Long-term follow-up of laser trabeculoplasty.

In a retrospective study 274 eyes of 207 patients with glaucoma were followed, after they had undergone laser trabeculoplasty (LTP). We evaluated the success of the laser treatment and followed the course of the intraocular pressure (IOP) during 5 1/2 years after treatment. Three diagnosis-groups were formed. Group I consisted of primary open angle glaucoma (n = 208), secondary glaucoma (n = 8) and pigmentary glaucoma (n = 3). Group II (n = 29) consisted of low tension glaucoma. Group III (n = 26) had the diagnosis narrow angle glaucoma. Success was defined as follows: a reduction in IOP, no progressive visual field loss, no visual acuity loss due to glaucoma, no filtering surgery and no repeat LTP. Follow-up was continued until the moment of failure. In the case of success the minimum follow-up was 6 months. The mean decrease in IOP after LTP stabilized in all three groups. During a follow-up of 5 1/2 years the IOP lowering effect did not diminish in successful eyes. To compute the rate of success we used the Kaplan-Meier method. The low tension glaucoma group had a success rate of 82% after 4 years. The probability of success in group I was 53% after 5 1/2 years and in group III 51% after 4 1/2 years. These success rates did not differ significantly. Resuming, this study shows that LTP has postponed the need for surgical intervention at least up to 5 1/2 years.