[Evaluation of retinal light damage in aphakic chicken eyes using monochromatic ERGs]

We evaluated light damage to cones using monochromatic electroretinograms (ERGs) in lensectomized chicken eyes. During exposure of the retina to light to produce light damage, an ultraviolet-absorbing (UV) filter was placed in front of some eyes (non-UV irradiated group) and not placed in front of others (UV irradiated group). Blue cone and red cone ERGs were recorded from the UV irradiated group before and at 1, 3, 5, 10, 15, and 30 days after the damage, and from the non-UV irradiated group before and at 1 day after the light exposure. From the ERG.b-wave amplitudes, spectral sensitivities of the blue and red cones were obtained. The blue cone sensitivity of the UV irradiated group was significantly attenuated compared with the non-UV irradiated group (p < 0.01), but recovered between 5 and 15 days after the damage. The present study suggested that the blue cones are more susceptible to light stress than the red cones and that this degree of blue cone damage is reversible. Ultraviolet rays seem to be mainly responsible for light damage to the blue cones.