Growth of congenital hypertrophy of the retinal pigment epithelium over 22 years

In vivo visualization of variable photoreceptor alteration in a case of peripapillary congenital hypertrophy of the retinal pigment epithelium using spectralis ® high magnification module

Purpose

To analyze using the high magnification module (HMM) a case of peripapillary congenital hypertrophy of retinal pigment epithelium (CHRPE) and to correlate the findings to multimodal imaging and swept-source optical coherence tomography angiography (SS-OCTA, PLEX® Elite 9000, Carl Zeiss Meditec, Dublin, California, USA) imaging.

Observations

A 57-year-old Caucasian woman presenting a peripapillary CHRPE of the left eye (LE) was examined using HMM and SS-OCTA, in addition to multimodal imaging. SS-OCTA disclosed the gradual changes, with four distinguishable zones: Zone 1 with complete outer retinal and retinal pigment epithelium (RPE) atrophy, Zones 2 and 3, corresponding to incomplete outer retinal (and RPE) atrophy presenting increased flow deficits, and normal choriocapillaris outside the lesion (Zone 4). High Magnification Module (HMM, Spectralis ®, Heidelberg Engineering) showed small polygonal hyperreflective outlines over the pigmented parts of the lesion (Zone 2), and partly over the narrow halo surrounding the lesion (Zone 3), with an absence of these outlines over the lacunae (Zone 1).

Conclusions and importance

HMM is a non-invasive imaging modality, allowing the in vivo visualization of a mosaic pattern, corresponding to the hyperreflective polygonal outlines, or absence thereof, in different zones of CHRPE.

•

High magnification module (HMM) is a non-invasive imaging modality.

•

HMM allows the visualization of a mosaic pattern/ absence thereof in congenital hypertrophy of retinal pigment epithelium

•

This may help improve the understanding and diagnosis of photoreceptor alteration in CHRPE.

The link between colon cancer and congenital hypertrophy of the retinal pigment epithelium (CHRPE)

PURPOSE

Clarify the differences between Familial Adenomatous Polyposis (FAP)-associated Congenital Hypertrophy of the Retinal Epithelium (CHRPE) and benign variants with regards to lesion characteristics and associated risk.

OBSERVATIONS

An eighteen-year-old man with no past medical history was found to have multiple lesions in both eyes that were consistent with FAP-associated CHRPE. Although family history was negative for colon cancer, a colonoscopy was performed, and hundreds of polyps were found extending from the rectum to the distal colon with pathological findings of tubular adenoma. Genetic testing was consistent with a possible de novo Adenomatous Polyposis Coli (APC) mutation.

CONCLUSIONS

FAP is an autosomal dominant syndrome that causes colorectal cancer by age thirty-five in ninety-five percent of cases. There has been no established relationship between the benign variants of CHRPE and FAP, and patients with benign variants have no increased risk of colon cancer. While the lack of distinction in nomenclature and similar lesion appearance often leads to misdiagnosis and overtreatment, there are distinct ocular exam features that can provide the correct diagnosis. The exam findings that distinguish FAP-associated CHRPE lesions are (1) bilateralism, (2) occurrence in multiple quadrants, (3) pisiform shape, and (4) irregular borders. Knowing these features can be of great aid, especially in the setting of suspected de novo Familial Adenomatous Polyposis.