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April 29, 2007
Validity of the keratometric index: Large population-based study
JCRS Pages 686-691 (April 2007)
To determine the accuracy of the keratometric index of 1.3315 based on the Gullstrand model eye in predicting the power of the posterior cornea, Gullstrand's model was compared to a calculated keratometric index derived from actual measurements of the cornea.
One eye of 2429 subjects with a mean spherical equivalent of −5.32 diopters (D) was measured with the Orbscan II (Bausch & Lomb). The following variables were analyzed: anterior radius of curvature (ranterior), posterior radius of curvature (rposterior), radius of keratometry (rsimK), and central pachymetry.
Results
The ranterior, rposterior, and rsimK were normally distributed, with a mean of 7.87 mm 6.46 mm , and 7.71 mm respectively. The mean ratio between the anterior corneal curvature and posterior corneal curvature was 1.22 . Based on the measurements of each eye, the mean calculated keratometric index, Ncalc, was 1.3273 . Using Ncalc, the posterior corneal power was predicted to within ±0.50 D of the actual posterior power in 98.3% of eyes. The mean absolute error between the actual and calculated posterior power was 0.157 ± 0.123 D using Ncalc and 0.326 ± 0.133 D using the Gullstrand model.
Conclusion
Modifying the keratometric index increased the accuracy of predicting the posterior corneal power.
Posted by alireza habibollahi at 09:04 PM | Comments (0)
Successful treatment of cystoid macular edema with valdecoxib
JCRS Pages 682-685 (April 2007)
To evaluate the safety and efficacy of the COX-2 inhibitor valdecoxib in treating macular edema after cataract surgery.
The COX-2 inhibitor valdecoxib (Bextra) was administered systemically to patients with significant visual loss resulting from macular edema in a prospective clinical trial.
Results
Ten patients were enrolled. Valdecoxib was tolerated well and led to a significant visual improvement within 10 days of therapy in all patients.
Conclusion
The fast and persistent control of macular edema with valdecoxib warrants further investigation.
Posted by alireza habibollahi at 09:01 PM | Comments (0)
Comparison of the corneal response to laser in situ keratomileusis with flap creation using the FS15 and FS30 femtosecond lasers: Clinical and confocal microscopy findings
JCRS Pages 673-681 (April 2007)
To compare the response of the cornea to LASIK with flap creation using the IntraLase FS15 or FS30 femtosecond laser (IntraLase Corp.).
Twenty-three patients (31 eyes) who had LASIK with flap creation using the FS15 or FS30 laser were assessed by clinical examination and confocal microscopy in a nonrandomized parallel treatment group comparative trial. Eight FS15 patients (15 eyes) were examined preoperatively and 3 months postoperatively, and 14 FS30 patients (15 eyes) were examined 3 months postoperatively.
Results
No patient in either group had clinically significant flap interface haze. One FS15 eye and 1 FS30 eye had significant keratocyte activation at the flap interface. The mean difference between the actual flap thickness and intended flap thickness was 16.8 μm and 13.9 μm in the FS15 group and FS30 group, respectively . The mean measured interface reflectivity was 156.4 confocal backscatter units (CBU) and 104.8 CBU, respectively The mean density of interface particles was 21.4 particles/mm2 in the FS15 group and 11.0 particles/mm2 in the FS30 group .
Conclusions
Both the FS15 and FS30 lasers provided more reproducible flap thickness and fewer interface particles than previously observed using microkeratomes. The response of corneal keratocytes to intra-LASIK was reduced compared with previous results in which higher raster energies were used. Compared with the FS15, there was an apparent reduction in overall interface reflectivity and fewer interface particles with the FS30 laser.
Posted by alireza habibollahi at 08:53 PM | Comments (0)
April 27, 2007
Changes in Higher Order Aberrations and Contrast Sensitivity after Implantation of a Phakic Artisan Intraocular Lens
Ophthalmologica, 04/26/07
To evaluate higher-order aberrations (HOAs) and contrast sensitivity (CS), and investigate their relationship, after implantation of a phakic Artisan intraocular lens (IOL) for high myopia...Conclusions: Phakic Artisan IOL implantation for the correction of high myopia resulted in a small increase of HOAs under photopic conditions. At 1 month, CS was decreased, but returned to baseline at 3 months under photopic conditions
Posted by mehdi khanlari at 07:22 PM | Comments (0)
Cataract surgery for congenital cataract: Endothelial cell characteristics, corneal thickness, and impact on intraocular pressure
Journal of American Association for Pediatric Ophthalmology and Strabismus
Naveed Nilforushan MDa, Khalil Ghasemi Falavarjani MDa, , , Mohammad Reza Razeghinejadb and Pejman Bakhtiari MDa
To investigate whether central corneal thickness (CCT), endothelial cell characteristics, and intraocular pressure (IOP) are affected in patients with previous congenital cataract surgery and to focus on their clinical significance.......Conclusions:Although the corneas were clinically clear and there was no significant difference in endothelial characteristics of eyes with extracted congenital cataract and controls, central corneas of operated eyes were significantly thicker than those of controls. To differentiate the actual glaucoma from ocular hypertension in these patients, the central corneal thickness measurement should strongly be considered.
Posted by mehdi khanlari at 07:12 PM | Comments (0)
Early opacification and subsequent clearing of a MemoryLens intraocular lens
JCRS Pages 743-745 (April 2007)
A 74-year-old woman had cataract extraction with implantation of a MemoryLens posterior chamber intraocular lens (IOL) (model CV232, Ioltech). On the first postoperative day, she complained of hazy vision and an opaque area was found in the IOL. Explantation was scheduled but postponed when the patient's vision improved and the IOL cleared by the second postoperative day. To date, the IOL has remained clear. To our knowledge, this is the first report of resolving opacification in a MemoryLens. Two cases of opacification in the same IOL model have been reported; the opacification persisted, and the IOLs were explanted. In this case, early opacification and resolution suggest an acute process. With early IOL opacification, it may be beneficial to delay explantation for a few days.
Posted by alireza habibollahi at 06:16 PM | Comments (0)
Lowering IOP With the Trabectome
Review of Ophthalmogy April 2007
A number of new procedures and devices for treating glaucoma are currently in use or under investigation. One of the most promising, is the Trabectome. The Trabectome is a handheld instrument (approved by the Food and Drug Administration) that treats glaucoma by using microelectrocautery to ablate a strip of tissue from the trabecular meshwork and Schlemm’s canal, allowing the aqueous direct access to the eye’s drainage system......The Trabectome is inserted into the eye through a clear corneal incision; it is positioned across the anterior chamber, and the tip is inserted through the trabecular meshwork into Schlemm’s canal. The bent tip, which contains the electrodes, is coated on the back with a smooth insulating material. This creates a protective footplate that prevents the heat generated during electrocautery from damaging nontargeted tissues. It also guides the tip smoothly through Schlemm’s canal, while ablating the targeted trabecular and juxtacanalicular tissues. Simultaneous irrigation and aspiration remove the debris and maintain a stable anterior chamber.Technically, the Trabectome procedure is a trabeculectomy ab interno. It’s one of the newer trabecular surgeries, or internal filtering procedures, as I call them (to help differentiate them from external filtering procedures such as trabeculectomies and tube shunts). The Trabectome procedure is in the same class as trabecular stenting procedures, canaloplasty, viscocanalostomy and excimer laser trabeculostomy
Posted by mehdi khanlari at 06:00 PM | Comments (0)
Causes of intraocular lens opacification or discoloration
JCRS Pages 713-726 (April 2007)
Various pathologic processes may lead to clinically significant opacification or discoloration of the optic component of IOLs manufactured from different biomaterials and in different designs. Factors such as the patient's associated conditions, the manufacturing process, the method of IOL storage, the surgical technique and adjuvants, or a combination of these may be involved. The complication may be observed intraoperatively or postoperatively from a few hours after implantation to many years after surgery, depending on the processes involved. Based on a review of the literature as well as our own laboratory analyses, the following types of processes were identified: formation of deposits/precipitates on the IOL surface or within the IOL substance; opacification by excess influx of water in hydrophobic materials; direct discoloration by capsular dyes or medications; coating by substances such as ophthalmic ointment and silicone oil; and a slow, progressive degradation of the IOL biomaterial.
Posted by alireza habibollahi at 05:56 PM | Comments (0)
Causes of intraocular lens opacification or discoloration
JCRS Pages 713-726 (April 2007)
Various pathologic processes may lead to clinically significant opacification or discoloration of the optic component of IOLs manufactured from different biomaterials and in different designs. Factors such as the patient's associated conditions, the manufacturing process, the method of IOL storage, the surgical technique and adjuvants, or a combination of these may be involved. The complication may be observed intraoperatively or postoperatively from a few hours after implantation to many years after surgery, depending on the processes involved. Based on a review of the literature as well as our own laboratory analyses, the following types of processes were identified: formation of deposits/precipitates on the IOL surface or within the IOL substance; opacification by excess influx of water in hydrophobic materials; direct discoloration by capsular dyes or medications; coating by substances such as ophthalmic ointment and silicone oil; and a slow, progressive degradation of the IOL biomaterial.
Posted by alireza habibollahi at 05:56 PM | Comments (0)
Novel AMD drug being tested on 15 patients
Ophthalmology Times April 2007
Redwood City, CA—The first of 15 patients has received CGC-11047, a novel poly-amine analog that targets choroidal neovascularization associated with age-related macular degeneration.The drug, in a phase I dose-escalation study, is designed to halt cell growth and induce apoptosis by displacing certain cell components from their natural binding sites and preventing cell replication. The drug has demonstrated an ability to suppress the growth of vascular lesions under the retina and to cause a regression in neovascular swelling and leakage.A total of 15 patients will be treated subconjunctivally, avoiding the need to inject into the eye, in cohorts of escalating doses.CGC-11047 also is being studied as a treatment for certain cancers using a different dose formulation.
Posted by mehdi khanlari at 11:29 AM | Comments (0)
re-treatment for off-axis ablation in 2 stages
Ophthalmology times Apr
.....Dr. Maloney also recommended that re-treatment for an off-axis ablation be approached in two stages.First, use conventional re-treatment to reduce the astigmatism to a manageable level. Then, use wavefront-guided re-treatment to improve the quality of vision by eliminating aberrations and residual refractive error
Posted by mehdi khanlari at 10:46 AM | Comments (0)
Cataract surgery may trigger NAION in patients with prior unilateral NAION
BJO May 2007
This retrospective study finds that cataract surgery in the fellow eye of patients with previous unilateral NAION increased the risk of NAION in the fellow eye by nearly four times. Two-thirds developed NAION within the first six months after surgery.
Posted by kjalali at 10:37 AM | Comments (0)
Avastin may worsen macular edema in some patients with retinal vein occlusion
Retina, April/May 2007
Authors describe three patients who initially responded to treatment, but later experienced a recurrence of edema in excess of that observed before treatment. Authors conclude that these cases suggest a potential limitation of using relatively short-acting VEGF antagonists in chronic retinal vascular disease.
Posted by kjalali at 10:35 AM | Comments (0)
Avastin shows promise as a primary treatment for diabetic macular edema
Ophthalmology, April 2007
This retrospective study of 64 patients (78 eyes) followed for at least six months finds that 55.1 percent of eyes showed anatomical and functional improvement. Treatment benefits peaked in the first month and were maintained over six months. Re-injections were deferred until recurrence: 20.5 percent needed a second injection at a mean of 13.8 weeks, and 7.7 percent needed a third at a mean of 11.5 weeks.
Posted by kjalali at 10:33 AM | Comments (0)
AMD associated with incident myocardial infarction
Ophthalmology, April 2007
This prospective analysis of Medicare claims data finds that baseline AMD, especially wet AMD, is associated with higher risk of incident MI, independent of baseline demographic factors and co-morbidities, such as diabetes and hypertension status. Smoking and other lifestyle co-variables were not measured in this study.
Posted by kjalali at 10:28 AM | Comments (0)
April 24, 2007
Corneal Endotheliitis Associated with Evidence of Cytomegalovirus Infection
Ophthalmology April 2007
Aqueous of eyes with corneal endotheliitis was analyzed for viral DNA by polymerase chain reaction (PCR)
Corneal endotheliitis was seen in 12 eyes of 10 patients during the study period. There were 8 men and 2 women, and all were Chinese. Their mean age was 49 years (range, 25–61 years). The corneal involvement ranged from small areas of focal endotheliitis to diffuse bullous keratopathy. The keratic precipitates had a variable appearance. There was only mild anterior chamber inflammation with no posterior synechiae. Two thirds of eyes had diffuse iris atrophy. All the eyes had elevated IOP. Eleven of the 12 eyes were positive for CMV DNA. None of the patients were positive for HIV. All patients had received local or systemic immunosuppression, or both, before corneal endotheliitis developed. Ten eyes of 8 patients were treated with systemic antiviral therapy. After treatment, the endotheliitis resolved completely in 7 eyes, and 3 eyes had significant improvement in corneal translucency. The IOP was normal, with no medications in all but 1 eye. Repeat PCR analysis in all the treated eyes was negative for CMV DNA.
Conclusions
Cytomegalovirus infection is an important cause of corneal endotheliitis in our patients, and appropriate antiviral therapy may prevent more ocular damage.
Posted by mmiraftab at 07:20 PM | Comments (0)
A Prospective Study of Endothelial Cell Loss during the 2 Years after Deep Lamellar Endothelial Keratoplastyophthalmology April 2007
The average (and standard deviation) ECD at 6 months was 2140±426 cells/mm2, representing a mean cell loss from preoperative donor cell measurements of 25±15%. At 12 months, ECD was 2090±448 cells/mm2 (26±16% cell loss), and at 24 months, it was 1794±588 cells/mm2 (37±27% cell loss). The additional cell loss from 1 to 2 years was significant (P<0.001). In the subset of large-incision DLEK eyes (n = 36), the cell loss from preoperatively to 6 months was 23%; 12 months, 22%; and 24 months, 27%. In the subset of small-incision DLEK eyes (n = 62), the cell loss from preoperatively to 6 months was 25%; 12 months, 28%; and 24 months, 43%. The cell loss from small-incision DLEK surgery was significantly greater than that from large-incision DLEK surgery at the 12-month (P = 0.013) and 24-month (P<0.001) postoperative measurements.
Conclusions
Although the initial cell loss from DLEK surgery is minimally changed from 6 to 12 months postoperatively, there is an acceleration of cell loss from 1 year to 2 years postoperatively. The small-incision DLEK technique, which involves folding of the donor tissue, results in a significantly higher endothelial cell loss at 1 and 2 years than that found after large-incision DLEK surgery, wherein the tissue is not folded.
Posted by mmiraftab at 07:16 PM | Comments (0)
Monocanalicular silastic intubation for the initial correction of congenital nasolacrimal duct obstruction
Journal of AAPOS,April,2007
Treatment of persistent nasolacrimal duct obstruction traditionally has consisted of simple probing. The most common complication with this approach has been recurrent obstruction, requiring another probing, often with the use of bicanalicular silastic intubation. Monocanalicular silastic tubing offers the possibility of increased success rates over simple probing while theoretically minimizing the insertion and removal difficulaties posed by bicanalicular techniques. We report, to our knowledge, the largest series to date of patients undergoing monocanalicular silastic intubation, as well as the first report evaluating this technique as the primary treatment for congenital nasolacrimal duct obstruction obstruction.We identified 635 children who underwent probing with monocanalicular intubation as the primary treatment for congenital nasolacrimal duct obstruction obstruction (mean age at time of probing 18 months). The success rate for treatment performed in infants younger than 24 months of age (684 eyes) was 97%, declining to 90% when surgery was performed in infants older than 24 months of age (119 eyes; p < 0.001). These success rates compare favorably to previous reports of primary probing without silastic intubation.
Conclusions:Probing with monocanalicular silastic intubation as the initial surgical procedure for patients with congenital nasolacrimal duct obstruction obstruction is associated with a very high success rate and low complication rate, especially when performed by the age of 24 months.
Posted by afarahi at 06:52 PM | Comments (0)
Study finds phakic IOLs can benefit children with neuro-behavioral disorders.
OSN SuperSite Top Story 4/17/2007
Phakic IOL implantation can be an effective option for improving visual function in children with high myopia and neuro-behavioral disorders who also have difficulties wearing glasses, according to a study presented here.
Gi Yoon Huang, MD, and colleagues studied 20 eyes of 12 ametropic children aged 4 to 17 years who were implanted with an iris-enclaved Verisyse phakic IOL (Advanced Medical Optics). All children had ametropia beyond the range that can be corrected by excimer laser refractive surgery, said Dr. Huang, who presented the study results at the American Association for Pediatric Ophthalmology and Strabismus meeting.
The study included children with myopia over 10 D and an anterior chamber deeper than 3.2 mm.At 11 months mean follow-up, 17 of the 20 eyes were corrected to within ±1 D of target refraction, which ranged from 0 D to 1 D. The remaining three eyes were corrected to within ±2 D of target refraction.They found that surgery improved children's mean uncorrected visual acuity from 20/3550 preoperatively to 20/53 postop.
Commenting on the study, Evelyn A. Paysse, MD, said she found the results interesting and the study well done.However, she said she wished the study had included data on amblyopia improvement and questioned why only uncorrected visual acuity results were reported.Dr. Paysse also noted that she feels that a threshold of –10 D is a bit low to qualify patients for phakic IOL implantation "when such good results are obtained from excimer procedures."
Posted by afarahi at 06:15 PM | Comments (0)
Anorexiant-induced transient myopia after myopic laser in situ keratomileusis
JCRS Pages 746-749 (April 2007)
We report a case of acute transient myopia associated with ciliochoroidal effusion induced by anorexiants. The patient had had myopic laser in situ keratomileusis 7 years earlier. Acute bilateral myopia associated with anterior chamber shallowing, intraocular pressure elevation, diffuse ciliochoroidal effusion, and perimacular retinal folds was relieved 14 days after discontinuation of anorexiant medications. Tropicamide and atropine were used to deepen the anterior chamber. Sympathomimetic drugs such as phendimetrazine and ephedrine are used as anorexiants and may induce transient myopia associated with ciliochoroidal effusion, shallow anterior chamber, and acute angle-closure glaucoma.
Posted by alireza habibollahi at 04:02 PM | Comments (0)
Anorexiant-induced transient myopia after myopic laser in situ keratomileusis
JCRS Pages 746-749 (April 2007)
We report a case of acute transient myopia associated with ciliochoroidal effusion induced by anorexiants. The patient had had myopic laser in situ keratomileusis 7 years earlier. Acute bilateral myopia associated with anterior chamber shallowing, intraocular pressure elevation, diffuse ciliochoroidal effusion, and perimacular retinal folds was relieved 14 days after discontinuation of anorexiant medications. Tropicamide and atropine were used to deepen the anterior chamber. Sympathomimetic drugs such as phendimetrazine and ephedrine are used as anorexiants and may induce transient myopia associated with ciliochoroidal effusion, shallow anterior chamber, and acute angle-closure glaucoma.
Posted by alireza habibollahi at 04:02 PM | Comments (0)
Pigmented free-floating retrolental space cyst
JCRS Pages 741-742 (April 2007)
We report an unusual case of a free-floating pigmented retrolental cyst, which was diagnosed after examination by slitlamp, B-scan ultrasonography, and ultrasound biomicroscopy. Pigmented cysts, which may arise from the ciliary body epithelium, are embryologically and morphologically different from clear cysts.
Posted by alireza habibollahi at 03:58 PM | Comments (0)
Posttraumatic Aspergillus terreus endophthalmitis masquerading as dispersed lens fragments
JCRS Pages 739-740 (April 2007)
A 20-year-old man developed increasing inflammation with a hypopyon 3 weeks after primary repair of a corneal laceration. An occult anterior capsule puncture was suspected as the stimulus for the inflammation. When aspiration of the suspected hydrated lens material was not curative, a vitrectomy with injection of intravitreal antibiotic agents including amphotericin (0.0125 mg) was done the following day; the culture failed to grow fungal organisms. A repeat vitrectomy was performed 1 week later, and the culture grew Aspergillus terreus. This was determined to be resistant to amphotericin so voriconazole was injected intravitreally. The inflammation recurred, and the eye required enucleation because of blindness and intractable pain. Fungal endophthalmitis should be considered in cases of delayed-onset inflammation after trauma and may be due to organisms resistant to amphotericin
Posted by alireza habibollahi at 03:54 PM | Comments (0)
Postoperative cilium entrapment by clear corneal incision
JCRS Pages 733-734 (April 2007)
A 75-year-old man had routine phacoemulsification cataract extraction with posterior chamber intraocular lens implantation in the left eye using a temporal corneal incision and inferior paracentesis. Examinations at 1 day and 1 week were unremarkable; however, at the 6-week assessment, a cilium was noted to have penetrated the external ostium of the paracentesis, with the proximal (follicle) end abutting the internal ostium of the wound. While the cilium was removed without incident, this chance finding may aid our understanding of how intraocular cilia are occasionally discovered following routine small-incision sutureless cataract surgery.
Posted by alireza habibollahi at 03:52 PM | Comments (0)
Postoperative infectious endophthalmitis after triamcinolone-assisted anterior vitrectomy
JCRS Pages 731-732 (April 2007)
Extracapsular cataract extraction and intraocular lens (IOL) implantation was performed in the left eye of a 64-year-old woman. Preoperative assessment showed a hypermature cataract in the left eye with visual acuity of hand movement. During IOL implantation, a posterior capsule rupture occurred in the inferior area. Triamcinolone was injected into the anterior chamber to visualize the vitreous and helped in thorough removal of the prolapsed vitreous. However, when postoperative infectious endophthalmitis developed, the signs and symptoms were vague. Careful examination, specific patient instructions, and close follow-up are necessary after a triamcinolone-assisted anterior vitrectomy
Posted by alireza habibollahi at 03:50 PM | Comments (0)
Primary piggyback implantation of 3 intraocular lenses in nanophthalmos
JCRS Pages 727-730 (April 2007)
45 of 54
We present a patient with bilateral nanophthalmos who had uneventful cataract extraction in the right eye with primary implantation of 3 intraocular lenses (IOLs) of 2 different materials: a 30 diopter (D) acrylic IOL and a 9 D silicone IOL in the capsular bag and a 30 D silicone IOL in the ciliary sulcus. Subsequently, cataract extraction was done in the left eye with bag–sulcus implantation of two 30 D silicone IOLs. The use of 3 IOLs in 1 eye was necessary because the highest available power of acrylic and silicone IOLs at our institution was 30 D. The only short-term complications were temporary corneal edema and partial displacement of the sulcus IOL anterior to the iris in the right eye and bilateral posterior capsule opacification. The late complication of interlenticular opacification was not present 1 year after piggyback IOL implantation.
Posted by alireza habibollahi at 03:48 PM | Comments (0)
JCRS Pages 648-653 (April 2007)
33 of 54
Comparison of outcomes of 2 channel sizes for intrastromal ring segment implantation with a femtosecond laser in eyes with keratoconus
To compare the outcomes of 2 channel sizes for intrastromal ring segment (Intacs, Addition Technology, Inc.) implantation using a femtosecond laser in eyes with keratoconus.
A retrospective outpatient study included 159 consecutive keratoconic eyes of 103 patients. Patients were classified into 2 groups according to channel dissection size: wide (6.7 mm × 8.2 mm) and narrow (6.6 mm × 7.6 mm). Dissections were created with an IntraLase femtosecond laser (IntraLase Corp.). The 2 groups were compared according to UCVA , BCVA , refractive error (manifest sphere, manifest cylinder, and manifest refractive spherical equivalent), mean K-value, and complications within 6 months postoperatively.
Results
The wide-channel group comprised 97 eyes of 65 patients with a mean age of 27.64 years The narrow-channel group comprised 62 eyes of 38 patients with a mean age of 26.62 years. At 6 months, the UCVA and BCVA had significantly improved in 63.9% and 70.1% of eyes, respectively, in the wide-channel group and in 72.5% and 75.8% of eyes, respectively, in the narrow-channel group. The change in mean BCVA and change in mean UCVA in both groups were not statistically significant .There was no between-group difference in the improvement in manifest spherical refraction, cylindrical refraction, manifest refractive spherical equivalent, or mean K-readings.Epithelial plug, yellow–white deposits, tunnel haze around segments, and upward movement of the inferior segment without extrusion were observed more frequently in the narrow-channel group than in the wide-channel group.
Conclusions
The refractive outcomes of wide channels and narrow channels for Intacs treatment in eyes with keratoconus were similar 6 months postoperatively. The narrow-channel group had a higher rate of mild to moderate complications than the wide-channel group.
Posted by alireza habibollahi at 03:43 PM | Comments (0)
Zernike versus Fourier treatment tables for myopic patients having CustomVue wavefront laser in situ keratomileusis with the S4 excimer laser
JCRS Pages 654-657 (April 2007)
To compare the efficacy, predictability, and safety of Zernike-based versus Fourier-based treatment tables in myopic eyes 1 year after CustomVue wavefront LASIK using the S4 excimer laser (Visx).
A prospective analysis of 32 eyes of 16 patients with myopia who had CustomVue LASIK with the S4 excimer laser was conducted using Zernike or Fourier treatment tables. Mean SE, UCVA, BSCVA, and higher wavefront analyses were determined.
Results
The mean postoperative SE was −0.27 diopter (D) in Zernike-treated eyes and −0.20 D in Fourier-treated eyes. Twenty-eight of 32 eyes were available for analysis. Ninety-two percent of eyes in the Zernike group and all eyes in the Fourier group had 20/20 or better acuity .Seventy-nine percent and 92%, respectively, were within ±0.50 D of emmetropia (P = .68). All eyes in the Zernike group and 93% of eyes in the Fourier group had no change or gained at least 1 Snellen line of BSCVA (P = .85). Mean higher-order aberration values (μm) in the Zernike group and Fourier group were as follows: total root mean square, 0.91 and 0.99, (P = 0.95); defocus, 0.71 and 0.74, (P = 0.98); astigmatism, 0.15 and 0.31, (P = 0.81); coma, 0.21 and 0.20, (P = 0.99); trefoil, 0.11 and 0.11, (P = 1); and spherical aberration, 0.17 and 0.30, (P = 0.85), respectively.
Conclusions
Myopic eyes that had CustomVue LASIK had better visual outcomes in the Fourier group than in the Zernike group. Higher-order wavefront aberration results were similar between the 2 groups.
Posted by alireza habibollahi at 03:37 PM | Comments (0)
Effect of a yellow intraocular lens on scotopic vision, glare disability, and blue color perception
JCRS Pages 658-666 (April 2007)
To compare the photopic and scotopic contrast sensitivity with and without glare as well as blue color perception between eyes with an AcrySof SN60AT Natural intraocular lens (IOL) (Alcon Laboratories Inc.) and eyes with a conventional AcrySof SA60AT IOL.
Right eyes of 38 patients with an AcrySof Natural IOL and right eyes of 38 age-matched patients with a conventional AcrySof SA60AT IOL were included in a study. Contrast sensitivity was measured with the Functional Acuity Contrast Test under photopic conditions. Scotopic contrast sensitivity in the presence or absence of glare was measured using the Mesotest II (Oculus GmbH). Blue–green color vision was evaluated with the Moreland equation of the HMC Anomaloskop MR (Oculus GmbH).
Results
The mean age of patients was 66.6 years in the Natural IOL group and 66.4 years in the conventional IOL group. There was no statistically significant difference in photopic contrast sensitivity, scotopic contrast sensitivity with and without glare, or disability glare between the 2 groups .Photopic and scotopic contrast sensitivity with and without glare significantly decreased with age in both groups (P<.01). There was no statistically significant difference in anomaloscope scores between the 2 groups (P>.05). The Moreland middle match point showed a significant shift toward blue with age in both groups (P<.01).
Conclusions
The AcrySof SN60AT Natural IOL provided contrast sensitivity under photopic and scotopic conditions (with and without glare) and blue color perception comparable that obtained with the AcrySof SA60AT IOL. Scotopic vision and blue color discrimination decreased with age with both IOLs.
Posted by alireza habibollahi at 03:31 PM | Comments (0)
Effect of a yellow intraocular lens on scotopic vision, glare disability, and blue color perception
JCRS Pages 658-666 (April 2007)
To compare the photopic and scotopic contrast sensitivity with and without glare as well as blue color perception between eyes with an AcrySof SN60AT Natural intraocular lens (IOL) (Alcon Laboratories Inc.) and eyes with a conventional AcrySof SA60AT IOL.
Right eyes of 38 patients with an AcrySof Natural IOL and right eyes of 38 age-matched patients with a conventional AcrySof SA60AT IOL were included in a study. Contrast sensitivity was measured with the Functional Acuity Contrast Test under photopic conditions. Scotopic contrast sensitivity in the presence or absence of glare was measured using the Mesotest II (Oculus GmbH). Blue–green color vision was evaluated with the Moreland equation of the HMC Anomaloskop MR (Oculus GmbH).
Results
The mean age of patients was 66.6 years in the Natural IOL group and 66.4 years in the conventional IOL group. There was no statistically significant difference in photopic contrast sensitivity, scotopic contrast sensitivity with and without glare, or disability glare between the 2 groups .Photopic and scotopic contrast sensitivity with and without glare significantly decreased with age in both groups (P<.01). There was no statistically significant difference in anomaloscope scores between the 2 groups (P>.05). The Moreland middle match point showed a significant shift toward blue with age in both groups (P<.01).
Conclusions
The AcrySof SN60AT Natural IOL provided contrast sensitivity under photopic and scotopic conditions (with and without glare) and blue color perception comparable that obtained with the AcrySof SA60AT IOL. Scotopic vision and blue color discrimination decreased with age with both IOLs.
Posted by alireza habibollahi at 03:31 PM | Comments (0)
April 21, 2007
Objective evaluation of cataract progression associated with a high dose intravitreal triamcinolone injection
Eye April 2007
Conclusion A high-dose (25 mg) intravitreal triamcinolone acetonide injection induces the progression of cortical and posterior subcapsular opacity in patients with diabetic macular oedema and retinal vein occlusion
Posted by mehdi khanlari at 11:48 PM | Comments (0)
Does an iridotomy provide protection against narrowing of the anterior chamber angle during Valsalva maneuvre in eyes with primary angle closure
Eye April 2007
... To evaluate changes at the anterior chamber angle during Valsalva manoeuver, in eyes having primary angle closure (PAC) and a patent laser peripheral iridotomy.....Twenty-three eyes of 23 consecutive patients underwent a recording of applanation tonometry, measurement of the anterior chamber angle recess, angle opening distance, iris thickness, anterior chamber depth, and pupil size on ultrasound biomicroscopy before and during the Valsalva maneuver. The Valsalva manoeuver was standardized to a pressure of 40 mmHg for 15 s, using a manometer....Conclusions The induction of Valsalva maneuver in day-to-day activities can lead to significant anterior segment angle shallowing and can lead to progression from the PAC stage to primary angle closure glaucoma in such predisposed eyes. The presence of a patent laser iridotomy may not prevent irido trabecular apposition during the Valsalva maneuver.
Posted by mehdi khanlari at 11:44 PM | Comments (0)
Altered Nitric Oxide System in Patients With Open-Angle Glaucoma
Arch Ophthalmol. 2007;125:494-498.
... To investigate the ocular blood flow response to systemic nitric oxide synthase inhibition in patients with primary open-angle glaucoma.Methods In 12 patients with glaucoma and 12 age-matched control subjects, subfoveal choroidal blood flow, optic nerve head blood flow, ocular fundus pulsation amplitude, intraocular pressure, and systemic hemodynamic parameters were measured at baseline and after inhibition of nitric oxide synthase by intravenous administration of NG-monomethyl-L-arginine....Conclusions This is the first in vivo study providing evidence for an altered ocular L-arginine/nitric oxide system in patients with glaucoma. Normalization of the ocular nitric oxide production may be beneficial in terms of normalization of ocular blood flow and neuroprotection of retinal ganglion cells
Posted by mehdi khanlari at 11:41 PM | Comments (0)
The long term results of LASIK for high myopia risk of ectasia
JCRS April 2007
Patrick I. Condon, M.Ch., FRCS, FRCOphth, Michael O’Keefe, M.Ch., FRCS., FRCOphth., Perry S. Binder, M.S.,M.D.
In this retrospective, longitudinal study the aim of investigators was to determine the long-term stability of highly myopic eyes. Investigators reviewed charts of 107 such eyes that underwent LASIK between 1994 and 1998. Patients included here had myopia from –10 to –35 D. At the five year mark, 78% of eyes were reviewed, after seven years 63% were checked, and between nine and 11 years 14% were examined. Only one case of ectasia occurred — this in a patient who had a refraction of –28 D preoperatively. Investigators determine that while high myopia was considered a risk factor for ectasia, in this series did not produce the condition. To decrease the risk the recommendation here was to put in place proper screening and to use careful intraoperative pachymetry
Posted by mehdi khanlari at 11:33 PM | Comments (0)
Bimanual micro versus micro-coaxial
Eyeworld April 2007
Published in the March issue of the Journal of Cataract and Refractive Surgery a comparaative study has found both bimanual micro-phacoemulsification and micro-coaxial phacoemulsification techniques to be safe and effective for cataract surgery.Gian Maria Cavallini, M.D., Institute of Ophthalmology, University of Modena, Modena, Italy, and colleagues evaulated two phacoemulsification techniques to assess the potential advantages of bimanual micro-phacoemulsification over micro-coaxial phacoemulsification.The controlled clinical trial involved 100 eyes of 50 patients with cortico-nuclear cataract of grade 2 to 4 on the Lens Opacities Classification System III. Through randomization, 50 eyes had surgery by the bimanual technique and 50 eyes had surgery by the micro-coaxial technique.Intraoperative parameters were mean phacoemulsification time, total phacoemulsification percentage, effective phacoemulsification time (EPT), total volume of balanced salt solution (BSS) used, total surgical time, and final size of the corneal incision. While postoperative parameters were visual acuity, astigmatism changes by vector analysis, corneal thickness, endothelial cell count, and presence of flare and cells in the anterior chamber.Results showed no significant difference between the two techniques except that with bimanual microphacoemulsification, significantly less BSS was used and total surgical time was significantly shorter than with the coaxial method.
Posted by mehdi khanlari at 11:08 PM | Comments (0)
Sutureless Descemet’s Stripping Endothelial Keratoplasty with SF6 Technique,”
Eyeworld April 2007
Dr. Ambati will demonstrate how he uses a 4 mm temporal cornea incision, and removes the central 8mm of Descemet’s membrane in the recipient cornea. He then uses an 8mm punch to harvest Descemet’s membrane in the donor cornea and then inserts that through the wound and unfolds it and gets it positioned with SF6.“The reason [for using] the SF6 as opposed to filtered air is that the SF6 lasts a bit longer and tends to have less dislocation,” Dr. Ambati said.He has performed this technique in 12 cases so far beginning last April, he said and it has worked well.
Posted by mehdi khanlari at 11:05 PM | Comments (0)
Light treatments for dry eye
Eyeworld April 2007
....the use of dermatologic light treatments — intense pulsed light (IPL) and broadband light (BBL) — for patients with dry-eye syndrome.
....According to Dr. Toyos, IPL and BBL have been effective in treating patients with dry eye of non-immune etiology. IPL and BBL are more commonly used in dermatology to treat rosacea. Dr. Toyos said he is the first to investigate the use of these light treatments for dry eye.“It started when some of my rosacea patients began IPL treatments for their skin condition,” he said. “IPL eliminates superficial blood vessels of the face. We administered these treatments in our aesthetic clinic. These patients would come back to our eye clinic and tell us that their eyes felt great.”
The treatments had improved meibomian gland function in these patients, Dr. Toyos said, so he began applying the technology to patients with dry eye and found similar results.,,,,. Both treatments increased tear break-up time and the results of Schirmer’s test with anesthesia. Contralateral eyes not receiving treatment also showed improvement with both modalities, but not as much improvement as treated eyes.
Posted by mehdi khanlari at 10:18 PM | Comments (0)
intracameral preservative-free lidocaine 1% provided rapid, effective mydriasis comparable to that of topical mydriatics.
One recent study published in the January issue of the Journal of Cataract & Refractive Surgery evaluated pupil dilation by an intracameral injection of 1% Xylocaine (nonpreserved lidocaine, AstraZeneca PLC, London) during phacoemulsification cataract extraction and compared the results to those using conventional topical mydriatics.Aminollah Nikeghbali M.D., Eye Research Center Rassoul Akram Hospital, Iran University of Medical Sciences, Tehran, and colleagues conducted a prospective comparative case series study that included 57 patients who were given topical mydriatics (30 eyes) or intracameral lidocaine (27 eyes) to dilate the pupil for phacoemulsification and IOL implantation. “The topical group received three drops of cyclopentolate 1% and phenylephrine 5% given five minutes apart, starting 60 minutes before surgery. The intracameral group received preservative-free lidocaine 1% (0.2 to 0.3 mL) injected just before the procedure began. No epinephrine was added to the irrigating solution,” the researchers wrote in the study.The researchers measured the horizontal pupil diameter before and after pupil dilation using the same caliper in both groups. And they recorded total surgical time, need for a mydriatic agent during the procedure, and subjective surgical performance The researchers reported that the mean pupil dilation was 4.52 mm +/– 0.08 (SD) in the intracameral group and 4.06 +/– 0.09 mm in the topical group. They wrote the difference between groups was statistically significant (P = 0.001). In addition, the researchers found no significant difference between groups in the overall subjective surgical performance (P = 0.74).“No patient in the intracameral group and two patients in the topical group required an intracameral mydriatic injection,” the research-ers reported.They concluded that during phacoemulsification, intracameral preservative-free lidocaine 1% provided rapid, effective mydriasis comparable to that of topical mydriatics.
Posted by mehdi khanlari at 10:11 PM | Comments (0)
April 15, 2007
Surgical findings with the tinted AcrySof intraocular lens in children
Journal of AAPOS,April,2007
The AcrySof foldable acrylic intraocular lens (IOL) has become an accepted and frequent means of treating pediatric aphakia. A new version of this lens with blue-light filtering properties purports to offer superior retinal protection. A chart review identified 29 eyes of 21 children (tinted lens group; age 11 months to 13 years) who had the tinted IOL implanted. The standard lens group consisted of 38 eyes (31 patients; age 11 months to 15 years). Most eyes had an intact posterior capsule at the time of implantation.
The tinted lens group showed a higher incidence of transient inflammation than the standard lens group (p=0.03) but the rates of nontransient sequelae (posterior synechiae, iris synechiae, membranes formation, capsule, or IOL opacification) were similar (66% versus 47%; p=0.11). Posterior capsule opacification occurred in 15 eyes in the tinted lens group and 16 eyes in the standard lens group (p=0.15) but was visually significant in only 10 and 11 eyes, respectively (p=0.77).
Conclusions:Transient inflammation is higher with implantation of tinted versus nontinted IOLs, but long-term inflammatory sequelae are roughly equal, as is the rate of posterior capsule opacification. The question as to whether the chromophore in the tinted lens caused the higher incidence of transient inflammation is unresolved.
Posted by afarahi at 10:46 PM | Comments (0)
Cataract surgery for congenital cataract: Endothelial cell characteristics, corneal thickness, and impact on intraocular pressure
Journal of AAPOS,April,2007
CCT and IOP measurements and specular microscopy were performed in 31 eyes of 17 cases of extracted congenital cataracts and 40 eyes of 20 age- and sex-matched participants as control group. The mean of three pachymetry measurements of the central cornea was taken as CCT. IOP was checked using an applanation tonometer.
Although the corneas were clinically clear and there was no significant difference in endothelial characteristics of eyes with extracted congenital cataract and controls, central corneas of operated eyes were significantly thicker than those of controls. To differentiate the actual glaucoma from ocular hypertension in these patients, the central corneal thickness measurement should strongly be considered.
Posted by afarahi at 10:43 PM | Comments (0)
Unilateral lens extraction for high anisometropic myopia in children and adolescents
Journal of AAPOS,April,2007
Clinical course and outcome data were collated retrospectively in a group of 7 children and adolescents (mean age, 9.1 years; range, 4-20 years) with neurobehavioral disorders and noncompliance with spectacle wear for anisometropic myopia. Myopia in the 7 eyes ranged –11.9 to –24.5 D (mean, –16.7 D). Goal refraction was 0 to + 4 D. Correction was achieved by lensectomy in 5 eyes and lensectomy with intraocular lens implantation in 2 eyes. Primary posterior capsulectomy/subtotal vitrectomy was performed during the primary procedure in 5 eyes (71%). Mean follow-up was 3.8 years (range, 0.5-5.4 years).Myopia correction averaged 17.3 D. A total of 86% (6 eyes) were corrected within ± 3 D of the goal refraction and the remaining 14% to within ± 4 D. Uncorrected visual acuity improved postoperatively in all 7 eyes.Myopic regression averaged ∼0.43 D/year. Capsular opacification necessitated YAG-laser membranectomy in the 2 eyes that had preservation of the posterior capsule at the primary procedure. Retinal detachment has not occurred in any of the eyes during the follow-up period.
Conclusions:Refractive myopic lensectomy reduced high anisometropia and improved functional vision in children who have high myopia beyond the range of excimer laser correction and who will not wear glasses. Further study is indicated to determine the long-term safety of this procedure in similar pediatric populations.
Posted by afarahi at 08:00 PM | Comments (0)
A Prospective, Population-Based Study of the Role of Visual Impairment in Motor Vehicle Crashes among Older Drivers
Investigative Ophthalmology and Visual Science.April,2007
To determine the role of vision and visual attention factors in automobile crash involvement.One hundred twenty (6.7%) of the 1801 drivers were involved in a crash during the observation interval. Glare sensitivity and binocular field loss were significant predictors of crash involvement (P < 0.05). Worse UFOV(Useful Field of View Test ) score was associated with increased crash risk.
CONCLUSIONS. Glare sensitivity, visual field loss, and UFOV were significant predictors of crash involvement. Acuity, contrast sensitivity, and stereoacuity were not associated with crashes. These results suggest that current vision screening for drivers’ licensure, based primarily on visual acuity, may miss important aspects of visual impairment.
Posted by afarahi at 07:39 PM | Comments (0)
Paediatric pseudophakia: analysis of intraocular lens power and myopic shift
Clinical & Experimental Ophthalmology, April, 2007
This study is a retrospective review children undergoing small incision posterior chamber foldable IOL implantation between age 1 month and 18 years, from 1995 to 2005. 163 eyes of 126 patients underwent surgery. All patients were followed for a minimum of 6 months postoperatively. The children were divided into four groups at time of surgery: Group A: 1-24 months, Group B: 25-48 months, Group C: 49-84 months, Group D: 85 months−18 years. The mean target refraction for the groups were: Group A: +6.37 D, Group B: +4.66 D, Group C: +1.95 D, and Group D: +0.97 D. Children under 4 years experienced the most myopic shift and the largest mean rate of refractive change per year. Mean change Group A: −5.43 D, Group B: −4.16 D, Group C: −1.58 D, Group D: −0.71 D. Eighty-nine per cent of patients with unilateral cataracts had a postoperative refraction within 3.00 D of the fellow eye at last follow-up visit (mean = 3.16 years).
Conclusions:The rate of myopic shift is high in children under age 4 years at time of surgery, shifting as much as −12.00 D. The mean postoperative target refraction should probably be increased from previous literature recommendations. The patient's age at time of cataract surgery and the refractive power of fellow eye are all factors to consider when deciding what power IOL to surgically implant in a paediatric patient.
Posted by afarahi at 06:52 PM | Comments (0)
April 08, 2007
Effect of stromal hydration of clear corneal incisions: Quantifying ingress of trypan blue into the anterior chamber after phacoemulsification
JCRS Pages 623-627 (April 2007)
To use trypan blue as a quantifiable ingress tracer to determine whether stromal hydration reduces ocular surface fluid ingress at the end of phacoemulsification.
A prospective randomized study included 80 eyes having phacoemulsification through 2.2 mm incisions. These eyes were divided into 2 equal groups: 1 had stromal hydration (surgery completed by injecting fortified balanced salt solution [BSS Plus] to hydrate the lateral walls and internal entry of incision) and the other had no stromal hydration. One half milliliter of 0.0125% sterile trypan blue was instilled on the ocular surface and allowed to remain for 2 minutes. One-tenth milliliter of aqueous fluid was aspirated from the anterior chamber, and its optical density was measured using ultraviolet spectrophotometry. Logs of dilution of trypan blue were used for statistical analysis using the nonparametric Mann-Whitney U test.
Results
There was a statistically significant decrease and difference between groups in mean dilution of trypan blue in the aqueous aspirate (P<.001). The mean was 1:11 337 in the stromal hydration group and 1:220 in the no stromal hydration group. Logs of mean dilution of trypan blue had statistically significant lower values in the stromal hydration group than in the no stromal hydration group (3.21 and 2.14, respectively) (P<.001).
Conclusions
Stromal hydration of clear corneal incisions reduced ingress into the anterior chamber of the trypan blue instilled on the ocular surface. Clinically, these findings may have a beneficial effect in reducing the risk for postoperative endophthalmitis.
Posted by alireza habibollahi at 10:49 PM | Comments (0)
Contrast sensitivity and glare disability after implantation of AcrySof IQ Natural aspherical intraocular lens: Prospective randomized masked clinical trial
JCRS 603-610 (April 2007)
To evaluate contrast sensitivity and glare disability after implantation of an AcrySof IQ Natural SN60WF aspherical intraocular lens (IOL) (Alcon Laboratories).
120 patients who had PE in a prospective triple-masked trial were randomized to receive an AcrySof SA60AT IOL (40 eyes), AcrySof Natural SN60AT IOL (40 eyes), or AcrySof IQ SN60WF IOL (40 eyes). At 3 months, contrast sensitivity was measured using the CSV-1000E contrast sensitivity chart test face (Vector Vision) at 3, 6, 12, and 18 cycles per degrees (cpd) under photopic conditions (85 cd/m2) and mesopic conditions (2.7 cd/m2) with 4.0 mm and 6.0 mm fixed central apertures, with and without glare. The Kruskal-Wallis test was used and a pair-wise comparison performed. The main outcome measure was the difference in contrast sensitivity between IOLs at each spatial frequency.
Results
The best corrected visual acuity was similar between the 3 IOL groups (P = .6). The AcrySof IQ group had significantly higher contrast sensitivity at 18 cpd under photopic conditions (P = .008); at 3, 6, 12, and 18 cpd during mesopic testing with a 4.0 mm aperture without glare (P = .018, P = .011, P = .007, and P = .0001, respectively) and with glare (P = .003, P = .006, P = .005, and P = .004, respectively); and at all spatial frequencies during mesopic testing with a 6.0 mm aperture without glare (P = .018, P = .006, P = .009, and P = .0001, respectively) and with glare (P = .019, P = .002, P = .01, and P = .017, respectively).
Conclusion
Eyes with the AcrySof IQ SN60WF IOL had significantly higher contrast sensitivity than eyes with an AcrySof SA60AT or AcrySof Natural SN60AT IOL at all spatial frequencies during mesopic testing (with and without glare) with 4.0 and 6.0 mm artificial pupil.
Posted by alireza habibollahi at 10:43 PM | Comments (0)
Customized photoastigmatic refractive keratectomy using combined topographic and refractive data for myopia and astigmatism in eyes with forme fruste and mild keratoconus
JCRS Pages 591-602 (April 2007)
To examine the outcomes of PARK using corneal and refractive parameters for myopia and astigmatism in eyes with forme fruste and mild keratoconus.
PARK was performed with a Star 1 or Star 2 laser (Visx) in 45 eyes with forme fruste or mild keratoconus using the Alpins vector planning technique. Inclusion requirements were best corrected visual acuity (BCVA) 20/40 or better, no slitlamp signs of keratoconus, mean keratometry less than 50.00 diopters (D), and corneal and refractive stability for at least 2 years.
Results
Thirty-two eyes had follow-up of 5 years and 9 eyes, of 10 years. Preoperatively, the mean refractive astigmatism was −1.39 D (range 0.45 to −5.04 DC) and the mean corneal astigmatism was 1.52 D (range 0.35 to 4.75 D) by manual keratometry and 1.70 D (range 0.32 to 5.32 D) by topography. 1 Y F/U the mean refractive astigmatism was −0.43 ± 0.40 D and the mean corneal astigmatism was 1.05 D by keratometry and 1.02 D by topography, UCVA was 20/20 or better in 56% of eyes and 20/40 or better in all eyes. The BCVA was 20/20 or better in 89% of eyes and 20/30 or better in all eyes. Seven eyes had a loss of BCVA, and 16 eyes had a gain. There were no cases of keratoconus progression.
Conclusions
PARK in forme fruste and mild keratoconus was safe and effective for myopia and astigmatism in carefully selected patients with refractive and corneal stability. The incorporation of the corneal astigmatism data into the applied treatment parameters may improve visual and total astigmatism results.
Posted by alireza habibollahi at 10:36 PM | Comments (0)
Simple test to confirm cleavage with air between Descemet's membrane and stroma during big-bubble deep anterior lamellar keratoplasty
JCRS Pages 570-572 (April 2007)
We describe a simple test to confirm big-bubble formation in deep anterior lamellar keratoplasty by observing the position and movements of small air bubbles injected into the anterior chamber through a limbal paracentesis. The test also allows evaluation of the extension of Descemet's membrane cleavage from the posterior stroma relative to the margins of the corneal trephination.
Posted by alireza habibollahi at 10:32 PM | Comments (0)
April 06, 2007
“Retinal migraine” is really retinal vasospasm
Specialty News and Views: Neuro-Ophthalmology/Orbit - March 2007
In a recently published paper, Hill et al performed a broad-based literature search of reported cases of transient monocular visual loss suggesting “retinal migraine.” They noted that only 5 of 142 cases meet the criteria of the International Headache Society (IHS) for retinal migraine, which require “at least 2 attacks” of “fully reversible” monocular visual loss “associated with migraine headache.”
Perhaps the mislabeling of retinal migraine stemmed from the fact that migraine itself was previously felt to originate from the vasospasm of cortical vessels. This paradigm of migraine has been replaced by the concept of a spreading depression of cortical neuronal activity that has not been demonstrated in the retina. Hill et al concluded that “retinal migraine,” as defined by the IHS criteria, is an exceedingly rare event, and that most cases deemed “retinal migraine” are in fact “presumed retinal vasospasm.”
Posted by afarahi at 07:01 PM | Comments (0)
April 05, 2007
An Optical Coherence Tomography-Guided, Variable Dosing Regimen with Intravitreal Ranibizumab (Lucentis) for Neovascular Age-related Macular Degeneration
AJO, April 2007
After three consecutive monthly Lucentis injections, 40 patients were re-treated based on changes in OCT findings. A mean of 4.5 months passed before another injection was required. At 12 months, patients received an average 5.6 injections without sacrificing improvement in visual acuity.
Posted by kjalali at 11:37 PM | Comments (0)
Endophthalmitis after Uncomplicated Cataract Surgery with the Use of Fourth-Generation Fluoroquinolones: A Retrospective Observational Case Series
Ophthalmology, April 2007
This multi-center, retrospective study of 20,013 patients finds a 0.07 percent infection rate; well within the range of previously reported endophthalmitis rates. Researchers observed no statistical difference in the infection rate between moxifloxacin and gatifloxacin.
Posted by kjalali at 11:33 PM | Comments (0)
April 04, 2007
AMD risk factors differ for drusen and pigmentary abnormalities
OSN SuperSite
A study investigating 5-year risk factors for the development of age-related macular degeneration found differences between the risk factors for the development of drusen and pigmentary abnormalities. Alcohol consumption was found to decrease the risk of drusen formation and to increase the risk of pigmentary abnormalities. Married participants were also found to have less risk of soft drusen, while single people had less risk of hypopigmentation compared with those who were widowed or divorced. Dietary fiber-rich vegetable (tomatoes, red peppers and cucumbers) intake was also a factor for AMD. Those who consumed vegetables one to two times a week or less while between the ages of 40 and 60 years had a marked increased risk of drusen, compared with those who consumed dietary fiber-rich vegetables four to seven times a week. Likewise, infrequent meat consumption in people between the ages of 20 and 60 years resulted in an increased risk of soft drusen, as opposed to those who ate such products four to seven times a week. However, less frequent consumption of meat and meat products was found to be protective for pigmentary abnormalities.
Posted by kjalali at 08:56 AM | Comments (0)
Transplanted human stem cells prevented vision loss in rat retinal disease model
OSN SuperSite
Researchers injected human neural progenitor cells (hNPCs) subretinally into rats at an age just preceding major photoreceptor loss. At 90 to 100 days postnatal, investigators found that hNPC-treated eyes retained retinal electrical activity and visual field. They also had near-normal visual acuity. Functional efficacy was further enhanced when hNPCs were genetically engineered to secrete glial cell line-derived neurotrophic factor. At 150 days postnatal, histological examinations showed that hNPCs had formed a nearly continuous pigmented layer between the retina and retinal pigment epithelium. The pigmented layer was also distributed within the inner retina. These results underscore the potential therapeutic utility of hNPC in the treatment of retinal degenerative diseases and suggest potential mechanisms underlying their effect in vivo.
Posted by kjalali at 08:49 AM | Comments (0)
Intraocular fluid-air exchange decreased retinal ganglion cell activity, experimental study finds
OSN SuperSite
Researchers investigated how intraocular fluid-air exchange affects retinal ganglion cell activity in a cat model. Investigators performed lensectomy and vitrectomy on two animals and inserted up to two fiber microelectrodes via scleral ports. After 2 weeks, they performed fluid-air exchange. The researchers found that fluid-air exchange led to a "rapid reduction" of spontaneous and visually evoked retinal ganglion cell activity. The decrease began within a few minutes and halved about every 3 minutes thereafter. At 1 hour post-refill, retinal activity had only partly recovered. The authors attributed the decreased retinal activity to mechanical stress-induced drying of the inner retinal surface. It may also potentially have caused changes in extracellular ion concentrations. Since even moderate airstream-based fluid-air exchanges can lead to retinal damage, the surgeon should minimize the quantity of air passing open sclerotomy sites until a better understanding of the retinal effects of this essential technique in modern vitrectomy is available.
Posted by kjalali at 08:44 AM | Comments (0)
Positive interim phase 2 data reported for VEGF Trap-Eye
OSN SuperSite
The phase 2 study involves 150 patients with neovascular age-related macular degeneration randomly assigned to one of five treatment groups. Two groups received either 0.5 mg or 2 mg intravitreal injections of VEGF Trap-Eye every 4 weeks, and three groups received a single dose of either 0.5 mg, 2 mg or 4 mg. The interim analysis involved data for the first 78 patients who completed 12 weeks' follow-up. Investigators reported no serious drug-related adverse events, and treatment was generally well tolerated by patients.At 12 weeks' follow-up, VEGF Trap-Eye led to a statistically significant mean decrease in retinal thickness of 135 microns compared with baseline. In addition, visual acuity improved an average of 5.9 letters (P < .0001).
Posted by kjalali at 08:31 AM | Comments (0)
April 02, 2007
Clinical Performance of a Mid-Viscosity Artificial Tear for Dry Eye Treatment
This study reports the results of 3 studies conducted to evaluate the performance of a 1.0% carboxymethylcellulose (CMC) mid-viscosity artificial tear compared to currently marketed low-viscosity tears.
This 1% CMC mid-viscosity tear showed protection of the ocular surface after instillation and significant reduction in signs and symptoms of dry eye. Improvements were greater than with low-viscosity tears. The mid-viscosity artificial tear was rated well in comfort, duration of benefit, and general acceptability
Posted by afarahi at 11:27 PM | Comments (0)
Detection of Abnormal Visual Cortex in Children With Amblyopia by Voxel-Based Morphometry
Thirteen children with amblyopia and 14 normally sighted children underwent magnetic resonance (MR) examination. Comparison between amblyopic and control groups was derived for the gray matter of the entire brain using parametric statistics.
The results of VBM analysis indicated that the amblyopic group had decreased gray matter density in the middle frontal gyrus, parahippocampal gyrus, fusiform gyrus, inferior temporal gyrus of the left hemisphere, and the bilateral calcarine cortices. The radii of these regions ranged from 12 to 36 voxels. These abnormalities were consistent with morphologic changes in brain regions related to visual function,which may indicate developmental abnormalities of visual cortex during the critical growth period.
Posted by afarahi at 11:19 PM | Comments (0)
April 01, 2007
Adjunctive therapy: prostaglandins
In light of the growing popularity of prostaglandin use, Kuldev Singh, M.D., M.P.H., professor, Ophthalmology, Stanford University School of Medicine, Calif., reviewed surgeons’ options in adjunctive therapy. Dr. Singh highlighted that adjunctive therapy has its limitations, referring to diminishing returns, side effects, cost and compliance, a trough effect, development of tolerance, and conjunctival toxicity.He also said that using a prostaglandin alone is not enough for patients to reach the target IOP. As such, Dr. Singh advised surgeons, when selecting an adjunctive agent, to consider a complementary mechanism of action as well as the safety and tolerability of the agent and its dosing regimen. Although beta blockers were considered first line therapy prior to prostaglandins use, Dr. Singh asked physicians to consider if that meant they would automatically be the next choice, should prostaglandins not be an option for their patient.Dr. Sing negated this by recommending that topical carbonic anhydrase inhibitors (CAIs) be considered next as beta-blockers do not decrease IOP during nocturnal hours when the patient is in the supine position.
Posted by mehdi khanlari at 10:20 PM | Comments (0)
Conductive keratoplasty
Daniel S. Durrie, M.D., clinical associate professor, Ophthalmology, University of Kansas Medical Center, Kansas City, discussed conductive keratoplasty (CK)
“Doctors don’t understand why they should do it,” he said, before going on to explain where CK is today. “CK is the only FDA procedure for near vision improvement in the presbyopic patient and the safest refractive procedure ever performed,” Dr. Durrie said in his presentation. “CK is also the most misunderstood, misrepresented procedure in refractive surgery.”
He called it an “anti-aging procedure,” unlike refractive surgery.
Presenting three-year data by Jason Stahl, M.D., Overland Park, Kansas, on CK for presbyopia treatment, Dr. Durrie showed the drastic improvement in pre-op vision, with 100% of patients (n, 9) achieving uncorrected near visual acuity (UCVA) of at least < J3 at one year post-op and at three years post-op, 78% of patients had at least < J3. In addition, 100% of patients achieved at least < 20/25 and < J3 in both distance and near binocular uncorrected visual acuity in the first year post-op. And by the third year, that figure had gone down to 78% with 89% achieving at least < 20/40 and < J7.Dr. Durrie also presented the results of a CK post-LASIK FDA Clinical Trial where he was one of the clinical investigators. The prospective multicenter study evaluated the safety and effectiveness of the ViewPoint CK system for the improvement in near vision in post LASIK emmetropes using CK.The three-month progress report on the study detailed 72 eyes of 72 patients who underwent conservative treatment of 8 spots at 8 mm. In terms of safety, there were no adverse events or flap complications and best spectacle-corrected visual acuity (BSCVA) was preserved. In terms of efficacy, 8 spots at 8 mm had 1.17 D of effect. There was improvement in both near and intermediate UCVA, as well. Furthermore, the researchers found high satisfaction ratings and improvement in functional vision from pre- to post-CK.Dr. Durrie said that a successful presbyopia practice has CK as its cornerstone.
Posted by mehdi khanlari at 10:16 PM | Comments (0)
Stronger olopatadine solution more effective and as safe than weaker solution
Pataday (olopatadine HCl 0.2%, Alcon Laboratories, Fort Worth Texas) is twice as strong as its predecessor, Patanol (olopatadine HCl 0.1%, Alcon) but its just as safe and is the only once-per-day antihistamine on the market, said Francis S. Mah, M.D., University of Pittsburgh. Dr. Mah reported that almost 50% of the U.S. population has allergies, and of that group, 72% suffer from ocular symptoms. Itchiness and redness are the key symptoms to look for, he said, but chemosis, eyelid swelling and tearing also are symptoms. When seeing a patient with allergies, the physician should ask the patient what drugs they are using including any over-the-counter drugs, because unless asked specifically, many patients will not volunteer that information because they do not think of them as drugs. Dr. Mah added that there are several antihistamines on the market, but they all are approved by the Food and Drug Administration (FDA) for treating only itchiness or redness. Patanol, however, is approved for treating both.
Posted by mehdi khanlari at 10:10 PM | Comments (0)
Simple LRI nomogram works for symmetric and asymmetric corneal topography
Kevin M. Miller, M.D., Jules Eye Institute, Los Angeles, proposed a simple nomogram for limbal relaxing incisions (LRIs). For symmetric bowtie astigmatism on the corneal topography, the nomogram is to make two paired, peripheral corneal incisions just inside the limbus 450 to 600 microns deep and as long in clock hours as the cornea is steep in diopters (D). The longest incisions are three clock hours in length to correct three diopters of corneal astigmatism. If the bowtie is asymmetric, Dr. Miller said to make a longer incision on the side of the cornea that is steeper. After that, the rest of the nomogram applies. Dr. Miller said that a phacoemulsification incision reduces the effect of an LRI by 0.5 D if it is made 90 degrees away. Also increasing one’s age enhanced the effect of the LRIs by 0.12 D per decade.
Posted by mehdi khanlari at 10:08 PM | Comments (0)
Patients treated with prednisolone and nepafenac did not develop macular edema
Eyeworld MARCH 2007
Data analysis supports the prophylactic use of topical non-steroidal anti-inflammatory drugs (NSAIDs) in addition to topical steroids in preventing pseudophakic cystoid macular edema (CME) following routine cataract surgery, said Richard E. Braunstein, M.D., director, Division of Refractive Surgery and Miranda Wong Tang associate professor, Clinical Ophthalmology, Columbia University, New York. Dr. Braunstein went as far as to recommend topical NSAIDs for all patients and extended use (up to eight weeks) for high-risk patients. In a retrospective chart review of 450 patients who underwent uncomplicated phacoemulsification with intraocular lens (IOL) implantation, 240 patients were treated post-operatively with topical prednisolone (various manufacturers) and 210 patients were treated with prednisolone and Nevanac, (nepafenac, Alcon Laboratories, Fort Worth, Texas). In the group of patients that received both drugs, not one patient had developed CME by four to six weeks post-op; furthermore, only five patients that received only prednisolone did develop CME.
Posted by mehdi khanlari at 10:05 PM | Comments (0)
Needling a bleb with MMC and lidocaine
When filtering surgery fails, Marlene R. Moster, M.D., Wills Eye Institute, Philadelphia, recommending needling the bleb with mitomycin C (MMC). In a retrospective study of 44 patients, Dr. Moster performed a bleb needle revision with a mixture of 0.1 mL MMC (0.4 mg/mL) mixed with 0.1 mL non-preserved 1% lidocaine. Dr. Moster reported that after 12 months, 28 patients (64%) were considered a success or qualified success. The baseline IOP in these patients was 26.7 ± 8.2 mm Hg using an average of 1.5 ± 1.5 glaucoma medications. The IOP after one year was 13.6 ± 4.0 (range 6 to 21 mm Hg) with an average of 0.5 ± 0.8 medications. In conclusion, bleb needle revision with high-dose MMC was effective in reducing the IOP in 64% of eyes with a failed filtering bleb with minimal long-term complications
Posted by mehdi khanlari at 10:03 PM | Comments (0)
Incomitant Esotropia Following Pterygium Excision Surgery
Arch Ophthalmol.March, 2007
A retrospective review of 6 consecutive patients who developed incomitant esotropia, limited abduction, and diplopia following unilateral pterygium excision surgery.
Conclusions Incomitant esotropia is an uncommon but serious complication following pterygium excision surgery. Medial rectus muscle recession combined with scar tissue removal is required to eliminate diplopia in the primary position. Conjunctiva-perimuscular scar tissue removal may suffice to improve diplopia in the abduction gaze position.
Posted by afarahi at 10:54 AM | Comments (0)
Primary Intraocular Lens Implantation in Pediatric Uveitis
A multicenter, retrospective, interventional case series. The setting included 3 medical centers in Israel. The interventions were cataract surgery and intraocular lens implantation. Aggressive preoperative and postoperative systemic and topical anti-inflammatory treatment was instituted. The main outcome measures included postoperative inflammation, complications, and visual outcome.
Conclusions Compared with those with non–JRA-associated uveitis, children with JRA-associated uveitis tend to have more severe manifestations of disease when first seen and after surgery, but there is no significant difference in postoperative course or complications. Intraocular lens implantation, including small-incision, foldable, intraocular lenses, is well tolerated, when combined with aggressive medical treatment, for controlling inflammation. We believe that intraocular lens implantation is not contraindicated in those with pediatric uveitis, including uveitis associated with JRA.
Posted by afarahi at 10:40 AM | Comments (0)