ECHOGRAPHIC EVALUATION OF PRIMARY CYSTS OF THE IRIS PIGMENT-EPITHELIUM

PURPOSE: Primary cysts of the iris pigment epithelium frequently appea r to be focal elevations of the peripheral iris, To differentiate them from other anterior segment tumors requires the ability to assess the distribution, tissue characteristics, and progression of such lesions , which we accomplished by using anterior segment echography. METHODS: We reviewed the medical records of 49 consecutive patients referred t o the Doheny Eye Institute for echographic evaluation of focal bulging of the peripheral iris. Echography of the anterior segment was perfor med on each patient by using an immersion technique, Clinical examinat ion was also performed on 20 (41%) patients at the time of initial exa mination. RESULTS: We identified 52 iris pigment epithelial cysts in 5 2 eyes of the 49 patients studied. All lesions were single, localized to the posterior iris surface, and demonstrated a well-circumscribed, echolucent structure on B-scan echography, Aver age maximal sagittal t hickness was 1.6 +/- 0.4 mm. Cysts were most frequently located in the inferotemporal temporal quadrant (31%). Minimal increase in size or r egression of lesions was noted in the nine patients (ten eyes) for who m follow-up echographic examinations were available. CONCLUSIONS: Prim ary iris pigment epithelial cysts possess characteristic features with regard to location, size, and internal structure, which can be accura tely documented with echography, Clinically evident lesions tend to be between 1 and 4 mm in maximum sagittal thickness, conform to the cont our of posterior chamber structures without distortion, produce anteri or bulging of the peripheral iris, are preferentially located in the i nferotemporal quadrant, and demonstrate limited potential for growth.