Abstract
Purpose :
To describe the multimodal imaging characteristics of retinal pigment epithelial hamartomas associated with familial adenomatous polyposis (RPEH-FAP).
Methods :
Prospective, observational case series.
Results :
Twenty-four eyes of 12 patients diagnosed with FAP were included. The mean age of the patients was 46.8 years (range 20-72 years). There were 4 males, 8 females, and every patient was Caucasian. Two hundred and thirty-one RPEH-FAPlesions were identified (mean 9.6 lesions per eye, range 1-31). The superotemporal quadrant was the most common location (n = 91, 39.4%). Most lesions were outside the posterior pole (n = 206, 89.2%). The most common lesion appearance were small pigmented dots (42.4%), with larger lesions being more posteriorly located, non-circular and variable in pigmentation The mean dimensions for lesions were 0.6 mm x 0.2 mm (range 0.1 mm – 4.7 mm). Depigmented halos or fish-tails were seen in 112 (48%) lesions. The pigmented portion of the lesion was hypoautofluorescent in 137 of 147 (93%) of cases, and when present the depigmented halos/fish tails were either isoautofluorescent (n = 36/76) or hyperautofluorescent (n = 29/76). OCT was obtained for 48 lesions. The mean RPE thickness was increased to 37.8 µm, and irregular in 22 cases (46%). Retinal thinning of the outer retina was seen in a majority of cases, with thinning or absence of the outer nuclear layer in 83.3% of cases. Hyper-reflective retinal spots were seen in 9 cases (18.8%) and pigment epithelial detachment (PED) in 11 cases (22.9%). None of the lesions demonstrated lacunae, cystoid edema, subretinal fluid, or blood flow on OCTA.
Conclusions :
Patients with FAP have a mean of almost 10 RPEH-FAP lesions per eye. The superotemporal quadrant is the most commonly involved and most lesions are outside the posterior pole. These RPEH-FAP lesions are usually hypoautofluorescent with outer retinal loss on OCT scans and as such are similar to CHRPE lesions not associated with FAP. Key differences of RPEH-FAP lesions associated with FAP are the presence of an iso- or hyperautofluorescent depigmented halo or fish tail in almost half of lesions and the absence of associated lacunae or cystoid edema. The presence of PEDs are a new finding.
This abstract was presented at the 2024 ARVO Annual Meeting, held in Seattle, WA, May 5-9, 2024.