Viscocanalostomy versus trabeculotomy ab externo in primary congenital glaucoma: 1-year follow-up of a prospective controlled pilot study

Abstract

Aim: To study the effectiveness of viscocanalostomy in patients with primary congenital glaucoma of the isolated trabecular dysgenesis category and compare it with trabeculotomy ab externo.

Methods: Eight patients with bilateral primary congenital glaucoma were enrolled in the study. After establishing the diagnosis, the more severely affected eye was randomly selected to undergo either trabeculotomy ab externo or viscocanalostomy, whereas the second eye underwent the other surgery 2 weeks after the first. The patients were examined on day 1, week 1, week 4 and thereafter every 4 weeks. Intraocular pressure (IOP) and corneal diameter measurements were obtained at week 1, month 6 and at the last reported follow-up. The paired-sample’s Student’s t test was applied for statistical analysis.

Results: The mean (standard deviation (SD)) follow-up period was 12.5 (1.86) months. Preoperative IOP of eyes undergoing trabeculotomy (34.0 (2.6) mm Hg) and that of eyes undergoing viscocanalostomy (32.3 (4.1) mm Hg) showed no significant difference (p>0.1). A drop in IOP was noted in both groups at week 1, month 6 and at the last follow-up visit (p<0.001). Similarly, a decrease in the postoperative vertical and horizontal corneal diameters was noted in the two study groups.

Conclusion: Viscocanalostomy proved to be as effective as trabeculotomy ab externo in lowering IOP. Moreover, it is likely to be a good surgical alternative with a higher long-term success rate in eyes with more aggressive disease.