Abstract
Purpose :
To investigate the long term effect and safety of collagen crosslinking on patients with bullous kearatopahy in a randomized control manner.
Methods :
Patients with bullous keratopathy (BK) were recruited. If the subjects agreed to participate in the study, they were randomized by drawing envelopes either to receive CXL using riboflavin according to standard protocol as in treating keratoconus (treatment arm) or to receive a sham treatment (control arm). The patient were not informed of their treatment arm.
Patients were assessed pre-treatment and post-treatment at 2 weeks, 1 month, 3 months, 6 months and 12 months by another investigator not performing the CXL so he was blinded to the procedure the patients received.
Primary outcome measures included pain score in visual analogue scale (0-10), central corneal thickness (CCT), and presence of complications. Secondary outcome measures would be visual acuity (VA), corneal clarity (score given by physician B from 0 to 10) and intraocular pressure (IOP).
Results :
Forty-two patients participated in the study treatment, including 21 males and 21 females. There were 26 subjects in the CXL group (62%) and 16 in the control group (38%).
In CXL treatment group, pain score significantly decreased at 2, 4, 12 and 52 weeks comparing to the baseline. No significant changes in BCVA, CCT, IOP and corneal clarity were identified in both control and CXL treatment groups.
There were no side effects reported in the control group. However, in CXL group, 3 patients (12%) suffered from epithelial defect at 4 weeks after CXL, 1 recovered at 12 weeks and 2 of them required subsequent amniotic membrane transplantation (AMT) at 12 weeks. At 12 weeks, another subject was found to have epithelial defect, but spontaneously recovered at 26 weeks.
Conclusions :
CXL decreased pain score throughout the follow up till 12 months although CCT remained grossly unchanged. However, CXL was also associated with more recurrent epithelial defect (12%), and 2 out of the 3 subjects with epithelial defect required AMT. CCT and other parameters remained relatively stable throughout the entire course of follow up. Therefore, CXL may be a treatment options for patients with significant ocular pain. However, patients should be warned of the side effects of CXL, especially recurrent epithelial defect, which might requirement further treatment, including amniotic membrane transplant.
This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.