To investigate the efficacy and safety of ab externo or ab interno transluminal trabeculotomy in the treatment of secondary glaucoma following pars plana vitrectomy (PPV).

An observational case series method was performed.Seventeen eyes of 17 patients with glaucoma following PPV were enrolled in Henan Eye Hospital and Beijing Tongren Hospital from May 2016 to Feburary 2022.Primary conditions of patients receiving PPV included retinal detachment in 13 eyes, vitreous hemorrhage in 3 eyes, and entophthalmia in 1 eye.All the subjects underwent ab externo (11 eyes) or ab interno (6 eyes) transluminal trabeculotomy.The scope of all cases accepted trabeculotomy was ≥300°(11 cases of 360°, 4 cases of 330° and 2 cases of 300°).Before and at 1 week, 1 month, 6 months and 12 months after surgery, the intraocular pressure (IOP) was evaluated by Goldmann Tonometer and the best corrected visual acuity (BCVA) was measured using a standard visual acuity chart and converted to logrithm of minimal angle of resolution (LogMAR).The number of anti-glaucoma drug applications and surgery-related complications were recorded.The primary outcomes evaluated were IOP and surgical success rate.Secondary outcomes were medication quantity, BCVA (LogMAR) changes, and complications.Surgical success was defined as IOP reduction to <21 mmHg (1 mmHg=0.133 kPa) with or without the use of IOP-lowering medication.This study adhered to the Declaration of Helsinki.The study protocol was approved by the Ethics Committee of Henan Eye Hospital (No.HNEECKY-2021[41]).Written informed consent was obtained from each subject.

Preoperative, 1-week, 1-month, 6-month, and 12-month postoperative mean IOP was (34.41±5.11), (21.88±11.72), (20.77±7.67), (19.50±7.01), and (16.32±4.68)mmHg, respectively, with an statistically significant overall difference (F=20.779, P<0.001).IOP at difference time points after surgery were lower than that before surgery, showing statistically significant differences (all at P<0.01).Compared with before surgery, IOP was reduced more than 40% at 12 months after surgery in 14 eyes.Surgical success rates at 6 and 12 months after surgery were both 76.5%.The number of IOP-lowing drugs decreased significantly after operation (Z=-4.580, P<0.001).The difference in BCVA between before and 6 months after surgery was not statistically significant (Z=-1.311, P=0.190).No serious complications were seen in any of the operated eyes postoperatively.

Ab externo or ab interno transluminal trabeculotomy is safe and effective in the treatment of secondary glaucoma after PPV.

Glaucoma, secondary; Abexterno or ab interno transluminal trabeculotomy; Vitrectomy; Efficacy; Safety