Combined Surgeries Effectively Limit Angle Closure Glaucoma in Patients With BEST1

The BEST1-associated retinopathies — autosomal recessive bestrophinopathy (ARB) and Best’s vitelliform macular dystrophy (BVMD) — present high-risk for angle-closure glaucoma and stubbornly high intraocular pressure (IOP), posing a “huge challenge”, explain investigators of a study published in Ophthalmology and Therapy. Their case series shows robust success using a triple surgery approach: trabeculectomy, anterior pars plana vitrectomy, and phacoemulsification with intraocular lens implantation.

The population included 19 patients with angle-closure glaucoma who were initially treated at a large eye hospital in China, or referred there from a local medical center between January 2014 and November 2021. This retrospective series features 5 individuals (10 eyes) with a mean age of 33 years who received trabeculectomy only in 1 eye and the triple surgery approach in the other. In addition to ophthalmic treatment, genetic testing was offered. Success was defined as an IOP lower than 21 mm Hg with or without antiglaucoma drugs, but with no further procedures.

Investigators diagnosed 4 participants with ARB, and 1 with BVMD — all displayed bilateral secondary angle-closure glaucoma. Baseline IOP with maximum medications was 31.4±4.7 mm Hg. Upon single trabeculectomy in 5 eyes, all exhibited by 1 week postoperatively “shallow or flat” anterior chamber, even with strong cycloplegics and anti-glaucoma meds, with persistent high IOP at a median of 26 mm Hg (range 18 to 54 mm Hg). These eyes received another procedure; phacoemulsification with IOL implantation, and anterior pars plana vitrectomy (PPV). 

All eyes experienced significant IOP reduction — at final follow-up, mean IOP was 16 mm Hg (P =.043), and 1 patient needed anti-glaucoma medicine. No complications occurred after the triple operation. Anterior chamber depth increased for all measured and was stable at the last clinic visit. Follow-up ranged from 31 to 87 months for trabeculectomy with subsequent PPV, and 2 to 54 months after triple surgery. All individuals retained best-corrected visual acuity (BCVA) and visual field — 1 participant’s vision improved after cataract removal.

Previous case studies have shown success using primary PPV with posterior chamber drainage implant that returned IOP to normal and reversed disc cupping in a patient, or supplementary low-dose transscleral cyclophotocoagulation that lowered IOP and increased anterior chamber depth in another individual. The investigators suggest that vitreous plays an important role — solid, unliquefied vitreous may create posterior pressure, with forward momentum, potentially reducing anterior chamber depth.

The case series shows “vitrectomy was required in those cases, potentially relieving the peripheral vitreous pressure, restoring the orientation of the ciliary body, and deepening the anterior chamber,” according to the investigators. “A combined approach to simultaneously address all conditions would be advantageous to patients in terms of reduced costs and potentially faster visual recovery.”

Five eyes that underwent the combination secondary procedure gained comparable outcomes for ACD, BCVA, and IOP to those with the initial triple procedure (P >.05).

Limitations of this study involve a small cohort due to the rare nature of secondary angle-closure glaucoma with ARB, and only 2 patients had long follow-up after triple surgery. Also, inter-eye bias may have occurred due to trabeculectomy being the initial treatment in eyes with earlier angle-closure glaucoma. A strength is that it is the first series to use a self controlled design of trabeculectomy alone compared with a triple surgical combination in the same individuals.