Kaiser Hedwig J. M.D.; Flammer, Josef M.D.; Messmer, Christian M.D.; Stiimpfig, Daniela; Hendrickson, Phillip Ph.D.Journal of Glaucoma: October 1992 Original Article: PDF Only Abstract Summary We reported earlier on a prospective, randomized, double-masked study in which 36 patients with open-angle glaucoma were treated with either 0.5% betaxolol or 0.5% timolol in both eyes twice daily. In that previous report, we described that both drugs reduced the intraocular pressure significantly, whereby timolol had a slightly larger influence than betaxolol. However, betaxolol-treated patients had a slightly but statistically significantly better visual field survival in this 18-month period. Of these 36 patients, 29 could be followed up under the same previous treatment for an additional 12 months. Twelve of these patients were treated with timolol and 17 with betaxolol. Three of the five drop-outs in the timolol-treated group showed a clear tendency toward deterioration of the visual field, whereas the dropouts in the betaxolol-treated group had stable visual function. The present analysis is based on a 30-month period. The intraocular pressure remained stable and was slightly but not statistically significantly lower in the timolol-treated patients. The visual fields remained stable, as well. In relation to the baseline, the mean sensitivity had improved more in the betaxolol-treated patients. The difference to the timolol-treated patients was not statistically significant in this relatively small sample size. © Williams & Wilkins 1992. All Rights Reserved.