AIM: Membrane formation in the chamber angle induced by argon laser trabeculoplasty (ALT) can be a cause of treatment failure. Identification of risk factors for membrane formation was the primary aim of this retrospective study. METHODS: Semithin sections of trabeculectomy specimens obtained in a 2 year period were examined by light microscopy. 122 eyes which were treated with one or more ALTs before trabeculectomy were identified. In 46 eyes, a sufficient amount of trabecular meshwork was obtained to permit morphological analysis. RESULTS: Eyes treated with ALT had a significantly higher incidence of membrane formation (p=0.001). In 23/46 specimens a cellular and collagenous membrane was observed covering the entire trabecular meshwork. In 14/23 specimens (61%), this membrane was readily visible at low power magnification (x40). Comparison of these eyes with those without membrane formation revealed a significant difference in the number of ALTs (mean 2.07 (SD 0.73) v 1.48 (0.59); p=0.026) and in preoperative IOP (32.0 (9. 7) v 26.2 (8.4) mm Hg; p=0.04). CONCLUSIONS: Membrane formation in the chamber angle is a frequent cause of ALT failure. The major risk factor is the number of ALTs performed.
AIM: Membrane formation in the chamber angle induced by argon laser trabeculoplasty (ALT) can be a cause of treatment failure. Identification of risk factors for membrane formation was the primary aim of this retrospective study. METHODS: Semithin sections of trabeculectomy specimens obtained in a 2 year period were examined by light microscopy. 122 eyes which were treated with one or more ALTs before trabeculectomy were identified. In 46 eyes, a sufficient amount of trabecular meshwork was obtained to permit morphological analysis. RESULTS: Eyes treated with ALT had a significantly higher incidence of membrane formation (p=0.001). In 23/46 specimens a cellular and collagenous membrane was observed covering the entire trabecular meshwork. In 14/23 specimens (61%), this membrane was readily visible at low power magnification (x40). Comparison of these eyes with those without membrane formation revealed a significant difference in the number of ALTs (mean 2.07 (SD 0.73) v 1.48 (0.59); p=0.026) and in preoperative IOP (32.0 (9. 7) v 26.2 (8.4) mm Hg; p=0.04). CONCLUSIONS: Membrane formation in the chamber angle is a frequent cause of ALT failure. The major risk factor is the number of ALTs performed.
Authors: R M Feldman; R L Gross; G L Spaeth; W C Steinmann; R Varma; L J Katz; R P Wilson; M R Moster; D Spiegel Journal: Ophthalmology Date: 1989-03 Impact factor: 12.079
Authors: Raul E Ruiz-Lozano; Jimena Alamillo-Velazquez; Gustavo Ortiz-Morales; Lucas A Garza-Garza; Manuel E Quiroga-Garza; Carlos Alvarez-Guzman; Alejandro Rodriguez-Garcia Journal: Int Ophthalmol Date: 2022-08-13 Impact factor: 2.029