Corneal collagen cross-linking with and without simultaneous intrastromal corneal ring segment implantation: One-year pilot study

Abstract

Aim: The aim of this study was to assess and compare the visual, refractive, and topographic outcomes of keratoconic eyes treated with corneal collagen cross-linking combined with and without same day intrastromal corneal ring segment over the first 12 months. Methods: This prospective randomized study analyzed 38 eyes of 30 consecutive keratoconus patients aged 26.21 ± 6.97 (range = 15–41) years. A total of 20 eyes were treated with collagen cross-linking alone, and 18 eyes underwent collagen cross-linking combined with simultaneous femtosecond laser-assisted intrastromal corneal ring segment. Visual acuity, manifest refraction, and corneal topography (using a rotating Scheimpflug topographer) were assessed and compared between the two groups at baseline, 6, and 12 months. Results: On an average follow-up duration of 12.2 ± 0.50 (range = 11–13) months, both collagen cross-linking alone and collagen cross-linking with simultaneous intrastromal corneal ring segment implantation were effective. However, collagen cross-linking plus intrastromal corneal ring segment resulted in an additional improvement of uncorrected distance visual acuity of 0.16 (95% confidence interval = 0.01 to 0.32) logarithm of the minimum angle of resolution units (p = 0.035), cylindrical power by 1.16 D (95% confidence interval = 0.25 to 2.06, p = 0.014), and spherical equivalent by 1.40 D (95% confidence interval = −2.71 to −0.08, p = 0.038) at 1 year. During the study period, no serious intraoperative or postoperative complications were noted in either group. Conclusion: One-year follow-up results suggest that collagen cross-linking with simultaneously combined intrastromal corneal ring segment implantation could yield an additive visual and refractive outcome. The combined procedure is safe and merits consideration for the treatment of progressive keratoconus to achieve better visual rehabilitation.

Evaluation of the effectiveness of combined staged surgical treatment in patients with keratoconus

“…Coshkunseven et al reported an efficacy and safety of combined treatment, including posterior chamber toric phakic Visian ICL implantation after Keraring ICRS implantation followed by CXL in a three-step procedure in 14 keratoconic eyes with extreme myopia and astigmatism [ 16 ]. These works present mainly the results of combined treatment and there are just a few studies comparing the efficacy of various types of combined treatment [ 7 , 23 ]. Hosny et al presented the comparative results of two variations of combined surgical treatment in keratoconus, including different CXL types: a combination of intra-tunnel CXL with ICRS implantation and a combination of epithelium-off CXL with ICRS in 20 eyes.…”

“…One of the strengths of our study is that we compared not only the results of a combined keratoconus treatment method (CXL and ICRS) with non-combined options [ 1 , 5 , 7 , 12 ], but also different types of two-stage surgical treatment of keratoconus with the use of transepithelial TG-PRK. CXL and ICRS, as well as a combined version (CXL+ICRS) followed by TG-PRK are more clinically effective than methods without use of TG-PRK.…”

“…Keratoconus is a progressive bilateral pathology of cornea, which is manifested by its thinning and protrusion that lead to astigmatism and deterioration of vision [ 1 ]. Different treatment options, such as spectacles and contact lenses [ 2 ], intrastromal corneal ring segments (ICRS) [ 3 – 7 ], keratoplasty (penetrating and deep anterior lamellar), corneal collagen cross-linking (CXL) [ 8 – 11 ] with topography-guided customized excimer laser ablation treatment—photorefractive keratectomy (PRK) [ 12 – 21 ], and combinations of the above-mentioned methods [ 16 , 21 – 23 ] with the application of novel ray-tracing excimer laser customization [ 24 ] could be used in patients with keratoconus, depending on its severity and grade. All treatment methods are reported to be effective and safe.…”

“…However, longer-term postoperative complications and a high rate of postoperative disease progression made confirmation of the safety and stability of the procedure challenging [ 12 ]. Interesting data about the clinical efficacy of the combination of ICRS with CXL in the treatment of keratoconus was presented by different researchers [ 4 – 7 , 23 ]. A more extended and detailed review of the protocols for the combined use of CXL (CXL plus) with different other treatment modalities demonstrates that further studies are required to determine the most effective treatment strategy [ 23 ].…”

Keratoconus: A Review of Medical and Surgical Options

“…A prospective study suggested that CXL with simultaneous ICRS implantation gives an additional improvement in UDVA with significant reduction in cylinder and spherical equivalent. 24 Debate still exists as to which procedure should be performed first, with an additional option of performing the procedures simultaneously. A 2018 meta-analysis reviewing best corrected visual acuity (BCVA) and uncorrected visual acuity (UCVA) outcomes for those patients undergoing subsequent (CXL then ICRS) versus simultaneous procedures found superior refractive outcomes in the patient group undergoing simultaneous procedure.…”