Abstract
Purpose:
To describe the use of a motorized milling drill to perform nonpenetrating glaucoma surgery and to assess its safety.
Setting:
Instituto Oftalmológico de Alicante, Miguel Hernandez University, School of Medicine, Alicante, Spain.
Methods:
This prospective noncomparative study included 16 eyes (13 patients) diagnosed with primary open-angle glaucoma. The eyes were divided into 2 groups. Group 1 (8 eyes) had a milling procedure, and Group 2 (8 eyes) had combined phacoemulsification and milling. A fornix-based conjunctival flap was created, and then the milling procedure was performed using a notched hemispherical metallic tip. Evolution of intraocular pressure (IOP), visual outcomes, and the development of intraoperative and postoperative complications were evaluated.
Results:
The mean age of the patients was 67.9 years ± 10.9 (SD) (range 50 to 80 years). In Group 1, the mean IOP preoperatively was 27.6 ± 10.1 mm Hg (range 18 to 50 mm Hg) and after 6 months, 15.8 ± 5.2 mm Hg (range 12 to 24 mm Hg). The mean IOP reduction 6 months postoperatively was 15.4 ± 10.6 mm Hg, a 55.7% decrease from preoperatively. In Group 2, the mean IOP preoperatively was 21.7 ± 4.6 mm Hg (range 13 to 30 mm Hg), and after 6 months, 16.2 ± 3.4 mm Hg (range 13 to 23 mm Hg). The mean reduction in IOP at 6 months was 5.5 ± 2.8 mm Hg, a decrease of 25.3% from the preoperative value. In Group 1 at 6 months, 5 eyes (62.5%) had a diffuse filtering bleb and 3 (37.5%), localized filtration. In Group 2, 7 eyes (87.5%) had a diffuse filtering bleb and 1 (12.5%) had fibrosis of the bleb and reduction of filtration.
Conclusion:
The motorized milling drill can be safely used to mill and refine the remaining scleral thickness, eliminating the rupture of trabeculo-Descemet's membrane.