PURPOSE: To evaluate the anatomical relationships of the iris in pigmentary glaucoma before and after laser iridotomy and to evaluate the effect on intraocular pressure. METHODS: Ultrasound biomicroscopy (UBM, Humphrey-Zeiss) of the anterior segment was performed in 28 eyes of 28 patients (20 male, 8 female, mean age 43 years, mean untreated IOP 24.3 mmHg) with pigmentary glaucoma before and after laser iridotomy. The slope of intraocular pressure was documented. Mean follow-up was 9 months. For statistical analysis the Wilcoxon test was used. RESULTS: Ten out of 28 eyes showed iridozonular contact and concavity of the midperipheral iris. Laser iridotomy resulted in a significant pressure drop (P <0.05) in these 10 eyes (24.6 mmHg to 18.3 mmHg). Eighteen eyes, however, 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 every patient with pigmentary glaucoma. Therefore, it seems possible that more than one pathogenic mechanism is involved in pigmentary glaucoma. In patients with iridozonular contact, however, laser iridotomy significantly reduces intraocular pressure.
