Flat irregular pigment epithelial detachment over time and outcome of different treatment regimens.

To present long-term visual and structural outcome of treatment in two forms of flat irregular pigment epithelial detachment (FIPED): avascular (aFIPED) and vascularized (vFIPED) in eyes within pachychoroid spectrum. Prospective interventional case series. FIPED were classified into two subgroups; aFIPED and vFIPED based on OCTA. aFIPED underwent PDT, and vFIPED underwent either PDT, IVB, or combination of PDT&IVB. Vision, subretinal or intraretinal fluid, and choroidal biomarkers such as choroidal thickness, area, choroidal vascular index (CVI), and PED area were measured at baseline and last follow-up. Fifteen eyes with aFIPED were followed for a mean of 14.7 ± 10.8 months. Their vision improved, (0.44 ± 0.37-0.33 ± 0.40 LogMAR, p = 0.009) with significant reduction of fluid, choroidal area, thickness, PED area and increase in CVI. Twenty eyes with vFIPED were followed for a mean of 16.5 ± 8.2 months. The same pattern of choroidal alterations without visual improvement was observed in eyes underwent PDT alone. Combination therapy resulted in improvement of vision (0.38 ± 0.10-0.23 ± 0.17 LogMAR, p = 0.006) with reduction of choroidal area and thickness, with an increase in CVI. IVB alone could not change vision or choroidal structure. Single session PDT may lead to sustained visual improvement and structural change in eyes with aFIPED. Combination of PDT and IVB may be a better choice in eyes with vFIPED.