What can we learn from the features and presentation of retinal pigment epithelium hypertrophy?

Abstract

Figures

Clinical spectrum of retinal pigment epithelium (RPE) hypertrophy. Solitary RPE hypertrophy (A and B). A. A wide-field color fundus photograph showing a large flat dark gray to black lesion with scalloped margins in the inferotemporal periphery associated with lacunae skin pigmentation; B. Autofluorescence (AF) showing sharp lesion margins and blockage of the autofluorescence despite the areas of lost pigment; Bear-track lesions (C and D). C. A wide-field color fundus photograph showing diffuse small light-gray patches of retinal pigment epithelium hyperplasia in a clumping pattern consistent

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Dear Editor,

We read with great interest the article by Carvalho et al., describing the use of congenital hypertrophy of the retinal pigment epithelium (CHRPE) as a phenoty-pic marker for familial adenomatous polyposis (FAP)^(1)^. The study highlights the importance of CHRPE as a risk factor for FAP, particularly in cases with bilateral fish-tail lesions^(2^,^3)^. This is an informative and important finding that motivated us to add further insights into the clinical spectrum of retinal pigment epithelium (RPE) hypertrophy through a review of the three distinct presentations. Knowledge of these is critical for accurate diagnosis and differentiation.

Figure 1. Clinical spectrum of retinal pigment epithelium (RPE) hypertrophy. Solitary RPE hypertrophy (A and B). A. A wide-field color fundus photograph showing a large flat dark gray to black lesion with scalloped margins in the inferotemporal periphery associated with lacunae skin pigmentation; B. Autofluorescence (AF) showing sharp lesion margins and blockage of the autofluorescence despite the areas of lost pigment; Bear-track lesions (C and D). C. A wide-field color fundus photograph showing diffuse small light-gray patches of retinal pigment epithelium hyperplasia in a clumping pattern consistent with the “bear-track” configuration; D. AF image in which lesions completely block the fundus fluorescence. Fish-tail lesions (E and F). E. A wide-field color fundus photograph showing two small gray-black flat lesions in the inferior periphery with associated whitish fish-tail edges (indicated by the white arrow); F. AF image in which the lesions block some of the AF showing. The hyper-AF associated with the fish-tail effect can be seen at the lesion margins.

We believe a more detailed discussion of these forms of RPE hypertrophy would add to the utility of Carvalho et al.’s findings and assist your readers in distinguishing between FAP-associated lesions and other RPE abnormalities.^(2)^

We also feel that the use of the term “congenital” in this context is problematic as there is no evidence to indicate, which if any of these variations are truly congenital. The lesions are known to grow in more than 50% of cases. In clinics, patients with RPE hypertrophy merit an annual fundus evaluation to monitor for lesion enlargement and the other aforementioned risks.

We commend the authors for their significant contribution and for raising awareness of CHRPE as an important screening finding. We hope the points we have made will broaden the discussion of this condition and further emphasize the importance of early diagnosis and multidisciplinary approaches to hereditary syndromes like FAP.