Solitary congenital hypertrophy of the retinal pigment epithelium features by high-definition optical coherence tomography

Advances in multimodal imaging for diagnosis of pigmented ocular fundus lesions

Pigmented ocular fundus lesions can range from benign to malignant. While observation is reasonable for asymptomatic benign lesions, early recognition of tumours that are vision or life threatening is critical for long-term prognosis. With recent advances and increased accessibility of multimodal imaging, it is important that providers understand how to best use these tools to detect tumours that require early referral to subspecialty centres. This review aims to provide an overview of pigmented ocular fundus lesions and their defining characteristics using multimodal imaging. We cover the spectrum of pigmented ocular fundus lesions, including freckle and focal aggregates of normal or near-normal uveal melanocytes, retinal pigment epithelium (RPE) hyperplasia, congenital hypertrophy of the RPE, RPE hamartoma associated with familial adenomatous polyposis, congenital simple hamartoma of the RPE, combined hamartoma of the retina and RPE (congenital hypertrophy of the RPE), choroidal nevus, melanocytosis, melanocytoma, melanoma, adenoma, and RPE adenocarcinoma. We describe key diagnostic features using multimodal imaging modalities of ultra-widefield fundus photography, fundus autofluorescence, optical coherence tomography (OCT), enhanced-depth imaging OCT, ultrasonography, fluorescein angiography, indocyanine green angiography, and OCT angiography (OCTA), with particular attention to diagnostic features that could be missed on fundus examination alone. Finally, we review what is on the horizon, including applications of artificial intelligence. Through skilled application of current and emerging imaging technologies, earlier detection of sight- and life-threatening melanocytic ocular fundus tumours can lead to improved patient prognosis.

Optical Coherence Tomography Characteristics of the Choroid Underlying Congenital Hypertrophy of the Retinal Pigment Epithelium

Purpose

This study evaluates and characterizes the choroid underlying congenital hypertrophy of the retinal pigment epithelium (CHRPE).

Methods

Retrospective observational study of CHRPE at least 2 mm in diameter. Choroidal vascular architecture was qualitatively examined. Choroidal thickness was measured by 2 independent observers using enhanced depth imaging spectral domain optical coherence tomography.

Results

Forty-six eyes of 46 patients with CHRPE were included. Thirty-two lesions had imaging sufficient for analysis. Haller's layer was healthy in 18 (56%), thin in 13 (41%), and absent in 1 (2%). Sattler's layer was atrophic in 30 (94%), and choriocapillaris was atrophic in 31 (97%). CHRPE with thinned Haller's layer had significantly larger diameter. The mean sub-CHRPE choroidal thickness was 82.4 ± 7.9 µm, compared to a thickness of 148.4 ± 9.6 µm in the normal adjacent choroid (p < 0.0001). Mean retinal thickness overlying the CHRPE was 77.3 ± 4.3 µm, compared to a retinal thickness of 137.8 ± 2.9 µm overlying the normal adjacent choroid (p < 0.0001). Sub-CHRPE choroidal thickness was a mean of 56.2 ± 3.1% of the adjacent normal choroidal thickness.

Conclusion

The underlying choroid CHRPE is thinner than the adjacent normal choroid. All layers of the choroid can be thin with a preference of the inner Sattler's and choriocapillaris layers.