RISK-FACTORS FOR TRABECULECTOMY FAILURE

Background Trabeculectomy is today the filtering procedure of choice, because complications are rare and success-rates high. A modification of our technique (fornix-based conjunctival flap closed by a running s uture) introduced 3 years ago, has lead us to this retrospective asses sment of complications and success-rates. Some of the risk factors for failure are known, others however remain obscure. This retrospective series was also used to further identify some of these risk factors fo r trabeculectomy failure. Patients and Methods All 388 trabeculectomie s performed between January 1992 and June 1994 at our hospital were in cluded in the study. Important pre- and postoperative data were retros pectively assessed from patients case notes, with a special interest i n the course of post-operative intra-ocular pressure (IOP). Two major groups were differentiated: Those with open-angle glaucoma (GAG) (i.e. primary open-angle glaucoma (POAG), pseudoexfoliation glaucoma (PEX) and pigment dispersion syndrome(PDS)), and other various glaucoma diag noses. Risk factors were assessed using Cox-proportional hazard model adopting three different criteria for success. Results The best succes s-rate after 12 months of follow-up had patients with narrow angle gla ucoma (93.1%)(at least those suitable for filtering surgery), followed by patients with POAG (92.8%), 2 degrees open-angle glaucoma (81.8%), aphakic (75%), juvenile (70.6%) and PDS (52.9%). Pseudophakia and dev elopment of an encapsulated bleb (Tenon' cyst) were identified as sign ificant (p < 0.05) risk factors for failure. In addition, YAG-Laser Ir idotomy in GAG-group and Aphakia in the group of various glaucoma diag noses were identified as risk factors for successful post-operative IO P control. Conclusions Filtering surgery (trabeculectomy) is a potent method to reduce IOP. Pseudophakia and an encapsulated bleb are the ma in risk factors for surgical failure. Because of amazingly high succes s-rates we tend to perform filtering surgery today earlier than ten ye ars ago, especially as previous long-term topical antiglaucoma treatme nt map reduce filtering surgery success.