Intra-Operative Ostial Irido-Zonulo-Hyaloido-Vitrectomy with Primary Posterior Capsulectomy for Prevention of Post-Operative Aqueous Misdirection in Combined Phaco-Trabeculectomy in Primary Angle Closure Glaucoma

Purpose: The aim of this study is to investigate the ability of ostial irido-zonulo-hyaloido-vitrectomy (ostial IZHV) with primary posterior capsulectomy (PPC) in preventing aqueous misdirection (AM) in combined cataract and filtration surgery in a high-risk group of angle closure disease.

Materials and Methods: Comparative case series–data collection of consecutive adult subjects (>18 years) with angle closure, undergoing phaco-trabeculectomy, when per-operatively anterior chamber depth (ACD) remained shallow, putting them at high risk for development of AM post-operatively.

Study subjects were compared to controls, who also underwent combined surgery in angle closure, but did not have shallow AC per-operatively, in the study period of January 2012 to December 2016.

Ostial-IZHV was done through sclerostomy and iridectomy created routinely as part of the filtration procedure. Main outcome measure- post-operative deep ACD and comparison of biometric (optical) parameters between study subjects and controls.

Results: Twelve eyes of 11 primary angle closure glaucoma subjects who underwent ostial-IZHV intra-operatively (study subjects) in the study period were included. None of the subjects developed post-operative AM.

The median IOP pre-procedure decreased significantly at average follow-up of 18.25 months (SD 14.1) post-procedure (p = .003). There was significant decrease in use of anti-glaucoma medications too (p < .001) post-procedure.

When compared to controls, study patients were younger (p = .006); these eyes demonstrated greater quadrantic synaechial angle closure on gonioscopy (p < .001), higher pre-operative intraocular pressure (p = .001) and were also found to be smaller (p = .011), shallower (p < .001) with significantly more lens rise (p = .013). Although lens thickness did not differ (p = .689), it appeared to be relatively anteriorly placed (p = .005) in all those eyes that required ostial-IZHV.

Conclusions: Ostial IZHV may be considered in eyes in a sub-group of glaucoma patients with high-risk characteristics for prevention of AM in the post-operative period. The anterior segment surgeon can successfully accomplish ostial-IZHV, effectively reducing dependence on a vitreo-retinal surgeon.