To report on 4-year postoperative visual performance with the Toric Implantable Collamer Lens (TICL) for stable keratoconus

Forty eyes of 24 patients with stable keratoconus with myopia between 0.00 and -18.00 diopters (D) and astigmatism between 1.25 and 8.00 diopters were evaluated in this prospective interventional study (https://clinicaltrials.gov/ct2/show/NCT02833649). We evaluated refraction, Visual outcomes, astigmatic changes analyzed by Alpins vector, contrast sensitivity, aberrometry, Modulation transfer functions (MTF), defocus curve, subjective satisfaction, and operative and postoperative complications

At 4-year follow-up, 45% had 20/20 vision or better and 100% had 20/40 or better uncorrected visual acuity (UCVA). Vector analysis of refractive astigmatism shows that, the SIA (3.20±1.46D) wasn’t significantly different from the TIA (3.14±1.42 D) (p= 0.620). At 4 years postoperatively, none of the eyes showed a decreased in UCVA, in contrast to 24 eyes in which UCVA was increased by ≥1 lines, with contrast sensitivity and improvement in total aberrations and MTF value at 5 per degree (p*꞊0.004 ) after TICL implantation. The cumulative 4-year corneal endothelial cell loss was ≤5%. No patients reported dissatisfaction, and 100% of patients reported they would choose implantable collamer lens (ICL) implantation again. At the end of follow-up, the vault was 658±54.33µm (range, 500-711) and the intraocular pressure (IOP) was 11.7±2.08 mmHg. Occurrences of glare and night-driving troubles diminished after TICL surgery

The results from this standardized clinical investigation support TICL implantation from clinical and optical viewpoints in patients with stable keratoconus