A critical analysis of the trabeculectomy results by a prospective follow-up design

Trabeculectomy was carried out 145 times on 113 eyes of 100 patients, with primary open-angle glaucoma (POAG), primary angle-closure glaucoma (PACG) or secondary glaucoma. The complications of this surgery found during the follow-up period from 0.5 to 3 years were analyzed according to the preplanned protocol. The shallow anterior chamber (AC), i.e. AC depth being less than half of the depth before surgery, was found in 51.7%, flat AC, i.e. iridocorneal contact from the periphery to the pupillary margin, in 15.9%, hyphema in 17.9% and choroidal detachment in 33.9%. The shallow AC usually disappeared within several days and only in 2.8% was this complication prolonged over one week. The choroidal detachment disappeared within 3 days in most cases, and in only 0.7% was surgical intervention required for its treatment. Progression of cataract, as defined by diminution of the visual acuity more than 2 lines of the acuity chart, was found in 38.6%. The choroidal detachment and cataract progression were significantly more frequent in eyes with the shallow AC. Simple statistics gave a figure of about 70% for the rate of IOP control below 21 mmHg. A life-table analysis gave the 2-year success probability of about 57% in POAG after the first trabeculectomy. After repeating the procedure twice in the same eye, the success probability was about 37%, but after 3 or more repeated operations it was only 10% after one year.