Archive for May 2015

Genetic Testing for Age-Related Macular Degeneration Not Indicated Now

Age-related macular degeneration is a very common condition that is caused by a complex interplay of genetic and environmental factors. It is likely that, in the future, genetic testing will allow physicians to achieve better clinical outcomes by administering specific treatments to patients based on their genotypes. However, improved outcomes for genotyped patients have not yet been demonstrated in a prospective clinical trial, and as a result, the costs and risks of routine genetic testing currently outweigh the benefits for patients with age-related macular degeneration.

Full Paper: Genetic Testing for Age-Related Macular Degeneration Not Indicated Now
(197K PDF)

Page

Repeated Intravitreous Ranibizumab Injections for Diabetic Macular Edema and the Risk of Sustained Elevation of Intraocular Pressure or the Need for Ocular Hypotensive Treatment

Importance

For the management of retinal disease, the use of intravitreous injections of anti–vascular endothelial growth factor has increased. Recent reports have suggested that this therapymay cause sustained elevation of intraocular pressure (IOP) and may potentially increase the risk of glaucoma for patients with retinal disease. OBJECTIVE To assess the risk of sustained IOP elevation or the need for IOP-lowering treatments for eyes with diabetic macular edema following repeated intravitreous injections of ranibizumab.

Design, Setting, and Participants

An exploratory analysiswas conducted within a Diabetic Retinopathy Clinical Research Network randomized clinical trial. Study enrollment dates were from March 20, 2007, to December 17, 2008. Of 582 eyes (of 486 participants) with center-involved diabetic macular edema and no preexisting open-angle glaucoma, 260 were randomly assigned to receive a sham injection plus focal/grid laser treatment, and 322 were randomly assigned to receive ranibizumab plus deferred or prompt focal/grid laser treatment.

Main Outcomes and Measures

The cumulative probability of sustained IOP elevation, defined as IOP of at least 22mmHg and an increase of at least 6mmHg from baseline at 2 consecutive visits, or the initiation or augmentation of ocular hypotensive therapy, through 3 years of follow-up.

Results

The mean (SD) baseline IOP in both treatment groups was 16 (3)mmHg (range, 5-24mmHg). The cumulative probability of sustained IOP elevation or of initiation or augmentation of ocular hypotensive therapy by 3 years, after repeated ranibizumab injections, was 9.5%for the participants who received ranibizumab plus prompt or deferred focal/grid laser treatment vs 3.4%for the participants who received a sham injection plus focal/grid laser treatment (difference, 6.1%[99%CI, −0.2%to 12.3%]; hazard ratio, 2.9 [99% CI, 1.0-7.9]; P = .01). The distribution of IOP and the change in IOP from baseline at each visit through 3 years were similar in each group.

Conclusions and Relevance

In eyes with center-involved diabetic macular edema and no prior open-angle glaucoma, repeated intravitreous injections of ranibizumab may increase the risk of sustained IOP elevation or the need for ocular hypotensive treatment. Clinicians should be aware of this risk and should consider this information when following up with patients who have received intravitreous injections of anti–vascular endothelial growth factor for the treatment of diabetic macular edema.

Full Paper: Repeated Intravitreous Ranibizumab Injections
(231K PDF)

Page

The Effect of Light Deprivation in Patients With Stargardt Disease

AUTOSOMAL RECESSIVE STARGARDT DISEASE (STGD1) is the most common inherited juvenile macular degeneration.1 Most patients develop bilateral loss of vision in childhood or early adulthood. This subtype of Stargardt disease is caused by mutations in the ABCA4 gene, which encodes a retina-specific transporter protein (ABCR) in the rims of rod and cone photoreceptor outer segment discs.2–4 Retinal degeneration in ABCA4-linked Stargardt disease is believed to result from the toxic effects of lipofuscin that accumulates in the retinal pigment epithelium (RPE) and the subsequent degeneration of photoreceptors.5

Light can induce photochemical injury at the ocular fundus. Depending on the level and duration of the irradiance, the primary site of damage can be either the photoreceptors or the RPE.6 In ABCA4-linked retinopathies, products generated by the visual cycle accumulate and contribute to retinal damage via both direct toxic effects and increased photosensitivity. A major fluorophore of lipofuscin, bis-retinoid N-retinylidene-N-retinyl-ethanolamine (A2E), accumulates with other, currently unidentified lipofuscin constituents within the RPE.7–9 Thus, an excessive accumulation of A2E has been observed in both Abca4-/- mice and patients with Stargardt disease.5,10 Lipofuscins (and A2E in particular) are potent photosensitizers11–14 that can induce oxidative damage, thereby accelerating light-induced retinal damage and RPE atrophy.14–16 This oxidative damage may affect the rate of disease progression in patients with Stargardt disease…

Full Paper: The Effect of Light Deprivation in Patients With Stargardt Disease
(1.33M PDF)

Page