Philip Storey, MD, MPH
Vitreoretinal Surgery Fellow
Mid Atlantic Retina / Wills Eye Hospital
Susan Bressler evaluated whether baseline characteristics in the DRCR Protocol S affected outcomes in proliferative diabetic retinopathy (PDR) for patients receiving intravitreal ranibizumab versus pan retinal photocoagulation (PRP). In terms of visual impairment, no characteristic was associated with superiority of PRP over ranibizumab while a greater benefit of ranibizumab was found in patients with a higher mean arterial pressure and for eyes with high-risk PDR or without prior focal/grid laser. In terms of macular edema, a greater benefit of ranibizumab was found in non-white participants and in individuals with higher mean arterial pressure.
Jeffrey Gross presented the 5-year outcomes of Protocol S. Mean number of visits over the 5 years was 43 in the ranibizumab group and 21 in the PRP group. Mean number of injections was 19 in the ranibizumab group and 5 in the PRP group. At 2 years, visual acuity was significantly better in the ranibizumab group but was no different at 5 years with both groups gaining 3 letters compared to baseline visual acuity. Peripheral visual field was decreased in the PRP group by one year while the ranibizumab group showed no decrease in visual field. However, at year 3 the ranibizumab group began to show a decrease in peripheral field for unclear reasons.
Daniel Su presented outcomes for patients with proliferative diabetic retinopathy lost to follow-up who had received PRP versus anti-VEGF intravitreal injections. Dr. Su noted that recent randomized controlled trials have shown non-inferiority or even superiority of anti-VEGF compared to PRP for PDR. However, these trials had lost to follow up rates of 5-15%. Real world data has shown lost to follow-up of approximately 25%. Su et al. evaluated outcomes in patients who were initially treated with only anti-VEGF or only PRP who were then lost to follow-up for at least 6 months and returned for treatment. Visual and anatomical outcomes were found to be significantly worse in the anti-VEGF group with 1/3 of patients who only received anti-VEGF injections developing tractional retinal detachments.