Abstract
Purpose:
To demonstrate the effect of scleral crosslinking by the photosensitizer riboflavin and ultraviolet A on the development of axial myopia in a rabbit eye model.
Methods:
Twenty two, 13 day-old new zealand white rabbits were divided equally to control and study groups. The eyes axial lengths were determined by A-scan ultarsonography. Only the right eye in each rabbit had surgery. Eleven eyes in the control group had 360 degrees conjunctival peritomy followed by tarrsorhaphy. Eleven eyes in the study group had 360 degrees conjunctival peritomy and scleral crosslinking followed by tarrsorhaphy: 0.1% riboflavin-5-phosphate dextran free (Concept for pharmacy Ltd. Kfar-Saba, Israel) was dropped onto the scleral irradiation zone 20 seconds before the irradiation and every 20 seconds during the 200 sec. irradiation time. Each eyeball was divided to four quadrants and every quadrant had two or six scleral irradiation zones ( 8 eyes had two and 3 eyes had six) - each zone had a radius of 2 mm and an area of 0.2 cm2. UVA irradiation (370 nm) was applied over the sclera, which was irradiated at 570 mW/cm2 for an area of 0.2 cm2. This method provides a total UVA light dose of 5.7 J/cm2. Fifty five days later, the tarrsorhaphies were removed and the eyes had a second A-scan ultrasonography for axial length measurement.
Results:
In the control group the mean right eye axial length was 10.50+ 0.67 mm before eyelid suture and 15.69+ 0.39 mm 55 days later, with a mean difference of 5.19+ 0.85 mm. In the experimental group the mean right eye axial length was 10.68+ 0.74 mm before eyelid suture and 14.29+ 0.3 mm 55 days later, with a mean difference of 3.61+ 0.76 mm. This difference was statistically significant (p<0.001, Mann-Whitney non-parametric test).
Conclusions:
Scleral crosslinking by the photosensitizer riboflavin and ultraviolet A is an effective procedure to prevent axial elongation induced by occlusion in a rabbit eye model.
Keywords: 605 myopia •
708 sclera