Multimodal imaging and functional correlations identify unusual cases of macular retinal pigment epithelium hypopigmentation occurring without functional loss.

ABSTRACT

PURPOSE: Patients with unusual macular retinal pigment epithelium (RPE) hypopigmentation are described and analyzed using retinal multimodal imaging. METHODS: We report three cases of patients with unilateral (2) or bilateral (1) macular lesions discovered incidentally on fundoscopy. A comprehensive ophthalmic examination including visual acuity, fundoscopy, spectral-domain optical coherence tomography (SD-OCT), short-wavelength light and near-infrared autofluorescence, fluorescein angiography, microperimetry, multifocal electroretinogram, adaptive optics (AO), and OCT-angiography (OCT-A) has been performed. RESULTS: Visual acuity was 20/20 in both eyes of all patients. The lesion appeared hyperautofluorescent on short-wavelength light and hypoautofluorescent on near-infrared light. Fluorescein angiography revealed a sharply demarcated macular hyperfluorescence without any leakage, suggesting a window defect. Interestingly, SD-OCT revealed only a choroidal hyperreflectivity in relation to the lesions without any abnormality of the outer retinal layers. Microperimetry was normal except for 1 patient with bilateral lesion and subtle decrease in macular sensitivity. Mf ERG was normal in all three patients. AO showed a well-preserved cone mosaic, suggesting that the abnormality was localized under the photoreceptor layers. OCT-A revealed hyperreflectivity just below the RPE layer, corresponding to the macular lesion observed on fundoscopy and the choroidal hyperreflectivity seen on SD-OCT. CONCLUSIONS: Macular RPE hypopigmentation should be considered in case of an isolated macular lesion without functional visual impairment or anatomical defect on SD-OCT.