Офтальмохирургия (Apr 2013)
Lens phacoemulsification in cases of anterior chamber angle block after laser iridectomy
Abstract
ABSTRACT Purpose. To estimate by ultrasound biomicroscopy the features of iridocilliary zone in cases of primary angle closure glaucoma (PACG) and uncompensated intraocular pressure (IOP) level after laser iridectomy and to determine indications to pathogenic operation. Material and methods. 43 patients (48 eyes) with PACG and uncompensated intraocular pressure (IOP) level after laser iridectomy have been selected for this investigation. The comparative group included 38 health persons (46 eyes) without glaucoma and with transparent lens. All cases and controls underwent complete ophthalmic examinations. Parameters of iridocilliary structures, configuration of the anterior and posterior chambers were measured using ultrasound biomicroscopy (UBM «Humphrey-840», USA). Results. UBM allowed determining the specific evidences of block induced by lens in all cases of PACG, despite having a patent laser peripheral iridectomy. In these cases there was the displacement lens-iris diaphragm forward independent of lens thickness and its opacity. Distance between iris and lens shortened up to 0.18±0.01mm and was significantly less than normal eyes (0.33±0.01mm). The posterior chamber has been lost the correct three-angular configuration decreasing of its area and volume. The indications for phacoemulsification were determined in all cases of block induced by lens independed of its opacity. After phacoemulsification with IOL intraocular pressure decreased from a mean preoperative level by 11.6±1.9mmHg. Visual acuity became better: 0.8-1.0 in 66.7%. Phacoemulsiaicftion eliminates block induced by lens restoring anatomic topographic relationships of structures of iridocilliary zone in all cases. Anterior chamber depth increased significantly: from 1.58±0.03 mm preoperatively to 3.16±0.08mm postoperatively. Cornea-iris contact was disappeared and correct configuration of posterior chamber was restored. Conclusion. Lens phacoemulsification is pathogenic operation in cases of PACG with anterior chamber angle block induced by lens after laser iridectomy. Phacoemulsiaicftion allowed to decrease of intraocular pressure, to achieve of its stability and to restore anatomic topographic relationships of iridocilliary zone.
