The effects of posterior chamber intraocular lens implantation on accommodative function in high myopia

Abstract

Objective: To investigate the effects of implantable Collamer lens (ICL) with a central hole on the accommodative function of patients with high myopia at different ages after implantation. Methods: A retrospective cohort study was conducted on 75 patients (150 eyes, 23 men and 52 women) with high myopia who underwent ICL implantation in Department of Ophthalmology of First Affiliated Hospital of Army Medical University from January 2017 to December 2018. The age was (28.99±7.26) years (range, 18-48 years). Forty patients (80 eyes) aged 18-34 years were included in the younger group and 35 patients (70 eyes) aged 35-48 years were included in the elderly group. To compare the changes and differences of accommodative function between the two groups, the uncorrected visual acuity, best corrected visual acuity, spherical equivalent error, amplitude of accommodation (AMP), negative relative accommodation (NRA), positive relative accommodation, single and both eyes' accommodation of facility (AF), fused cross cylinder, near and far distance horizontal phoria, accommodative convergence/accommodation and visual satisfaction questionnaire before surgery and at 1, 3, 6 and 12 months after surgery were analyzed. ANOVA for repeated design, LSD, unpaired sample t-test, Paired t-test, Chi-square test and Fisher's exact test were used for data analyses. Results: At each time point before and after operation, there were significant differences between the two groups in the AMP (F=16.511, P<0.05). The AMP of the younger group increased from (8.88±2.27) D at baseline to (9.51±1.34) D at 12 months, while it was decreased in the elderly group from (7.67±2.36) D at baseline to (6.56±2.63) D at 12 months. The trend of changes was significantly different (F=15.044,P<0.05). The AMP of the elderly group was significantly lower than that of the younger group at all time points (F=47.678, P<0.05). The NRA of the younger group was better than that of the elderly group (F=13.459, P<0.05), but the NRA had no significant changes in both groups postoperatively (F=1.788, P=0.141). We could not find any significant changes of positive relative accommodation between two groups (F=1.447, P=0.233). The monocular and binocular AF of two groups was increased significantly after surgery (F=34.296, 21.839, P<0.05). The AF of the younger group was better than that of the elderly group (F=80.327, 43.08, P<0.05). The fused cross cylinder was improved from baseline (0.12±0.32) D to (0.38±0.49) D at 12 months (F=4.752, P<0.05), while the difference was not found in the younger group (F=2.110, P=0.151). We could not find any significant changes of accommodative convergence/accommodation between two groups (F=0.389, P=0.505) or in each group (F=1.049, P=0.309) preoperatively and at 1, 3, 6 and 12 months after surgery. Conclusions: ICL implantation is effective in the treatment of high myopia. The visual acuity, AMP, monocular and binocular AF may increase obviously. Big improvements in the accommodative function and high satisfaction of vision can be achieved, especially in younger patients. (Chin J Ophthalmol, 2021, 57: 113-121).