Presumed Natural History of Combined Hamartoma of the Retina and Retinal Pigment Epithelium (CHRRPE).

Abstract Purpose To correlate structural changes of combined hamartoma of the retina and retinal pigment epithelium (CHRRPE) with patient age. Design Retrospective study. Subjects There were 50 eyes of 49 patients (age range 1-74 years) with CHRRPE studied at nine tertiary vitreoretinal institutions. Methods We analyzed the clinical findings with respect to lesion topography and pigmentation as well as investigated the optical coherence tomography (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 outcomes Clinical and imaging findings of CHRRPE at different ages. Results Analysis of 50 CHRRPE revealed younger patients were more likely to have 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 have an increase in central macular thickness independently of tumor location. Conclusion Based on these findings, we believe that CHRRPE typically begins in the inner retina and continues towards the outer retina over time, with increase in central macular thickness, despite the location of the tumor.