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Updated: Apr 5, 2026
Retinal Pigment Epithelium Transplantation in a Non-human Primate Model for Degenerative Retinal Diseases
Published on: June 14, 2021
Unilateral Retinal Pigment Epithelium Dysgenesis-The Expanded Spectrum and New Insights From Multimodal Imaging
Andrea Trinco1, Francesco Romano2, Martina Matteucci3
1From the Eye Clinic (A.T., F.R., C.O., M.C., A.I., G.S., M.P.), Department of Biomedical and Clinical Sciences, Ospedale Luigi Sacco, University of Milan, Milan, Italy.
Purpose:
To describe the clinical spectrum, novel imaging features, and associations of unilateral retinal pigment epithelium dysgenesis (URPED), expanding its phenotypic and pathogenetic framework.
Design:
Retrospective, longitudinal, multicenter case series.
Subjects:
Ten eyes of ten patients with URPED and two eyes with combined hamartoma of the retina and retinal pigment epithelium (RPE) exhibiting URPED-like changes, examined between 2011 and 2025 at Luigi Sacco Hospital (Milan, Italy) and Macquarie University Hospital (Sydney, Australia).
Methods:
Comprehensive multimodal imaging was performed, including color fundus photography, near-infrared reflectance, short-wavelength fundus autofluorescence (SW-FAF), fluorescein and indocyanine green angiography (FA/ICGA), and spectral-domain optical coherence tomography (SD-OCT). Lesions were classified as overt, when diagnosis was achievable on noninvasive imaging alone, or covert, when ICGA was required. Near-infrared reflectance, SW-FAF, FA, and ICGA patterns were correlated with structural OCT findings. Lesion area was manually measured at baseline on SW-FAF and ICGA, and at last follow-up on SW-FAF.
Main Outcome Measures:
URPED phenotypic patterns; multimodal imaging characteristics; frequency of associated hamartomatous lesions and other complications.
Results:
Seven eyes (70%) were classified as overt URPED, displaying scalloped (n = 4), mottled (n = 1), or mixed (n = 2) SW-FAF patterns; three eyes (30%) were categorized as covert URPED, detectable only on ICGA. The classic inverted SW-FAF/FA pattern occurred exclusively in overt scalloped or mixed lesions. SD-OCT consistently demonstrated Bruch membrane-RPE separation with overlying "sawtooth" changes (10/10, 100%). Evidence of iRORA/cRORA was present in six eyes (60%), and choroidal caverns in six eyes (60%). Hamartomatous lesions were identified in four eyes (40%), three retinal capillary hemangiomas, and one choroidal osteoma; all topographically colocalizing with URPED. Choroidal neovascularization developed in four eyes (40%), all responding favorably to anti-VEGF therapy. Lesion size remained largely stable over a median follow-up of 27.5 months, with excellent intergrader reproducibility (intraclass correlation coefficient = 0.98-0.99).
Conclusions:
URPED encompasses a broader phenotypic continuum than previously recognized, ranging from overt to covert forms unified by Bruch membrane-RPE dysgenesis. The frequent coexistence with hamartomatous lesions supports a shared developmental origin. Multimodal imaging is essential for diagnosis and phenotypic classification, with ICGA playing a pivotal role in detecting covert forms.
