Ultrasound biomicroscopy of ZSAL-4 anterior chamber phakic intraocular lens for high myopia

Purpose: To evaluate the intraocular location and anatomic relationship to other structures of the ZSAL-4 angle-supported anterior chamber phakic intr aocular lens (IOL) for high myopia using ultrasound biomicroscopy (UBM). Setting. Clinica de Nuestra Senora de la Concepcion, Funclacion Jimenez Dia z, and Instituto de Investigaciones Oftalmologicas Ramon Castroviejo, Madri d, Spain. Methods: Eight phakic myopic eyes corrected by ZSAL-4 angle-supported anter ior chamber phakic IOLs were examined by UBM. The distance between the corn eal endothelium and the IOL at the central and peripheral cornea and betwee n the phakic IOL and the iris was measured. Results: The mean distance between the central cornea and the IOL was 2361. 37 mum +/- 109.62 (SD); between the edge of the IOL optic and the endotheli um, 1646.24 +/- 27.06 mum; and between the IOL and the iris, 354.46 +/- 41. 61 mum. The IOL footplates appeared to be correctly positioned in the anter ior chamber angle in all eyes. Conclusion: The space between the IOL and the endothelium was greater in ey es with the ZSAL-4 angle-supported phakic IOL than in eyes with other angle -supported phakic IOLs. The possibility of intermittent contact between the IOL edge and the midperipheral cornea plays a minor role in the mechanism of endothelial damage with this lens model. (C) 2001 ASCRS and ESCRS.