Purpose Bleb dysfunction may occur as a late complication following glaucoma filtration surgery. Over-filtering, thinning and cystic blebs can lead to hypotony, leak and corneal dellen. We report our surgical management and outcomes of this specific entity using donor scleral patch grafts. Methods This is a 10-year non-comparative, retrospective interventional case series. Bleb reconstruction involved excision of encysted conjunctiva and sclera to identify the original fistula. A functioning donor scleral patch graft was sited over this with fixed and releasable sutures and the conjunctiva advanced. Intraocular pressure, visual acuity and post-operative issues were assessed. Results A total of 18 eyes of 17 patients with mean age 65 years (standard deviation 13.5) were included. Trabeculectomy was the primary procedure in 72% ( n = 13) and deep sclerectomy in 28% ( n = 5). Bleb leak accounted for 61% ( n = 11), hypotony 33% ( n = 6) and corneal dellen 6% ( n = 1). Mean pre-operative intraocular pressure was 7 mm Hg (standard deviation 4.6) which increased to 18.5 mm Hg (standard deviation 12) at day 1 ( p < 0.001), 11.8 mm Hg (standard deviation 4.6) at 3 months ( p < 0.05), 12.1 mm Hg (standard deviation 4.2) at 1 year ( p < 0.01) which was maintained at 12.1 mm Hg (standard deviation 5.3) at last follow-up ( p < 0.001). Post-operative interventions included bleb needling, re-suturing, suture removal, further glaucoma management, bleb leak and cataract surgery. Visual acuity also improved post-operatively and was maintained. Conclusion Reconstruction of the filtering bleb architecture with donor sclera results in improved intraocular pressure while maintaining visual acuity. Post-operative care is required to support the restored bleb function. Our findings support the use of scleral patch graft as an effective and safe method for the long-term management of hypotony and bleb leak as a late complication of glaucoma filtration surgery.
Safe management of a late-onset bleb leak with a needling technique
