Author: Aditya Bansal (Canada)
Co-authors: Wei Wei Lee, David Sarraf, Srinivas Sadda, David T. Wong, Roxane J. Hillier, Rajeev H. Muni
To assess the incidence of post-operative persistent subretinal fluid (PSRF) in pneumatic retinopexy (PnR) vs pars plana vitrectomy (PPV) with en face and cross-sectional spectral-domain optical coherence tomography (SD-OCT) following rhegmatogenous retinal detachment (RRD) repair and to determine the association of persistent subfoveal fluid (PSFF) with functional outcomes.
This is a post hoc analysis of the PIVOT randomized trial at St Michael's Hospital/Unity Health Toronto, Toronto, Canada. The trial was registered at ClinicalTrials.gov (identifier, NCT01639209). This study was approved by the Research Ethics Board at St. Michael’s Hospital/Unity Health Toronto in Toronto, Canada, and adhered to the Declaration of Helsinki.
Eyes with gradable en face and cross-sectional SD-OCT at 1-month postoperatively were included in the study. Two masked graders assessed the images, and any disagreement was adjudicated by a third senior masked grader. The primary outcome was the proportion of patients with PSRF following PnR versus PPV at 1-month postoperatively. Secondary outcomes included the association of PSFF with functional outcomes (ETDRS letter score & quantitative metamorphopsia score with MCHARTs).
92.04% (81/88) in PnR and 87.5% (77/88) in PPV group had gradable month 1 post-operative OCT scans. Baseline characteristics were similar between groups. Intergrader agreement (Cohen’s Kappa) for PSFF and PSRF were 0.870 and 0.905, respectively. The incidence of PSRF was 30.9% (25/81) in the PnR group and 24.7% (19/77) in the PPV group (p=0.386; OR=1.36, 95% CI 0.68-2.75). Similarly, proportion of eyes with PSFF was 16% (13/81) following PnR and 10.4% (8/77) after PPV (p = 0.295; OR=1.65, 95% CI 0.64-4.23). PSFF gradually resolved over time with no significant difference between groups at any time point. The median ETDRS letter score at 3 months postoperatively between eyes with and without PSFF was 65 (IQR=26) and 78 (IQR=14), respectively (difference=13 letters, p=0.037). At 6 and 12 months postoperatively this difference was 6 letters, (p=0.478) & 1.5 letters, (p=0.37), respectively. The median metamorphopsia scores in patients with vs without PSFF was, horizontal: 0.2 (IQR=0.5) versus 0 (IQR=0.2) (difference=0.2, p=0.228) and vertical: 0.3 (IQR=0.5) versus 0 (IQR=0.3) (difference=0.3, p=0.148) respectively
The proportion of eyes with PSRF was similar in PnR and PPV. Eyes with PSFF had delayed visual recovery, although there was no significant impact on functional outcomes at one year.