Characterization of Choroidal Nevi with Dark-Field Infrared Scanning Laser Ophthalmoscopy

To compare dark-field (DF) scanning laser ophthalmoscopy (SLO) against en face OCT and color fundus photography (CFP) in imaging of choroidal nevi and determining lesion area and to describe the characteristics of choroidal nevi using DF SLO.

Prospective cohort study.

Multimodal imaging, including DF SLO, OCT, and CFP, was performed in 24 patients (24 eyes; 10 men and 14 women; mean age, 45.1±13.4 years) with choroidal nevi and 14 healthy age-matched volunteers (24 eyes).

For each imaging method, the area under the receiver operating characteristic curve was constructed to evaluate the ability to identify choroidal nevi. Using DF SLO, each nevus was characterized according to the intensity of the shadow, clarity of the borders, and presence of additional pigmentation. The lesion area was measured by 2 graders for each imaging method. The intraclass correlation coefficient and intergrader correlation coefficient were calculated.

Agreement of DF SLO with CFP and en face OCT in visualization of choroidal nevi.

Dark-field SLO showed the highest area under the receiver operating characteristic curve, 1.0, compared with en face OCT and CFP, 0.9 (P = 0.04) and 0.88 (P = 0.025), respectively. Using DF SLO in 17 patients (70.8%) and 7 patients (29.2%), nevus demonstrated dense and partially transparent shadow, respectively. In 10 patients (41.7%) and 14 patients (58.3%), nevus demonstrated sharp and blurred borders, respectively. Additional pigmentation was found in 5 patients (20.8%). The agreement in the evaluation of the area of the nevus between DF SLO and en face OCT and between DF SLO and CFP for grader 1 was 0.89 and 0.95, respectively, and for grader 2 was 0.95 and 0.95, respectively. Weighted κ values in reproducibility analysis for DF SLO, en face OCT, and CFP were 0.8, 0.71, and 0.67, respectively.

Dark-field SLO demonstrated excellent potential for identifying choroidal nevi and was in full agreement with conventional methods in the evaluation of the area of choroidal nevi.