Hypotony-associated Complications After Deep Sclerectomy: Incidence, Risk Factors, and Long-term Outcomes

Abstract

Precis: Chronic hypotony is not uncommon following deep sclerectomy (DS), but only a minor proportion of patients develop hypotony-associated complications. Numerical hypotony does not affect the visual outcomes. This study identifies factors associated with hypotony.Purpose: To investigate the incidence and risk factors of hypotony and hypotony-associated complications after DS.Methods: Retrospective cohort study of 1765 eyes (1385 patients) undergoing DS with or without cataract extraction between 2001 and 2020 in 2 UK centers. Chronic hypotony was defined as intraocular pressure (IOP) ≤ 5 mm Hg in ≥ 2 consecutive visits lasting > 90 days or as any IOP ≤ 5 mm Hg associated with hypotony-related complications or requiring surgical intervention. Clinical hypotony was defined as the presence of: serous or hemorrhagic choroidal detachment, hypotony maculopathy, flat anterior chamber requiring reformation, decompression retinopathy. The incidence of hypotony was calculated with Kaplan-Meier statistics, and Cox regression was used to identify risk factors. Results:The median (interquartile range) age and follow-up were 76 (67 to 82) years and 45.4 (20.9 to 79.8) months, respectively. The incidence (95% confidence interval) of chronic and clinical hypotony at 5 years was 13.4% (11.5%-15.3%) and 5.6% (4.3%-6.9%), respectively. Sixteen eyes (15.7%) with hypotony-associated complications had IOP > 5 mm Hg. Male sex (hazard ratio [HR]: 1.89,

Deep sclerectomy-trabeculectomy with mitomycin C in treating glaucoma: postoperative long-term results

“…The incidence of bleb leak in our study was also comparable to studies evaluating glaucoma filtering procedures [1,31] . The rate of hypotony requiring bleb revision in our study was lower than other similar studies and those reporting complications of DS and trabeculectomy [1,33] . Bleb needling with anti-fibrotic agent when there were signs of bleb failure evidenced by increased bleb vascularity with progressive IOP elevation or bleb encapsulation in our current study were less common than that reported by Sangtam et al [1] and Kozobolis et al [6] , which were 50% and 20.7% respectively.…”

Same-site trabeculectomy with mitomycin and Ologen™ following failed non-penetrating deep sclerectomy

“…Although 13% of the eyes showed chronic hypotony, the occurrence of hypotony-related complications was much less common (estimated 5-year incidence of 5.6%). 27 Similarly, Saeedi analyzed this complication in 753 eyes that underwent TRAB and also found that a minor proportion of the 14.9% of the eyes with late low IOP hypotony (defined as IOP ≤ 5 mmHg at or after 3 months postoperatively and all eyes that had objective signs of hypotony (choroidal detachment, shallow AC, hypotony maculopathy) and all eyes that had revision surgery for low IOP, regardless of time after surgery) suffered hypotony-related complications or required surgical intervention (8% and 5% of the eyes respectively). 28 In the same way, 62.5% of the eyes in our study had statistical hypotony but it was not associated with complications or required further interventions in most of the cases.…”

Risk factors and management of choroidal effusions

“…For instance, deep sclerectomy, a nonpenetrating glaucoma surgery wherein the inner wall of Schlemm's canal and juxtacanalicular trabecular meshwork are removed, previously had reported rates of choroidal effusion development ranging from 7.6 to 11% [16], falling within the lower range of rates reported in GDD and trabeculectomies. However, Rabiolo et al [19] recently reported even lower rates of effusion development (43/1765 eyes, 2.4%) in eyes undergoing deep sclerectomy between 2001 and 2020 in two UK centres [19]. Even with the addition of procedures to further lower IOP following deep sclerectomy, rates of choroidal effusions are still relatively small.…”