Retinal pigment epithelium defects, sealed and unsealed: a lifecycle and disease agnostic terminology

PURPOSE: To describe two recurrent phenotypes of retinal pigment epithelium (RPE) defects, sealed and unsealed, which may occur in various diseases. METHODS: Medical records and multimodal imaging of 17 patients (70.3 ± 9.3 years) with RPE defects, including RPE apertures, RPE detachment (RPED) devoid of RPE, and serous maculopathy with the absence of RPE (SMARPE), were retrospectively analyzed. Proposed pathogenic mechanisms are presented, revising current terminology. RESULTS: Eyes with RPE apertures (12/17, 70.6%) and SMARPE (1/17, 5.9%) presented RPE defects connecting the subretinal and sub-RPE spaces with subretinal fluid (SRF) and intact outer retina. These features are consistent with patent RPE defects, termed 'unsealed'. RPED devoid of RPE defects developed in ¾ eyes (75%) over a serous PED without collapse. The lesions occurred beneath a degenerated outer retina that adheres to the RPE defect without SRF, supporting the term 'sealed'. CONCLUSIONS: RPE defects beneath a disrupted photoreceptor layer may become "sealed" by reactive Müller cell gliosis, preventing the occurrence of SRF. RPE defects with intact photoreceptors remain "unsealed", resulting in SRF accumulation. We propose "sealed" and "unsealed" as disease agnostic terms, which can be used for cases previously described as "RPE aperture," "SMARPE," and "RPED devoid of RPE".