SUBRETINAL PIGMENT EPITHELIUM OPTICALLY EMPTY STRUCTURES IN POLYPOIDAL CHOROIDAL VASCULOPATHY: A Novel Optical Coherence Tomography Finding.

Abstract

Purpose: To describe the appearance of a novel optical coherence tomography (OCT) feature in polypoidal choroidal vasculopathy and report its prevalence in a clinical cohort.

Methods: We retrospectively analyzed the OCT and indocyanine green angiography images of eyes with polypoidal choroidal vasculopathy. Main outcome measures included the appearance, prevalence, and longitudinal changes of "optically empty subretinal pigment epithelium (RPE) structures" on OCT and correlate them with indocyanine green angiography and OCT angiography.

Results: We evaluated OCT of 55 patients. Each patient had monthly OCT from baseline to month 12. Presence of sub-RPE optically empty structures at any visit was detected in 10 eyes (7 at baseline, three during follow-up). These lesions are located under the RPE and are characterized by homogenously hyporeflective content similar to the vitreous cavity, which appear optically empty. Additional features include hypertransmission tail into choroid, round/polygonal in shape surrounded by thin wall and fuzzy overlying RPE. When compared with indocyanine green angiography, these structures can be colocalized to the area of pooling associated with polypoidal lesions but can persist after polyp regression. No flow signal was detected within the center of these optically empty structures.

Conclusion: Sub-RPE optically empty structures likely represent spaces not filled with blood and are distinct from the lumen of a polypoidal lesion.