Gonioscopic changes after implantation of a posterior chamber lens in phakic myopic eyes

Purpose: To evaluate the effects of posterior chamber implantation of phaki c intraocular lenses on angle structures and the correlation with intraocul ar pressure (IOP). Setting: Department of Ophthalmology, University Hospital of Vienna, Vienna , Austria. Methods: A Staar implantable contact lens (ICL) was implanted in 20 white p atients (34 eyes) with high myopia. The patients were followed for a mean o f 2.3 years (range 0.8 to 6.0 years), Two subgroups were created: One had a follow-up of 2.4 to 6.0 years and the other, 0.8 to 2.3 years. The mean sp herical power of the implanted ICL was -16.8 diopters (D) (range -9.0 to -2 1.0 D). The angle structures were examined by gonioscopy using the Spaeth t echnique, and optical pachymetry and IOP were measured in dilated and undil ated pupils. Trabecular pigmentation was measured semiquantitatively. The I CL models included a few prototypes (6 eyes), the V2 model (10 eyes), the V 3 model (6 eyes), and the V4 model (12 eyes). Results: The anterior chamber angle was between 11 and 20 degrees in 41% of eyes, between 21 and 30 degrees in 21%, larger than 30 degrees in 21%, and 10 degrees or smaller in 17%, An apparent iris root insertion was above Sc hwalbe's line in 6% of eyes, behind Schwalbe's line in 12%, at the scleral spur in 67%, and in a deep angle recess behind the scleral spur in 15%. The curvature of the iris was regular in 19 eyes and steep in 15 eyes. The mea n pigmentation in all 4 quadrants was 1.3. (Grade 1 was defined as trace pi gmentation.) The mean pachymetry from the endothelium to the ICL anterior s urface was 2.7 mm and from the endothelium to the anterior surface of the c rystalline lens, 3.2 mm. The mean IOP was 14.1 mm Hg in undilated pupils an d 12.1 mm Hg in dilated pupils. There was no correlation between angle pigm entation and IOP. Conclusion: Trace pigmentation in the trabecular meshwork was common after ICL implantation. However, there was no direct influence on IOP. Long-term follow-up is necessary to evaluate the effect and progress of trabecular pi gmentation in eyes with an (C) 2001 ASCPS and ESCRS.