Nonsense mutations have been identified in two rod phototransduction proteins, arrestin  and rhodopsin kinase (RK) ,both involved in terminating activation of the phototransduction cascade and thereby restoring photoreceptor sensitivity after exposure to light. In Oguchi disease the rods therefore behave as if they are light adapted and thus unresponsive to light at low levels of illumination. The key function, of both rhodopsin kinase and arrestin, in the normal deactivation and recovery of the photoreceptor after exposure to light, is entirely consistent with the delayed recovery seen in Oguchi disease. Evidence from knock-out mice models suggests that patients with RK or arrestin mutations may be more susceptible to light-induced retinal damage; it may therefore be advisable to encourage patients to wear tinted spectacles, thereby restricting excessive light exposure [8,9].
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