PHOTOCOAGULATION VERSUS RANIBIZUMAB FOR PROLIFERATIVE DIABETIC RETINOPATHY: Should Baseline Characteristics Affect Choice of Treatment?

PURPOSE: Among eyes with proliferative diabetic retinopathy, identify whether baseline characteristics impact the benefit of ranibizumab over panretinal photocoagulation (PRP) in DRCR.net Protocol S. METHODS: Participants had proliferative diabetic retinopathy, visual acuity of 20/320 or better, and no previous PRP. Eyes were randomized to PRP or intravitreous 0.5-mg ranibizumab. RESULTS: Ranibizumab was superior to PRP for change in visual acuity and development of vision-impairing central-involved diabetic macular edema over 2 years (P < 0.001). Among 25 characteristics, there were none in which participants assigned to PRP had superior outcomes relative to ranibizumab-assigned participants. The relative benefit of ranibizumab over PRP for change in visual acuity seemed greater in participants with higher mean arterial pressure (P = 0.03), without previous focal/grid laser (P = 0.03), with neovascularization of the disk and elsewhere on clinical examination (P = 0.04), and with more advanced proliferative diabetic retinopathy on photographs (P = 0.02). For development of vision-impairing central-involved diabetic macular edema, the relative benefit of ranibizumab over PRP seemed greater among nonwhite participants (P = 0.01) and those with higher mean arterial pressure (P = 0.01). CONCLUSION: There were no characteristics identified in which outcomes were superior with PRP compared with ranibizumab. These exploratory analyses provide additional support that ranibizumab may be a reasonable alternative to PRP for proliferative diabetic retinopathy over a 2-year period.

Panretinal Photocoagulation Versus Ranibizumab for Proliferative Diabetic Retinopathy: Factors Associated with Vision and Edema Outcomes.

PURPOSE: To identify baseline factors associated with change in visual acuity or development of vision-impairing central-involved diabetic macular edema (DME) over 2 years when treating proliferative diabetic retinopathy (PDR) with ranibizumab or panretinal photocoagulation (PRP). DESIGN: Post hoc analyses of randomized, multicenter clinical trial data. PARTICIPANTS: Eyes completing the 2-year visit (n = 328) or without vision-impairing central-involved DME at baseline (n = 302) in Diabetic Retinopathy Clinical Research Network Protocol S. METHODS: Intravitreous ranibizumab (0.5 mg/0.05 ml) or PRP. MAIN OUTCOME MEASURES: Change in visual acuity (area under the curve) and development of vision-impairing (20/32 or worse) central-involved DME over 2 years. RESULTS: After multivariable model selection with adjustment for baseline visual acuity and central subfield thickness, no factors were identified as associated with change in visual acuity or development of vision-impairing central-involved DME within the ranibizumab group. In the PRP group, worse change in visual acuity was more likely with higher hemoglobin A1c level (-0.6 letters per 1% increase; 95% confidence interval [CI], -1.2 to -0.1 letters; continuous P = 0.03), more severe diabetic retinopathy (difference between high-risk PDR or worse vs. moderate PDR or better, -2.8 letters [95% CI, -5.5 to -0.2 letters]; continuous P = 0.003), and higher mean arterial pressure (difference between ≥100 mmHg vs. <100 mmHg, -2.0 letters [95% CI, -4.6 to 0.5 letters]; continuous P = 0.009). Development of vision-impairing central-involved DME was more likely with higher hemoglobin A1c level (hazard ratio [HR] per 1% increase, 1.31 [95% CI, 1.13-1.52]; continuous P < 0.001), more severe diabetic retinopathy (HR for high-risk PDR or worse vs. moderate PDR or better, 1.46 [95% CI, 0.73-2.92]; continuous P = 0.03), and the presence of cystoid abnormalities within 500 µm of the macula center (HR, 2.90 [95% CI, 1.35-6.24]; P = 0.006). CONCLUSIONS: For eyes managed with PRP, higher hemoglobin A1c level and more severe diabetic retinopathy were associated with less vision improvement and an increased risk of vision-impairing central-involved DME developing. When managing PDR with ranibizumab, eyes gained vision, on average, with no baseline characteristics identified as associated with visual acuity or central-involved DME outcomes.

Evaluation of visual acuity measurements after autorefraction vs manual refraction in eyes with and without diabetic macular edema.

OBJECTIVE: To compare visual acuity (VA) scores after autorefraction vs manual refraction in eyes of patients with diabetes mellitus and a wide range of VAs. METHODS: The letter score from the Electronic Visual Acuity (EVA) test from the electronic Early Treatment Diabetic Retinopathy Study was measured after autorefraction (AR-EVA score) and after manual refraction (MR-EVA score), which is the research protocol of the Diabetic Retinopathy Clinical Research Network. Testing order was randomized, study participants and VA examiners were masked to refraction source, and a second EVA test using an identical supplemental manual refraction (MR-EVAsuppl score) was performed to determine test-retest variability. RESULTS: In 878 eyes of 456 study participants, the median MR-EVA score was 74 (Snellen equivalent, approximately 20/32). The spherical equivalent was often similar for manual refraction and autorefraction (median difference, 0.00; 5th-95th percentile range, -1.75 to 1.13 diopters). However, on average, the MR-EVA scores were slightly better than the AR-EVA scores, across the entire VA range. Furthermore, the variability between the AR-EVA scores and the MR-EVA scores was substantially greater than the test-retest variability of the MR-EVA scores (P < .001). The variability of differences was highly dependent on the autorefractor model. CONCLUSIONS: Across a wide range of VAs at multiple sites using a variety of autorefractors, VA measurements tend to be worse with autorefraction than manual refraction. Differences between individual autorefractor models were identified. However, even among autorefractor models that compare most favorably with manual refraction, VA variability between autorefraction and manual refraction is higher than the test-retest variability of manual refraction. The results suggest that, with current instruments, autorefraction is not an acceptable substitute for manual refraction for most clinical trials with primary outcomes dependent on best-corrected VA.