Evaluation of a Toric Implantable Collamer Lens After Corneal Collagen Crosslinking in Treatment of Early-Stage Keratoconus

Abstract

The aim of this study was to assess the predictability, efficacy, safety, and stability in patients who received a toric implantable collamer lens (TICL) after collagen crosslinking in early-stage keratoconus. This prospective interventional case series study was conducted at the Alexandria Main University hospitals, University of Alexandria, Egypt. Sixteen eyes underwent implantation of a TICL (STAAR Surgical Inc) after crosslinking. The mean spherical refraction was -5.98 ± 4.39 diopters (D) (range, -0.50 to -14.50 D), and the mean cylinder was -4.91 ± 1.51 D (range, -2.50 to -7.75 D). Uncorrected distance visual acuity (UDVA), manifest and cycloplegic refraction, corrected distance visual acuity (CDVA), vault, intraocular pressure, and endothelial cell count (using specular microscopy) were evaluated during a 3-year follow-up. The mean Snellen decimal CDVA improved from 0.56 ± 0.13 (range, 0.40-0.80) preoperatively to 0.89 ± 0.17 (range, 0.60-1.20) at 3 years of the follow-up (P < 0.0001). The mean UDVA also improved significantly from 0.63 ± 0.14 before ICL implantation to 0.88 ± 0.18 after 3 years of the follow-up (P < 0.001). At 3 years, the mean spherical and cylindrical manifest refractions were 0.00 ± 0.18 D and -0.05 ± 0.14 D, respectively. At the end of the follow-up, the vault was 509.75 ± 141.47 μm (range, 320-900) and the intraocular pressure was 11.94 ± 1.12 mm Hg. No complications occurred during the surgical procedures. No eye needed explantation or repositioning of the TICL. The endothelial cell count loss after 3 years was -8.98%. Correction of spherical and cylindrical refractive errors in keratoconic eyes by TICL implantation 12 months after crosslinking gave significantly promising outcomes, particularly in the astigmatic component of refraction.