[Preliminary efficacy of penetrating canaloplasty in primary angle-closure glaucoma]

Objective: To evaluate the preliminary efficacy and safety of penetrating canaloplasty for treating primary angle-closure glaucoma (PACG). Methods: It is a prospective interventional case series study. Twenty-two patients (24 eyes) with PACG were treated with penetrating canaloplasty (video attached) at the Eye Hospital of Wenzhou Medical University from June 2015 to August 2018. This modified canaloplasty was performed by making a window at the corneal-scleral bed. Aqueous was redirected to the opening of Schlemm's canal after the canaloplasty with intension sutures. Postoperative follow-up was made at 1 day, 7 days, 1 month, 3 months, and 6 months. Surgical success was defined as intraocular pressure (IOP) ≤ 21 mmHg (1 mmHg=0.133 kPa) with glaucoma medication (quantified success) and without any glaucoma medication (complete success). Main outcome measures included IOP, number of medication, surgical success rate, complications, and filtering bleb status. One-way repeated measure ANOVA and rank sum test were used in statistical analysis. Results: Due to the failure of circumferential catheterization of the canal, 4 eyes converted to trabeculectomy. A total of 19 PACG patients (20 eyes) achieved the successful 360-degree catheterization of the canal, including 11 males and 8 females. The mean age was (54±7) years old (range: 41-65 years old), and the mean angle-closure range was (326.3±46.6) degrees. The mean preoperative IOP was (38.0±11.9) mmHg with the median medication number of 3 (range: 2-5). The mean postoperative IOP was (14.5±11.1), (16.1±6.0), (17.7±5.5), (15.7±5.0), and (15.4±3.7) mmHg at 1 day, 7 days, 1 month, 3 months, and 6 months, respectively. There was significant difference in IOP between postoperative and preoperative (all P<0.01). The median medication number (range) was 0 (0-3), 0 (0-2), 0(0-3), 0(0-2), and 0 (0-2) at the 5 time points, respectively. There was significant difference in medication number between postoperative and preoperative (all P<0.01). The quantified success rate was 95%(19/20), and the complete success rate was 90%(18/20) at 6 months. Postoperative complications were observed in 7 eyes (35%) of 20 PACG eyes, including 3 eyes (15%) with hyphema, 2 eyes (10%) with shallow anterior chamber, 1 eye (5%) with Descemet membrane detachment, and 1 eye (5%) with filtration obstruction at the trabeculum ostium. According to the results of slit lamp and ultrasound biomicroscopy examinations, 70% of the eyes (14/20) had no filtering bleb. Eight eyes (40%) with IOP spike were observed. Conclusion: Preliminary study shows penetrating canaloplasty is safe and effective in the treatment of PACG, but needs a longer follow-up. (Chin J Ophthalmol, 2019, 55: 448-453).