Purpose: To study multimodal imaging features of combined hamartoma of the retina and retinal pigment epithelium (CHRRPE).
Methods: Six patients (3 males, mean age 11 years) and a healthy age-matched control group made up of 15 healthy subjects (8 males, mean age 12.6 years) were included in the analysis. Complete ophthalmologic examination was performed, including best-corrected visual acuity, anterior and posterior segment slit-lamp evaluation, and tonometry. The multimodal imaging protocol included fundus images, structural optical coherence tomography (OCT), and swept-source OCT angiography (OCTA). The main outcome measures included the qualitative evaluation of both OCT and OCTA features of CHRRPE, retinal and choroidal thickness measurements, and the quantitative analysis of superficial capillary plexus, deep capillary plexus, and choriocapillaris vessel densities.
Results: Optical coherence tomography features of CHRRPE were examined extensively. Multiple little hyperreflective triangular outer retinal alterations were found at the CHRRPE edges in all patients; these were dubbed the "shark-teeth" sign. Optical coherence tomography angiography showed rarefaction and morphologic alterations of all retinal plexa. Moreover, quantitative analysis revealed a statistically significant decrease in superficial capillary plexus, deep capillary plexus, and choriocapillaris vessel densities in patients affected by CHRRPE compared with the control group.
Conclusion: Optical coherence tomography and OCTA analyses allowed the accurate qualitative and quantitative analyses of CHRRPE features. Further studies are needed to better define OCTA changes of CHRRPE better and to improve our understanding of the possible causes of the shark-teeth sign.