Ultrasound biomicroscopic imaging of posterior chamber phakic intraocular lens.

BACKGROUND: Phakic intraocular lens (IOL) implantation represents a major technique for the correction of high myopia. The STAAR collamer posterior chamber phakic IOL--trade named Implantable Contact Lens--is an emerging technology in refractive surgery. We studied the relative position of the posterior chamber phakic IOL using ultrasound biomicroscopy.

METHODS: The posterior chamber phakic intraocular lens was inserted in 9 eyes of 8 patients with high myopia. Ultrasound biomicroscopy was performed before and after implantation of the phakic IOL to assess its relative position in the anterior segment of the eye. The parameters measured and compared were anterior chamber depth, angle opening distance 500 microns from the scleral spur, iris-crystalline lens contact distance, iris-IOL contact distance, and IOL-crystalline lens distance.

RESULTS: Ultrasound biomicroscopy showed contact between the iris and the IOL in all eyes and between the IOL and the crystalline lens in 8 eyes. Reduction in the anterior chamber depth and localized narrowing of the angle opening were observed in all eyes.

CONCLUSION: IOL-iris touch, IOL-crystalline lens touch, and anterior chamber shallowing raise concerns of pigmentary dispersion, cataractogenesis, and narrow angle glaucoma following posterior chamber phakic intraocular lens implantation. Clinical data are needed to determine if these problems occur.