The influence of residual astigmatism on the postoperative visual quality in patients with implantation of an extended depth of focus intraocular lens

Abstract

Objective: To investigate the influence of residual astigmatism on the postoperative visual acuity in cataract patients with implantation of an extended depth of focus intraocular lens (IOL). Methods: Retrospective cohort study. A total of 56 eyes of 56 cataract patients who underwent phacoemulsification combined with extended depth of focus IOL implantation from January 2019 to December 2020 at Eye & ENT Hospital of Fudan University were included. There were 29 males and 27 females in all patients, and the age was (65±9) years. Patients were divided into two groups according to their postoperative residual astigmatism: low astigmatism group (<0.75 D, 28 eyes) and high astigmatism group (0.75 to 1.50 D, 28 eyes). At 3 months after surgery, measurements were completed, including postoperative uncorrected distance (5 m) visual acuity, uncorrected intermediate (80 cm) visual acuity, uncorrected near (40 cm) visual acuity, best corrected visual acuity (all the visual acuity was converted to the logarithm of the minimum angle of resolution visual acuity), defocus curves, quick contrast sensitivity function, wavefront aberration, and VF-14 questionnaire scores. The independent samples t-test and Mann-Whitney U test were used for data analysis. Results: The low astigmatism group and high astigmatism group's uncorrected distance visual acuity [M (Q1, Q3)] were 0.05 (-0.06, 0.10), 0.08 (0.00, 0.22), their uncorrected intermediate visual acuity were 0.11 (0.00, 0.20), 0.14 (0.10, 0.21), their uncorrected near visual acuity were 0.28 (0.20, 0.32), 0.26 (0.20, 0.30), and their best corrected visual acuity were 0.17 (0.05, 0.30), 0.14 (0.04, 0.22), respectively. The differences were not statistically significant (all P>0.05). No significant difference was found in the defocus curves from +1.00 to -4.00 D, at intervals of +0.50 D, between the two groups (all P>0.05). No significant difference was found in the quick contrast sensitivity of low, middle and high frequency of dark vision between the low astigmatism group and high astigmatism group (all P>0.05), and the area under Log contrast sensitivity function of the two groups were 0.87±0.28 and 0.77±0.30 (P>0.05). The total whole-eye aberrations were 0.59±0.18 and 0.74±0.51, and the total higher-order aberrations were 0.30±0.13 and 0.37±0.25 in the two groups at 4.0-mm pupil diameter. The differences were not statistically significant when the total whole-eye aberration, total higher-order aberration, coma, cloverleaf aberration, and spherical aberration were compared (all P>0.05). The differences of the total VF-14 visual scores, near visual acuity scores and the distance visual acuity scores of the two groups were not statistically significant (all P>0.05). Conclusion: Cataract patients with residual postoperative astigmatism 0.75 to 1.50 D can obtain as good visual quality as those with postoperative residual astigmatism<0.75 D after implantation of an extended depth of focus IOL.