Transepithelial accelerated corneal crosslinking for keratoconus eyes with maximum keratometry values larger than 58 diopters

Abstract

Purpose: To evaluate the safety and efficacy of transepithelial accelerated corneal crosslinking (CXL) for advanced keratoconus eyes with maximum keratometry (Kmax) values >58 diopters (D).

Setting: Department of Ophthalmology, Eye and ENT Hospital, Fudan University, Shanghai, China.

Design: Prospective parallel control study.

Methods: 41 keratoconus eyes from 41 patients (mean age, 21.93 ± 5.48 years) who underwent transepithelial accelerated CXL were included prospectively. The enrolled eyes were divided into 2 groups according to their Kmax values (Group A, Kmax ≥58.0 D; Group B, Kmax <58.0 D). The examinations including assessment of uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), corneal topography, and corneal endothelial cell density count were conducted preoperatively, at 1 day, 1 month, 3 months, 6 months, and 1 year postoperatively.

Results: All 41 eyes finished 1 year follow-up. No statistical difference was noted between the mean UDVA and CDVA in both groups throughout the follow-up duration. At 1-year postoperative follow-up, the CDVA increased by ≥2 lines in 45% (9/20) and 28.6% (6/21) eyes in Groups A and B, respectively. The mean preoperative Kmax in Groups A and B were 62.51 ± 3.34 D and 49.98 ± 4.32 D, respectively, and that at postoperative 1-year follow-up were 61.94 ± 4.11 D and 50.24 ± 4.72 D, respectively. The Kmax values of 30% (6/20) eyes in Group A and 4.8% (1/21) eyes in Group B decreased by more than 1 D. Deduction of flat K, steep K, mean K, and Kmax showed no significant difference between the 2 groups at 1-year postoperative follow-up. Moreover, 20% (4/20) and 23.8% (5/21) of eyes in Groups A and B, respectively, showed progress at postoperative 1-year follow-up.

Conclusions: Transepithelial accelerated CXL can safely treat advanced keratoconus eyes with Kmax values ≥58.0 D with some extent of efficacy and has similar progressive rate as Kmax values <58.0 D.

Figure 1.

Changes in Snellen lines (%) of UDVA (A) and CDVA (B) at 1-year postoperative follow-up in both groups.

Figure 2.

Difference in ΔKmax between Groups A (Kmax ≥58 D) and B (Kmax <58 D) at each postoperative visit. ΔKmax is defined as the difference in Kmax preoperative and each postoperative follow-up.

Figure 3.

Changes in Kmax (ΔKmax) for individual patients in Groups A (Kmax ≥58 D) and B (Kmax <58 D) at 1-year postoperative follow-up. ΔKmax is defined as the difference in Kmax preoperative and 1-year postoperative follow-up. Dashed lines indicate 1 D of change.