Objectives: The objective of the investigation is to examine the long term efficacy, safety, and predictability of ICL-V4c implantation for high and super-high myopic patients in order to provide reliable guidance for the selection of refractive surgical procedures.
Methods: We reviewed 125 eyes from 64 patients who implanted ICL-V4c at the Refractive Surgery Center of West China Hospital in Chengdu, China, between May 2015 and January 2017. These eyes were divided into two groups based on their preoperative spherical equivalent (SE) degree: high myopia (≥ -10D) and super-high myopia groups (< -10D). We followed up with the patients over 5 years and evaluated several parameters, including uncorrected visual acuity (UDVA), corrected visual acuity (CDVA), axial length (AL), refractive error, endothelial cell density (ECD), intraocular pressure (IOP), white-to-white distance (WTW), and vault.
Results: The efficacy indices of ICL-V4c implantation in high and super-high myopia groups were 0.91 ± 0.23 and 0.80 ± 0.25, respectively at 5 years after operation. Compared to high myopia group, the efficacy index of super-high myopia was obviously decreased (p = 0.020) and the △AL of super-high myopia was significantly increased (p = 0.001). The mean safety indices were 1.10 ± 0.15 and 1.10 ± 0.21 respectively in high and super-high myopia groups (p = 0.850). At the 5-year mark, 11.67% vs 20.00% (High vs Super-high) of eyes were within ±0.50 D (Spherical Equivalent), and 75.00% vs 70.77% (High vs Super-high) of eyes were within ±2.00 D. No significant difference of ECD was found in the high (2823.45 ± 274.75 cells/mm2) and super-high myopia (2856.71 ± 323.53cells/mm2) at the visit of 5 years. Compared to baseline, we observed a significant increase in IOP at the 1-week follow-up, which decreased significantly at the one-month visit. Furthermore, there was a significant difference of vault between the high and super-high groups at 1-month (p = 0.042) and 5-year (p = 0.002) after surgery.
Conclusions: ICL-V4c implantation is effective, safe, and stable for correcting high and super-high myopia. However, ophthalmologists need to be aware of the potential for greater myopia regression in super-high myopic patients, as well as the increase in axial length and associated fundus complications.
Keywords: High myopia; ICL-V4c; implantation; posterior chamber phakic; super-high myopia.