Volume 10, Number 25
Monday, June 28, 2010



In this issue: (click heading to view article)
Association Between CNV and Graft Failure and Rejection Following Keratoplasty
Degree of Vision-Specific Distress and Depressive Symptoms in People with Vision Impairment
Review of Variation in Early Biomechanical Effects of Hyperopic and Myopic LASIK
Visual Acuity in ROP with Early Treatment
Briefly










Association Between CNV and Graft Failure and Rejection Following Keratoplasty

Preoperative corneal neovascularization (CNV) is thought to be associated with an increased rate of corneal graft failure and potentially also graft rejection. The authors of this paper searched electronic databases and corneal registries (up through September 2008) in an effort to re-evaluate the known data about the role of CNV in keratoplasty.

They reported results both descriptively for each study and using random effects meta-analysis. Additionally, they examined potential moderating factors for the association between vascularization and graft failure and rejection using meta-regression analysis.

The study authors included 19 studies reporting on a total of 24,944 grafts undergoing keratoplasty and they noted an increase in the risk of graft failure and rejection in the presence of pathologic CNV in studies with a pooled risk ratio of 1.32 (95% confidence interval [CI], 1.15–1.49) for graft failure and 2.07 (95% CI, 0.98–3.15) for graft rejection. Moreover, they observed evidence of incremental increase of risk for graft failure and rejection as more corneal quadrants were affected by neovascularization and the two factors predictive of increased risk of neovascularization and graft failure were increased recipient age (p=0.003) and male gender (p=0.046).

Graft failure and rejection risk increase with an increasing number of corneal quadrants affected by neovascularization before keratoplasty, the authors concluded. These data support the study of novel topical antiangiogenic therapies at the cornea to precondition such a cornea for future corneal grafting.

SOURCE: Bachmann B, Taylor RS, Cursiefen C. Corneal neovascularization as a risk factor for graft failure and rejection after keratoplasty: an evidence-based meta-analysis. Ophthalmol 2010;June 3 [Epub ahead of print].





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Degree of Vision-Specific Distress and Depressive Symptoms in People with Vision Impairment

Investigators in Australia performed this cross-sectional study to determine the unique contribution of vision-specific distress in predicting depressive symptoms in people with vision impairment attending a tertiary eyecare clinic.

They conducted interview-administered surveys with 143 adult patients who had presenting visual acuity <03 logMAR and assessed depressive symptoms with the Patient Health Questionnaire-9 and vision-specific distress with the Impact of Vision Impairment (IVI) Questionnaire emotional well-being subscale. They also assessed level of restriction of participation in common daily activities due to vision impairment with the IVI and included measures of general physical health and social support.

According to the investigators, 21 (14.7%) of 143 participants reported clinically significant depressive symptoms and an additional 27.3% (n=39) had mild depressive symptoms. They reported that vision-specific distress was the strongest unique predictor of depressive symptoms (beta=0.37, p<0.001), with physical health (beta=–0.22, p<0.01), age (beta=–0.18, p<0.05) and experience of a negative life event (beta=0.15, p<0.05) also contributing significantly to depressive symptoms. Results also indicated that vision-specific distress mediates the impact of participation restriction due to vision impairment on depressive symptoms.

The study investigators determined that an assessment of vision-specific distress may be a useful tool with which to identify those at risk of depression or in need of early intervention in eye care or rehabilitation settings. They noted that depression treatment approaches or depression prevention strategies for people with vision impairment may benefit from a focus on vision-specific distress.


SOURCE: Rees G, Tee HW, Marella M, et al. Vision-specific distress and depressive symptoms in people with vision impairment. Invest Ophthalmol Vis Sci 2010;51(6):2891-2896.







Review of Variation in Early Biomechanical Effectsof Hyperopic and Myopic LASIK

To compare changes in corneal hysteresis (CH) and the corneal resistance factor (CRF) in myopic and hyperopic laser in situ keratomileusis (LASIK) and evaluate their relationship to the number of photoablative pulses delivered, a surrogate for ablation volume, preoperative and 1-week postop Ocular Response Analyzer measurements in eyes that had femtosecond-assisted LASIK were studied retrospectively. Changes in CH and CRF were compared and tested for correlation with the number of excimer laser pulses. With comparable flap thickness and attempted ablation volumes, myopic photoablation profiles were associated with greater decreases in CRF and CH than hyperopic profiles.

A total of 13 myopic eyes and 11 hyperopic eyes were evaluated and it was reported that preoperative corneal thickness, CH, CRF, programmed correction magnitude, flap thickness and total number of fixed spot-size photoablative pulses were similar in the two groups (p>.1). It was also noted that decreases in CH and CRF were greater after myopic LASIK than after hyperopic LASIK (p<.005), and changes in CRF were correlated with the number of excimer laser pulses in the myopic group only (r=–0.63, p=.02). Furthermore, regardless of ablation profile, changes in CH were more strongly correlated with preoperative CH values than with attempted ablation volume.

Results indicate that preoperative corneal biomechanical status, ablation volume and the spatial distribution of ablation are important factors that affect corneal resistance and viscous dissipative properties differently. Additionally, preferential tissue removal in the natively thicker paracentral cornea in hyperopia may partially account for the rarity of ectasia after hyperopic LASIK.

SOURCE: Witzel de Medeiros F, Sinha-Roy A, Alves MR, et al. Differences in the early biomechanical effects of hyperopic and myopic laser in situ keratomileusis. J Cataract Refract Surg 2010;36(6):947-953.







Visual Acuity in ROP with Early Treatment

The researchers in this study sought to compare visual acuity at 6 years of age in eyes that received early treatment for high-risk pre-threshold retinopathy of prematurity (ROP) with conventionally managed eyes.

They reported that infants with symmetrical, high-risk pre-threshold ROP (n=317) had one eye randomized to earlier treatment at high-risk pre-threshold disease and the other eye managed conventionally, treated if ROP progressed to threshold severity. For asymmetric cases (n=84), they randomized the high-risk pre-threshold eye to either early treatment or conventional management. Early Treatment Diabetic Retinopathy Study (ETDRS) visual acuity measured at 6 years of age by masked testers was the main outcome measure and the researchers assessed retinal structure as a secondary outcome.

They noted that analysis of all subjects with high-risk pre-threshold ROP showed no statistically significant benefit for early treatment (24.6% vs 29.0% unfavorable outcome; p=.15). Analysis of 6-year visual acuity results according to the Type 1 and 2 clinical algorithm showed a benefit for Type 1 eyes (25.1% vs 32.8%; p=.02) treated early but not Type 2 eyes (23.6% vs 19.4%; p=.37) and early-treated eyes showed a significantly better structural outcome compared with conventionally managed eyes (8.9% vs 15.2% unfavorable outcome; p<.001), with no greater risk of ocular complications.

The researchers in this study determined that early treatment for Type 1 high-risk pre-threshold eyes improved visual acuity outcomes at 6 years of age and that early treatment for Type 2 high-risk pre-threshold eyes did not. They advise that Type 1 eyes (not Type 2 eyes) be treated early. These results are particularly important considering that 52% of Type 2 high-risk pre-threshold eyes underwent regression of ROP without requiring treatment.

SOURCE: The Early Treatment for Retinopathy of Prematurity Cooperative Group. Final visual acuity results in the Early Treatment for Retinopathy of Prematurity Study. Arch Ophthalmol 2010;128(6):663-671.






  • QLT RELEASES RESULTS OF 24-MONTH PHASE II AMD STUDY. QLT Inc. recently announced final 24-month results from the Phase II Reduced Fluence Visudyn Anti-VEGF-Dexamethasone In Combination for AMD Lesions (RADICAL) study in patients with wet age-related macular degeneration (AMD). According to the company, the purpose of the study was to determine if Visudyne combined with Lucentis reduced retreatment rates compared with Lucentis monotherapy, while maintaining similar vision outcomes and an acceptable safety profile. Three Visudyne-Lucentis combination therapies were evaluated against Lucentis monotherapy and the results of the final 24-month analysis are consistent with the primary analysis results after 12-months of follow up. For example, the 24-month results showed that significantly fewer retreatment visits were required with combination therapies than with Lucentis monotherapy and mean visual acuity change from baseline was not statistically different among the treatment groups, although the sample sizes were insufficient to draw definitive conclusions regarding visual acuity outcomes. The full results of the 24-month final analysis of the study will be presented at the 28th Annual Meeting of the American Society of Retina Specialists in late August, but a summary of the study findings can be found here.
  • GANCICLOVIR FOR INJECTION SOON AVAILABLE IN U.S. APP Pharmaceuticals, Inc. has received approval from the FDA to market Ganciclovir for Injection, USP, which is therapeutically equivalent to the reference-listed drug Cytovene IV marketed by Roche Laboratories, Inc. Ganciclovir for Injection is an antiviral drug used in the treatment of cytomegalovirus (CMV) retinitis in immunocompromised patients, including patients with AIDS, as well as for the prevention of CMV disease in transplant recipients at risk for CMV disease. The company has plans to soon launch Ganciclovir for Injection and will package the product in single dose, 500 mg vials. APP Pharmaceuticals says the product is AP-rated, latex-free and bar-coded. Learn more here.
  • MULTIPLE-DOSE PHASE 2 CLINICAL TRIAL OF INO-8875 IN GLAUCOMA PATIENTS INITIATED BY INOTEK. In a recent press release, Inotek Pharmaceuticals Corp. announced that it has initiated dosing in a multiple-dose Phase 2 clinical trial to evaluate the efficacy and safety of its novel eye-drop INO-8875 in patients with glaucoma. INO-8875 was shown to significantly reduce IOP in glaucoma patients in an earlier Phase 1/2 single ocular dose clinical trial. INO-8875 is a highly selective adenosine-1 receptor agonist that reduces IOP by enhancing a natural mechanism for clearing protein material that clogs the trabecular meshwork as the eye with glaucoma ages. According to Inotek, the Phase 2 trial is a randomized, double-blind, placebo-controlled, dose-ranging study to evaluate the safety, tolerability, pharmacokinetics and efficacy of the eye drop formulation in patients with primary open-angle glaucoma or ocular hypertension. Click here for a more detailed description of the clinical trial protocol.
  • TOP PRIZE FOR FRENCH INNOVATIVE MEDICAL TECHNOLOGY COMPETITION GOES TO EYETECHCARE. EyeTechCare has won first prize in the 2010 Innovative Medical Technology competition organized by France's Alliance for Biological and Medical Engineering. EyeTechCare was awarded the prize for its development of the EyeOP1 medical device, which is a noninvasive treatment for glaucoma that is based on the use of high-intensity focused ultrasound (HIFUs). The company is currently developing noninvasive therapeutic medical devices for the ophthalmological market also based on the use of ultrasound. It anticipates EyeOP1 to be on the market no later than early 2011. Visit the company's web site for additional information.
  • AAO TASK FORCE CONTINUES EFFORTS TO AID HAITIAN OPHTHALMOLOGISTS. The American Academy of Ophthalmology's Task Force on Haiti Recovery, in cooperation with the Pan-American Association of Ophthalmology (PAAO), is coordinating donation and distribution of ophthalmic equipment and supplies to Haitian ophthalmologists, including several exam lanes, thousands of doses of pharmaceuticals, surgical supplies, educational materials and more. The Academy's Task Force on Haiti Recovery was created to respond to the urgent and ongoing need for quality eye care in Haiti and to coordinate ophthalmic recovery efforts. For more information, visit www.aao.org.