HIGHER SUBFOVEAL CHOROIDAL THICKNESS IN CHOROIDAL MELANOMAS THAN IN CHOROIDAL NEVI

To compare subfoveal choroidal thickness between eyes with choroidal melanoma and choroidal nevi.

Retrospective study of 126 consecutive patients in a tertiary ocular oncology center. Eyes with tumors located less than two disk diameters from the fovea were excluded. In eyes with nevi, factors of potential transformation into melanoma were recorded (orange pigment, subretinal fluid, thickness >2 mm, diameter >5 mm, ultrasound hollowness). Subfoveal choroidal thickness was assessed by three independent observers on horizontal spectral-domain optical coherence tomography scans.

Sixty-seven eyes with choroidal melanoma and 59 eyes with choroidal nevi were included. The melanoma and nevi groups did not differ in gender ( P = 0.14) nor age ( P = 0.34). There was a very good agreement between the three independent observers for subfoveal choroidal thickness measurements (intraclass correlation coefficient = 0.89). Mean subfoveal choroidal thickness was higher in melanomas (294.3 ± 89.9 µ m) than nevi (260.3 ± 76.7 µ m) ( P = 0.013), and the difference remained significant between melanomas and 28 nevi with ≥2 growth risk factors (256.3 ± 77.0 µ m) ( P = 0.027). In a multivariate model, the significant contributors to subfoveal choroidal thickness were presence of melanoma ( P = 0.004), younger age ( P < 0.0001), and shorter lesion distance to the fovea ( P = 0.016).

Subfoveal choroidal thickness may reflect the interplay between melanocytic tumors and their choroidal microenvironment. Its clinical utility should be explored in future studies.