Using Anterior Segment Optical Coherence Tomography to Assess Angle Anatomy in Patients with Neurofibromatosis Type 1

Abstract

SIGNIFICANCE Lisch nodules have been identified in more than 90% of patients 16 years or older with neurofibromatosis type 1 (NF1). According to our hypothesis, the presence of Lisch nodules in patients with NF1 might affect the anterior chamber angle (ACA) parameters. PURPOSE The aim of this study was to evaluate the anterior segment angle parameters using anterior segment optical coherence tomography in patients with NF1. METHODS A total of 42 eyes from 21 patients with NF1 (study group) and 42 eyes from 21 age- and sex-matched healthy individuals (control group) were included in this study. Angle opening distance at 500 (AOD500) and 750 μm (AOD750) anterior to the scleral spur, ACA, and iris thickness (IT) values were measured in the temporal (T) and nasal (N) quadrants using anterior segment optical coherence tomography. RESULTS The mean AOD500 and AOD750 values in both quadrants were significantly lower in the study group compared with the control group (T-AOD500: 548 ± 151 vs. 761 ± 288 [P < .001], T-AOD750: 705 ± 175 vs. 921 ± 334 [P < .001], N-AOD500: 599 ± 223 vs. 777 ± 292 [P = .002], and N-AOD750: 756 ± 268 vs. 948 ± 303 [P = .003], respectively). The mean ACA values in both quadrants were significantly narrower in the study group compared with the control group (T-ACA: 29.52 ± 6.36 vs. 40.83 ± 8.90 [P < .001] and N-ACA: 30.05 ± 7.11 vs. 41.29 ± 8.68 [P < .001], respectively). The IT values in both quadrants were significantly thicker compared with the control group (T-IT500: 406 ± 78 vs. 355 ± 59 [P = .001], T-IT750: 453 ± 103 vs. 362 ± 100 [P < .001], N-IT500: 416 ± 93 vs. 353 ± 54 [P < .001], and N-IT750: 437 ± 91 vs. 370 ± 95 [P = .002], respectively). CONCLUSIONS We have revealed lower angle opening distance values in individuals with NF1 than in the healthy ones, as well as significantly narrower ACA values and significantly thicker IT values.