Purpose: To study the clinical effectiveness of deep sclerectomy using the erbium:YAG (Er:YAG) laser in patients with open-angle glaucoma (OAG).
Setting: Department of Ophthalmology, Institut Universitari Dexeus, Universitat Autonoma de Barcelona, Barcelona, Spain.
Methods: This nonrandomized prospective clinical study was performed in 46 consecutive eyes with OAG. Seventeen patients had not received any treatment for glaucoma. Eight had received 1 medication; 14, 2 medications; and 7, 3 medications. The mean duration of treatment was 18.3 months +/- 9.4 (SD). After mitomycin-C 0.02% was administered for 2 minutes, a superficial 4.0 mm x 4.0 mm scleral flap was created and a deep 3.0 mm x 3.0 mm scleral ablation was performed with the Er:YAG laser. Schlemm's canal was removed, and the cornea was dissected to Descemet's membrane until aqueous humor percolated. The scleral flap and conjunctiva were closed. Postoperative follow-up examinations were done at 1, 3, and 7 days, 2, 3, and 4 weeks, and then every 3 months up to 15 months.
Results: The mean preoperative intraocular pressure (IOP) was 28.3 +/- 6.1 mm Hg. The mean postoperative IOP was 14.1 +/- 3.5 mm Hg at 24 hours, 16.3 +/- 4.2 mm Hg at 3 months, and 15.3 +/- 2.7 mm Hg at 15 months (P <.001). There were no statistically significant differences in IOP by sex or age. There was a statistically significant difference between patients receiving no medication and those who received more than 2 medications and a treatment period longer than 1 year preoperatively (P <.006). The presence of a filtering bleb was associated with a longer period of decreased IOP (P <.007). The success rate (IOP < or =18 mm Hg without medication) was 93.47% at 1 month and 84.78% at 15 months. The number of complications was significantly lower than in previous reports of trabeculectomy. One patient lost 2 lines of visual acuity because of cystoid macular edema.
Conclusions: Deep sclerectomy using the Er:YAG laser was safe and effective in eyes with OAG. More studies are needed to analyze the mechanism of lowering IOP.