Abstract
Purpose :
The efficacy and safety of corneal crosslinking (CXL) for keratoconus have been reported by several investigators, however, there has been no investigation with large number of Japanese patients. We retrospectively investigated the outcomes of CXL in Japanese patients with progressing keratoconus.
Methods :
A total of 122 eyes of 106 patients with progressing keratoconus (81 males and 25 females, 21.9 ± 6.5 years of age) were investigated. CXL was performed using the epithelium-off method. After instillation of 0.1% (w/v) riboflavin for 20 min, the thinnest corneal thickness (TCT) was measured. When the TCT was less than 400 µm, hypotonic solution was instilled until the corneal stroma had swollen to a thickness of ≥400 µm. Then samples were irradiation with UVA (3.0 mW/mm2) for 30 min (conventional CXL; C-CXL) or 18.0 mW/mm2 for 5 min (accelerated CXL; A-CXL) using KERA-X® (Peschke, Germany) or KXL-System® (Avedro, USA). The best-corrected visual acuity (BCVA), manifest refraction, steepest keratometric value (Ks), TCT, and corneal endothelial cell density (ECD) were analyzed pre- and postoperatively (for up to 12 months after the procedure). Corneal flattening was quantified as a delta Ks value (the difference between the pre- and postoperative Ks values).
Results :
BCVA, TCT, and ECD did not change significantly after CXL. The Ks did not change significantly for up to 6 months, but was significantly reduced 12 months after CXL (p < 0.0001). The BCVA, TCT, and ECD of C-CXL and A-CXL did not differ. Ten eyes (8.2%) exhibited further keratoconus progression (>1.0 D Ks) during the 12 postoperative months. Age, sex, and preoperative factors were not significantly correlated with progression after CXL. The delta Ks values were negatively correlated with the preoperative Ks values and positively with the preoperative TCTs (p < 0.0001 and p < 0.0001, respectively). One eye exhibited sterile infiltration and another showed a persistent corneal epithelial defect immediately after the procedure. Mild to moderate stromal opacity was observed in nine eyes after 3 months; however, no eyes exhibited reduced visual function.
Conclusions :
CXL was effective for halting keratoconus progression in Japanese patients. Accelerated UVA irradiation (18 mW/mm2 for 5 min) yielded outcomes no different from those of conventional CXL in both efficacy and safety. Flattening was more apparent in advanced cases.
This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.