Aims: To investigate conversion of pachychoroid pigment epitheliopathy (PPE) lesions and the development of other pachychoroid spectrum diseases in patients with PPE during follow-up.
Methods: We retrospectively reviewed medical records of 46 eyes of 44 patients who had a diagnosis of PPE and were followed up for at least 3 years.
Results: Eyes with PPE (17.4%) developed central serous chorioretinopathy (CSC), and none developed pachychoroid neovasculopathy or polypoidal choroidal vasculopathy. Of 74 initial PPE lesions, 21.6% were retinal pigment epithelium (RPE) thickening, 36.5% were pigment epithelium detachment (PED), and 41.9% were RPE elevation with microbreak appearance (REwM). Five (62.5%) of the eight initial PPE lesions progressing to CSC were REwM. Two developed directly from the REwM and three REwMs transformed to PED first, and then progressed to CSC. Three initial PEDs progressed to CSC. REwMs can also transform to PED and RPE thickening. No initial PEDs or RPE thickenings transformed to a REwM. Of the new PPE lesions, 60% were REwM, 26.7% were PEDs, and 13.3% were RPE thickening.
Conclusion: The smallest PPE lesion that can be detected is a REwM of RPE. It may be the precursor lesion for pachychoroid spectrum disease, but further large-scale prospective studies are required.
Keywords: Central serous chorioretinopathy; Choroidal hyperpermeability; Microbreak; Pachychoroid neovasculopathy; Pachychoroid pigment epitheliopathy; Polypoidal choroidal vasculopathy.