Outer Retinal Folds after Pars Plana Vitrectomy vs. Pneumatic Retinopexy for Retinal Detachment Repair Post hoc analysis from PIVOT

PURPOSE: To assess the incidence of postoperative outer retinal folds (ORFs) after pars plana vitrectomy (PPV) vs. pneumatic retinopexy (PnR) for rhegmatogenous retinal detachment (RRD) repair and to determine the association of ORFs with functional outcomes at 1 year. DESIGN: Randomized controlled trial. PARTICIPANTS: Patients with primary macula-off RRD meeting the Pneumatic Retinopexy versus Vitrectomy for the Management of Primary Rhegmatogenous Retinal Detachment Outcomes Randomized (PIVOT) trial criteria who were randomly assigned to undergo PPV or PnR. METHODS: Post hoc analysis of the PIVOT trial. The incidence and quantitative morphologic features of ORFs were assessed using en face and cross-sectional OCT at 1 month postoperatively by 2 masked graders. The ETDRS letter score was measured and quantitative assessment of metamorphopsia was performed at 1 year. MAIN OUTCOME MEASURES: Proportion of patients with ORFs at 1 month postoperatively among those who underwent PPV versus PnR. The secondary outcomes included the association of ORFs with visual acuity (ETDRS letter score) and metamorphopsia via metamorphopsia charts at 12 months postoperatively. RESULTS: Of 176 participants enrolled in PIVOT, 88 were macula-off RRDs. Of them, 94.3% (83 of 88) underwent postoperative OCT scans that were gradable at month 1, 93.2% (41 of 44) in the PPV group and 95.5% (42 of 44) in the PnR group. The incidence of ORF formation was 34.1% (14 of 41) in the PPV group and 14.3% (6 of 42) in the PnR group (P = 0.034). The ETDRS letter score at 1 year was 65.7 ± 6.6 letters in patients with ORFs vs. 75.1 ± 1.4 letters in those without ORFs (difference = 9.4 letters, 95% confidence interval [CI] = 7.5-11.3, P = 0.047). Among patients in the PPV group alone, the mean ETDRS letter score at 1 year in patients with ORFs was 62.8 ± 24.7 letters, compared with 75.4 ± 9.2 letters in patients without ORF formation (difference = 12.6 letters, 95% CI = 0.05-24.59, P = 0.04). Horizontal and vertical metamorphopsia scores were similar in patients with and without ORFs: horizontal, 0.35 ± 0.12 vs. 0.29 ± 0.07 (difference = 0.06, 95% CI = 0.01-0.11, P = 0.69); vertical, 0.25 ± 0.07 vs. 0.29 ± 0.07 (difference = 0.04, 95% CI = 0-0.08, P = 0.60). There was a negative correlation between the closest distance of an ORF from the fovea and vertical metamorphopsia score (r = -0.507, P = 0.045). CONCLUSIONS: There is greater risk of developing ORFs after PPV compared to PnR for primary RRD. Outer retinal folds at 1 month are associated with significantly worse ETDRS visual acuity letter scores at 1 year.