Retrospective and prospective studies examined the surgical effects in lowering intraocular pressure levels of trabeculotomy ab externo in adult eyes with either primary open angle glaucoma or pseudoexfoliation syndrome. We report the results of primary trabeculotomy as an intervention for glaucoma.
Included in the retrospective study were 357 eyes of 227 patients with primary open angle glaucoma and 82 eyes of 65 patients with pseudoexfoliation syndrome, each of which underwent trabeculotomy ab externo alone and none of which had a history of laser or surgical treatment for ocular disease. Included in the prospective study were 33 eyes of 22 patients with primary open angle glaucoma and 17 eyes of 15 patients (older than 40 years) with pseudoexfoliation syndrome.
A life-table analysis for the retrospective study showed that the final success probability (mean±SE) at 5 years after surgery was 73.5%±6.3% in eyes with pseudoexfoliation syndrome, which is significantly better than 58.0%±3.1% in eyes with primary open angle glaucoma (P<.05). Also, the higher the preoperative intraocular pressure levels are, the less likely that the postoperative intraocular pressure levels will be brought under control (P<.01). Surgical outcome in the prospective study demonstrated success in 27 (79%) of 34 eyes after 3 years and in 16 (64%) of 25 eyes after 5 years, with medication. Complications included Descemet's membrane detachment (one eye), cyclodialysis (one eye), and decreased visual acuity due to progression of cataract (four eyes).
The surgical results of trabeculotomy ab externo remain effective in controlling intraocular pressure levels for a long time in selected patients. It thus appears that trabeculotomy ab externo can be considered as an alternative choice of surgical treatment in some cases of glaucoma.