Abstract
Purpose :
Retinal displacement leads to worse functional outcomes following rhegmatogenous retinal detachment (RRD) repair. Although fundus autofluorescence (FAF) imaging can detect retinal displacement, there is a concern regarding its sensitivity & specificity. This study compares the accuracy with which FAF detects the presence and extent of retinal displacement.
Methods :
A retrospective study of all patients with infrared (IR) images available before the occurrence of RRD and after RRD repair. At least 4 corresponding RPE and choroidal landmarks were marked on pre-RRD & post-RRD IR images extracted from the Heidelberg optical coherence tomography (OCT) software. Overlay of IR images based on the marked landmarks utilized a computer code in Python to compute the homography and then align the two images. The same procedure was carried out in the contralateral normal eyes to validate the technique. Two masked graders analyzed both the post-operative FAF and the IR overlay images to detect the presence and extent of retinal displacement.
Results :
14 eyes had both a pre-RRD & post-RRD repair OCT and a post-RRD FAF. In 8 patients, the contralateral eye had no other pathology or history of RRD. Homography was able to perfectly align the contralateral eye IR images in 100% (8/8) of cases (Fig 1). Retinal displacement was detected in 64.3% (9/14) of FAF images and in 92.8% (13/14) of IR overlay images respectively. The extent of retinal displacement was far greater as observed on the IR overlay images with a mean number of displaced vessels of 1.1 ± 0.88 in the FAF group and 2.9 ± 1.05 in the IR overlay group (p=0.00004). Qualitatively, the IR overlay method was superior at demonstrating both the presence and extent of retinal displacement compared to FAF (Fig 2). The IR overlay showed more extensive displacement in 92.8% (13/14) of cases.
Conclusions :
FAF does not demonstrate the full extent of retinal displacement that is present and reveals only the “tip of the iceberg”. When available, overlay of pre-RRD & post-RRD repair IR images generated by OCT provides a better assessment of retinal displacement.
This abstract was presented at the 2022 ARVO Annual Meeting, held in Denver, CO, May 1-4, 2022, and virtually.