Mutations in the RPE65 gene in patients with autosomal recessive retinitis pigmentosa or Leber congenital amaurosisHiroyuki Morimura, Gerald A. Fishman, Sandeep Grover et al.|Proceedings of the National Academy of Sciences|1998 RPE65 is a protein of unknown function expressed specifically by the retinal pigment epithelium. We examined all 14 exons of this gene in 147 unrelated patients with autosomal recessive retinitis pigmentosa (RP), in 15 patients with isolate RP, and in 45 patients with Leber congenital amaurosis (LCA). Sequence anomalies that were likely to be pathogenic were found in two patients with recessive RP, in one patient with isolate RP recategorized as recessive, and in seven patients with LCA. Cosegregation analysis in each available family showed that all affected individuals were either homozygotes or compound heterozygotes and that all unaffected individuals were either heterozygote carriers or homozygous wild type. In one family, there was one instance of a new mutation not present in either parent of the affected individual. In another family, affected members with recessive RP in three branches (i.e., three distinct pairs of parents) were compound heterozygotes for the same two mutations or homozygous for one of them. Based on our results, mutations in the RPE65 gene appear to account for approximately 2% of cases of recessive RP and approximately 16% of cases of LCA.
Effect of Initial Management With Aflibercept vs Laser Photocoagulation vs Observation on Vision Loss Among Patients With Diabetic Macular Edema Involving the Center of the Macula and Good Visual AcuityImportance: Intravitreous injections of antivascular endothelial growth factor agents are effective for treating diabetic macular edema (DME) involving the center of the macula (center-involved DME [CI-DME]) with visual acuity impairment (20/32 or worse). The best approach to treating patients with CI-DME and good visual acuity (20/25 or better) is unknown. Objective: To compare vision loss at 2 years among eyes initially managed with aflibercept, laser photocoagulation, or observation. Design, Setting, and Participants: Randomized clinical trial conducted at 91 US and Canadian sites among 702 adults with type 1 or type 2 diabetes. Participants had 1 study eye with CI-DME and visual acuity of 20/25 or better. The first participant was randomized on November 8, 2013, and the final date of follow-up was September 11, 2018. Interventions: Eyes were randomly assigned to 2.0 mg of intravitreous aflibercept (n = 226) as frequently as every 4 weeks, focal/grid laser photocoagulation (n = 240), or observation (n = 236). Aflibercept was required for eyes in the laser photocoagulation or observation groups that had decreased visual acuity from baseline by at least 10 letters (≥ 2 lines on an eye chart) at any visit or by 5 to 9 letters (1-2 lines) at 2 consecutive visits. Main Outcomes and Measures: The primary outcome was at least a 5-letter visual acuity decrease from baseline at 2 years. Antiplatelet Trialists' Collaboration adverse events (defined as myocardial infarction, stroke, or vascular or unknown death) were reported. Results: Among 702 randomized participants (mean age, 59 years; 38% female [n=264]), 625 of 681 (92% excluding deaths) completed the 2-year visit. For eyes with visual acuity that decreased from baseline, aflibercept was initiated in 25% (60/240) and 34% (80/236) in the laser photocoagulation and observation groups, respectively. At 2 years, the percentage of eyes with at least a 5-letter visual acuity decrease was 16% (33/205), 17% (36/212), and 19% (39/208) in the aflibercept, laser photocoagulation, and observation groups, respectively (aflibercept vs laser photocoagulation risk difference, -2% [95% CI, -9% to 5%]; relative risk, 0.88 [95% CI, 0.57-1.35; P = .79]; aflibercept vs observation risk difference, -3% [95% CI, -11% to 4%]; relative risk, 0.83 [95% CI, 0.55-1.27; P = .79]; laser photocoagulation vs observation risk difference, -1% [95% CI, -9% to 6%]; relative risk, 0.95 [95% CI, 0.64-1.41; P = .79]). Antiplatelet Trialists' Collaboration vascular events occurred in 15 (7%), 13 (5%), and 8 (3%) participants in the aflibercept, laser photocoagulation, and observation groups. Conclusions and Relevance: Among eyes with CI-DME and good visual acuity, there was no significant difference in vision loss at 2 years whether eyes were initially managed with aflibercept or with laser photocoagulation or observation and given aflibercept only if visual acuity worsened. Observation without treatment unless visual acuity worsens may be a reasonable strategy for CI-DME. Trial Registration: ClinicalTrials.gov Identifier: NCT01909791.
Retinal Thickness in People with Diabetes and Minimal or No Diabetic Retinopathy: Heidelberg Spectralis Optical Coherence TomographyKakarla V Chalam, Susan B. Bressler, Allison R. Edwards et al.|Investigative Ophthalmology & Visual Science|2012 PURPOSE: To evaluate macular thickness in people with diabetes but minimal or no retinopathy using Heidelberg Spectralis optical coherence tomography (OCT). METHODS: In a multicenter, cross-sectional study of mean retinal thickness, on Spectralis OCT in the nine standard OCT subfields, spanning a zone with 6-mm diameter, center point, and total retinal volume were evaluated. Central subfield (CSF) thickness was evaluated for association with demographic and clinical factors. Stratus OCT scans also were performed on each participant. RESULTS: The analysis included 122 eyes (122 participants) with diabetes and no (n = 103) or minimal diabetic retinopathy (n = 19) and no macular retinal thickening on clinical exam. Average CSF thickness was 270 ± 24 μm. Central subfield thickness was significantly greater in males relative to females (mean 278 ± 23 μm vs. 262 ± 22 μm, P < 0.001). After adjusting for gender, no additional factors were found to be significantly associated with CSF thickness (P > 0.10). Mean Stratus OCT CSF thickness was 199 ± 24 μm. CONCLUSIONS: Mean CSF thickness is approximately 70 μm thicker when measured with Heidelberg Spectralis OCT as compared with Stratus OCT among individuals with diabetes in the absence of retinopathy or with minimal nonproliferative retinopathy and a normal macular architecture. CSF thickness values ≥ 320 μm for males and 305 μm for females (~2 SDs above the average for this normative cohort) are proposed as gender-specific thickness levels to have reasonable certainty that diabetic macular edema involving the CSF is present using Spectralis measurements.