[Visual field progression after trabeculectomy in primary open-angle glaucoma: preliminary results].

INTRODUCTION: Our purpose was to evaluate the changes in the visual field (VF) after trabeculectomy and to indentify factors influencing variation for a better follow-up of patients with primitive open-angle glaucoma (POAG). MATERIAL AND METHODS: We conducted a prospective study at the A. Le Dantec Hospital in Dakar, Senegal. Seventeen eyes of POAG patients were studied. The parameters noted for each patient were age, sex, affected eye, pre- and postoperative intra-ocular pressure (IOP), cup disk, sensitivity thresholds on pre- and postoperative perimetry, severity of glaucoma, and medication taken by the patient. Each patient had a frequency doubling technology (FDT) visual field examination before and the after surgery. None of them had an associated pathology that could cause VF troubles. The postoperative visual field was noted. All these parameters were correlated using the chi square test in order to determine factors influencing a threshold variation. RESULTS: Our patients were new in 70.6% of cases, and the mean age was 45 years. The mean preoperative IOP was 25.7mmHg, 29.4% of the eyes had a cup disk up to 0.7. The VF showed severe glaucoma in 58.8%; 70.6% of eyes had only beta-blocker treatment. Peritomy with limbic hinge was performed in 88.2% of trabeculectomies. No surgical complication was noted. After trabeculectomy, the mean IOP was 14mmHg with a mean decrease of 42.8%. Before surgery, 94.1% of eyes had lower temporal quadrant involvement. For 94.1% of eyes, central vision was preserved. After surgery, progression was better in 18%, stable in 41%, and worse in 41% of cases. Of the factors studied, only age and graded follow-up time from surgery had a statistically significant influence on VF after trabeculectomy. CONCLUSION: Trabeculectomy was necessary in treatment of POAG, because of poor observance of medical treatment and severity of lesions at the time of diagnosis. The results (59% improvement or stability), in spite of the small sample size, argue in favor of this surgical treatment for some patients with POAG in our country.