Ultrasound biomicroscopy in pigmentary glaucoma

Purpose: To evaluate the anatomical relationships of the iris in pigmentary glaucoma before and after laser iridotomy and to evaluate the effect on in traocular pressure. Methods: Ultrasound biomicroscopy (UBM, Humphrey-Zeiss) of the anterior seg ment was performed in 28 eyes of 28 patients (20 male, 8 female, mean age 4 3 years, mean untreated IOP 24,3 mmHg) with pigmentary glaucoma before and after laser iridotomy. The slope of intraocular pressure was documented. Me an follow-up was 9 months. For statistical analysis the Wilcoxon test was u sed. Results: Ten out of 28 eyes showed iridozonular contact and concavity of th e midperipheral iris. Laser iridotomy resulted in a significant pressure dr op (P<0.05) in these 10 eyes (24.6 mmHg to 18.3 mmHg). Eighteen eyes, howev er, did not show iridozonular contact and intraocular pressure did not drop sufficiently (P>0.05; 25.1 mmHg to 23.1 mmHg) after laser iridotomy. Conclusion: The results show that iridozonular contact does not exist in ev ery patient with pigmentary glaucoma. Therefore, it seems possible that mor e than one pathogenic mechanism is involved in pigmentary glaucoma. In pati ents with iridozonular contact, however,laser iridotomy significantly reduc es intraocular pressure.