One-Year Clinical Outcomes Of Intra-Corneal Ring Segment Implantation And Corneal Collagen Cross-Linking Using Intra-Corneal Riboflavin Injection

This study evaluates the one-year postoperative visual and refractive outcomes following femtosecond laser-assisted intra-corneal ring segment (ICRS) implantation combined with corneal collagen cross-linking (CXL) using intra-corneal riboflavin injection. The procedure aims to improve visual acuity and corneal stability in patients with keratoconus or post-LASIK ectasia.

Minoru Tomita Eye Clinic Ginza, Tokyo, Japan.

This retrospective study included 441 eyes of 294 patients with keratoconus or post-LASIK ectasia (mean age: 37.83±12.68 years old). All eyes underwent OCT-guided LDV Z8 femtosecond laser-assisted ICRS implantation, followed by corneal CXL. Riboflavin 0.25% was injected into the tunnel, followed by a 5-minute absorption period, irrigation with BSS, and UVA exposure (18mW/cm² for 5 minutes). Preoperative and postoperative visual acuity, refraction, and keratometry at 1, 3, 6, and 12 months were statistically analyzed.

At 12 months, mean keratometry (K mean) improved from 49.68±5.43D preoperatively to 46.45±4.85D, while K max decreased from 58.24±8.53D to 57.04±8.33D. Astigmatism reduced from 4.31±2.96D to 4.00±2.60D. Uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), and manifest refraction spherical equivalent (MRSE) improved significantly from 1.08±0.49, 0.18±0.26, and -7.58±5.96D preoperatively to 0.64±0.52, 0.07±0.29, and -5.43±8.54D at 12 months.

OCT-guided femtosecond laser-assisted ICRS implantation followed by corneal CXL is an effective and efficient treatment for keratoconus and post-LASIK ectasia. The procedure significantly improved visual acuity, refraction, and corneal shape, demonstrating its potential as a long-term therapeutic option.