EFFECTS OF PAX6 MUTATIONS ON RETINAL FUNCTION - AN ELECTRORETINOGRAPHIC STUDY

PURPOSE: To investigate the retinal function in aniridic patients with documented PAX6 mutations to determine the range of electroretinogram abnormalities in aniridic patients and to relate electroretinogram fi ndings with specific PAX6 mutations. METHODS: Eleven patients with typ ical aniridia and fully characterized PAX6 mutations underwent electro retinography. RESULTS: In all 11 patients, electroretinogram recording s were abnormal, ranging from mild to severe. Rod-related and cone-rel ated activities were equally affected. The amplitude of the oscillator y potentials was the most reduced, followed by the b-wave, then to a m ilder degree the a-wave. Mutations affecting the paired domain of the PAX6 protein had the biggest impact on the electroretinogram amplitude s. Implicit times were increased in a subgroup with mutations affectin g only the homeodomain. CONCLUSION: Patients with aniridia have varyin g degree of retinal dysfunction, ranging from severely abnormal to alm ost normal. The paired domain appears to have more impact on retinal f unction than other regions of the PAX6 protein, It is unclear whether mutations affecting the homeodomain lead to alteration of the photorec eptor function. (Am J Ophthalmol 1998;126: 211-218. (C) 1998 by Elsevi er Science Inc. All rights reserved.).