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September 30, 2006
Botox injections above 100 U appear effective for some refractory blepharospasm patients
OSN SuperSite Top Story 9/27/2006
Patients with refractory essential blepharospasm may benefit from treatment with botulinum toxin type A at doses higher than the standard 100 U injections, a prospective study suggests.Richard L. Levy, MD, and colleagues at Wilmer Eye Institute evaluated the efficacy of increased botulinum toxin type A (Botox, Allergan Inc.) in eight consecutive patients with essential blepharospasm or Meige's syndrome. All patients had been receiving bilateral 50 U botulinum toxin injections bimonthly for at least 6 months. Upon enrollment, researchers increased patients' dosages to either 62.5 U or 75 U per side, with repeat injections administered at least 14 days apart.Investigators found all patients generally tolerated the supramaximal doses. No vision- or life-threatening adverse events were reported, and no patients reported experiencing adverse events, such as rash, diplopia or increased facial weakness, according to the study.Four patients opted to continue receiving the supramaximal dosing regimen, three of whom had Meige's syndrome. Among these patients, the average time between repeat injections improved from 68 days to 90 days. Two patients reported improved reading ability and one patient reported less awareness of their condition, as well as an improvement in measures of quality of life.The remaining four patients opted to return to 100 U injections, although intervals between injections increased from 72 days to 90 days. One patient noted she was less aware of her condition. However, the remaining three patients reported no change or increased difficulty with shopping or driving, according to the study.It may be that patients with Meige's syndrome are so debilitated from their condition that any improvement significantly improves their overall quality of life, whereas patients with isolated [essential blepharospasm] have higher expectations," the study authors said.In contrast to prior studies, no patients in the current study experienced an increased incidence of ptosis from the higher botulinum toxin doses. This may be due to the study's injection protocol, which involved injections above the eyebrows and in the lateral canthal regions rather the upper eyelids, the authors noted.The study is published in the September issue of Ophthalmology.
Posted by mehdi khanlari at 11:45 PM | Comments (0)
Learning Effect of Short-wavelength Automated Perimetry in Patients With Ocular Hypertension
Journal of Glaucoma
Rossetti, Luca MD, et al. - Conclusions: The results of this study demonstrate a significant learning effect at full-threshold SWAP. This may limit the efficacy of this kind of perimetry in detecting early glaucoma, and should therefore be carefully considered when creating normative databases for new SWAP strategies...
Posted by mehdi khanlari at 11:34 PM | Comments (0)
Variations in Primary Open-Angle Glaucoma Prevalence by Age, Gender, and Race: A Bayesian Meta-Analysis
Investigative Ophthalmology and Visual Science
Conclusions: Although black populations had the highest prevalence of OAG at all ages, white populations showed the steepest increase in OAG prevalence with age. Men were more likely than women to have OAG...
Posted by mehdi khanlari at 11:31 PM | Comments (0)
Intrastromal Diathermal Keratostomy: A New Micropenetrating Clear-Cornea Glaucoma Procedure
Journal of Glaucoma. 15(5):437-445, October 2006.
The filtering intrastromal diathermal keratostomy (IDK) was developed to comply with the call for a low postoperative intraocular pressure (IOP) and a bleb morphology without a thin, cystic appearance. A diathermal microkeratostomy (150 to 200 [mu]m) was created into the anterior chamber, anterior to the Schwalbe line through the floor of a surgical corneoscleral tunnel incision into the subconjunctival space. A newly developed, bipolar diathermal microneedle was used to create the keratostomy, replacing the Holmium laser used previously. Subconjunctival injections of 3 [mu]g mitomycin C were used in each eye 1 week before the IDK to obtain maximum antiproliferative effect at the time of the operation. Nine patients (10 eyes) with complicated, refractory primary and secondary open-angle glaucoma are discussed.Results: Histologic examination of the IDK and clinical postoperative ultrasound biomicroscopy showed an optimal appearance of the diathermal microkeratostomy. After 34 months (range 24 to 42 mo) the mean IOP was 11 mm Hg (SD+/-3, range 6 to 16) without medication in all 10 eyes. IDK revision with internal needling of postoperative subconjunctival fibrosis through the tunnel incision was performed in 5 eyes after an average of 3 months (range 0.2 to 7 mo). After 33 months (range 19 to 38 mo), the postrevision mean IOP was 10 mm Hg (SD+/-2, range 8 to 14) without medication in all 5 eyes. All 10 eyes showed noncystic diffuse blebs with optimal spongy subepithelial morphology: in 2 eyes the blebs were totally avascular and in 8 eyes they were relatively avascular.Conclusions: The preliminary results of the new clear-cornea IDK seem promising because of postoperative IOP of about 10 mm Hg despite a low dose of mitomycin C and noncystic bleb morphology.
Posted by mehdi khanlari at 11:30 PM | Comments (0)
Nonproliferative diabetic retinopathy and macular edema progression after phacoemulsification: Prospective study
Journal of Cataract & Refractive Surgery
To determine the incidence of diabetic retinopathy (DR) progression after phacoemulsification in patients with type II diabetes Service of Ophthalmology, University of Sant Joan, Barcelona, Spain.This prospective study evaluated 132 patients with diabetes mellitus who had monocular phacoemulsification. A control group comprised the patients' contralateral eyes. Data analysis included preoperative retinal findings and DR status; hemoglobin A1c (HbA1c), low-density lipoprotein cholesterol, and triglycerides levels; insulin treatment; and arterial hypertension.Postoperative visual acuity increased by 2 or more lines in 105 patients (79.55%); the mean postoperative acuity was 0.63 ± 0.28 (SD). Diabetic retinopathy in the operated eye progressed in 31 patients (23.48%) and in the fellow eye in 28 patients (21.21%). The progression was associated with high levels of HbA1c and diabetes mellitus duration in both groups. Diabetic macular edema occurred in the operated eye in 8 patients (6.06%) and in the fellow eye in 6 patients (4.54%). Pseudophakic macular edema developed in 2 eyes (1.52%). The progression of diabetic macular edema was not associated with the risk factors studied Conclusion
Uneventful phacoemulsification cataract surgery may not cause DR progression
Posted by mehdi khanlari at 11:27 PM | Comments (0)
HRT may affect post-op LASIK outcomes
Eyeworld SEP 2006
That's because a study published in the April issue of the Journal of Refractive Surgery found that women on HRT are at an increased risk for refractive regression after LASIK However, the investigators did not find major post-op refractive changes in patients who took oral contraceptive pills compared with a control group.The study builds on research and anecdotal observations that females who are pregnant or breastfeeding should avoid LASIK because of corneal changes that increase the risk for unstable outcomes. “There's been a lot of speculation in the field about how hormone changes affect refractive changes,” said Louis E. Probst, M.D.,
Posted by mehdi khanlari at 11:08 PM | Comments (0)
September 29, 2006
Vehicle of triamcinolone may cause retinal toxicity and transient increased lens density
Graefe's Archive for Clinical and Experimental Ophthalmology, September 2006
This controlled study shows rabbit eyes injected with non-reduced, vehicle-containing triamcinolone experienced significant transient increases in lens density, especially at the highest dose, 25 mg. Pathological examination showed obvious retinal toxicity in vehicle-containing groups. Researchers suggest vehicle of triamcinolone be eliminated or reduced before injection to avoid potential toxicity.
Posted by kjalali at 04:20 AM | Comments (0)
Cataracts appear to significantly affect RNFL thickness as measured by OCT
Journal of Glaucoma, August 2006
Researchers used Stratus OCT to measure RNFL thickness in 25 patients before and after cataract surgery. Postoperative measurements were higher in all quadrants and in the 360-degree average. More advanced degrees of lens opacity correlated to a higher decrease in RNFL thickness values.
Posted by kjalali at 04:18 AM | Comments (0)
Pfizer to acquire worldwide license to develop possible new wet AMD treatment
INDUSTRY NEWS
Pfizer would acquire Quark's novel human gene RTP-801, which has the potential to treat wet AMD by blocking the expression of the RTP-801 gene through RNA interference or RNAi. The agreement is subject to clearance by the U.S. Federal Trade Commission
Posted by kjalali at 04:16 AM | Comments (0)
FDA approves Alcon’s Travatan Z solution for glaucoma
INDUSTRY NEWS
The new formulation was approved for patients with open-angle glaucoma or ocular hypertension who are intolerant of or insufficiently responsive to other intraocular pressure lowering medications. The new drug replaces benzalkonium with the gentler Sofzia.
Posted by kjalali at 04:14 AM | Comments (0)
September 24, 2006
Comparison of Pentacam and Orbscan IIz on Posterior Curvature Topography Measurements in Keratoconus Eyes
Ophthalmology Volume 113, Issue 9 , September 2006, Pages 1629-1632
Thirty-six eyes of 29 patients were analyzed. The average radius for posterior best-fit sphere was 5.97 μm (range, 4.69–6.79) for the Pentacam and 6.00 μm (range, 4.97–6.55) for Orbscan IIz. The mean difference (Pentacam − Orbscan IIz) for the radius generated for the best-fit sphere was −0.03±0.22 SD with a 95% confidence interval (CI) of −0.11 to 0.04 and a 95% LOA of −0.46 to 0.40 (P = 0.362). The mean posterior elevation by best-fit sphere fixed to the apex was 34.86 μm (range, 3–120) for the Pentacam and 48.50 μm (range, 11–118) for Orbscan IIz. The mean difference was −13.64±26.08 SD (95% CI, −22.46 to −4.81; 95% LOA, −64.75 to 37.48; P = 0.003). The average thinnest point for the Pentacam was 443.6 μm (range, 164–587), and that for Orbscan IIz was 445.9 μm (range, 204–597). The mean difference in the thinnest point for the Pentacam and Orbscan IIz was −2.28±35.55 (95% CI, −14.31 to 9.75; 95% LOA, −71.95 to 67.39; P = 0.703).
Conclusion
Both the Pentacam and Orbscan IIz determine similar thinnest points but have a measurable difference in posterior elevations above the best-fit sphere, despite similar radii of curvature. This difference may be important in the screening of patients for refractive surgery to avoid surgery on patients with early keratoconus. This study cannot determine if the Pentacam is underestimating the posterior vault or if Orbscan is overestimating this height, and further studies with a standardized test object are needed.
Posted by mmiraftab at 10:44 AM | Comments (0)
Retreatment after Wavefront-Guided and Standard Myopic LASIK
Ophthalmology Volume 113, Issue 9 , September 2006, Pages 1623-1628
At the last visit, mean spherical equivalents (SEs) were −0.17±0.42 diopters (D) in the SM group and −0.11±0.34 D in the WM group (P = 0.394). An SE of ±0.50 D was achieved in 87% (88/101) of SM eyes and 91% (49/53) of WM eyes. Seventy-five percent of eyes in both groups had UCVA≥20/20. All eyes in the WM group and 98% of eyes in the SM group had 20/30 or better UCVA. All eyes in both groups had a postoperative BSCVA of 20/25 or better. No eyes lost 2 lines of BSCVA in either group. No sight-threatening complications were encountered. The number of eyes with pre-retreatment optical symptoms was reduced to half after retreatment.
Conclusions
Our results suggest that retreatment with conventional LASIK is a safe, effective, predictable way of dealing with different types of residual refractive errors after both wavefront-guided and standard myopic LASIK.
Posted by mmiraftab at 10:42 AM | Comments (0)
Risk Factors for Corneal Ectasia after LASIK
Ophthalmology Volume 113, Issue 9 , September 2006, Pages 1618-1622
One hundred forty-eight consecutive patients (148 eyes) were included in this study. Thirty-seven patients who underwent LASIK at other refractive centers experienced corneal ectasia in 1 eye after LASIK. One hundred eleven eyes of 111 patients who underwent successful LASIK during the same period were age and gender matched and served as controls.
Intervention
All patients underwent preoperative and postoperative topographic analysis of the cornea. The follow-up period in both groups of patients ranged from 2 to 5 years, with a mean follow-up of 3.6 years. All patients underwent LASIK for myopia (spherical equivalent, −4.00 to −8.00 diopters).
Main Outcome Measures
Corneal keratometry, oblique cylinder, pachymetry, posterior surface elevation, difference between the inferior and superior corneal diopteric power, and posterior best sphere fit (BSF) over anterior BSF were given a grade of 1 to 3 each. An ectasia grading system was established, and the cumulative risk score was assessed.
Results
Patients who had a grade of 7 or less showed no evidence of corneal ectasia, whereas 16 (59%) of 27 patients who had a grade of 8 to 12 had corneal ectasia. Twenty-one (100%) of 21 patients with a grade of more than 12 had corneal ectasia after LASIK (P<0.0001).
Conclusions
A risk score may help in the prediction of patients who are at risk of experiencing corneal ectasia after LASIK. A prospective clinical study is needed to assess the validity of these risk factors.
Posted by mmiraftab at 10:39 AM | Comments (0)
Surgical embolus removal in retinal artery occlusion
British Journal of Ophthalmology 2006;90:1252-1255
Methods: Prospective study of seven patients with RAO of <36 h duration. All eyes underwent pars plana vitrectomy and a longitudinal incision of the anterior wall of the occluded arteriole in an attempt to remove the embolus. Outcome measures included visual acuity and arteriolar reperfusion, as evaluated with fluorescein angiography.
Results: Surgical removal of the embolus was achieved in six of the seven (87.5%) patients, visual acuity improved from a median of 20/400 (range: hand movements 20/25) to 20/40 (range: hand movements 20/25), and reperfusion of the occluded vessel was angiographically confirmed in four of the six patients in whom the embolus was successfully removed.
Conclusion: Surgical removal of retinal arterial emboli seems to be an effective and safe treatment for RAO, but a randomised and controlled clinical trial will be necessary to establish an evidence base for the role, if any, of this intervention.
Posted by mmiraftab at 10:35 AM | Comments (0)
September 19, 2006
Are artificial corneas within sight?
INDUSTRY NEWS
This week at the annual meeting of the American Chemical Society, an engineer presented a novel biomimetic material called Duoptix, which has water concentration and mechanical properties that rival those of the natural cornea. Researchers are now testing the material for biocompatibility in animal models.
Posted by kjalali at 01:26 PM | Comments (0)
Promising results for new treatment for wet AMD
INDUSTRY NEWS
Acuity Pharmaceuticals reports that results from a Phase II trial show bevasiranib sodium (formerly Cand5) is well tolerated. Bevasiranib is a small interfering RNA (siRNA) therapeutic designed to silence the genes that produce vascular endothelial growth factor.
Posted by kjalali at 01:24 PM | Comments (0)
FS laser allows for simpler, more accurate corneal wedge resection to correct high astigmatism after penetrating keratoplasty
JCRS, September 2006
The femtosecond laser allowed for an easier, more controlled and more precise excision of tissue in width, length and depth, which may improve the reproducibility of the technique. The risk for corneal perforation may be reduced when using an FS laser.
Posted by kjalali at 01:21 PM | Comments (0)
Intraoperative MMC may reduce endothelial cell density after PRK
AJO, September 2006
This randomized, placebo-controlled study of nine patients (18 eyes) finds that a single intraoperative application of MMC 0.02 percent for 30 seconds induced a statistically significant endothelial cell loss: 14.7 at one month and 18.2 at three months.
Posted by kjalali at 01:20 PM | Comments (0)
Paired opposite clear corneal incisions correct corneal astigmatism better than single clear corneal incisions
JCRS, September 2006
This randomized, prospective clinical study of 40 patients (40 eyes) with astigmatism of more than 1.50 D finds patients with paired incisions experienced a mean astigmatic change of 1.60 D compared to 0.59 in patients with single clear corneal incisions.
Posted by kjalali at 01:18 PM | Comments (0)
Benefits of pegaptanib maintained for two years in patients with AMD
Ophthalmology, September 2006
The VISION trials show patients given 0.3-mg of pegaptanib every six weeks for two years had superior visual outcomes compared to those who discontinued treatment after one year or those prescribed usual care, suggesting this treatment is important throughout the evolution of active neovascular AMD.
Posted by kjalali at 01:17 PM | Comments (0)
Course of glaucoma varies in pregnant women
Archives of Ophthalmology, August 2006
This retrospective study finds that 57.1 percent of 28 eyes (15 women) experienced no increase in IOP and no change in visual fields. But 35.7 percent did experience an increase in IOP or a progression of visual field loss during pregnancy. Many of these women required additional medication to control their IOP.
Posted by kjalali at 01:15 PM | Comments (0)
Intravitreal triamcinolone can improve vision in patients with advanced diabetic macular edema
Ophthalmology, September 2006
After two years of follow-up, this randomized study of 43 patients (69 eyes) finds that best-corrected visual acuity improved by five or more letters in 56 percent of treated patients, compared to 26 percent in the placebo group. Foveal thickness decreased by 59 μm more in the treatment group than in the placebo group. Progression of cataract and elevated IOP were common but appear manageable.
Posted by kjalali at 01:14 PM | Comments (0)
September 12, 2006
Bausch & Lomb and Talecris collaborate on ocular treatments
INDUSTRY NEWS
The companies will co-develop rPlasmin, a derivative of the human blood component plasmin used in treating blood clots. Bausch & Lomb is enrolling patients in early-stage clinical trials to evaluate Plasmin’s therapeutic potential to relieve retinal traction.
Posted by kjalali at 08:25 PM | Comments (0)
Patients on tamsulosin have a sluggish iris and small pupillary diameter, making cataract surgery more demanding
Investigative Ophthalmology & Visual Science, September 2006
Before surgery, the pupils of 21 patients taking tamsulosin were about 1 mm smaller than the 21 controls. During surgery, every patient on the drug had a sluggish hypotonic iris, along with a tendency toward miosis and a tendency for prolapse of the iris into the phaco tunnel or into the side port. The iris remained floppy after a 28-day interruption in tamsulosin use.
Posted by kjalali at 08:23 PM | Comments (0)
Larger retinal arteriolar caliber appears significantly associated with incident retinopathy in children and adolescents with type 1 diabetes
Ophthalmology, September 2006
A large case-control study finds this association was independent of known risk factors such as age, gender, diabetes duration, glucose control, blood pressure, puberty stage and BMI.
Posted by kjalali at 08:22 PM | Comments (0)
Arteriovenous nicking and focal arteriolar narrowing appear associated with an increased risk of developing age-related maculopathy
Ophthalmology, September 2006
An evaluation of participants in the Blue Mountains Eye Study finds eyes with mild (2.7 percent) or severe (4.6 percent) arteriovenous nicking are more likely to develop late ARM than eyes without this sign (1.5 percent), and that retinal arteriolar and venular caliber are not associated with ARM.
Posted by kjalali at 08:19 PM | Comments (0)