Intrastromal Corneal Ring Segment Implantation Followed by Simultaneous Topography-Guided Photorefractive Keratectomy and Corneal Cross-Linking for Contact Lens-Intolerant Keratoconus

Abstract

Purpose: This study aimed to evaluate the efficacy and safety of Keraring implantation followed by simultaneous topography-guided photorefractive keratectomy (TGPRK) and corneal cross-linking (CXL) in the management of keratoconus.

Methods: This is a single-center, private practice, retrospective review. Patients with keratoconus who were intolerant to contact lens wear underwent implantation of the Keraring, followed by TGPRK with CXL from 2 to 36 months after implantation. Main outcome measures were uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), refraction (cylinder and spherical equivalent), keratometry (steep, maximum, and central), and central corneal thickness (CCT). Patients were followed up for 3 to 60 months postoperatively.

Results: Fifty-seven eyes from 45 patients were included. The mean time between Keraring and TGPRK/CXL was 6.0 ± 6.0 months. Patients were followed up for a mean of 28.6 ± 20.1 months after Keraring insertion. At 12-month follow-up, there was a statistically significant improvement in mean UDVA (0.94 ± 0.49-0.35 ± 0.23, P < 0.01), CDVA (0.39 ± 0.26-0.17 ± 0.15, P < 0.01), cylinder (-4.97 ± 2.68 to -1.74 ± 1.25, P < 0.01), steep keratometry (51.25 ± 3.37-45.03 ± 2.27, P < 0.01), central keratometry (52.59 ± 4.98-46.99 ± 3.53, P < 0.01), and maximum keratometry (58.78 ± 4.22-50.76 ± 3.42, P < 0.01). These results were sustained at 48-month follow-up. CCT decreased at 12 months after TGPRK (461.84 ± 27.46-418.94 ± 45.62, P < 0.01) and remained stable at 60 months. Postoperatively, 2 eyes (3.51%) had corneal haze, resulting in decrease in CDVA; 1 was treated successfully with repeat PRK; and 1 patient (1.75%) had wound melt due to partial Keraring extrusion, which settled with repositioning.

Conclusions: Keraring implantation followed by simultaneous TGPRK and CXL appears to be effective in the long term in improving UDVA, CDVA, cylinder, CCT, and keratometry in patients with keratoconus who are intolerant to contact lenses.