In vivo analysis of iridocorneal angle parameters with spectral-domain optical coherence tomography in children with Neurofibromatosis type 1.

Abstract

Purpose: To evaluate iridocorneal angle (ICA) parameter measurements with spectral-domain optical coherence tomography (SD-OCT) in children with Neurofibromatosis type 1 (NF1) and to compare them with those in healthy children.

Methods: Twenty children with NF1 and 33 age- and sex-matched healthy controls were enroled. All subjects underwent ICA imaging with SD-OCT. Schlemm canal diameter (SCD), anterior chamber angle (ACA), angle opening distance (AOD500 and AOD750), trabecular-iris space area (TISA500 and TISA750) and scleral spur length (SSL) were examined in the temporal sections and measured with customized software. Also, iris thickness (IT) was measured as the distances between the anterior and posterior iris surface, at 1 mm (IT-1), 2 mm (IT-2) and 3 mm (IT-3) from the edge of the pupil.

Results: Mean ACD was significantly narrower in NF1 group (p = 0.003). Mean levels of SCD (p < 0.001), ACA (p = 0.001), AOD500 (p = 0.001), AOD750 (p < 0.001), TISA500 (p < 0.001) and TISA750 (p < 0.001) were significantly lower in NF1 group. Mean SSL-1 (p = 0.19) and SSL-2 (p = 0.56) measurements were found to be similar between the groups. Mean IT-1 (p < 0.001), IT-2 (p < 0.001) and IT-3 (0.03) were observed to be significantly higher in NF1 group. There was significant correlation between ACD and IT. Also, ACD and IT showed significant associations with the ICA parameters.

Conclusion: There was a significantly narrower ICA morphology in NF1 children. SCD was significantly decreased in children with NF1. A significantly thicker iris in NF1 children may offer a possible impact of iris morphology on narrower ICA parameters and SCD.