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February 28, 2006
Memantine protects neurons from shrinkage in the lateral geniculate nucleus in experimental glaucoma.
Archives of ophthalmology. 2006 Feb;124(2):217-25
To determine whether memantine as a treatment for glaucoma prevents neuron shrinkage in the lateral geniculate nucleus, the major target for retinal ganglion cells.Sixteen monkeys with right-eye unilateral experimental glaucoma for 14 months were studied and treated with memantine (n = 9) or vehicle only (n = 7). Left lateral geniculate nucleus relay neurons (layers 1, 4, and 6) were examined following parvalbumin immunolabeling. Cell body cross-sectional areas and neuron numbers were assessed using unbiased methods. Memantine- and vehicle-treated glaucoma groups were compared using t tests and analysis of covariance. Compared with vehicle-treated animals, memantine-treated animals showed significantly less mean +/- SD neuron shrinkage in layers 1 (-4.0% +/- 13.9% vs 28.2% +/- 17.4%; P = .001) and 4 (24.9% +/- 10.0% vs 37.2% +/- 12.3%; P = .04). For layer 6, the difference was not statistically significant (34.2% +/- 10.1% vs 45.3% +/- 14.5%; P = .10). Analysis of covariance results showed significantly less neuron shrinkage in the memantine-treated group for layers 1, 4, and 6 (P < .001; P < .02; and P < .04, respectively). This difference was greatest in layer 1. In each of these layers, neuron numbers did not differ significantly between groups. CONCLUSION: Monkeys with glaucoma that were treated with memantine showed significantly less neuron shrinkage in the lateral geniculate nucleus than the vehicle-treated glaucoma group. CLINICAL The finding that memantine protects adult visual neurons from transsynaptic atrophy in experimental glaucoma could have therapeutic value. Currently, memantine is being tested in an ongoing clinical trial as a treatment for glaucoma.
Posted by s.tavakolizadeh at 08:28 AM | Comments (0)
February 27, 2006
Some patients willing to risk blindness, death for glaucoma cure
Would your glaucoma patients be willing to live a shorter life for a glaucoma cure? Would they be willing to risk complete blindness or even death?A study in Singapore found that 35.7% of respondents, all with primary open-angle glaucoma (POAG) or primary angle-closure glaucoma (PACG), would give up some of their remaining lifespan to completely cure their glaucoma. In addition, 27.3% were willing to risk death and 34.3% were willing to risk blindness for perfect vision.The amount of risk a patient was willing to take for perfect vision increased with the severity of glaucoma the patient experienced.....read more
Posted by mehdi khanlari at 10:50 PM | Comments (0)
Ozone depletion means higher incidence of cataracts
In less than 50 years, the incidence of cortial cataracts could increase above expected levels by 1.3% to 6.9%. Researchers at Johns Hopkins Wilmer Eye Institute in Baltimore blame the predicted trend on the increasing hole in the ozone layer.With more ultraviolet B radiation pouring through the hole from the sun, eyes will suffer . Exposure data were modeled under conditions of 5% to 20% ozone depletion.they... predicted that 167,000 to 830,000 additional cases of cataract will be reported. Also, in light of the high incidence of cataract in senior citizens-at a cost of $3,370 per cataract operation in 2003-the expected increase of cases in 2050 could represent an additional cost of $563 million to $2.8 billion.
The researchers came to these conclusions by using data on the relationship between dose-response ocular exposure to ultraviolet B radiation and cortical cataract from the Maryland population-based study, which included more than 2,500 subjects ages 65 to 84.
Posted by mehdi khanlari at 10:39 PM | Comments (0)
A new regression formula offers predictable outcomes for many post-LASIK patients
...The greater the amount of the excimer ablation—myopic or hyperopic—the greater the error in reading the corneal power. Dr. Masket became aware of this relationship early on. After garnering significant experience with previously myopic and hyperopic patients, he was able to consider a correcting factor. “In my early experience, after patients had myopic PRK or LASIK, I found that I had approximately 1 D of error in IOL power for each 3 D of photoablation This means that if a patient undergoes 6 D of myopic treatment and it is measured in the standard fashion, the IOL will be underpowered by about 2 D.
.... To use the formula, the patient is examined as if he had no prior surgery. Dr. Masket uses the IOL Master (Carl Zeiss Meditec, Dublin, Calif.) to first measure the patient’s eyes. He then enters the results, as he normally would, into either the SRK-T formula for previously myopic eyes, or the Hoffer Q, formula for patients who have had prior hyperopic ablations. He then determines the IOL power adjustment with the aid of the regression formula:
IOL D Adjustment (from that calculated by IOL Master) = D (prior laser treatment) X –0.315 + 0.101With the formula, the IOL adjustment is determined by multiplying the amount of the laser vision correction in diopters by a factor of –0.315 and then adding 0.101. For example, for a patient who had had undergone 6 D of myopic treatment the practitioner would multiply –6 by a factor of –0.315 and then add 0.101.This calculation would result in an adjusting factor of +1.88 D. This number would then be rounded up to + 2.0 D. In this case, if the SRK-T formula had given a reading of 18 D, the practitioner would add the adjusting factor to this and implant a 20 D lens.
Posted by mehdi khanlari at 10:31 PM | Comments (0)
A useful augmented lateral tarsal strip tarsorrhaphy for paralytic ectropion.
Ophthalmology. 2006 Jan;113(1):84-91
Patients with paralytic ectropion and lagophthalmos may experience keratitis and may pose a functional and aesthetic surgical challenge. Various methods are used to reduce the vertical palpebral aperture, including lateral tarsal strip (LTS) or a lateral tarsorrhaphy. We modified the LTS to differentially shorten and elevate the lower lid more than the upper: an augmented LTS tarsorrhaphy (aug-LTS-T). This study aimed to evaluate the technique. Prospective noncomparative surgical trial in which preoperative and postoperative symptoms, margin reflex distances, vertical palpebral aperture (PA), lagophthalmos, and corneal findings were recorded. The data were analyzed at 6 months after surgery using the Wilcoxon sign-rank test for nonparametric data Fourteen consecutive adult patients (15 eyelids) with chronic lagophthalmos and paralytic ectropion. Patients underwent aug-LTS-T. This consisted of a long strip (10-15 mm) that is attached to the outer temporal orbital rim, at a point higher than a conventional LTS. It included removal of a small part of the upper eyelid anterior lamella laterally to pass the long strip up high enough. Improvement of symptoms, reduction of lower margin reflex distance, lagophthalmos, and improvement of corneal signs. Minimum follow-up was 6 months. There was a significant reduction in PA (P = 0.005) and lagophthalmos (P = 0.0002) with improvement of corneal signs (14 of 15 eyelids = 93%). Surgery was successful anatomically in 14 of 15 eyelids (93%) with low morbidity. We describe the augmented LTS tarsorrhaphy and find it effective in the treatment of severe lower eyelid ectropion resulting from facial palsy.
Posted by s.tavakolizadeh at 10:31 PM | Comments (0)
Cataract surgery profile remains unchanged, study finds
Of the 8,257 patients, a statistically significant number of the patients were women (58%), they said. Women also were significantly older than men. Women were 74.89 ± 11.03 years old compared to men who were 72.32 ± 12.21 years old.But while the women were older than men, the investigators noted that the average ages did not significantly increase for either sex....The investigators speculated that one reason why more women are having cataract surgery than men may have to do with the fact that women, on average, live longer than men....
Posted by mehdi khanlari at 10:10 PM | Comments (0)
A New, X-linked Endothelial Corneal Dystrophy
American Journal of Ophthalmology Volume 141, Issue 3 , March 2006, Page 478
We examined a total of 60 members of a family with this dystrophy at the slit-lamp. Light and electron microscopic findings of the corneal button were recorded following one male patient’s penetrating keratoplasty. A panel of 25 microsatellite markers covering the X chromosome was typed in genomic DNA from 50 family members. The data were analyzed using the ALLEGRO program to obtain two-point and multipoint likelihood of the odds (LOD) scores and to generate haplotypes.
Results
A total of 35 trait carriers were identified in four generations of the family. Nine male patients demonstrated severe corneal opacifications: two congenital corneal cloudings in form of ground glass, milky appearance and seven subepithelial band keratopathies combined with endothelial changes resembling moon craters. Twenty-two female and four male patients disclosed only endothelial alterations resembling moon craters. No instance of male-to-male transmission of the disease was encountered in the family. Light and electron microscopy disclosed focal discontinuities and degeneration of the endothelial cell layer and marked thickening of Descemet’s membrane. Multipoint analysis showed linkage with a maximum LOD score of 10.90 between markers DXS8057 and DXS1047.
Conclusions
To the best of our knowledge, this represents the first fully documented report of X-linked inheritance of an endothelial corneal dystrophy. Late subepithelial band keratopathy is a landmark of XECD. A locus for this corneal dystrophy maps to Xq25.
Posted by mmiraftab at 08:54 PM | Comments (0)
The Incidence and Risk Factors for Developing Dry Eye After Myopic LASIK
American Journal of Ophthalmology Volume 141, Issue 3 , March 2006, Pages 438-445
setting and study population: Participants were randomized to undergo LASIK with a superior or a nasal hinge flap. They were evaluated at 1 week and 1, 3, and 6 months after surgery. intervention: Bilateral LASIK with either a superior-hinge Hansatome microkeratome (n = 17) or a nasal-hinge Amadeus microkeratome (n = 18). main outcome measures: The criterion for dry eye was a total corneal fluorescein staining score ≥3. Visual acuity, ocular surface parameters, and corneal sensitivity were also analyzed. Cox proportional-hazard regression was used to assess rate ratios (RRs) with 95% confidence intervals.
Results
The incidence of dry eye in the nasal- and superior-hinge group was eight (47.06%) of 17 and nine (52.94%) of 17 at 1 week, seven (38.89%) of 18 and seven (41.18%) of 17 at 1 month, four (25%) of 16 and three (17.65%) of 17 at 3 months, and two (12.50%) of 16 and six (35.29%) of 17 at 6 months, respectively. Dry eye was associated with level of preoperative myopia (RR 0.88/each diopter, P = .04), laser-calculated ablation depth (RR 1.01/μm, P = 0.01), and combined ablation depth and flap thickness (RR 1.01/μm, P = 0.01).
Conclusions
Dry eye occurs commonly after LASIK surgery in patients with no history of dry eye. The risk of developing dry eye is correlated with the degree of preoperative myopia and the depth of laser treatment.
Posted by mmiraftab at 08:52 PM | Comments (0)
Intraoperative Enoxaparin Minimizes Inflammatory Reaction After Pediatric Cataract Surgery
American Journal of Ophthalmology Volume 141, Issue 3 , March 2006, Pages 433-437
To evaluate the effect of intraocular infusion of enoxaparin, a low-molecular-weight heparin, on postoperative inflammatory response in pediatric cataract surgery.Seventeen consecutive eyes (11 patients) underwent pediatric cataract surgery in two tertiary medical centers. During the procedure, balanced salt solution with enoxaparin (40 mg in 500 ml) was infused into the anterior chamber. Eleven consecutive eyes (eight patients) received balanced salt solution without enoxaparin in the infusion bottle. The inflammatory response in the anterior chamber was compared between the two groups by semiquantification with slit-lamp biomicroscopy. Postoperative inflammatory complications, including fibrin formation, intraocular lens precipitates, anterior and posterior synechiae, cyclitic and pupillary membrane formation, and anterior subluxation of the intraocular lens, were also compared. The follow-up period after surgery was between 3 and 36 months (average 12.3 months).
Results
The number of cells and the degree of flare were minimal in the group with enoxaparin in the infusion bottle (P < .001). The total number of postoperative inflammation-related complications was also lower in the enoxaparin-treated group (P = .007). All corneas remained clear, and the endothelial cell count, which was performed in two patients, did not show substantial decrease in their density or changes in shape and size. No other enoxaparin-related complications were observed.
Conclusions
Infusion of enoxaparin during pediatric cataract surgery may minimize the postoperative inflammatory response and decrease the number of postoperative inflammatory related complications. Enoxaparin should also be evaluated for cataract surgery in other conditions where postoperative inflammation may be exacerbated.
Posted by mmiraftab at 08:50 PM | Comments (0)
Longitudinal correlation of thyroid-stimulating immunoglobulin with clinical activity of disease in thyroid-associated orbitopathy
Ophthal Plast Reconstr Surg. 2006 Jan-Feb;22(1):13-19
To investigate the possible correlation between the changes in inflammatory active phase of thyroid-associated orbitopathy (TAO) with measured changes in thyroid-stimulating immunoglobulin (TSI) levels over time. This study was undertaken to evaluate the potential usefulness of measured TSI values in following and treating patients with TAO. 9 A retrospective chart analysis was performed on 23 patients who had been referred to a tertiary care oculoplastics service between July of 2002 and April of 2004 with suspected TAO. The activity status of patients with TAO was graded by using the TAO activity scale (TAOS), created to distinguish between the active and cicatricial phases of TAO. Laboratory values of TSI reported during the course of the study period were compiled for each study patientLinear regression analysis revealed a statistical correlation between the changes in activity of TAO, as measured by the TAOS score, and changes in measured values of TSI over time. A statistically significant correlation was also found between the activity of TAO (measured by the TAOS score) and TSI valueIt was found that changes in inflammatory phase of TAO, as measured by the TAOS score, statistically correlate with changes in measured TSI. An additional correlation was also found between the absolute score of TAO activity and measured level of TSI. These findings suggest that serial TSI measurements may be an adjunct in assessing clinical inflammatory activity of TAO and may help direct clinical decision making regarding treatment decisions in TAO.
Posted by mmiraftab at 07:46 PM | Comments (0)
February 25, 2006
Strabismus in Down Syndrome
Patients with Down syndrome attending the Izmir Association for Supporting Patients With Down Syndrome in Izmir, Turkey, were screened for strabismus and refractive errors. All patients underwent a complete eye examination including cycloplegic refraction and dilated fundus examination. Ocular alignment was evaluated using the cover test and either the Krimsky or the Hirschberg corneal reflex test depending on the cooperation of the patient. Strabismic and nonstrabismic patients were compared for refractive errors, anisometropia, and amblyopia.
Fifty-seven patients with an average (± standard deviation) age of 9.30 years (± 6.14 years; range, 1 to 31 years) were screened. Twentyfive (44%) were female and 32 (56%) were male. Eleven patients (19%) had strabismus. Ten (18%) had esotropia and 1 (2%) had exotropia. Infantile esotropia was observed in 3 patients who had no significant refractive errors. Seven patients had acquired esotropia; they had clinically significant refractive errors and anisometropia. A higher frequency of hypermetropia was noted in patients with strabismus (P < .05).
Esotropia and hypermetropia are common in patients with Down syndrome. Early diagnosis and treatment of strabismus and associated ocular conditions such as refractive errors and amblyopia may improve the quality of life for these patients.
Posted by s.tavakolizadeh at 08:10 AM | Comments (0)
February 24, 2006
New technologies explored to reduce lens chatter
The first modality is continuously variable pulse phacoemulsification. As the surgeon compresses the phaco pedal, each pulse of the phaco needle is sharper and higher, but separated farther from the next pulse.“It’s like if you’re a boxer, instead of a rapid series of punches, it’s punch-wait, punch-wait, and you have sharper, shorter punches,”
The other method is torsional phaco, with rotation of the phaco tip.“When you rotate it at the same pulse rate as the phaco, you actually induce the same kinds of pulse waves, but instead of going in and out, it goes rotationally, and that also reduces the chatter because you’re not hitting it. You’re just rubbing against it,” Dr. Arshinoff said. “So that way you’re transmitting the energy in a way that has less chatter.”Dr. Arshinoff expects that the best option will be to combine continuously variable pulse and torsional phacoemulsification to produce effective results while significantly reducing chatter. “
Posted by mehdi khanlari at 11:55 PM | Comments (0)
Transpupillary silicone oil through planned
The use of transpupillary silicone oil through a planned posterior capsulotomy may be performed in topical surgery, according to a recent study. Jost Jonas, M.D., University of Heidelberg, Germany, and his co-investigators said that the use of topical anesthesia is beneficial because there are fewer risks than peribulbar or retrobulbar injections, and because topical anesthesia is less invasive and cheaper.In the study, which was published in the Journal of Cataract & Refractive Surgery, September 2005, the investigators reviewed 37 patients having transpupillary silicone oil removal combined with cataract surgery. The physicians used four to five drops of oxybuprocaine .4% (Minims benoxinate hydrochloride, Chauvin Pharmaceuticals, England), prior to surgery.The physicians were able to carry out all of the cataract surgeries without needing to switch to any other type of anesthesia. Also, none of the patients complained about severe pain during the surgery or post-op, and there were not any severe complications.The increased motility of the eye under the topical anesthesia may partially be an advantage since the patients can be asked to look in different directions so that bridle sutures through the superior rectus muscle or through the limbus may be avoided, the investigators wrote
Posted by mehdi khanlari at 11:46 PM | Comments (0)
Age-Related Eye Disease, Visual Impairment, and Survival
Arch Ophthalmol. 2006;124:243-249.
To investigate the relationship of age-related maculopathy, cataract, glaucoma, visual impairment, and diabetic retinopathy to survival during a 14-year period.....Results As of December 31, 2002, 32% of the baseline population had died (median follow-up, 13.2 years). After adjusting for age, sex, and systemic and lifestyle factors, poorer survival was associated with cortical cataract (hazard ratio [HR], 1.21; 95% confidence interval [CI], 1.06-1.37), any cataract (HR, 1.16; 95% CI, 1.03-1.32), diabetic retinopathy (HR per 1-step increase in 4-level severity, 1.36; 95% CI, 1.14-1.63), and visual impairment (HR, 1.24; 95% CI, 1.04-1.48) and marginally associated with increasing severity of nuclear sclerosis (HR, 1.07; 95% CI, 0.99-1.16). Age-related maculopathy and glaucoma were not associated with poorer survival. Associations tended to be slightly stronger in men than women.Conclusions Cataract, diabetic retinopathy, and visual impairment were associated with poorer survival and not explained by traditional risk factors for mortality. These ocular conditions may serve as markers for mortality in the general population.
Posted by mehdi khanlari at 11:31 PM | Comments (0)
Magnetic Resonance Imaging of the Brain in Patients with Pseudoexfoliation Syndrome and Glaucoma
To evaluate ischemic changes in brain magnetic resonance images in patients with pseudoexfoliation syndrome (PXS) and pseudoexfoliation glaucoma (PXG) and compare them with age- and sex-matched control subjects. Each subject underwent a comprehensive ophthalmological examination. In all participants, an axial T1-, T2- and proton-density-weighted and coronal cerebral 1.5-tesla magnetic resonance imaging (MRI) scan was made. White matter hyperintensities (WMH) were considered present if these were hyperintense on both proton-density- and T2-weighted images and not hypointense on T1-weighted images. White matter lesions were classified into two parts as the subcortical and periventricular regions. . Conclusion: We found a significantly higher prevalence of MRI-defined WMH in patients with a clinical diagnosis of pseudoexfoliation with or without glaucoma versus control subjects. We think that the findings in this study may shed light on a possible link between ischemic brain lesions and pseudoexfoliation, which is not related with the presence of glaucomatous optic neuropathy. Further investigations are required to resolve the underlying associations.
Posted by mehdi khanlari at 11:15 PM | Comments (0)
Endoscopy-Guided Subretinal Fluid Drainage in Vitrectomy for Retinal Detachment
To study the usefulness of endoscopy-guided subretinal fluid drainage in pars plana vitrectomy (PPV) for rhegmatogenous retinal detachment (RRD). Participants/Methods: A prospective non-comparative study of a small number of RRD cases. The study involved examining 10 eyes of 10 patients with RRD that received PPV. Two eyes had hazy corneas, which hindered the observation by surgical microscopy. Fluid-gas exchange was performed and then subretinal fluid was drained through a primary retinal break guided by an endoscope. No drainage retinotomy was made. Each clinical feature was studied and the surgical outcome and complications were evaluated. Results: All eyes had retinal reattachment by a single operation. No serious complication related to surgery was experienced. Conclusions: Endoscopy-guided subretinal fluid drainage is the safe and effective procedure in PPV for RRD.
Posted by mehdi khanlari at 11:09 PM | Comments (0)
Clinical results of the blue-light filtering AcrySof Natural foldable acrylic intraocular lens
Journal of Cataract & Refractive Surgery December 2005
....No statistically significant differences were discovered between the 2 patient groups in visual acuity, contrast sensitivity evaluated under mesopic and photopic conditions, or the number of patients who passed the Farnsworth D-15 color perception test. There were no lens-related adverse events in either group.Conclusions The blue-light filtering AcrySof Natural IOL was equivalent to the conventional AcrySof lens in terms of postoperative visual performance. Additional long-term clinical studies should show whether the IOL actually provides the theoretical benefits to retinal health.
Posted by mehdi khanlari at 11:02 PM | Comments (0)
Comparative study of 2 anesthesia techniques for pediatric refractive surgery
JCRS,Dec,2005
This prospective clinical study was of children ranging in age range from 3 to 12 years who were followed for myopic anisometropia with amblyopia after failure of conventional correction or patients with superficial stromal corneal opacities. The children were scheduled to have refractive surgery under general anesthesia using propofol/fentanyl (P/F group) or ketamine/midazolam (K/M group). All drugs were administered intravenously.
Conclusions:Propofol offered some advantages for brief procedures outside the traditional operating rooms. It is short acting, and has a rapid offset resulting in shorter postoperative monitoring and a smoother recovery profile. It has greater potential for respiratory depression than ketamine. Hence, greater vigilance and experience with the pediatric airway is recommended with its use.
Posted by afarahi at 08:10 PM | Comments (0)
Macugen demonstrates long-term safety
INDUSTRY NEWS
A two-year review of safety data from a trial evaluating Macugen as a wet AMD treatment shows this anti-VEGF is not associated with an increased risk of cardiovascular adverse events such as blood clots, excessive bleeding or hypertension.
Posted by kjalali at 08:12 AM | Comments (0)
Promising results for diabetic macular edema treatment
INDUSTRY NEWS
Bausch & Lomb says three-year follow-up data from its multi-center, randomized, controlled clinical trial shows that significantly more patients receiving Retisert had improved visual acuity (an increase of three or more lines on the Snellen chart) compared to than those receiving standard treatment. Retisert is surgically implanted into the eye and releases a constant amount of fluocinolone acetonide.
Posted by kjalali at 08:10 AM | Comments (0)
Ophthalmic NSAID inhibits IOP reduction by latanoprost in patients with glaucoma
BJO, March 2006
This prospective double blind study included 16 patients with primary open-angle glaucoma (10 patients) or ocular hypertension (six patients) who were given only 0.005 percent latanoprost for six weeks. Additional administration of the non-steroidal anti-inflammatory drug (NSAID) ophthalmic solution, sodium 2-amino-3-(4-bromobenzoyl) phenylacetate sesquihydrate, was given in one eye for 12 weeks, while sodium hyaluronic acid ophthalmic solution was administered into the other eye (control group). The difference in IOP between the control group and the NSAID group was an average of 1.08 mmHg. Although the difference in IOP between the two groups may appear clinically insignificant, the researchers conclude that it may be an important finding in terms of considering the mechanism by which latanoprost reduces IOP. It also shows a need to study the effects of NSAIDs on other prostaglandin-related ophthalmic solutions used to treat glaucoma. Since ophthalmic NSAIDs are frequently used, their action should be taken into consideration when administering ophthalmic NSAIDs to glaucoma patients for long periods of time.
Posted by kjalali at 08:07 AM | Comments (0)
Increase of Peak Intraocular Pressure During Sleep in Reproduced Diurnal Changes by Posture
Archives of Ophthalmology, February 2006
Researchers measured IOP in 148 patients with untreated glaucoma by noncontact tonometry. Measurements were taken 12 times over the course of 24 hours, including every three hours during the night. Each time, they measured the pressure when the patient was sitting as well as lying down so that each patient had three levels: the sitting pressure, the lying pressure and the reproduced pressure, which was calculated by combining the sitting values when the patient was awake and lying values when the patient was asleep. The average peak pressure for seated patients was 16 mm Hg; for those lying down, it was 18.9 mm Hg; and the peak reproduced pressure was 17.5 mm Hg. In patients with primary open-angle glaucoma and IOPs less than 21 mm Hg during clinic hours, 20 percent had a reproduced pressure of 21 mm Hg or greater when sleeping, compared with only 3 percent who had an IOP of 21 mm Hg or greater while sitting. The authors conclude that measuring pressure only during the day provides an incomplete account of patients' risks, and that diurnal IOP changes should be reproduced with consideration for patients’ posture.
Posted by kjalali at 08:04 AM | Comments (0)
Multifocal VEPs effective in detecting optic neuritis, and may identify which patients are at a higher risk of developing MS
Ophthalmology, February 2006
In this cross-sectional study, researchers used McDonald multiple sclerosis (MS) criteria to classify 64 patients with a confirmed diagnosis of optic neuritis (past and acute) into three groups: those who did not have MS (27 eyes), possible MS (25 eyes) and definite MS (24 eyes). Multifocal visual evoked potentials (mVEPs) amplitude and latency values were analyzed within each group and were compared with a control group of 20 normal patients. Of all eyes with optic neuropathy, 97.3 percent were abnormal on mVEP testing. Amplitude values were abnormal in 92.6 percent of not-MS eyes, 92 percent of possible MS eyes and 100 percent of those with MS; latency was abnormal in 33.3 percent, 76 percent, and 100 percent, respectively. The authors conclude that if this latency pattern does reflect future clinical course, then mVEPs could provide a means of differentiating between those with a greater risk of future MS in the early post-acute stage of optic neuropathy from those with purely inflammatory optic neuritis. For patients with higher latency z-scores, they suggest immediately starting treatment aimed at lowering progression rates to MS, whereas those with lower latency z-scores should continue to be monitored.
Posted by kjalali at 08:03 AM | Comments (0)
Indocyanine green may adversely affect RNFL thickness, and cause visual field defects post-vitrectomy
Ophthalmology, February 2006
In this retrospective case series, researchers used optical coherence tomography to analyze retinal nerve fiber layer (RNFL) thickness in 34 eyes (32 patients) after macular hole surgery. Eyes were divided into three groups: those that developed visual field defects after indocyanine green–assisted vitrectomy (11 eyes), eyes that didn’t develop defects after indocyanine green (nine eyes) and eyes without defects that underwent vitrectomy without indocyanine green (14). RNFL thickness in eyes with visual defects after indocyanine green-assisted surgery was significantly less than in eyes without visual field defects, suggesting that decreased RNFL thickness is associated with postoperative visual field defects and that indocyanine green might have an adverse affect on RNFL thickness. Researchers conclude that even if a minimal dose is used and no postoperative visual field defects are observed, surgeons should recognize the potential toxic effects of indocyanine green. They advise careful, long-term follow-up for these patients.
Posted by kjalali at 08:00 AM | Comments (0)
February 23, 2006
Intraoperative Enoxaparin Minimizes Inflammatory Reaction After Pediatric Cataract Surgery
American Journal of Ophthalmology March 2006, Pages 433-437
To evaluate the effect of intraocular infusion of enoxaparin, a low-molecular-weight heparin, on postoperative inflammatory response in pediatric cataract surgery Seventeen consecutive eyes (11 patients) underwent pediatric cataract surgery in two tertiary medical centers. During the procedure, balanced salt solution with enoxaparin (40 mg in 500 ml) was infused into the anterior chamber. Eleven consecutive eyes (eight patients) received balanced salt solution without enoxaparin in the infusion bottle. The number of cells and the degree of flare were minimal in the group with enoxaparin in the infusion bottle (P < .001). The total number of postoperative inflammation-related complications was also lower in the enoxaparin-treated group (P = .007). All corneas remained clear, and the endothelial cell count, which was performed in two patients, did not show substantial decrease in their density or changes in shape and size. No other enoxaparin-related complications were observed.ConclusionsInfusion of enoxaparin during pediatric cataract surgery may minimize the postoperative inflammatory response and decrease the number of postoperative inflammatory related complications. Enoxaparin should also be evaluated for cataract surgery in other conditions where postoperative inflammation may be exacerbated.
Posted by mehdi khanlari at 07:29 PM | Comments (0)
Intermediate vision and Restore IOL
....Intermediate vision is critical for individuals with active lifestyles, where working on the computer, cooking, and grocery shopping are part of their daily activities. In comparison, the ReStor is a bifocal IOL that has no separate focal point for intermediate vision. One can “push out” the near focal point to overcome the excessive add by aiming for a slightly hyperopic endpoint, which shifts the defocus curve to the left and leads to a more comfortable reading distance. Unfortunately, there is also an equal amount of loss in uncorrected distance vision when a hyperopic post-op goal is achieved.
Posted by mehdi khanlari at 07:23 PM | Comments (0)
Matching lenses with patient types
There is no definitive way to use these lenses, although surgeons have their own preferences regarding how to use them and for which patients.... said David F. Chang, M.D., clinical professor, University of California, San Francisco.“Based upon the known differences in optical design, I lean toward ReStor in myopes, in patients with very small pupils, and in patients who dilate widely in the dark,” . “I would lean toward ReZoom if intermediate focus is more important, such as in many hyperopes. While I hesitate to use a multifocal if there is early macular pigmentary change, I think the ReZoom might be better if someone developed dry age-related macular degeneration because the central 2 mm is 100% distance, and could be brought up close with reading glasses.”
R. Bruce Wallace III, who was an investigator for the ReStor lens, said he would prefer to implant a ReStor lens for people who perform needlework for extended periods“Very fine near work might be better off with ReStor,”.“However, ReZoom seems to offer some better intermediate vision, which might be better in the initial phase with the ReZoom lens,” Dr. Wallace said. “If people are active computer users, cell phone users, digital camera users-and even for just eating food, intermediate vision is critical to enjoyment of everyday visual activities.”Meanwhile, Richard L. Lindstrom, M.D., clinical professor of ophthalmology, University of Minnesota, Minneapolis, said if he implanted a ReStor in a patient's first eye, and the patient said he or she had terrible night vision symptoms, “I would give the patient a CrystaLens in the second eye or an aspheric monofocal lens, both of which might reduce night vision symptom complaints.”
Posted by mehdi khanlari at 06:23 PM | Comments (0)
Rezoom study ....
Premarket approval data for the ReZoom was not available from the FDA's premarket approval (PMA) database. The company used Array (AMO) clinical visual acuity data along with the FDA-approved Sensar (AMO) acrylic platform and the Balanced View Optics technology, proven by bench testing, to get ReZoom approved for the market quickly, company officials said. Together, the company's submission was approved by FDA as a PMA supplement, company officials said.However, company officials said a European study was performed on ReZoom, which conformed to FDA standards and included more than 200 patients. In study results provided by company officials, 93.3% of ReZoom patients reported independence from glasses for distance. For intermediate, 91.4% of patients reported independence from glasses. Meanwhile, 66.7% of patients reported independence from glasses for near.Additionally, 93.0% of patients never or only occasionally wore glasses, according to the data
Posted by mehdi khanlari at 06:17 PM | Comments (0)
February 21, 2006
Intraocular Pressure Measurement-Comparison of Dynamic Contour Tonometry and Goldmann Applanation Tonometry
Journal of Glaucoma. 15(1):2-6, February 2006
Conclusions: Dynamic contour tonometry seems to be a reliable method for intraocular pressure measurement, which unlike Goldmann applanation tonometry is not influenced by central corneal thickness. In clinical practice, advantages from dynamic contour tonometry can be expected for cooperative patients, outpatients, and patients with sufficient bilateral ocular fixation, whereas Goldmann applanation tonometry measurements are more reliable in case of patients with inadequate cooperation, poor vision, or nystagmus.
Posted by mmiraftab at 03:31 PM | Comments (0)
Deep sclerectomy and low dose mitomycin C: a randomised prospective trial in west Africa
British Journal of Ophthalmology 2006;90:310-313
Methods: Prospective, randomised, controlled trial. Trial participants were Nigerian patients with medically uncontrolled primary open angle glaucoma undergoing primary surgery at Maja Hospital, Lagos, Nigeria. 39 eyes of 39 patients undergoing DS were randomised into receiving intraoperative MMC 0.25 mg/ml for 2 minutes at the end of procedure (DS-MMC) and a control group (DS-noMMC).
Results: There were 21 patients in the DS-noMMC and 18 in the DS-MMC group with no difference in the preoperative characteristics of the groups. Mean follow up was 16.4 (SD 11.3) months. The probability of maintaining an intraocular pressure less than 18 mm Hg with or without additional medications (95% confidence intervals) at 1 year was 70% (47–92%, 95%) and 79% (57–100%), and at 18 months was 35% (8–62%) and 38% (7–69%) for the DS-noMMC and DS-MMC groups, respectively, with no difference in success rates (p = 0.6). An IOP of less than 18 mm Hg without additional medication was maintained in 65% (41–89%) and 73% (49–96%) at 1 year and 24% (8–48%) and 13% (13–46%) at 18 months for the DS-noMMC and DS-MMC groups, respectively (p = 0.5). There were no serious complications related to the procedure.
Conclusions: The success rates of DS in black west African glaucoma patients, as performed in this study, were low. The study did not achieve sufficient power to detect whether low dose intraoperative MMC application can increase success rates of DS.
Posted by mmiraftab at 03:28 PM | Comments (0)
Refractive change in thyroid eye disease (a neglected clinical sign)
British Journal of Ophthalmology 2006;90:307-309
Background/aims: The literature on refractive change in thyroid eye disease (TED) is limited. This study documents the refractive change in patients with TED undergoing orbital decompression. The authors propose possible mechanisms for their acquired refractive error.
Methods: This is a retrospective observational case study of five patients with progressive TED. Their detailed eye examinations including refractive state preoperatively and postoperatively are presented.
Results: An acquired hypermetropic shift with active TED before orbital decompression of up to 3.75D spherical equivalent refraction (SER) is reported in one patient. Post-orbital decompression, an induced myopic shift of between 1.00–2.50D SER for all patients is observed, noted to range from 1 day following surgery to up to 9 months, dependent on the availability of data. Axial length increased in two cases corresponding to postoperative myopic shift. Magnetic resonance imaging findings of one patient demonstrate flattening of the posterior pole as a cause of the acquired preoperative hypermetropia.
Conclusions: TED has a significant effect on the refractive state of patients. The proposed mechanism of acquired hypermetropia relates to increased volume of orbital contents with flattening of the posterior globe. This is reversed with successful orbital decompression. Documentation of refractive error in all cases of progressive TED is recommended. Progressive acquired hypermetropia may be suggestive of TED activity.
Posted by mmiraftab at 03:26 PM | Comments (0)
Do retinopathy signs in non-diabetic individuals predict the subsequent risk of diabetes?
British Journal of Ophthalmology 2006;90:301-303
Background/aims: Isolated retinopathy signs are common in non-diabetic individuals and have been shown to be associated with impaired glucose metabolism. In a cohort of people without diabetes, the association of these retinopathy signs and subsequent development of diabetes were examined.
Methods: A population based cohort study of 7992 people aged 49–73 years without diabetes was conducted. Retinal photographs of these participants were evaluated for the presence of retinopathy signs according to a standardised protocol. Incident cases of diabetes were identified prospectively.
Results: After a follow up of 3 years, 291 (3.6%) people developed incident diabetes. In the total cohort, retinopathy was not significantly associated with incident diabetes (4.7% v 3.6%, multivariable adjusted odds ratio (OR) 1.1, 95% confidence intervals (CI), 0.7 to 1.9). However, among participants with a positive family history of diabetes, retinopathy was associated with incident diabetes (10.4% v 4.8%, multivariable adjusted OR 2.3, 95% CI, 1.0 to 5.3). Among participants without a family history of diabetes, retinopathy was not associated with incident diabetes
Conclusions: In individuals with a family history of diabetes, retinopathy signs predict subsequent risk of clinical diabetes.
Posted by mmiraftab at 03:24 PM | Comments (0)
Corneal calcification following intensified treatment with sodium hyaluronate artificial tears
British Journal of Ophthalmology 2006;90:285-288
Methods: Five cases of deep calcium deposition in the cornea associated with ocular surface disease and frequent use of hyaluronic acid artificial tears are described. All patients used one formulation of phosphate buffered hyaluronate eye drops when rapid calcification developed. All eyes required corneal graft surgery for visual rehabilitation. Specimens at keratoplasty were available for light microscopy and investigation by dispersive x ray analysis. The phosphate concentration in the medication used for topical treatment was measured and compared to alternative hyaluronate preparations.
Results: Light microscopy showed dense mineralisation of the entire stroma. The crystalline deposits consisted of hydroxyapatite, Ca5(PO4)3OH. A 50-fold higher concentration of phosphate was measured in the sodium hyaluronate eye drops used for treatment (50.9 mmol/l) when compared with normal serum. The other hyaluronate formulations showed phosphate concentrations from <0.1 mmol/l to 10.9 mmol/l.
Conclusions: The hyaluronate artificial tear formulation "Hylo-Comod" favours the formation of insoluble crystalline calcium phosphate deposits in presence of epithelial keratopathy. This is because of its high phosphate concentration and typically frequent instillation. Manufacturers and prescribers should be aware that topical preparations may contain considerable amounts of phosphate which may lead to sight threatening corneal complications.
Posted by mmiraftab at 03:21 PM | Comments (0)
Controlling Contagious Bacterial Conjunctivitis
Journal of Pediatric Ophthalmology and Strabismus ,January/February ,2006
Recent outbreaks (epidemics) of Streptococcus pneumoniae conjunctivitis, involving hundreds of patients, underscore the importance of following recommended guidelines to minimize disease transmission. These include the use of antimicrobial agents capable of minimizing patients’ symptoms and the duration of the infectious period when disease can be transmitted to others.
Isolates of S. pneumoniae from three patients were exposed to selected ophthalmic antibiotic products: moxifloxacin 0.5%, tobramycin 0.3%, gentamicin 0.3%, and polymyxin B 10,000 IU—trimethoprim 1.0%. Moxifloxacin killed actively growing S. pneumoniae faster and to a greater extent than did the other three antibiotic products when tested at concentrations corresponding to tear film concentrations 5 to 10 minutes and 30 to 60 minutes after instillation of the products.
CONCLUSIONS:Moxifloxacin killed S. pneumoniae in vitro faster than did the other antibiotics. Consequently, its use should complement other generally accepted measures for minimizing patients’ symptoms and limiting the contagiousness of bacterial conjunctivitis. Also, this is consistent with the recommendations of other investigators to prescribe the most recent generation of fluoroquinolone antibiotics for the specific purpose of limiting the spread of bacterial resistance.
Posted by afarahi at 11:01 AM | Comments (0)
Distribution and Determinants of Intraocular Pressure in a Normal Pediatric Population
PURPOSE
To examine the intraocular pressure (IOP) of a normal pediatric population under topical anesthesia without sedation and its correlation with other ocular parameters.
SUBJECTS AND METHODS
The IOP of 810 eyes of 405 patients with ages ranging from 0 to 12 years was measured using the Perkins applanation tonometer. Cooperative patients also underwent pachymetry, refraction, and biometry measurements.
RESULTS
The mean (± standard deviation) age was 6.68 (± 3.28) years, with a mean (± standard deviation) IOP of 12.02 (± 3.74) mm Hg. IOP showed an increasing trend with age (correlation coefficient [r] = 0.49) and tended to approach adult levels by 12 years of age. The IOP correlated directly with refraction (r = 0.69) and pachymetry (r = 0.39) and inversely with axial length (r = -0.1).
CONCLUSIONS
The IOP in children is much lower than that in adults. It was noted to increase with age, hyperopia, and corneal thickness and was inversely proportional to axial length.
Original Articles
Distribution and Determinants of Intraocular Pressure in a Normal Pediatric Population
Journal of Pediatric Ophthalmology and Strabismus Vol. 43 No. 1 January/February 2006
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Ramanjit Sihota, MD, FRCS, FRCOphth; Deven Tuli, MS; Tanuj Dada, MD; Viney Gupta, MD; Murli Manohar Sachdeva , DCT Orthoptics
PURPOSE
To examine the intraocular pressure (IOP) of a normal pediatric population under topical anesthesia without sedation and its correlation with other ocular parameters.
SUBJECTS AND METHODS
The IOP of 810 eyes of 405 patients with ages ranging from 0 to 12 years was measured using the Perkins applanation tonometer. Cooperative patients also underwent pachymetry, refraction, and biometry measurements.
RESULTS
The mean (± standard deviation) age was 6.68 (± 3.28) years, with a mean (± standard deviation) IOP of 12.02 (± 3.74) mm Hg. IOP showed an increasing trend with age (correlation coefficient [r] = 0.49) and tended to approach adult levels by 12 years of age. The IOP correlated directly with refraction (r = 0.69) and pachymetry (r = 0.39) and inversely with axial length (r = -0.1).
CONCLUSIONS
The IOP in children is much lower than that in adults. It was noted to increase with age, hyperopia, and corneal thickness and was inversely proportional to axial length.
J Pediatr Ophthalmol Strabismus 2006;43:14-18.
AUTHORS
The authors are from the Department of Ophthalmology, Dr. R. P. Centre for Ophthalmic Sciences, All India Institute of Medical Sciences, New Delhi, India.
Originally submitted May 29, 2004.
Accepted for publication December 7, 2004.
Address reprint requests to Dr. Deven Tuli, A 58 Kailash Colony, New Delhi - 110 048, India.
The authors have no industry relationships to disclose.
The audience is advised that this continuing medical education activity may contain references to unlabeled uses of FDA-approved products or to products not approved by the FDA for use in the United States. The faculty members have been made aware of their obligation to disclose such usage.
The material presented at or in any Vindico Medical Education continuing education activity does not necessarily reflect the views and opinions of Vindico Medical Education or SLACK Incorporated. Neither Vindico Medical Education or SLACK Incorporated, nor the faculty endorse or recommend any techniques, commercial products, or manufacturers. The faculty/ authors may discuss the use of materials and/or products that have not yet been approved by the U.S. Food and Drug Administration. All readers and continuing education participants should verify all information before treating patients or utilizing any product.
Posted by s.tavakolizadeh at 08:28 AM | Comments (0)
February 20, 2006
Triple therapy for CNV shows potential
OSN
A treatment regimen that combines dexamethasone, anti-VEGF injection and photodynamic therapy is showing promising results at the 4-month follow-up in choroidal neovascularization patients with age-related macular degeneration. 46 patients (all had either occult or classic lesions) have undergone the treatment so with PDT, then added 1.25 mg of Avastin and 800 µg of dexamethasone. By week 18, none of the patients had regressed to pre-treatment visual acuity and none of the patients reported any side effects from the triple therapy. They use dexamethasone instead of intravitreal triamcinolone because there’s less potential of an IOP spike.
Posted by kjalali at 06:58 AM | Comments (0)
February 18, 2006
Visual field defects are uncommon in eyes with buried optic nerve drusen
American Journal of Ophthalmology, February 2006
This evaluation of 41 patients (58 eyes) with buried optic nerve drusen (OND) reveals that just three eyes had inferior arcuate scotomas, while the other 55 eyes had no visual field defects. The authors speculate that visual field loss occurs only when these deeply situated drusen are associated with other ophthalmoscopically visible drusen. When these eyes do have visual field defects, they are most likely to be shallow or early defects. For patients with buried OND and a visual field defect, the authors suggest considering other causes for the defect, especially if the defect is substantial. Although eyes with buried OND have normal average RNFL thickness, some of these eyes have focal areas of RNFL thinning, which suggests that some of these eyes may have sustained ganglion cell damage that has not manifested as a visual field defect.
Posted by mriazi at 09:51 AM | Comments (0)
No apparent link between APOE gene and early ARM in middle-aged patients
Ophthalmology, February 2006
This population-based, cross-sectional study analyzed participants from the Atherosclerosis Risk in Communities Study (10,139 people, ranging in age from 49 to 73). Retinal photography was performed on one randomly selected eye which was then graded using a modification of the Wisconsin ARM Grading System. Early ARM was defined as the presence of either soft drusen alone, retinal pigment epithelial depigmentation alone or a combination of soft drusen with increased retinal pigment and/or depigmentation. Though researchers say their analysis suggests it’s unlikely APOE is a major determinant of early ARM in younger people, they do not exclude the possibility of a weaker association or that APOE may influence only the development of late ARM in older populations, as reported in other studies. Ophthalmology, February 2006
Posted by mriazi at 09:49 AM | Comments (0)
February 17, 2006
Cigarette smoke may stimulate AMD damage, lab study finds
OSN,Feb,2006
The study by Ivan Suñer, MD, and colleagues at Bascom Palmer Eye Institute and Duke University is the first to explore how cigarette smoke “generates biological changes in the eye that lead to vision loss” in AMD, according to a press release from Duke.
In the study, female mice were fed a high-fat diet for 4.5 months. The mice were divided into two major groups and then subdivided to assess the effects of cigarette smoke and hydroquinone. One group was exposed either to blue-green light (positive controls) or to whole cigarette smoke. A third group with no intervention served as the negative control. The second major group received a purified diet with hydroquinone (0.8%) with low or high fat content for 4.5 months.
“Eyes of the mice exposed to whole cigarette smoke or to hydroquinone in the food demonstrated a variable degree of basal laminar deposits and diffusely thickened Bruch’s membrane,” the researchers said.
“The interesting thing about hydroquinone is that it is in pollution in the atmosphere, and we are seeing more and more macular degeneration developing in areas with high pollution rates,” Dr. Suñer said in the release.
The study is published in the February issue of Investigative Ophthalmology & Visual Science.
Posted by afarahi at 06:36 PM | Comments (0)
A Procedure to Minimize Lower Lid Retraction During Large Inferior Rectus Recession in Graves Ophthalmopathy
AJO,Feb,2006
Data from patients (39 eyes) with Graves ophthalmopathy undergoing inferior rectus recession were collected retrospectively. Inferior rectus recession was performed by limbus-based incision with adjustable suture. Simultaneous detachment of the fascia of the capsulopalpebral head was achieved by sharp dissection and severing of the fascia. Inferior rectus recession with simultaneous detachment of the fascia of the capsulopalpebral head was performed in 27 eyes and without detachment in 12 eyes. Margin reflex distance (MRD2) was documented preoperatively and 3 months postoperatively.Of the 39 eyes included in this study, four eyes with preexisting lower lid retraction in the detachment group improved after surgery. Eighteen eyes in the detachment group exhibited the same MRD2 values, and only five eyes showed increased MRD2 values. In contrast, all but one of the 12 eyes in the nondetachment group showed increased MRD2 values. The average change in the MRD2 value 3 months after surgery was 0.04 ± 0.59 mm in the detachment group and 1.58 ± 0.73 mm in the nondetachment group. There was a statistically significant difference between the two groups (P < .01).
Conclusions:Simultaneous detachment of the fascia of the capsulopalpebral head during inferior rectus recession can minimize the possibility of lower lid retraction.
Posted by afarahi at 06:23 PM | Comments (0)
Ocular Surface Restoration Using Non-Surgical Transplantation of Tissue-Cultured Human Amniotic Epithelial Cells
American Journal of Ophthalmology, February, 2006
Cultivated autologous oral mucosal epithelial sheets were created using amniotic membrane and buccal mucosal epithelium from 12 patients (age range, 14 to 81) with Stevens-Johnson syndrome, chemical and thermal injury, pseudo-ocular cicatricial pemphigoid and idiopathic ocular surface disorder. Epithelial sheets were generated from all patients, and were transplanted onto 15 of their eyes. At two days postop, 14 of 15 sheets transplanted demonstrated total re-epithelialization on the cornea. During the follow-up (mean of 20 months), the ocular surface was stable and transparent without any major complications among 67 percent of patients, and the transplanted epithelium survived for at least 34 months (longest followup). This technique also provided rapid epithelial covering without the threat of an immunologic rejection, as well as a significant improvement in ocular reconstruction compared to conventional epithelial transplantation. In fact, this study improved surgical results in two cases failed by conventional therapy
Posted by afarahi at 06:18 PM | Comments (0)
New contact lens said to enhance vision, athletic performance
SPECIALTY NEWS
Bausch & Lomb and athletic apparel company Nike are set to begin marketing their new sport-tinted contact lens, MaxSight. The daily wear lens has been tinted to selectively filter out 90 percent of blue light and 95 percent of ultraviolet A (UVA) and ultraviolet B (UVB) rays in order to reduce glare and enhance contrast for contact lens wearers engaged in outdoor athletic activities. Lenses are available in +4.00 to -9.00D powers. A plano lens is also available. A grey-green tint is suggested for golf; amber, for baseball, rugby and faster moving sports. Nike recommends limiting use of the contact lenses to sports related activities, as they distort color perception.
Posted by kjalali at 08:44 AM | Comments (0)
Preservative-free eye drops in multiple application containers are at risk for microbial contamination
BJO, February, 2006
Of the 95 eye drop bottles collected and tested at a single hospital in Britain, significant bacterial growth was observed in eight bottles, for an overall incidence of 8.4 percent. Contamination did not occur in any of the 53 antibiotic eye drop bottles. For the 42 non-antibiotic bottles, the overall incidence of contamination was 19 percent. Seven different types of organisms were identified from the eye drop bottles, including Staphylococcus aureus, a type of bacteria that is increasingly becoming resistant to standard antibiotics. Some of the contaminated bottles grew more than one type of contaminant. Researchers suggest the design of multiple application containers is to blame, since the pipette attached to the cap of the bottle comes completely out of the container during administration, exposing the open contents of the bottle. They add that content spillage and poor technique may also increase the risk of contamination. The authors suggest caution when prescribing these drops to patients with compromised ocular surface defenses.
Posted by kjalali at 08:37 AM | Comments (0)
February 14, 2006
Initial Results of Small Incision Deep Lamellar Endothelial Keratoplasty (DLEK)
AJO February 2006
Fifteen eyes of 15 patients (six males and nine females) with endothelial dysfunction were included in this study. Through a 5-mm scleral incision, a deep lamellar pocket was created across the cornea, followed by excision of an 8.0-mm disk of posterior lamellar corneal tissue. Same size lamellar donor disk was prepared and placed in position without the need of suture fixation. Best spectacle-corrected visual acuity (BSCVA), refraction, endothelial cell density, corneal topography, and corneal thickness were analyzed.
Results
Average BSCVA preoperative was 20/200 (range 20/40 to hand movements (HM)), improving to 20/50 (range 20/20 to 20/120) at a mean follow-up of 7.2 months. Average refractive astigmatism at last follow-up was 1.46 ± 1.21 diopters (range, 0 to 4 diopters). Preoperative average donor endothelial cell density was 2047 ± 311 cells/mm2, and that at last follow-up was 1732 ± 514 cells/mm2. Preoperative average pachymetry was 801.4 ± 211.3 μm, improving to 553 ± 90.4 μm at last follow-up.
Conclusions
Initial results with small incision DLEK procedure indicate that it is a safe procedure that provides healthy donor endothelial cell count and function postoperatively, with encouraging visual results.
Posted by aman at 01:13 AM | Comments (0)
Thermal Imaging Study Comparing Phacoemulsification With the Sovereign With WhiteStar System to the Legacy With AdvanTec and NeoSoniX System
AJO February 2006
To assess intraoperative thermal levels at the wound site during divide-and-conquer phacoemulsification with the Sovereign with WhiteStar (SWS) system or the Legacy with AdvanTec and NeoSoniX (LAD) system.
Twenty-six subjects from a private clinical practice underwent divide-and-conquer phacoemulsification with either the SWS system or the LAD system. CB/CF settings (60%/33% duty cycles) were utilized with SWS and 12 pulses per second with the LAD system. Key criteria assessed were peak wound-site temperature, mean temperature change at the wound site, effective phaco time, average phaco power, procedure time, amount of BSS used, and surgical complications.
Results
Mean temperature change at the wound site was greater for the LAD than the SWS group. There was a statistically significant difference (P = .0002) in mean peak wound temperatures, with the LAD group having higher mean peak temperatures (42.47 ± 5.33°C) than the SWS group (36.59 ± 1.33°C). Highest wound-site temperature was 51°C for the LAD group and 39.3°C for the SWS group. A statistically significant difference (P = .0031) in mean peak temperature was found between the LAD and SWS systems for subjects with a cataract density of 4: higher mean peak temperatures were observed for LAD patients with a cataract density of 4.
Posted by aman at 01:03 AM | Comments (0)
Comparison of Topical Gatifloxacin 0.3% and Ciprofloxacin 0.3% for the Treatment of Bacterial Keratitis
AJO February 2006
Prospective, randomized clinical trial.
A total of 104 eyes of 104 patients with bacterial keratitis seen at a tertiary eye-care center were randomized to treatment with gatifloxacin 0.3% eyedrops (GAT group, 50 eyes) or ciprofloxacin 0.3% eyedrops (CIP group, 54 eyes). Patients and the treating physician were masked to the antibiotic being used. Main outcome measure studied was healing of the ulcer. Patients lost to follow-up before complete healing were excluded from further analysis.
Results
A significantly higher proportion of ulcers in the GAT group exhibited complete healing compared with those in the CIP group (39 eyes [95.1%] vs 38 [80.9%]; P = .042). Gatifloxacin demonstrated a significantly better action than ciprofloxacin against gram-positive cocci in vitro (P < .001), and the percentage of ulcers caused by these pathogens that healed in the GAT group was significantly better than in the CIP group (P = .009). Mean time taken for healing of ulcer and the efficacy against gram-negative bacteria did not significantly differ between the two groups.
Conclusions
Gatifloxacin had a significantly better action against gram-positive cocci both in vitro and in vivo when compared with ciprofloxacin. In view of these organisms being the leading cause of keratitis worldwide, gatifloxacin may be a preferred alternative to ciprofloxacin as the first-line monotherapy in bacterial keratitis.
Posted by aman at 12:53 AM | Comments (0)
Evaluation of the Glaucoma Suspect
Glaucoma today
Evaluating a patient with a possible diagnosis of glaucoma is a challenge. A glaucoma suspect is an individual who is at risk of losing visual function from glaucoma but in whom glaucomatous damage is not clearly evident.1 The term glaucoma suspect refers to a situation where the angle is open on gonioscopy and there is an absence of secondary causes of glaucoma such as pigment dispersion syndrome, pseudoexfoliation, inflammation, or trauma. An individual can be classified as a glaucoma suspect based on an elevated IOP (ocular hypertension), a suspicious optic disc appearance, a suspicious visual field, significant risk factors, or a combination thereof.
RISK FACTORS
Ophthalmologists have long recognized ocular hypertension (IOP>21 mm Hg) as a risk factor for glaucoma. Other factors include African American race, a family history of glaucoma, and advanced age.1 The Ocular Hypertension Treatment Study2 helped define baseline factors that increase the risk of converting to glaucoma in eyes in which the pressure is elevated and the optic disc and visual field are normal. Those risk factors include a central corneal thickness of <556 µm, a C/D >0.4, and a larger-than-average pattern standard deviation on an otherwise normal threshold visual field.3 Additional ocular and systemic risk factors are diabetes, hypertension, high myopia, cardiovascular disease, and migraine/vasospasm, all of which the practitioner must take into account.
OPTIC DISC
When considering the disc itself, clinicians may become alert to the possibility of glaucoma owing to certain features. Increased cupping (diffuse or focal narrowing of the disc rim), asymmetric cupping, and recurrent disc hemorrhages are classic high-risk findings.
PERIMETRY
Practitioners typically assess a patient’s visual field with white-on-white threshold automated perimetry. A normal field does not preclude a diagnosis of glaucoma, however, because structural optic disc atrophy precedes field loss on standard threshold perimetry.7 Thus, other methods have been developed to assess “pre-perimetric” glaucoma.
Automated perimetric strategies that test a smaller subpopulation of retinal ganglion cells have the potential to detect visual field loss earlier. The tests we use in our practice are short wavelength automated perimetry (SWAP; Carl Zeiss Meditec Inc., Dublin, CA) and frequency doubling technology (Welch Allyn Medical Products, Skaneateles, NY). Various studies have shown that these methods may be able to detect visual field defects that predate those on standard perimetry by 3 to 5 years or to confirm questionable defects on standard perimetry.
Posted by aman at 12:12 AM | Comments (0)
February 13, 2006
Methods for decreasing pigment particles in the anterior chamber in exfoliation syndrome and pigment dispersion syndrome.
Glaucoma today Volum3 2005
The release of pigment into the anterior chamber is a well-known phenomenon in both exfoliation syndrome and pigment dispersion syndrome. The deposition of pigment in the trabecular meshwork is an underlying cause of elevated IOP and glaucoma.
EXFOLIATION SYNDROME
Friction between the anterior lens capsule and the iris disrupts the iris pigment epithelium, dispersing pigment throughout the anterior chamber. The result is corneal pigmentation, iris sphincter transillumination defects and a characteristic increase in the trabecular meshwork’s pigment .Pigment dispersion may occur before the physician even detects exfoliation syndrome with a slit-lamp examination.
The release of pigment into the anterior chamber is common and profuse after pupillary dilation in patients with exfoliation syndrome.3-8 Subsequent increases in IOP can be as high as 30 mm Hg above baseline and may peak as many as 2 or 3 hours after dilation.9 It is particularly important for physicians to measure IOP and assess the degree of pigment release in the anterior chamber after pupillary dilation. If the spread of pigment is extensive, the clinician should continue follow-up until the patient’s IOP is safely under control. Unrecognized pressure spikes may exacerbate glaucomatous damage, particularly in patients whose disease is moderate to severe. We have seen a patient with exfoliative glaucoma who suffered a central retinal vein occlusion and an IOP spike to 55 mm Hg after pupillary dilation.
Drug Therapy
In patients with exfoliation syndrome, inhibiting the release of pigment should slow glaucomatous progression by blocking the mechanism most responsible for elevated IOP in these eyes. Theoretically, miotics should be the first line of treatment. Decreasing pupillary movement may reduce iridolenticular friction and thus avert the liberation of iris pigment, slow the progression of trabecular blockage, and perhaps allow the meshwork to clear.
Although physicians’ use of pilocarpine decreased upon the introduction of newer classes of IOP-lowering medications, this agent may still have a role in exfoliation syndrome. One drop of pilocarpine 2% daily may be sufficient to reduce pupillary reactivity for 24 hours without severely constricting the pupil.10 Other IOP-lowering agents may be used concomitantly as needed. After undergoing treatment for sufficiently long periods with miotic therapy, we observed an early pigment reversal sign,10 which indicates that pigment has cleared from the trabecular meshwork.
PIGMENT DISPERSION SYNDROME
The mechanism underlying IOP elevation in patients with pigment dispersion syndrome and pigmentary glaucoma is analogous to that in exfoliation syndrome. In pigment dispersion syndrome and pigmentary glaucoma, the iris insertion is typically posterior, and the peripheral iris configuration tends to be concave. Iridozonular contact during accommodation as well as during normal pupillary constriction and dilation disrupts the iris pigment epithelium and results in the deposition of pigmentary granules throughout the anterior segment. The classic diagnostic triad consists of corneal pigmentation (Krukenberg’s spindle); slit-like, radial, midperipheral iris transillumination defects; and dense trabecular pigmentation.
Patients with pigment dispersion syndrome or pigmentary glaucoma can also experience sudden IOP spikes after pupillary dilation. The examination and treatment of these patients is similar to that described earlier for exfoliation syndrome.5,8,11 Although exercise may cause the shedding of pigment and a subsequent pressure spike in some patients with pigment dispersion syndrome,12,13 the majority of patients do not appear to be affected.13,14 Pigmentary shedding is most commonly associated with jogging or bouncing. Ultrasound biomicroscopy indicates that cycling increases the iris’ concavity in both healthy eyes15 and those with pigment dispersion syndrome.16 The effect was eliminated in the latter by laser iridotomy. Vibration-induced increases in trabecular pigmentation have also been reported in rock drillers.
Drug Therapy
Because miotics both constrict the pupil and increase aqueous outflow, they are, in principle, first-line therapy. In practice, pilocarpine completely stops the exercise-induced release of pigment and elevation of IOP,12,13,18,19 whereas dapiprazole has a lesser effect20 and iridotomy provides incomplete inhibition.21 Miotics convert the concave iris configuration to a convex one and eliminate iridozonular friction .Pilocarpine drops are poorly tolerated, however, because of accommodative spasm and induced myopia in younger patients. Pilocarpine Ocuserts were ideal for patients with pigment dispersion syndrome or pigmentary glaucoma, because these drugs were well tolerated and effective at both lowering IOP and inhibiting pigmentary release. Unfortunately, they are no longer manufactured, which has created a serious problem for our younger patients.
Laser Intervention
Laser iridotomy can eliminate reverse pupillary block, flatten the iris’ contour and reduce the extent of iridolenticular contact.22 The technique also appears to prevent the accentuation of the iris’ concavity that accompanies accommodation.23 Moreover, it decreases the number of melanin granules present in the anterior chamber.24 Although iridotomy may relieve IOP spikes, it does not lower baseline IOP, because it takes years for pigment to clear from the trabecular meshwork.
Posted by aman at 11:55 PM | Comments (0)
The “Sandwich Technique” for Iris-fixated Phakic Intraocular Lens Implantation
JRS Jan/Feb 2006
To describe a new technique of implantation of the Artisan/Verisyse phakic intraocular lens (PIOL).
After PIOL insertion into the anterior chamber, a bolus of a high viscosity ophthalmic viscosurgical device (OVD) is placed over the optic, separating it widely from the endothelium.
The technique decreases the chance of endothelial damage during enclavation
CONCLUSIONS
A bolus of a high viscosity OVD placed on the anterior surface of the Artisan/Verisyse PIOL may make enclavation safer.
Posted by aman at 09:24 PM | Comments (0)
Anterior Stromal Puncture in the Treatment of Loose Epithelium After LASIK
JRS Jan/Feb 2006
Edward J. Holland, MD
Six eyes of five LASIK patients had their microkeratome pass complicated by loose epithelium, central in one case. After repositioning the flap, a 25-gauge needle on a tuberculin syringe was used to puncture the anterior corneal stroma to just beneath Bowman’s layer in the affected area of irregular epithelium. A bandage contact lens was placed on two eyes, including the one with loose epithelium centrally.
Normal appearance of the corneal epithelium was noted by postoperative day 1; no eye developed DLK or significant epithelial ingrowth postoperatively. All eyes achieved >20/20 vision.
CONCLUSIONS
By obviating, in select cases, the need for bandage contact lenses, anterior stromal puncture could increase patient comfort and remove a potential source of infection.
Posted by aman at 09:20 PM | Comments (0)
Herbal medication shows promise in reducing ecchymosis after surgery
SPECIALTY NEWS
A prospective study shows that face lift patients who used arinica montana after surgery had less swelling and better color than those who had not. The pharmacologic implications are less obvious and the effective dose for aiding ecchymosis resolution remains unclear. As a result, it is better to advise against recommending the herbal medication to patients until a logical dosing scheme is determined.
Posted by kjalali at 09:08 PM | Comments (0)
Toyama Chemical and Nidek receive approval for new quinolone agent
INDUSTRY NEWS
The Japanese Ministry of Health, Labor and Welfare has granted manufacturing approval for an ophthalmic solution made of tosufloxacin tosilate, a new quinolone agent based on Toyama Chemical's antibacterial agent, Ozex tablet, used for treating infections such as blephartits, dacryocystitis and hordeolum. The agent will be distributed through two sales channels: Ozex 0.3 percent by Toyama Chemical and Otsuka Pharmaceutical, and Tosflo 0.3 percent by NIDEK.
Posted by kjalali at 09:06 PM | Comments (0)
European Commission approves Macugen for treatment of wet AMD
INDUSTRY NEWS
Pfizer says Macugen is the first therapy indicated in Europe for the treatment of all types of wet AMD, regardless of lesion subtype, size or visual acuity. Macugen is co-developed by Pfizer and OSI Pharmaceuticals.
Posted by kjalali at 09:03 PM | Comments (0)
February 12, 2006
Refractive results with secondary piggyback implantation to correct pseudophakic refractive errors
JCRS Pages 2101-2103 (November 2005)
10 pseudophakic eyes, 5 with a myopic residual refractive error and 5 with a hyperopic residual refractive error. All eyes had secondary piggyback IOL implantation with the IOL placed in the ciliary sulcus. Five types of IOLs were used to correct the residual refractive error.
Results
The mean pre-op myopia was −6.6 diopters and the refractive outcome was within 0.5 D of the desired refraction (range –1.5 [undercorrected] and +1.0 D [overcorrected]). The mean pre-op hyperopia was +3.8 D, and the refractive outcome was within 0.46 D of the desired refraction .All patients showed visual acuity improvement. BCVA improved from 20/44 to 20/30 .
Conclusion
An IOL type that is appropriate for implantation in the ciliary sulcus is a viable option for correcting pseudophakic refractive error using the piggyback technique.
Posted by alireza habibollahi at 11:34 PM | Comments (0)
To evaluate the safety and efficacy of LASIK to enhance refractive status following other corneal surgical procedures.
JCRS Pages 2093-2100 (November 2005)
Seventy-one eyes of 57 patients had LASIK for refractive errors following RK(n = 22),AK(n = 13), PRK(n = 18), and PKP(n = 18). A Moria LSK-1 microkeratome was used with a Visx S2 or Wavelight Allegretto excimer laser. Data were acquired by retrospective chart review of all appropriately qualified patients.
Results
The mean pre-op MRSE was −3.93 diopters (D) in myopic eyes and +1.43 D in hyperopic eyes. The mean time from the initial corneal surgical procedure to LASIK was 65.0 months. The mean post-LASIK follow-up was 9.40 months .Post-op mean MRSE was −0.85 D in myopic eyes and −0.16 D in hyperopic eyes . Enhancement by LASIK was required in 14% of eyes.
Conclusion
In eyes that have had a variety of previous corneal surgeries, LASIK offers a safe and predictable method for enhancing refractive results.
Posted by alireza habibollahi at 11:27 PM | Comments (0)
Posterior corneal surface changes after hyperopic laser in situ keratomileusis
JCRS Pages 2084-2087 (November 2005)
Japan.To evaluate posterior corneal surface topographic changes after hyperopic laser in situ keratomileusis (H-LASIK) using Orbscan I (Orbtek, Inc.).
Methods
In 25 eyes of 15 patients who had H-LASIK, the posterior corneal surface was measured with (Orbscan I) pre-op and 1 year post-op. The center as a fit zone and calculated posterior corneal surface changes were taken at 4 points: nasal, temporal, superior, and inferior sides in the 5.0 mm diameter. The posterior corneal topographic changes were analyzed using an analysis of variance. The post-op:pre-op magnification ratio of the posterior corneal surface was calculated in a theoretical eye model.
Results
When a “+” reading was defined as the forward displacement and “−” was defined as the backward displacement, the mean posterior corneal topographic changes were −2.8 μm at the nasal side, −4.5 μm at the temporal side, −3.9 μm at the superior side, and −2.3 μm at the inferior side. The posterior corneal surface between any 2 examined points showed no significant difference after H-LASIK. In addition, the hypothetical change in the posterior cornea was −8.3 μm after +3.0 diopter H-LASIK, which was approximately closer to the study results. In each side, the amount of the attempted correction was significantly correlated with the posterior corneal topographic change.
Conclusions
Clinical measurement of the posterior corneal displacement after H-LASIK with Orbscan revealed a backward shift. This change corresponded to the hypothetical artifactual changes with Orbscan; that is, changes in the magnification ratio
Posted by alireza habibollahi at 11:15 PM | Comments (0)
Contrast sensitivity function in eyes with diffractive bifocal intraocular lenses
JCRS Pages 2076-2083 (November 2005)
To evaluate the image quality of asymmetric Acri.Twin bifocal intraocular lenses (IOLs) (Acri.Tec) by comparing distance and near black–white contrast sensitivity function with that of the Pharmacia 811E IOL.
Thirty-two eyes of 16 patients were examined after contralateral implantation of 1 Acri.Twin near-weighted 733D IOL and 1 Acri.Twin distance-weighted 737D IOL. Twenty eyes in 10 patients were examined after binocular Pharmacia 811E IOL implantation. Best corrected distance and near visual acuities were determined. Individual reading distance was recorded and corrected to 40 cm for the near contrast test (Holladay Contrast Acuity Test). Distance contrast sensitivity function was evaluated using the Acuity Max (Science 2020) computer program.
Results
Best corrected distance visual acuity was significantly better in patients with the 737D IOL than in those with the 733D or 811E IOLs. For distance reading with best distance correction, the 733D IOL performed better than the 737D and the 811E. Individual reading distance with the Acri.Twin IOL and 811E IOL was 33.6 cm and 34.0 cm, respectively. Best distance-corrected near contrast sensitivity function was better in eyes with the near-weighted 733D IOL. Binocular testing showed a significant difference between the 2 groups only at low-contrast values. At distance, contrast sensitivity function was better with the 737D IOL, whereas no difference was found between the 733D and the 811E IOLs. Binocular contrast sensitivity function at distance revealed statistically significantly better results in the Acri.Twin group.
Conclusion
An asymmetric diffractive bifocal lens system was advantageous in terms of vision quality when implanted binocularly and superior to monocular stronger weighted focus compared with conventional bifocal IOLs.
Posted by alireza habibollahi at 11:04 PM | Comments (0)
FDA approves new OCT device
EYEWORLD WEEKLY NEWS
Heidelberg Engineering GmbH (Heidelberg, Germany) has received the Food and Drug Administration's approval for the company's SL-OCT product, a commercial optical coherence tomography (OCT) device used for cross-sectional anterior segment imaging, company officials said. The SL-OCT provides non-contact cross-sectional scans of the anterior segment, officials said. Chamber angle, pachymetry, flap thickness, corneal curvature and comprehensive biometric measurements are possible with the instrument, as well as pre- and post-surgical comparisons, officials said. The SL-OCT was first introduced in Europe, receiving CE mark certification in 2003.
Posted by aman at 10:23 PM | Comments (0)
Taiwanese company acquires biodegradable glaucoma implant
EYEWORLD WEEKLY NEWS
OculusGen Biomedical (Taiwan) announced that it has acquired Pro Top & Mediking, a Taiwan company that has developed Collagen Matrix, which significantly increased the success rate for glaucoma and other surgeries. OculusGen Collagen Matrix is a biodegradable implant that does not scar without fibroblast inhibition. It also can be used in other surgeries, such as pterygium excision, eye plastic surgery, strabismus correction surgery, conjunctiva scar removal surgery, and nasolacrimal duct surgery to prevent scar formation and speed up wound healing. It is now processing an application for the CE Mark and expects to attain the mark in April 2006. U.S. Food and Drug Administration IDE submission will be made in a month or two.
Posted by aman at 10:20 PM | Comments (0)
Laser in situ keratomileusis in patients with corneal guttata and family history of Fuchs' endothelial dystrophy
Journal of Cataract & Refractive Surgery Volume 31, Issue 12 , December 2005, Pages 2281-2286
Transient corneal edema was noted in the early postoperative period in 3 eyes of 2 patients. At 1 year, 6 of the 7 (86%) eyes had lost ≥2 lines of BSCVA. A statistically significant decrease in ECD of 12.4% ± 2.7% was observed at 1 year compared with baseline (P<.001). An increase in corneal thickness (P = .006) and a statistically significant myopic shift in spherical equivalent (P = .017) was also noted at 1 year compared with 3 months.
Conclusions
Patients with mild corneal guttata and a family history of Fuchs' dystrophy are prone to transient corneal edema, loss of BSCVA, endothelial cell loss, and myopic regression after uneventful LASIK for correction of myopia and myopic astigmatism.
Posted by mmiraftab at 10:57 AM | Comments (0)
Clinical results of the blue-light filtering AcrySof Natural foldable acrylic intraocular lens
Journal of Cataract & Refractive Surgery Volume 31, Issue 12 , December 2005, Pages 2319-2323
John Marshall PhD, , Robert J. Cionni MD, James Davison MD, Paul Ernest MD, Robert Lehmann MD, W. Andrew Maxwell MD, PhD and Kerry Solomon MD
No statistically significant differences were discovered between the 2 patient groups in visual acuity, contrast sensitivity evaluated under mesopic and photopic conditions, or the number of patients who passed the Farnsworth D-15 color perception test. There were no lens-related adverse events in either group.
Conclusions
The blue-light filtering AcrySof Natural IOL was equivalent to the conventional AcrySof lens in terms of postoperative visual performance. Additional long-term clinical studies should show whether the IOL actually provides the theoretical benefits to retinal health.
Posted by mmiraftab at 10:53 AM | Comments (0)
Limbal relaxing incisions versus on-axis incisions to reduce corneal astigmatism at the time of cataract surgery
Journal of Cataract & Refractive Surgery Volume 31, Issue 12 , December 2005, Pages 2261-2265
In a prospective single center study, patients having 1.5 diopters (D) or more of keratometric astigmatism were randomly assigned to 2 surgical techniques: on-axis incisions (OAIs) consisting of a single clear corneal cataract incision centered on the steepest corneal meridian or LRIs consisting of 2 arcuate incisions straddling the steepest corneal meridian and a temporal clear corneal incision. Vector analysis of the target axis flattening effect was used to assess the efficacy of treatment.
Results
Seventy-one eyes of 71 patients were evaluated, 33 in the OAI group and 38 in the LRI group. Six weeks postoperatively, the flattening effect was 0.41 D (median and interquartile range 0.15 to 0.78 D) in the OAI group and 1.21 D (range 0.43 to 2.25 D) in the LRI group (P = .002). After 6 months, the flattening effect was 0.35 D (range 0.00 to 0.96 D) and 1.10 D (range 0.25 to 1.79 D), respectively (P = .004).
Conclusion
The amount of astigmatism reduction achieved at the intended meridian was significantly more favorable with the LRI technique, which remained consistent throughout the follow-up period.
Posted by mmiraftab at 10:50 AM | Comments (0)
Surgery-Related Factors Influencing Corneal Neovascularization After Low-Risk Keratoplasty
American Journal of Ophthalmology Volume 141, Issue 2 , February 2006, Page 260
Forty-four (67%) out of 66 corneal grafts developed some degree of CNV after PK, most commonly from around the 12 o’clock position. The mean speed of CNV growth was 114 μm/month with the fastest growth occurring during the first six weeks after PK. There was an inverse correlation between CNV and LSD, LGD, and ISA (all P < .001). Ninety percent of all CNVs developed with LSD < 406 μm and with LGD < 1000 μm. Superior limbal localization between 11 and 1 o’clock is an independent risk factor for postoperative neovascularization, too (P < .001).
Conclusions
Small Limbus suture distance,smalllimbus graft distance,and narrow stitching with small inner suture angle were identified as potentially modifiable surgical risk factors for CNV after PK. The speed of CNV outgrowth was most pronounced in the first weeks after PK making early postoperative controls for CNV growth and initiation of antiangiogenic treatment important.
Posted by mmiraftab at 10:38 AM | Comments (0)
Results of Deep Lamellar Keratoplasty Using the Big-bubble Technique in Patients With Keratoconus
American Journal of Ophthalmology Volume 141, Issue 2 , February 2006, Page 254
Big bubble was successfully achieved in nine eyes (69.2%). Average postoperative best-corrected visual acuity was 20/25 (range 20/50 to 20/20) at a mean follow-up of 5 months. Intraoperative microperforation of Descemet membrane occurred in two eyes (15.3%). Three eyes (23%) developed a steroid-induced increase in intraocular pressure, which responded to medical therapy.
Conclusions
Deep lamellar keratoplasty that uses the big-bubble technique is safe and effective in patients with keratoconus. Visual outcome is comparable to standard penetrating keratoplasty, without the risk of endothelial rejection.
Posted by mmiraftab at 10:33 AM | Comments (0)
Long-Term Changes in Corneal Surface Configuration After Penetrating Keratoplasty
American Journal of Ophthalmology Volume 141, Issue 2 , February 2006, Page 241
Spherical equivalent power increased considerably for up to 1 month after PK, but thereafter showed no further appreciable change up to the final follow-up at 24 months. The regular astigmatism component decreased markedly for up to 6 months after PK, while the total irregular astigmatism (sum of the asymmetry and higher-order irregularity) component decreased considerably up to approximately 3 months, and then these showed no further relevant change for up to 24 months. Spectacle-corrected visual acuity also improved markedly until approximately 3 months after PK, after which it was virtually stable. Furthermore, important correlations were found between regular and irregular astigmatism and the spectacle-corrected visual acuity.
Conclusions
Corneal surface configuration after PK appears to be stable by approximately 6 months after PK, concurrent with postkeratoplasty stabilization of visual acuity.
Posted by mmiraftab at 10:30 AM | Comments (0)
Latanoprost, Travoprost and Bimatoprost appear similarly effective for 24-hour IOP control
Ophthalmology, February 2006
This double-masked, crossover study included 24 patients with primary open-angle glaucoma and 20 patients with ocular hypertension who were treated with latanoprost 0.005 percent, travoprost 0.004 percent and bimatoprost 0.03 percent for one month. Treatment sequence was randomized and washout lasted 30 days for each drug. All three drugs were highly effective in reducing IOP when compared to baseline. Mean IOP reductions were similar, and none of the differences among treatments reached statistical significance. The drugs’ effect was significantly greater during the day (9 a.m. to 9 p.m.) than at night (midnight to 6 a.m.) with all prostaglandin analogs. In 16 percent of patients, nocturnal IOP was significantly higher than diurnal IOP, both at baseline and under the three prostaglandin analogs.
Posted by mtmdop at 09:21 AM | Comments (0)
February 11, 2006
Xibrom Approved as Pain Treatment
Cataract and refractive surgery today,February 10,2006
Ista Pharmaceuticals, Inc. (Irvine, CA), was granted FDA approval for its supplemental New Drug Application for Xibrom (bromfenac ophthalmic solution) 0.09%, which broadens the agent's indications to include the treatment of pain in postoperative cataract patients. Xibrom, the company's topical, twice-daily, NSAID solution, had previously been approved for ocular inflammation following cataract surgery. Results of a phase 3 clinical study reportedly demonstrated that 75% of postsurgical patients experiencing pain were pain-free after 2 days of Xibrom treatment, and 98% were pain-free within 6 days of treatment.
Posted by afarahi at 07:39 PM | Comments (0)
Wavefront-Guided versus Standard LASIK Enhancement for Residual Refractive Errors
Ophthalmology,Feb,2006
This study compared 20 eyes (20 consecutive patients with SE of -2.01±1.36 D) treated with wavefront-guided Zyoptix Ablation Refinement software (ZAR) LASIK for both initial surgery and re-treatment with 20 eyes (20 consecutive patients with SE of -1.81±1.21 D) treated with standard Planoscan LASIK, for both initial surgery and re-treatment. At six months postop, no eye lost more than one line of BCVA, but in the ZAR group, two eyes gained one line and six eyes gained two lines or more. In the Planoscan group, three eyes gained one line. Also, wavefront-guided LASIK did not increase higher-order aberrations and did not modify contrast sensitivity compared with preoperative values.
Posted by afarahi at 05:41 PM | Comments (0)
February 10, 2006
Case of phacolytic glaucoma spontaneously recovers
EYEWORLD Feb2006
Pierre Blaise, M.D., department of ophthalmology, University of Liege, Belgium, and colleagues reported that a 79-year-old woman presented at their clinic with unbearable pain in her left eye.
She had developed a senile cataract, which was recorded five years prior to this clinic's visit, for which she refused surgery. Her best corrected visual acuity was 4/10 in the right eye and only mild light perception without projection in the left.
A nuclear cataract was revealed by slitlamp examination in the right eye and a totally opacified white cataract was revealed in the left. The left also included corneal edema and intense flare with iridescent particles in the anterior chamber. That anterior chamber angle was open.
Researchers diagnosed her with phacolytic glaucoma, with her IOP being 20 mm Hg in the right eye and 62 mm Hg in the left eye.
She was administered topical treatment with atropine and dexamethasone three times daily as well as timolol 0.5% (various manufacturers) twice daily. She also was prescribed acetazolamide (Diamox, Diamox Sequels, Wyeth-Ayerst Laboratories, St. Davids, Pa.) orally at 500 mg per day.
Her pain was relieved but IOP was still above 50 mm Hg in the left eye. She still refused surgery and returned home with topical medication (acetazolamide was changed to dorzolamide, a topical carbonic anhydrase inhibitor, orally twice per day). Seven months and missed appointments had passed when the patient returned to the clinic. While she had stopped her treatment, she reported significant improvement of vision in her left eye.
Upon examination, researchers discovered that the lens material had been absorbed and flare had disappeared. The capsular bag only had a thin white opacity. Her visual acuity increased to 5/10 with + 12 D. IOP also had fallen to 20 mm Hg.
Posted by aman at 02:26 PM | Comments (0)
Eyeing novel dyes for cataract surgery
EYEWORLD Feb2006
Dyes can be an invaluable adjunct to any cataract surgery practice, making it possible to see the capsule and perform a safe capsulorhexis in cases involving very dense cataracts.
Most practitioners are familiar with the likes of trypan blue (VisionBlue, Dutch Ophthalmic Research Corp., Zuidland, The Netherlands), indocyanine green (ICG, Akorn, Buffalo Grove, Ill.), and gentian violet.
However, these don’t necessarily fit the bill for all practitioners. Now, six new dyes are being investigated as possible alternatives.
A study published last year in Investigative Ophthalmology and Visual Science took a closer look at the staining characteristics of the six dyes for intraocular surgery.
The novel dyes included were dubbed light green SF (LGSF) yellowish, E68, bromophenol blue (BPB), Chicago blue (CB), rhodamine g6, and rhodulinblau-basic 3 (RDB-B3). To evaluate lens staining characteristics, investigators looked at the lens capsule tissue and epiretinal membranes from stained human lens capsules removed intra-operatively. The dyes were evaluated at concentrations of 1%, 0.5%, 0.2%, and 0.05%.
Investigators found that even at lower concentrations of 0.2%, five of the six dyes showed excellent staining effects. Only LGSF yellowish did not provide adequate staining, with concentrations of 0.5% or less.
Two dyes, rhodamine g6 and RDB-B3, were excluded when they showed toxic effects on retinal epithelial cell proliferation. Two others, LGSF yellowish and CB appeared to affect cell viability. The remaining two dyes, E68 and BPB, appeared to be non-toxic in vitro and investigators believe they show promise.
Posted by aman at 02:23 PM | Comments (0)
February 09, 2006
Cataract Surgery Innovations Point-counterpoint: ReZoom
EYEWORLD February 2006
benefits of the ReZoom IOL over the ReStor IOL.
The ReZoom is a second generation refractive IOL that differs from its predecessor in two significant ways: optical design and lens material. The ReZoom is based on the AR40e platform with a hydrophobic acrylic optic, PMMA haptics, and OptiEdge triple-edge design that reduces internal reflections, edge glare, and posterior capsular opacity formation.
The most notable difference with the ReZoom optical design is that distance dominant zone 3 is 80% larger and the near dominant zone 4 is 55% smaller, which leads to better distance vision and less glare and haloes in mesopic conditions. There is also a 5% larger near zone 2 to provide better reading vision in photopic conditions.
The ReStor lens will provide better reading vision in 2 mm pupils, but worse near vision in 5 mm pupils.
On the other hand, the ReZoom will provide better distance vision than the ReStor in 2 mm pupils, but potentially more glare and halos in mesopic conditions.
A distinguishing feature of the ReZoom is that this lens not only provides near and distance vision like the ReStor, but there is also a separate focal point for intermediate vision.
Intermediate vision is critical for individuals with active lifestyles, where working on the computer, cooking, and grocery shopping are part of their daily activities. In comparison, the ReStor is a bifocal IOL that has no separate focal point for intermediate vision. One can “push out” the near focal point to overcome the excessive add by aiming for a slightly hyperopic endpoint, which shifts the defocus curve to the left and leads to a more comfortable reading distance.
Unfortunately, there is also an equal amount of loss in uncorrected distance vision when a hyperopic post-op goal is achieved. With the ReZoom, because the effective add creates a more comfortable reading distance, one can target emmetropia to provide excellent distance vision with good near and functional intermediate vision. Lastly, the ReZoom is a refractive IOL at all pupil sizes, which theoretically leads to better contrast sensitivity, whereas the ReStor is a diffractive IOL and only uses 84% of transmitted light when the pupil is 2 mm and 86% of transmitted light when the pupil is 3 mm in diameter.
Bottom line
What all this means to our patients is that the ReStor lens is a bifocal IOL that does not provide any functional intermediate vision unless one aims for a hyperopic post-op refractive error, and this leads to worse uncorrected-distance vision.
Therefore, the ReStor does provide good near vision, but no intermediate vision unless distance vision is sacrificed. Also, in