Efficacy and Safety of Accelerated Transepithelial Corneal Crosslinking in Non-Pediatric Patients with Progressive Keratoconus: Insights from a Retrospective Cohort Study

Abstract

Background/objectives: Transepithelial accelerated corneal crosslinking (TE-ACXL) is a minimally invasive approach for stabilizing progressive keratoconus while preserving the corneal epithelium. This study aims to evaluate changes in visual acuity, refractive error, and corneal parameters before and six months after TE-ACXL.

Methods: A retrospective analysis was conducted on 30 eyes from 20 patients who underwent TE-ACXL between May 2021 and June 2023. Variables included were uncorrected distance visual acuity (UDVA) and corrected distance visual acuity (CDVA), spherical and cylindrical refractive error, and corneal tomography parameters such as maximum keratometry (Kmax), the symmetry index (Si), the keratoconus vertex (KV), Baiocchi-Calossi-Versaci index (BCV), thinnest corneal thickness (TCT), and central corneal thickness (CCT).

Results: CDVA improved from 0.20 ± 0.22 to 0.06 ± 0.11 LogMAR (p = 0.004), while UDVA improved from 0.47 ± 0.35 to 0.29 ± 0.30 LogMAR (p < 0.001). Spherical and cylindrical refractive error showed significant reductions from -2.18 ± 3.05 D to -1.31 ± 1.84 D (p < 0.001) and -3.33 ± 1.98 D to -2.33 ± 1.52 D (p < 0.001), respectively. Pachymetry values decreased significantly, with TCT reducing from 466.43 ± 31.24 µm to 438.63 ± 30.54 µm (p < 0.001) and CCT from 480.80 ± 33.24 µm to 451.23 ± 29.26 µm (p < 0.001). Kmax showed a modest reduction (52.33 ± 3.51 D to 51.19 ± 3.63 D, p < 0.001), while other topographic indices, including Si, KV, and BCV, exhibited minor, non-significant changes, except for BCV back (p = 0.031).

Conclusions: TE-ACXL was associated with significant improvements in visual acuity and refractive stability at six months postoperatively while maintaining a favorable safety profile. The procedure may serve as an effective option for early intervention in progressive keratoconus.

Keywords: corneal tomography; keratometry; pachymetry; progressive keratoconus; refractive stability; transepithelial accelerated corneal crosslinking; visual acuity.

Figure 1

Box plots of preoperative and postoperative visual and corneal parameters. (A) Logarithm of the minimum angle of resolution (LogMAR) uncorrected distance visual acuity (UDVA), (B) logarithm of the minimum angle of resolution (LogMAR) corrected distance visual acuity (CDVA), (C) spherical refractive error (sphere, in diopters [D]), (D) cylindrical refractive error (cylinder, in diopters [D]), (E) maximum keratometry (max K, in diopters [D]), (F) back Baiocchi–Calossi–Versaci index (BCV back), (G) thinnest corneal thickness (TCT, in micrometers [µm]), and (H) central corneal thickness (CCT, in micrometers [µm]). Colored dots are outliers.

Figure 1

Box plots of preoperative and postoperative visual and corneal parameters. (A) Logarithm of the minimum angle of resolution (LogMAR) uncorrected distance visual acuity (UDVA), (B) logarithm of the minimum angle of resolution (LogMAR) corrected distance visual acuity (CDVA), (C) spherical refractive error (sphere, in diopters [D]), (D) cylindrical refractive error (cylinder, in diopters [D]), (E) maximum keratometry (max K, in diopters [D]), (F) back Baiocchi–Calossi–Versaci index (BCV back), (G) thinnest corneal thickness (TCT, in micrometers [µm]), and (H) central corneal thickness (CCT, in micrometers [µm]). Colored dots are outliers.