Abstract
Purpose :
To study the biomechanical effects of epithelium-on crosslinking (CXL)
Methods :
It is a prospective observation study conducted at Woolfsen Eye Institute in Atlanta, GA, US. (IRB of Partners HealthCare, the Partners Human Research Committee (PHRC), ChesapeakeIRB (Columbia MD, Pro00023766) and registered with clinicaltrials.gov (NCT03220529). 33 (46 eyes) patients (30±11 yo, F/M: 14/19) with keratoconus undergoing epi-on CXL using riboflavin and UVA light were recruited for the study. Brillouin measurements were obtained preoperatively, and 3 months (n =12 (15 eyes), 31±8 yo, F/M: 6/6) or 6 months (n=14 (15 eyes), 30±10 yo, F/M: 4/10) post-CXL. Forty-one eyes of 26 subjects (38±12 yo, F/M: 16/10) with normal corneas Twenty to forty measurements were obtained to maximize coverage of each cornea. Results were analyzed using descriptive statistics.
Results :
A significant increase in the Brillouin shift ( >25 MHz, paired t-test, p<0.005) was seen in the postoperative measurements in the cone region (r < 1 mm form thinnest point) of keratoconic corneas following CXL, suggesting an increase in stiffness as a result of the surgical procedure. Mean Brillouin shift of the whole corneas increase by ~ 20 MHz.
Conclusions :
Brillouin microscopy is capable of detecting the corneal stiffening effect soon after a corneal crosslinking procedure that has been shown to increase vision and reduce the corneal curvature of corneas with keratoconus. Brillouin microscopy may provide a direct measurement of corneal stiffness that is induced by CXL. Brillouin technology hold a potential for treatment planning and efficacy evaluation.
This is a 2020 ARVO Annual Meeting abstract.