Photochemical Crosslinking of Upper Eyelid Tarsus Using Rose Bengal and Green Light.

Purpose: Crosslinking of the tarsal plate has shown promising effects to possibly increase tissue stiffness as a potential management for eyelid laxity in floppy eyelid syndrome. Here, the authors evaluate the crosslinking effect of rose bengal (RB) and green light (G-Light) on porcine tarsus tissue.

Methods: Thirty porcine upper eyelids' tarsoconjunctival tissues were crosslinked with riboflavin 5'-monophosphate sodium salt and ultraviolet-A (UV-A) or RB+G-Light. Un-crosslinked tarsoconjunctival tissues served as controls (N = 10 per group). Biomechanical tests were performed using a uniaxial actuator machine. Load (N) and displacement (tissue elongation, mm) were recorded for 6 seconds. Stress, strain, and Young's modulus were calculated using the continuously recorded data. One-way analysis of variance with post hoc Tukey's test was used to compare means.

Results: Load and tissue elongation at 6 seconds were 19.5 ± 1.8 N and 0.6 ± 0.05 mm for RB+G-Light, 12.6 ± 2.5 N and 0.6 ± 0.01 mm for riboflavin+UV-A, and 3.1 ± 0.2 N and 1.2 ± 0.01 mm for control tissues (p = 0.003 and p < 0.0001). The average Young's modulus of the control tarsoconjunctival tissues was 7.1 ± 1.6 MPa, significantly lower than those crosslinked with RB+G-Light (46.5 ± 6.4 MPa, p = 0.002) or riboflavin +UV-A (28 ± 4.5 MPa, p = 0.016).

Conclusions: This is the first study that shows RB+G-Light may increase the biomechanical strength of porcine tarsoconjunctival tissue. Future studies on human tarsal plates are necessary to evaluate the efficacy of the proposed photochemical crosslinking methodology and future utility.