Purpose: Implantable collamer lens (ICL) surgery results in the narrowing of the lens' angle. However, the mechanism underlying local changes in the region of fixed ICL haptic has not been examined. This study evaluated changes in the morphological parameters of the angle before and after ICL surgery in proximate and distant regions of the contact area of ICL haptic.
Participants and methods: At a single facility, 37 eyes of 19 patients underwent horizontal ICL fixation along the longitudinal axis. Anterior segment optical coherence tomography was used to measure the trabecular-iris space area 500 (TISA 500), angle opening distance 500 (AOD 500), and trabecular-iris angle 500 (TIA 500). The results were retrospectively evaluated in proximate (i. e., 22.5° from the nasal and temporal superior areas) and distant (i. e., 0° from nasal and temporal areas)regions of the fixed ICL haptic before and one month after the surgery.
Results: The results of TISA 500, AOD 500, and TIA 500 significantly decreased after the surgery (p<0.001, paired t-test, respectively). No significant differences were observed in the rate of parameter changes in four measurement points (i. e., proximate fixed ICL haptic regions and distant regions, p=0.78-0.93, one-way analysis of variance; p=0.53-0.94, paired t-test).
Conclusions: ICL surgery resulted in angle narrowing. There was no significant difference in the morphological change in the angle after ICL surgery between the proximate and distant regions of the fixed ICL haptic, and the morphological changes were uniform.
Nippon Ganka Gakkai Zasshi (J Jpn Ophthalmol Soc) 128：335-340, 2024.