TOPOGRAPHIC OPTICAL COHERENCE TOMOGRAPHY SEGMENTATION SHOWS LIMITED ELLIPSOID ZONE RECOVERY IN MILD...

Optical coherence tomography (OCT) cross-sections have shown limited ellipsoid zone (EZ) improvement in mild hydroxychloroquine (HCQ) retinopathy within a few years after drug cessation. However, the extent, functional significance, and stability of such changes over time remain unclear.

We created en face EZ maps using automated pixel-by-pixel segmentation for four patients with early-moderate HCQ toxicity followed for 6-8 years after drug cessation. These maps were compared with OCT cross-sections, fundus autofluorescence, and automated 10-2 visual fields.

One patient had no EZ line loss; one had stable EZ loss throughout follow-up; two showed 30 to 40% reduction in the area of loss, largely in the first 2 years. This limited recovery mostly occurred in regions where the EZ line was only thinned or fragmented; other similar areas did not improve. Fundus autofluorescence hyperfluorescence and visual fields did not show consistent correlation with topography.

Anatomic EZ recovery, when present, was restricted to regions of mild damage and did not correlate with fundus autofluorescence or improvement in visual fields. Topographic mapping seemed no more sensitive locally than cross-sectional OCT but may aid detection and longitudinal follow-up of toxicity by showing early damage or changes in the macula that could be missed with individual cross-sections.