IRIDOSCHISIS - HIGH-FREQUENCY ULTRASOUND IMAGING - EVIDENCE FOR A GENETIC-DEFECT

Aims - To elucidate changes in the anatomy of the anterior chamber ass ociated with iridoschisis, a rare form of iris atrophy, and their pote ntial contribution to angle closure glaucoma. Methods - Both eyes of a 71-year-old woman with bilateral iridoschisis and fibrous dysplasia a nd her asymptomatic 50-year-old daughter were scanned with a very high frequency (50 MHz) ultrasound system. Results - The symptomatic patie nt exhibited diffuse changes in the iris stoma with an intact posterio r iris pigmented layer in both eyes. These changes were clinically com patible with the lack of iris transillumination defects. Additionally. iris bowing with a resultant narrowing of the angle occurred. The asy mptomatic daughter showed discrete, but less severe iris stromal chang es. Conclusion - This is the first detailed study of high frequency ul trasonic imaging of the iris in iridoschisis. The observed structural changes suggest angle narrowing by forward bowing of the anterior iris stroma may be a mechanism of IOP elevation in this condition. The ult rasonic detection of iris changes in the asymptomatic daughter of the symptomatic patient and the association of iridoschisis with fibrous d ysplasia suggest a possible genetic component in the pathogenesis of t his condition.