Abstract
Purpose: :
To describe the clinical features and natural course of choroidal nevi associated with retinal pigment epithelial (RPE) trough.
Methods: :
Retrospective review of clinical, ultrasonographic, and optical coherence tomographic findings at initial and follow-up visits.
Results: :
Ninety eyes of 89 patients were studied. Median patient age was 58 years (range, 18-79 years), 87 (98%) patients were Caucasian, and 59 patients (66%) were female. The mean nevus thickness and basal diameter were 2.2 (range, 0.8-3.4) and 6.9 mm (range, 3.5-12), respectively. Eleven nevi (12%) were located in the macula, 76 (84%) between macula and equator, and 3 (3%) between equator and ora serrata. The mean nevus distance to optic disc and foveola was 4.3 (range, 0-12) and 3.6 mm (range, 0-12), respectively. At initial presentation, 83% of nevi did not have associated subretinal fluid and only 11 nevi (12%) had serous retinal detachment outside the nevus. Other features included overlying orange pigment in 8 (9%), drusen in 49 (54%), RPE atrophy in 85 (94%), RPE hyperplasia in 67 (74%), and RPE fibrous metaplasia in 33 nevi (37%).The largest and smallest basal dimensions of the RPE trough were a mean of 4.0 and 2.1 mm, respectively. The majority of RPE troughs [68 (76%)] were located inferior to the nevus, 14 (16%) at the temporal margin, 7 (8%) at the nasal margin, and only 1 (1%) at the superior margin. All troughs had RPE atrophy and 82% had RPE hyperplasia. Eighty of 90 nevi had at least 6 months of follow-up with a mean of 79 months (range, 8-464 months). One nevus (1%) transformed into frank melanoma and two other nevi (2%) showed slight increase in size and were treated as melanoma. None of the patients developed metastasis.
Conclusions: :
Choroidal nevi with associated RPE trough are thicker and larger than the average choroidal nevus seen at our service. RPE trough outside choroidal nevi results from absorption of prior long-standing subretinal fluid and should be considered a sign of senescence of choridal nevi. Despite their greater thickness and basal diameter, choroidal nevi with RPE trough are relatively stable with low rates of malignant transformation.
Keywords: oncology • clinical (human) or epidemiologic studies: natural history • retinal pigment epithelium