Refractive outcomes after V4c Toric collamer lens implantation over 1y of follow-up

AIM: To evaluate refractive outcomes and corneal astigmatism changes after Toric implantable collamer lens with a central port (V4c T-ICL) implantation over 1y of follow-up. METHODS: A retrospective study was performed including 50 eyes of 50 patients that underwent V4c T-ICL implantation. Uncorrected (UDVA) and corrected (CDVA) distance visual acuities, refraction, refractive and corneal astigmatism changes and corneal coupling correction were evaluated preoperatively, 1 and 12mo postoperatively. Vector analysis was used for astigmatism changes. Coefficient of adjustment (CAdj) was calculated for corneal coupling analysis. RESULTS: The mean UDVA achieved was 0.03 logMAR at 1mo and remained unchanged throughout the whole follow-up (P=0.193). At the last visit, 84% of the eyes achieved a CDVA of 0.00 logMAR or better. Regarding spherical equivalent refraction (SEQ), 96% of eyes were ranges of ±1.00 D and 84% of them within ±0.50 D. Also, 94% of eyes had a remaining refractive cylinder within ±1.00 D and 78% of them within ±0.50 D. Both, SEQ and refractive cylinder, remain stable over the postoperative follow-up (P=1.000 and P=0.660, respectively). In terms of surgically induced astigmatism (SIA), no statistically significant differences were found over the follow-up (P=0.102) and under correction was found with a correction index lower than the unit at each visit. A keratometric astigmatism induced of 0.59±0.53 (vector mean: 0.26×73º) D was reached at the last visit. No significant changes in terms of corneal astigmatism orientation were reported over post-surgery visits (P=0.129 and P=0.097 at 1 and 12mo respectively). No clinical significance was found for CAdj on with-the-rule astigmatism. No postoperative complications resulting from the surgery were found. CONCLUSION: Refractive outcomes suggest that the V4c T-ICL implantation for correction of myopic astigmatism was satisfactory in terms of effectiveness, safety, and stability during 1y of follow-up. Corneal astigmatism induced by the incision around 0.5 D is achieved according to the remaining refractive cylinder found at one-year post-surgery. Corneal coupling analysis results in no unexpected spherical change.