Clinical Trials in Surgical Retina
Protocols AG and AH 2021
Chan CK, Mein CE, Glassman AR, Beaulieu WT, Calhoun CT, Jaffe GJ, Jampol LM, MacCumber MW, Maguire MG, Maturi RK, Salehi-Had H, Rofagha S, Sun JK, Martin DF; DRCR Retina Network. Pneumatic Vitreolysis with Perfluoropropane for Vitreomacular Traction with and without Macular Hole: DRCR Retina Network Protocols AG and AH. Ophthalmology. 2021 May 12:S0161-6420(21)00353-5. doi: 10.1016/j.ophtha.2021.05.005. Epub ahead of print. PMID: 33989683.
The goal was to determine the effect of pneumatic vitreolysis (PVL) in eyes with vitreomacular traction (VMT) with and without full-thickness macular holes (FTMH).
Randomized clinical trial compared PVL with C3F8 gas to observation (sham injection) for VMT without FTMH (Protocol AG) and a single-arm study assessing PVL for FTMH (Protocol AH). Participants were adults with central VMT (vitreomacular adhesion was ≤3000 μm). In Protocol AG, VA was 20/32 to 20/400. In Protocol AH, eyes had a FTMH (≤250 μm at the narrowest point) and VA of 20/25 to 20/400.
Main Outcome Measures
Central VMT release at 24 weeks (Protocol AG) and FTMH closure at 8 weeks (Protocol AH).
The study had to be canceled for safety concerns; then, sample sizes were not met because of early termination. The original sample size calculations were based on anatomic, not visual, outcomes; thus, the power to detect modest differences between treatment groups were relatively low. The follow-up ended after 24 weeks, so data on long-term outcomes are unavailable.
From 2018 to 2020, participants were enrolled in Protocol AG 46, and in Protocol AH, 35. The studies had to be terminated for safety concerns for the high number of retinal detachments (10%) and tears (1.6%). In Protocol AG at 24 weeks, the central VMT release was 78% in the PVL group and 9% in the sham group; the mean change in VA from baseline was 6.7 letters in the PVL group and 6.1 letters in the sham group. In Protocol AH at 8 weeks, the FTMH closure was 29% in the PVL group and, the mean change in VA from baseline was –1.5 letters.
PVL induced hyaloid release solving most of the cases of VMT and one-third of the FTMH. However, the studies were terminated early because of safety concerns related to retinal detachments.
Pearls for clinical practice
PVL for VMT and FTMH carries a high risk of complications.