OPTICAL COHERENCE TOMOGRAPHY ANGIOGRAPHY MORPHOLOGY AFTER RHEGMATOGENOUS RETINAL DETACHMENT REPAIR: ALIGN Post Hoc Analysis.

PURPOSE: To compare foveal avascular zone (FAZ) geometric indices using optical coherence tomography angiography (OCTA) in pneumatic retinopexy (PnR) versus pars plana vitrectomy (PPV) for rhegmatogenous retinal detachment (RRD). FAZ morphology was assessed as a possible imaging feature of retinal displacement. METHODS: This ALIGN post hoc analysis included primary fovea-off RRDs that underwent successful PnR or PPV, and performed OCTA, and fundus autofluorescence at (FAF) 3 months postoperatively at St. Michael's Hospital, Toronto, Canada. FAZ area (mm 2 ), axial ratio, circularity, and roundness were measured, and FAF images were assessed for retinal displacement. RESULTS: Seventy-two patients were included, 78% (56/72) were male mean age was 60 ± 9 years, and 60% (43/72) were phakic. Sixty-five percent (47/72) and 35% (25/72) underwent PnR and PPV, respectively. The mean baseline logarithm of the minimum angle of resolution visual acuity was 1.49 ± 0.76. FAZ circularity was lower after PPV (0.629 ± 0.120) versus PnR (0.703 ± 0.122); P = 0.016. Sixty-six patients had gradable FAF images. Retinal displacement was present in 29% (19/66), 84.2% (16/19) of which had displacement in the macula. FAZ circularity was lower in eyes with displacement in the macula (0.613 ± 0.110) versus those without displacement (0.700 ± 0.124); P = 0.015. There was a moderate negative correlation between 12-month aniseikonia and FAZ circularity(r = -0.262; P = 0.041). CONCLUSION: FAZ circularity was lower after PPV and in eyes with retinal displacement in the macula. Circularity was negatively correlated with 12-month aniseikonia scores. FAZ circularity may be another imaging feature to consider postoperatively after RRD repair.

A Novel Method of Quantifying Retinal Displacement Using Ultra-Widefield Fundus Autofluorescence Imaging.

PURPOSE: To introduce a novel method of quantifying retinal displacement in three dimensions (3D) using ultra-widefield fundus autofluorescence (UWF-FAF). DESIGN: Prospective clinical cohort study. METHODS: Patients with primary macula-off rhegmatogenous retinal detachment (RRD) treated with pneumatic retinopexy (PnR) or vitrectomy were included. Masked graders selected corresponding points on retinal vasculature and retinal vessel printings (RVPs) within Zone 1, a circular region centered on the fovea with a radius extending to the optic disc (OD) center. Two-dimensional (2D) UWF-FAF was projected to 3D using OD and foveal coordinates. Vertical, horizontal, and diagonal distances between corresponding vessel and RVPs were calculated. Vector displacement of the RVPs to vessels were averaged. RESULTS: A total of 170 retinal vessel-RVP pairs were identified from 54 UWF-FAF images. Mean displacement in Zone 1 was 0.36 ± 0.38 mm, with an absolute mean angle of displacement of 94.93 ± 41.48° and directionality of 191.84 ± 97.39°. Mean Zone 1 displacement was 0.44 ± 0.42mm and 0.21 ± 0.27 mm in vitrectomy (n = 35) and PnR (n = 19) eyes, respectively (P = .041), with no differences in mean angle of displacement/directionality. CONCLUSIONS: A novel method of quantifying the magnitude and direction of retinal displacement is presented, accounting for the spherical 3D curvature of the eye by using corresponding points on retinal vessels and RVPs using UWF-FAF. This provides a 3D vector of displacement agnostic of a singular fixation point such as the optic disc. Accurately quantifying the magnitude and angle/direction of displacement may allow for a better understanding of the mechanisms involved in retinal displacement in various surgical techniques, and a better assessment of the association with functional outcomes.