Long-Term Change In Corneal Curvature Following Corneal Crosslinking For Keratoconus

Published 2026 - 44th Congress of the ESCRS

Reference: POCOR173 | Type: Free paper | DOI: 10.82333/t2vj-xq78

Authors: Dr Naoko Kato* ¹ , Dr Emiko Miki ¹ , Dr Teruki Fukumoto ¹ , Dr Ikuko Toda ¹

¹Minamiaoyama Eye Clinic,Tokyo,Japan

Purpose

Corneal crosslinking (CXL) is an effective and safe method to halt the progression of keratoconus. However, some cases showed re-progression even after the initial CXL and require the second CXL. The timing of the re-CXL has been reported from 1 year to several years after the initial CXL. We investigated in this study the postoperative outcome of eye with keratoconus, who underwent the CXL and could be followed 5 years, and evaluated the factors affecting re-progression or flattening of the corneal curvature after the surgery.

Setting

Minamiaoyama Eye Clinic

Methods

We retrospectively analyzed 63 eyes of 63 patients (50 males, 13 females; mean age 21.5 +/-7.0 years) with keratoconus who underwent CXL and were followed for at least 5 years. CXL was performed using the accelerated method with corneal epithelial removal and ultraviolet-A irradiation at 18.0 mW/cm² for 5 minutes. Postoperative outcomes were primarily assessed by visual acuity and steepest keratometric value (Ks) evaluated by corneal tomography. ΔKs was calculated as postoperative Ks minus preoperative Ks. Failure was defined an increase in Ks of ≥ 1.0 D (∆Ks ≥ 1.0 D). Re-CXL was performed when postoperative progression was observed, defined as a continuous increase of more than 1.0D in astigmatism, spherical equivalent, or Ks.

Results

The failure rate was 22.2% at 1 year, 17.5% at 3 years, and 25.4% at 5 years after the initial CXL. The ΔKs was −0.40 ± 2.90 D at 1 year, −1.46 ± 3.35 D at 3 years, and −1.42 ± 3.97 D at 5 years postoperatively. Ks significantly flattened between 1 and 3 years (p < 0.001), whereas no significant change was observed between 3 and 5 years (p = 0.75). Eyes with preoperative Ks > 55 D demonstrated greater flattening (−2.27 ± 3.65 D at 1 year, −4.29 ± 4.23 D at 3 years, and −4.58 ± 5.08 D at 5 years) compared with those with Ks ≤ 55 D (+0.47 ± 1.99 D, −0.14 ± 1.70 D, and +0.04 ± 2.16 D, respectively; p = 0.004, p < 0.001, and p < 0.001). One 17-year-old boy underwent repeat CXL. However, age was not significantly associated with failure rate.

Conclusions

CXL induced corneal flattening in majority of eyes with keratoconus. The flattening effect was more pronounced in eyes with advanced keratoconus (Ks > 55D) and progressed up to 3 years postoperatively, with no significant additional change thereafter. However, the failure rate increased at 5 years, suggesting the possibility of late re-progression after the initial CXL. Therefore, patients undergoing CXL procedure require long-term follow-up, as corneal curvature changes may occur even beyond 3 years after surgery.