Changes of dysfunctional lens index before and after implantable collamer lens V4c implantation in patients with moderate-to-high myopia.

BACKGROUND

Dysfunctional lens index (DLI) changing is rarely reported after implantable collamer lens (ICL) implantation. In the current research, we hope to investigate the changes of DLI by ray-tracing aberrometry before and after implantation of the posterior chamber phakic implantable collamer lens with a central artificial hole for patients with moderate-to-high myopia.

METHODS

This retrospective, observational case series included 206 eyes of 104 patients with moderate-to-high myopia who underwent ICL V4c implantation. Data were collected on ocular indicators preoperatively and at 1 day, 1, 3, and 6 months postoperatively. The i-Trace Visual Functional Analyzer was used to assess the DLI measurement.

RESULTS

The overall values of safety index and efficacy index were both more than 1. Preoperatively, the mean spherical equivalent (SE) of included 206 eyes was - 10.77 ± 3.46 diopter (D). Then at 1-day postoperation, the mean SE was - 0.22 ± 0.55 D, and barely changed from 1 day to 6 months postoperatively. Although the endothelial parameters had no significant differences between preoperation and postoperation, the mean loss of endothelial cells was 0.74 ± 0.98% at 6 months. Regarding the vault, there was a significant difference between each time of follow-up (P < 0.001). The mean of the vault decreased 109.6 ± 13.5 µm from 1-day post-op to 6 months post-op. The DLI values were 3.70, 9.26, 10.00, and 9.68 at baseline, 1, 3, and 6 months, respectively (P < 0.001), but no significant differences were found between 1, 3, and 6 months postoperatively (P > 0.05). The preoperative lnDLI showed a significant positive linear correlation (r = 0.621, P < 0.001) with the preoperative spherical equivalent (SE). The lnDLI was negatively correlated with the axial length (r = - 0.462, P < 0.001), corneal thickness (r = - 0.207, P = 0.003), preoperative LogMAR UDVA (r = - 0.189, P = 0.006), and preoperative LogMAR CDVA (r = - 0.306, P < 0.001).

CONCLUSIONS

The postoperative refractive parameters were confirmed excellent in efficacy, predictability, and stability in half a year. The DLI was significantly improved after the ICL V4c implantation in patients with moderate-to-high myopia and showed good stability during the follow-up periods. The DLI deserves a more comprehensive understanding and application in clinical services.