This study was done to check changes of retinal and choroidal parameters, scleral biomechanical strength, and ocular histopathology after scleral ultraviolet-A (UVA) cross-linking (CXL) in rhesus monkeys eyes, and to evaluate the safety and long-term biomechanical stability of scleral CXL for preventing myopia from progressing further in clinic.

The sample of six male rhesus monkeys were randomized to receive UVA-CXL procedures applied on the superotemporal equatorial sclera.

For central retinal thickness, choroidal thickness, and flow density of central retinal superficial vascular networks, no statistical difference was noted between CXL eyes and control eyes at 12 months postoperatively (P > .05). The biomechanical stability of sclera was increased. The scleral stress and Young modulus at 8% strain corresponded to 184% and 183%, respectively, of the control values at 12 months (each P < .001). No retinal damage was detected on histology in scleral CXL eyes. There was no obvious difference between scleral CXL eyes and control eyes by hematoxylin–eosin and TUNEL staining (P > .05).

The study concluded that scleral CXL with riboflavin/UVA in rhesus monkey eyes could strengthen the biomechanical properties of scleral tissues and maintain the stability for 12 months postoperatively. The UVA-CXL on the sclera of rhesus monkey eyes seems to be effective and safe