Combined Hamartoma of the Retina and Retinal Pigment Epithelium: An Optical Coherence Tomography-Based Reappraisal.

Purpose: To analyze the optical coherence tomography (OCT) characteristics of combined hamartoma of the retina and retinal pigment epithelium (CHRRPE) involving the macula.

Design: Retrospective, observational case series.

Methods: setting: Single institutional.

Study Population: Fourteen consecutive patients of CHRRPE were included.

Observation Procedures: The authors analyzed the clinical features, color fundus photography, and swept-source or spectral-domain OCT of all the involved eyes.

Main Outcome Measures: OCT characteristics, especially the involvement of the retinal pigment epithelium (RPE).

Results: A total of 16 eyes of 5 female and 9 male patients were analyzed. The mean age (± SD) was 17.9 ± 6.4 (range 10-34) years. Mean best-corrected visual acuity (± SD) in logMAR was 0.9 ± 0.5 (20/160 ± 20/60). The OCT was suggestive of a focal mass-like lesion primarily involving the inner retinal layers limited externally by the outer plexiform layer (OPL) in 15 eyes (93.7%). The OPL appeared to have a saw-tooth appearance ("intraretinal peaks") in 12 eyes (75%). The convolutions of the OPL were broader and deeper in some eyes (5 eyes, 31.2%), giving an "omega sign" (ω) appearance. The ellipsoid zone appeared intact in 13 eyes (81.2%). The RPE band appeared intact in all eyes.

Conclusions: Considering the OCT features, available evidence, and embryology, we propose that the true nature of CHRRPE should be reanalyzed. In our series, CHRRPE was noted to be primarily a hamartoma arising from the inner retinal layers. A majority of cases were limited posteriorly by the OPL without any involvement of the outer retinal layers and RPE.