Using either intravitreal aflibercept or vitrectomy with panretinal photocoagulation to treat eyes with vitreous hemorrhage from proliferative diabetic retinopathy (PDR) seemed to show no statistically significant difference in primary outcome of mean visual acuity letter score over 24 weeks after initial treatment, but the study where these results came from might be underpowered, researchers say.
The study results, published in JAMA, were culled from randomized clinical trials performed in 39 Diabetic Retinopathy Clinical Research (DRCR) Network sites around the United States and Canada. Researchers examined the treatment options for vitreous hemorrhage from PDR, which can cause visual loss. The study included 205 adult patients with vision loss from PDR, enrolled from November 2016 to December 2017, with final follow-up visit in January 2020.
A single eye per participant was randomly assigned to receive either 4 monthly injections of aflibercept anti-vascular endothelial growth factor (VEGF) (100 participants), or vitrectomy with panretinal photocoagulation (PRP) (105 participants). Patients in either group could have aflibercept or vitrectomy in the follow-up period, based on protocol criteria. Primary outcome was mean visual acuity letter score (range, 0-100; higher scores indicate better vision) spanning 24 weeks (area under the curve), and detecting a difference of 8 letters. The secondary outcomes included mean visual acuity at 4 weeks and 2 years. All participants completed the 24-week visit, while 90% (177 of 196, excluding 9 deaths) completed the 2-year visit.
They found that mean visual acuity letter score in the 24 weeks was 59.3 (Snellen equivalent, 20/63) in the aflibercept group and 63.0 (Snellen equivalent, 20/63) in the vitrectomy group (adjusted difference, −5.0, P =.06). In the 23 secondary outcomes, 15 showed no significant difference. Mean visual acuity letter score was 52.6 (Snellen equivalent, 20/100) in the aflibercept group and 62.3 (Snellen equivalent, 20/63) in the vitrectomy group at 4 weeks (adjusted difference, −11.2, P =.003) and 73.7 (Snellen equivalent, 20/40) vs 71.0 (Snellen equivalent, 20/40) at 2 years (adjusted difference, 2.7, P =.36).
In the course of the 2 years, 33 eyes (33%) assigned to aflibercept received vitrectomy and 34 eyes (32%) assigned to vitrectomy were on subsequent aflibercept.
“In this multicenter randomized clinical trial among participants whose eyes had vitreous hemorrhage from proliferative diabetic retinopathy, there was no statistically significant difference in the primary outcome of mean visual acuity letter score over 24 weeks between eyes initially treated with intravitreal aflibercept injections vs those treated with vitrectomy with panretinal photocoagulation, but the 95%CI was wide, and the study may have been underpowered to detect a clinically important benefit in favor of initial vitrectomy with panretinal photocoagulation,” they write.
The study was limited in that, while overall retention in the study was good, it was lower in the vitrectomy group (85% vs 96%, respectively), which might bias comparisons of that time point if loss was connected to treatment efficacy. Additionally, investigators and the participants weren’t masked to treatment because of the nature of these treatments. Also, aflibercept was the only anti-VEGF agent used. Finally, the study didn’t address the long-term effects of treatments.
Antoszyk AN, Glassman AR, Beaulieu WT, et al. Effect of intravitreous aflibercept vs vitrectomy with panretinal photocoagulation on visual acuity in patients with vitreous hemorrhage from proliferative diabetic retinopathy. JAMA. 2020;324(23):2383-2395. doi:10.1001/jama.2020.23027.