Case series: pachychoroid pigment epitheliopathy transformed to polypoidal choroidal vasculopathy after long-term follow-up

Background Pachychoroid pigment epitheliopathy (PPE), a retinal disorder that falls into the pachychoroid spectrum, is characterized by retinal pigment epithelium changes in pachychoroid eyes without existing or previous subretinal fluid or soft drusen. Previous reports have indicated that PPE may share some pathophysiologic component with other pachychoroid spectrum diseases and could transform into central serous chorioretinopathy (CSC) during follow-up. CSC transformation to PNV and PCV has also been reported, but PPE transformation to PCV has not been reported. Case presentation Seven eyes of seven patients (four male three female, aged 62.7 [+ or -] 8.4 years) who presented with PPE at baseline transformed to PCV during follow-up. All study eyes had baseline contralateral eye diagnoses of PCV. All PPE eyes reported no symptoms at baseline and were followed up regularly for the treatment of their contralateral eyes. All PPE presented as pigment epithelium detachment (PED) at baseline. The mean central macular thickness (CMT) was 217.6 [+ or -] 14.6 [micro]m, the mean subfoveal choroidal thickness (SFCT) was 354.9 [+ or -] 94.9 [micro]m, and the mean sub-PPE choroidal thickness was 332.3 [+ or -] 84.6 [micro]m. The mean PPE width and height were 1326.4 [+ or -] 791.4 [micro]m and 58.7 [+ or -] 23.6 [micro]m, respectively, at baseline. Disruption of the ellipsoid zone (EZ) was noted in 3 eyes, while choroidal vascular hyperpermeability (CVH) was noted in 5 eyes at baseline. The follow-up period was 75.0 [+ or -] 41.1 months, and the mean transformation time was 49.6 [+ or -] 24.8 months. All study eyes received no intervention before transformation. Conclusions PPE could transform to PCV after a long follow-up period. Regular follow-ups for a long time should be recommended for patients with PPE. Keywords: Pachychoroid, Pachychoroid pigment epitheliopathy, Polypoidal choroidal vasculopathy, Pachychoroid spectrum diseases