Visual function assessment of posterior-chamber phakic implantable collamer lenses with a central port

BACKGROUND: To investigate the short-term visual function of the V4c implantable collamer lens (ICL) for myopia using a Binoptometer 4P. METHODS: Eighty eyes from 40 patients (age, 28.75±6.57 years) who underwent ICL V4c implantation at Shenzhen Eye Hospital from August 2020 to June 2021 were enrolled. Uncorrected visual acuity (UCVA), best corrected visual acuity (BCVA), subjective manifest refraction, intraocular pressure (IOP), and corneal endothelial cell density (ECD) were evaluated 1 month after surgery. Corrected distance visual acuity (CDVA), corrected near visual acuity (CNVA), contrast sensitivity (CS), near stereoacuity (NSA), twilight vision, and glare sensitivity were measured using a Binoptometer 4P. RESULTS: The average logMAR (logarithmic minimum angle of resolution) UCVA postoperative was 0.07±0.13, which was significantly better than the preoperative BCVA (P=0.028). At 1 month postoperatively, the mean safety and efficacy indexes were 1.14±0.24 and 0.98±0.16, respectively. The mean spherical equivalent (SE) of all eyes was −8.98±3.20 D preoperatively, and −0.16±0.48 D postoperatively. None of the patients lost one or more lines of BCVA, 62.1% remained unchanged, 10.6% gained one line, and 27.3% gained two or more lines. CDVA, CNVA, CS, and NSA of both eyes were measured using a Binoptometer 4P, which were significantly better than the preoperative values. In addition, some patients had subjective symptoms in the early postoperative period, such as halo, glare, etc. CONCLUSIONS: ICL V4c implantation is a safe, effective, and predictable solution for myopia. We found that the short-term visual function of patients was improved significantly. The Binoptometer 4P is an effective and convenient visual testing device for assessing postoperative visual function after ICL V4c implantation.