Pneumatic trabeculectomy
Reviewed by Kurt Spiteri Cornish

The authors present a novel technique which uses constant pressure air infusion via the constellation vision system (Alcon Laboratories) to prevent anterior chamber (AC) collapse and intraocular pressure fluctuations during trabeculectomy in high-risk cases. This was a prospective, interventional, non-randomised, comparative pilot study comparing conventional trabeculectomy (group A) and pneumatic trabeculectomy (group B). In group A, air was injected into the AC to keep the AC formed at the time that the ostium and peripheral iridectomy (PI) were performed. Air was re-injected as and when required to keep the AC formed at all times. In group B, a continuous pressure air infusion at a pressure range of 8–12mmHg was maintained with the constellation machine throughout the procedure. There were 24 patients in each group. There was a statistically significant (p<0.001, paired t-test) decrease in intraocular pressure (IOP) in both groups compared to preoperative IOP. In group A, 83.3% of eyes had AC collapse during PI versus 4.17% of eyes in group B (p<0.001, Fischer’s test). Choroidal effusion occurred in 3 patients in group A but none in group B. The authors advocate for the use of this easy technique to reduce frequency of complications by using constant air pressure maintenance as opposed to repeated instillation of air, viscoelastic or balanced salt solution.

Pneumatic trabeculectomy: a modification in conventional trabeculectomy.
Gupta S, Arora M, Mahalingam K, et al. 
CURRENT EYE RESEARCH 
2025;50(9):951–5.