Long-term observation of glare and dynamic pupil after EVO ICL (implantable collamer lens) for myopia

Purpose To investigate the long-term changes in glare and dynamic pupil after EVO ICL implantation in myopic patients and their influencing factors. Method In this prospective, consecutive case study, 22 patients (44 eyes, Male/Female = 9/13) underwent EVO-ICL, with a mean age of 25.3 ± 5.4 years and spherical equivalent of -10.52 ± 3.02 D (range: -3.25 D ~ -18.00 D). Comprehensive examinations were performed before and after surgery and all patients were followed up for 5 years. Result At the final follow-up, the efficacy and safety indexes were 0.95±0.28 and 1.17±0.19, respectively. The postoperative glare decreased significantly at 1 week and 1 month (P< 0.01), then stabilized (P>0.05). 16/22 (72.7%) of the patients reported glare. Of these patients, 7/22 (31.8%) experienced glare bothersomeness, all rating mild. Additionally, 4/22 (18.2%) of the patients had mild problems with night-time driving. In dynamic pupillometry, the amplitude of pupil contraction significantly decreased during early period (P= 0.001), and restored after 5 years post-surgery (P= 0.081). Moreover, the pupil contraction and dilation velocity reduced significantly in the early-stage (P< 0.01), and later recovered after 5 years of surgery (P>0.05). The maximum pupil diameter did not alter significantly in the early-stage, however, it significantly decreased after 5 years post-surgery (P= 0.001). GEE showed that pupil dilation velocity, maximum pupil diameter, and ICL size were positively correlated with postoperative glare and were the main influences on the latter (all P< 0.01). Conclusion EVO ICL is safe and effective in correcting myopia. Post-operative glare is related to the pupil dilation velocity, maximum pupil diameter, and decreases over time. Most patients have no glare bothersomeness in the long term, some patients may even have their glare symptoms disappear. Only a few patients experience slight interference while nighttime driving.