Changes in accommodative facility after posterior chamber implantation of V4c implantable collamer lens

Objective  To investigate the changes in accommodative facility after implantation of V4c implantable collamer lens (ICL) using the intelligent flipper (iFLIP).

Methods  A serial case-control study was conducted.Forty patients (80 eyes) who underwent ICL implantation of V4c for myopia correction and completed the follow-up were enrolled at the Affiliated Hospital of Guizhou Medical University from April 2022 to April 2023.Monocular and binocular accommodative facility, adjustment time, and relaxation time were measured with iFLIP before operation and at 1 week, 1 month, 3 months, and 6 months after operation.This study adhered to the Declaration of Helsinki.The study protocol was approved by the Ethics Committee of the Affiliated Hospital of Guizhou Medical University (No.2023-983).Written informed consent was obtained from each subject.

Results  Monocular and binocular uncorrected visual acuity at 1 week, 1 month, 3 months and 6 months after surgery were significantly improved compared with before surgery, and the differences were statistically significant (all P<0.05).Monocular and binocular postoperative accommodative facility gradually increased over time, and the increase gradually decreased and gradually stabilized.Before operation and 1 week, 1 month, 3 months, and 6 months after operation, the monocular accommodative facility was (7.99±3.42), (10.19±4.25), (12.03±4.24), (13.10±4.66) and (13.64±4.40)cpm, and the binocular accommodative facility was (9.01±3.63), (9.56±3.38), (11.58±4.00), (13.31±3.64), and (14.03±3.72)cpm, respectively, with statistically significant overall differences ( F=24.02, 14.46; both P<0.001).Monocular accommodative facility was higher than before surgery at each time point after surgery, and was higher than 1 week after surgery at 1, 3, and 6 months after surgery, with statistically significant differences (all P<0.05).Binocular accommodative facility was higher at 1, 3, and 6 months after surgery than that before surgery and 1 week after surgery, and higher at 3 and 6 months after surgery than that at 1 month after surgery, with statistically significant differences (all P<0.05).With the extension of postoperative time, the monocular and binocular adjustment time and relaxation time gradually shortened, and the shortening gradually decreased and stabilized.Monocular adjustment time and relaxation time were shorter than before surgery at all time points after surgery.The monocular adjustment time was shorter at 1, 3 and 6 months after surgery than that at 1 week after surgery and shorter at 3 and 6 months after surgery than that at 1 month after surgery, and the monocular relaxation time was shorter at 3 and 6 months after surgery than that at 1 week after surgery, and the differences were statistically significant (all P<0.05).The binocular adjustment time was shorter at 1, 3 and 6 months after surgery than before surgery and at 1 week after surgery, shorter at 3 and 6 months after surgery than at 1 month after surgery and the binocular relaxation time was shorter at all time points after surgery than that before surgery, showing statistically significant differences (all P<0.05).

Conclusions  After ICL implantation, uncorrected visual acuity, accommodative facility, adjustment time and relaxation time all improve throughout the preoperative period and eventually stabilize.

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