To assess long term intraocular pressure (IOP) outcome after adult trabeculectomy surgery in Africa.Methods
All adult glaucoma patients who underwent trabeculectomy surgery in the Kabgayi Eye Unit, Rwanda between August 2003 and March 2008 were invited for a follow-up visit. Surgical and clinical data were collected from medical records. At the study visit best corrected visual acuity was measured and Goldmann applanation tonometry and biomicroscopy were done. Good IOP outcome was defined as both an intraocular pressure ≤ 15mmHg and achieving ≥ 30% reduction from the preoperative IOP. Odds ratios for good IOP outcome were calculated for potential predictors. For the first eyes multivariable analysis was done using logistic regression, as well as Kaplan–Meier survival curve analysis.Results
Participation rate was 74.2% (118 patients, 161 eyes). Preoperatively, the mean IOP was 31.2mmHg (SD 10.7, range 12-60). Anti-metabolites were applied during the operation in 79.5% of eyes. At the time of the follow-up study visit the mean postoperative IOP was 13.0 mmHg (SD= 5.1, range 4-35). A good IOP outcome was achieved in 66.9% (n=105) of eyes. Trabeculectomies using mitomycine C were 3 times as likely to have good IOP outcome than without (OR=3.0, CI= 1.2-7.1, P=0.008). The cumulative probability to maintain good IOP outcome reduced from 75% at a follow-up of 2 years to 25% after 5 years. At multivariable analysis long duration of follow-up (OR= 0.31, CI= 0.11- 0.7, P= 0.009) and the presence of an elevated bleb (OR= 3.2, CI= 1.3- 8.1, P= 0.012) remained significant predictors.Conclusion
Trabeculectomy with mitomycine C is effective in lowering IOP in Central Africa. However, the IOP control reduced at a follow-up duration beyond 2 years, highlighting the importance of regular long-term follow-up.