Presumed Natural History of Combined Hamartoma of the Retina and Retinal Pigment Epithelium

Purpose: To correlate structural changes of combined hamartoma of the retina and retinal pigment epithelium (CHRRPE) with patient age. Design: Retrospective study. Participants: Fifty eyes of 49 patients (age range, 1–74 years) with CHRRPE studied at 9 tertiary vitreoretinal institutions. Methods: We analyzed the clinical findings with respect to lesion topography and pigmentation as well as investigated the OCT findings regarding the thickness, vitreoretinal interface, outer plexiform layer distortion, ellipsoid zone disruption, and retinal pigment epithelium–Bruch's membrane complex involvement of CHRRPE. Main Outcome Measures: Clinical and imaging findings of CHRRPE at different ages. Results: Analysis of 50 CHRRPE patients revealed that younger patients were more likely to demonstrate partial thickness involvement of the retina (P = 0.009) with predominantly inner retinal layer involvement (P = 0.04). The inverse was true for older patients with CHRRPE. In addition, older patients more commonly showed pigmentary changes. Eyes with CHRRPE were more likely to show an increase in central macular thickness independently of tumor location. Conclusions: Based on these findings, we believe that CHRRPE typically begins in the inner retina and continues toward the outer retina over time, with increase in central macular thickness, despite the location of the tumor.