[Effects of ultraviolet laser beam irradiation on rabbit cornea and lens].

ABSTRACT

Rabbit eyes were irradiated by an ultraviolet laser beam in with to investigate its effects on the corneal endothelium, thickness of the cornea, and lens. An Excimer laser beam (gas; XeCl) with wave length of 308 nm and with energy intensity of 0.02, 0.07, 0.2, 0.6, 1.7, 3.0, 4.0, or 5.1 J/cm2 was irradiated to the right eye using 3 rabbits for each energy intensity (24 rabbits in all) in order to examine changes occurring in the right eye compared with the left eye from immediately after irradiation to 32 days thereafter. The results obtained were as follows 1. Corneal thickness UV laser beam irradiation at 0.02, 0.07, and 0.6 J/cm2 caused immediate thickening of the cornea (p less than 0.01). The cornea thickness returned to normal 14 days later. Irradiation at 3.0 and 4.0 J/cm2 resulted in remarkable thickening, which returned to normal 28 days after irradiation. By irradiation at 5.1 J/cm2, the corneal thickness increased markedly (0.333 +/- 0.019 mm in control eyes and 0.405 +/- 0.05 mm in irradiated eyes) immediately after irradiation. It tended to gradually return to normal and was reduced to the pre-irradiation thickness on the 32nd day after irradiation. 2. Corneal endothelial area and morphology (the number of angles) The area of the corneal endothelium increased after irradiation. However, no significant differences were noted at any energy intensity, because of the larger scattering of the values in the control eyes. The ratio of hexagonal cells tended to decrease even by energy intensities above 0.7 J/cm2. However, no significant differences were found at any energy intensity level.(ABSTRACT TRUNCATED AT 250 WORDS)