular hole formation. The vitreofoveal relationship did not change in 31 eyes during the 24-month period.
Conclusion
From an analysis of the changes in the vitreoretinal relationship identified by OCT, three (11%) of 27 fellow eyes in patients with unilateral idiopathic macular hole developed a full-thickness macular hole.

Posted by aman at 12:04 AM | Comments (0)

September 09, 2005

Vitrase trials show reduction in vitreous hemorrhage density

OSN Sep 2005
Vitrase was approved by the Food and Drug Administration as a spreading agent for ocular anesthesia in 2004. It was reviewed by an FDA advisory panel in 2003 for the indication of vitreous hemorrhage clearing but was not recommended for approval of that indication
Two randomized, double-masked, placebo-controlled international studies were conducted, enrolling a total of 1,306 patients. A North American study involved 750 patients who received either saline injection or 7.5 IU, 55 IU or 75 IU of Vitrase. A study outside North America included 556 patients who received either saline injection or 55 IU or 75 IU of Vitrase, according to the press release.
The goal of treatment with an intravitreous injection of ovine hyaluronidase is to provide a safe treatment alternative to reduce and/or clear vitreous hemorrhage density sufficiently to provide earlier visualization of the retina,” Dr. Grillone said. “This would facilitate the physician’s ability to diagnose the underlying retinal pathology and assess the need for additional treatment, as well as restore the subject’s visual acuity when there is adequate retinal function.”
The two phase 3 trials demonstrated that patients receiving a single Vitrase injection showed improved best corrected visual acuity by three or more lines from 1 month through 3 months after injection, compared to those who received saline injection, according to the release.
No serious safety issues” were observed following a single injection of Vitrase in the trials, according to the press release. The most common adverse effect during the trials was acute iritis, the release said.

Posted by aman at 12:41 PM | Comments (0)

Individual patient factors influence SLT success

EYE WORLD Sep 2005
In a prospective, consecutive series, Dr. Ahmed and his colleagues studied 796 eyes of 442 patients, with a mean follow-up of 14.5 months.
Overall, researchers found that SLT treatment was most successful when used as primary therapy, in patients 60 years of age or older, in patients with pre-op IOPs of 24 mm Hg or higher, or patients with pseudoexfoliation or pigmentary dispersion glaucoma.

Posted by aman at 12:33 PM | Comments (0)

Immune cell protein could aid development of eye disease therapies

EYE WORLD Sep 2005
The study, which examines the role of F4/80, was recently published in the Journal of Experimental Medicine.
F4/80, also known as glycoprotein, regulates immune cell activity in the eyes, brain, gastrointestinal and reproductive systems.
The protein prevents the usual immune response onset when confronted with foreign invaders such as bacteria, thereby protecting delicate eye tissue from inflammation.
“We believe that this discovery may ultimately help in the development of therapies for blinding eye diseases such as macular degeneration and autoimmune diseases that occur when the immune system goes awry,” said Joan Stein-Sreilein, Ph.D., senior scientist, Schepens Eye Research Institute, Boston.
First discovered 20 years ago and not understood until recently, F4/80 could be another piece of the immune privilege puzzle, said Dr. Stein-Sreilein.
Her research team followed immune cells containing F4/80, which also are known as antigen presenting cells.
In previous studies, the team found that that when these F4/80 containing cells bring antigens from the eye to the spleen, the spleen stimulates the production of regulatory “T” cells, which stops the immune response throughout the body as well as at the site where the invasion took place.
In the recent study, the Schepens team postulated that the protein had an important role in immune regulation.
Although the mechanism by which F4/80 stimulates the production of immune-suppressing “T” cells is unknown, the team believes that the protein may be involved in cell-to-cell communication.

Posted by aman at 12:26 PM | Comments (0)

Effectiveness of SLT in pseudophakic eyes

EYE WORLD Sep 2005
There is a perception that argon laser trabeculoplasty (ALT) doesn’t work well in pseudophakic eyes,” said Amy Bovell, ophthalmic medical technologist, University of Ottawa Eye Institute, Canada. “SLT is similar to ALT, but has potential benefits over conventional trabeculoplasty.”
These include lower energy, less meshwork damage, and potential repeatability, she said.
“Both types of laser appear to effectively lower IOP, but how well they work in pseudophakic eyes versus phakic eyes is not clear,” she said.
Ms. Bovell is part of a large, prospective randomized clinical trial that compares IOP-lowering efficacy of SLT to ALT. To examine the effect of lens status on IOP response to SLT, she and her colleagues performed a subgroup analysis of their prospectively collected data.
“Our study population consists of 175 eyes with open angle glaucoma,” she said. “They were randomized to treatment with either ALT or SLT, with approximately 50 spots over 180 degrees of meshwork, and then followed for up to one year.”
Of these, 88 eyes were randomized to SLT treatment: 78 were phakic and 10 were pseudophakic.
After one year of follow-up, “ALT and SLT provided equal IOP reduction in both phakic and pseudophakic eyes,” Ms. Bovell said.
Phakic eyes treated with SLT experienced an IOP change of 6 mm Hg (a drop from 23.9 to 17.9 mm Hg).
Pseudophakic eyes dropped 5.5 mm Hg (from 23.5 to 17.9 mm Hg). The difference between phakic and pseudophakic response to SLT was not statistically significant, although the group’s biostatistician, William Hodge, pointed out that the relatively small numbers might not have powered the study to detect clinically relevant differences in this sub-analysis.
Given the renewed interest in laser trabeculoplasty since the emergence of SLT, clarifying its role in the therapeutic arsenal of IOP-lowering therapies is important. And since cataract and glaucoma often coexist, said Ms. Bovell, the issue of phakic status and SLT response deserves careful consideration.

Posted by aman at 12:05 PM | Comments (0)

7 steps to systematic visual field evaluation

EYE WORLD Sep 2005
Step #1: “Understand the test parameters well.” This information is usually located in the upper left corner of the field printout. Is the test a 30-2 or a 10-2? A small central island on a 10-2 field is a much worse defect than on a 30-2 test. Was the testing strategy full threshold or SITA?
Step #2: Scan the reliability factors. These include fixation losses, false-positive responses, and false-negative responses — you can find these located under the test parameters on the printout — as well as short-term fluctuation, which is often located midway down the right side of the printout.
Step #3: The grayscale display. This is the large black-and-white map of the hill of vision located in the upper right-hand corner of the printout.
A quick glance gives an overview of field status — arcuate scotomas, altitudinal defects, and defects that respect the vertical meridian (potential non-glaucomatous defects) are easily seen on the grayscale plot.
But a word of caution: “Sometimes defects don’t show up at all on the grayscale display,” Dr. Cohen said.
Step #4: The Total Deviation plot.The total deviation plot is on the left side of the page, and represents the patient’s hill of vision after correction for age.
Step #5: The Pattern Deviation plot. This is the data immediately to the right of the total deviation plot. This data represents a statistical analysis that removes diffuse or generalized field loss in order to make focal defects more visible.
Step #6: The foveal threshold. The Humphrey perimeter provides a measure of foveal sensitivity, reported on the printout in the upper left-hand corner, just under the reliability indices.
If the foveal threshold is abnormal, a shaded box will appear beside the value, and the darkness of the box will indicate the level of significance of the deviation from normal (a dark black box is more significantly abnormal than a lightly-shaded box).
Step #7: Compare global indices from field to field for evidence of progression. The global indices — mean deviation (MD), pattern standard deviation (PSD), and corrected pattern standard deviation (CPSD) — are located along the right side of the printout, midway down the page. “Mean deviation is a single number representing the entire visual field,” Dr. Cohen said.
Increasingly negative mean deviation values is a sign of progression.

Posted by aman at 12:24 AM | Comments (0)

Blade changes the shape of cataract incision

EYE WORLD Sep 2005
A recent study in Japan showed that a 3.2-mm arched blade (Kojo Slit Blade, BD Medical-Ophthalmic Systems, Franklin Lakes, N.J.), designed to create a three-dimensional incision during cataract surgery to help prevent wound stretch, may reduce the risk for higher-order aberrations and surgically induced astigmatism and improve wound sealing compared with a 3.2-mm flat blade.
The study published in the May issue of the Acta Ophthalmologica Scandinavica included 112 eyes of 74 patients scheduled for cataract surgery.
Two surgeons were randomly assigned to use the 3.2-mm arched blade or a 3.2-mm conventional blade (BD Xstar Slit Knife) to make a temporal clear corneal incision for each case.
Surgeon A, who had just three years of experience, performed approximately 100 cataract surgeries per year, and surgeon B, a veteran surgeon, performed more than 3,000 cataract surgeries per year.
Researchers evaluated corneal topography before surgery and one week, one month, and three months after surgery.
They also determined corneal refractive power with a keratometer in all patients. Corneal wavefront aberrations were assessed before surgery and one week, one month, and three months after surgery only for patients of Surgeon B.
We found that using the arched blade reduced surgically induced astigmatism and higher-order aberrations, and corneal wounds had a high self sealing ability,”said Takashi Kojima, M.D., Social Insurance Chukyo Hospital, Nagoya, Japan
Richard S. Hoffman, M.D said thatthe arched blade gives you an incision length that’s the same as the flat blade, 3.2 mm, but the actual cord length from one end of the incision to the other is less, 2.9 mm,” he said. “That would probably explain why there’s less surgically induced astigmatism with lower higher-order aberrations” found by study investigators.
The manufacturer recommends that surgeons using the arched blade, which is currently available only in the 3.2-mm size, start their incision 0.8 mm from the conjunctiva to prevent conjunctival edema and suggested a tunnel longer than 1.8 mm.
However, Dr. Kojima said the blade is not suited for scleral incisions or cases in which the wound must be enlarged.

Posted by aman at 12:01 AM | Comments (0)

September 08, 2005

Patients feel less pain with topical anesthesia

EYE WORLD Sep 2005
Patients that received peribulbar anesthesia during phacoemulsification reported more pain than those who received topical anesthesia, according to a recent study.
This study assessed patient-perceived pain during phacoemulsification cataract surgery with peribulbar anesthesia (lidocaine 2%–bupivacaine 0.5% mixture) or with topical anesthesia (tetracaine drops); no patient received sedation.
The same surgeon performed all surgeries using a clear corneal approach and in-the-bag intraocular lens implantation. Approximately 15 minutes after surgery, patients in the topical anesthesia group (n=20) were asked to rate their pain during the procedure and patients in the peribulbar anesthesia group (n=21), during infiltration of the anesthetic solution.
Patients graded their pain using a 0- to 10-point visual analog scale (0=no pain; 10=unbearable pain). The results in the 2 groups were compared using the nonparametric Mann-Whitney U test.

Posted by aman at 11:57 PM | Comments (0)

On the lookout for ICL complications

Eye WORLD Sep 2005
One of the key concerns that have surrounded the implantable contact lens (ICL, STAAR Surgical, Monrovia, Calif.) is that a clinically significant cataract might result.
In a new study published in the March 2005 issue of the Journal of Cataract & Refractive Surgery, investigators took a closer look at the likelihood of adverse events that occur with implantation of the ICL in high myopes or high hyperopes.
The non-randomized, prospective clinical trial, which was led by Anna-Ulrika Sarikkola, M.D., Helsinki University Eye Hospital, Finland, included 26 eyes.
Patients were broken into two groups. Patients in group one had to be 45 years of age or younger, have myopia of –10 D or more or hyperopia of +6 D or more, and have a clinically clear crystalline lens. In this group, only the current ICL V4 lens was implanted.
Those in group two had similar refractive errors. However, these patients were older than 45 years of age or had preexisting crystalline lens opacities or other pre-op ocular conditions.
Patients in this group, which was dubbed the heterogeneous group, received V2, V3, or V4 lenses.
Investigators found that in group one, which had a mean follow-up of 13.2 months, the incidence of anterior subcapsular opacities was 7.7%; however, no eye developed a clinically significant cataract during this period.
In addition, none of the myopic patients in this group lost a line of best corrected visual acuity (BCVA). One hyperopic patient did lose a line of BCVA.
Meanwhile, those in group two did not fare as well. In this group, which had a mean follow up of 30.9 months, the incidence of anterior subcapsular opacities was 47.4% and 10 eyes (26.3%) developed clinically significant cataracts during this period.
While initial visual results were similar between the two groups, due to progressive opacities, 23.4% of eyes in the heterogeneous group lost BCVA during the follow-up period.
Investigators concluded that with the latest version of the lens, implantation of the ICL appeared to be a safe procedure with good visual results for patients with high myopic or high hyperopia.
In addition, they determined that risk factors for progressive lens opacification included preexisting lens opacities, older patient age, and implantation with the type V3 ICL.

Posted by aman at 11:48 PM | Comments (0)

Feasibility and Development of a High Power Real-Accommodating IOL

JCRS Sep 2005
In this study, investigators used a laboratory lens model to test the feasibility of developing an accommodating IOL that changes power with the ciliary body. They hope to develop a lens with a minimum of 8 D of accommodation. Such accommodation would be achieved by manipulating a flexible material between a sulcus fixated rigid plate and a ciliary muscle operated capsular diaphragm. In the laboratory lens model used, ciliary relaxation and contraction was achieved using pharmacological agents. Investigators determined changes in lens curvature in relation to the ciliary muscles using ultrasound biomicroscopy (UBM). Investigators found that over 50 D of accommodation could be achieved using the laboratory model. They determined that when using a flexible material with a refractive index of 1.41 that there were changes in lens curvature from nine to 53 diopters. Investigators concluded that when flexible material is placed between a scleral fixated rigid plane and the ciliary muscles operated capsular diaphragm it could be manipulated to achieve active change. Using this concept, over 40 D of change has been generated in monkey eyes.

Posted by aman at 11:43 PM | Comments (0)

Optimal Timing of Capsular Tension Ring Implantation

JCRS Sep 2005
Investigators evaluated whether in cases of zonular weakness it was preferable to implant a capsular tension ring (CTR), before or after removing the lens. Investigators implanted the 12.3 mm CTR in four cadaveric eyes. The CTR was implanted early in two eyes and after lens extraction in the other two eyes. To remove the lens a continuous curvilinear capsulorhexis was made and hydro/visco-dissection was performed. They found that when the CTR was implanted early, before removal of the lens, this resulted in significantly increased capsular torque. With early insertion there was also displacement of up to 4 mm compared to insertion in an empty capsular bag. In addition there were problems with zonular elongation and tension. They concluded that the best timing for CTR placement is after lens extraction and decompression of the capsular bag. This helps to minimize further zonular stress and capsular bag destabilization.

Posted by aman at 11:39 PM | Comments (0)

September 06, 2005

Amniotic membrane use in ophthalmology.

Current Opinion in Ophthalmology August 2005
The amniotic membrane is a biologic tissue that has been used as a graft for corneal and conjunctival reconstruction in a variety of ocular surface diseases. It is avascular and possesses antiangiogenetic, antiscarring and antiinflammatory properties. It is not a substitute but rather a substrate upon which cells can migrate and regenerate, forming new and healthy tissue. The amniotic membrane can also be used as a biologic patch, as a bandage, to treat acute inflammatory disorders. With the development of cell therapy, amniotic membrane can be also used as a carrier of limbal stem cells or their progeny, cultivated in vitro.
however, there is still a lack of scientific evidence based on randomized comparative studies to prove that its use is better than other alternative therapies for ocular surface reconstruction.

Posted by aman at 01:26 AM | Comments (0)

Visual complaints seen with neurodegenerative diseases

OPHTHALMOLOGY TIMES August 15, 2005
Neurodegenerative diseases, such as Alzheimer's disease, Parkinson's disease, and progressive supranuclear palsy, are characterized by visual complaints, which must be assessed carefully to establish the correct diagnosis.
Dr. Chung presented the case of a 72-year-old woman with short-term memory loss. The patient's chief complaint was difficulty seeing and reading. Examination revealed bilateral distance visual acuity of 20/20, J1+ at near, and a normal examination except for motility. The motility examination revealed slowed saccades and pursuits, limited upgaze, and convergence paresis.
One of the most striking eye movement abnormalities associated with Alzheimer's disease is a Balint's-like syndrome, characterized by the triad of simultanagnosia, defined as the inability to perceive more than one visual target; optic ataxia, the inability to reach for objects of interest; and psychic paralysis of gaze, which is similar to the oculomotor apraxia of childhood.
Parkinson's disease is the second most frequently occurring neurodegenerative disease. A loss of dopaminergic neurons in the substantia nigra is responsible for the signs and symptoms of the disease. Tremor, bradykinesia, rigidity, and postural instability are the manifestations.
Upgaze paralysis is seen commonly in aging individuals, but it develops far more frequently in patients with Parkinson's disease.
Convergence paresis, however, may be the most disabling problem for these patients, who will complain of blurred vision or diplopia on near visual tasks, according to Dr. Chung. Addition of prism to spectacles results in good management, but in some cases monocular occlusion is needed.

Posted by aman at 01:10 AM | Comments (0)

Intravitreal Sod2 injections able to rescue RGCs in mice

OPHTHALMOLOGY TIMES August 15, 2005
A potential new strategy has been proposed to treat optic neuritis and multiple sclerosis, namely, delivery of the superoxide dismutase (Sod) 2 gene. Intravitreal Sod2 injections in mice suppre