Long-term outcomes and risk factors for failure of glaucoma filtering surgery in eyes with vernal keratoconjunctivitis and steroid-induced glaucoma

Abstract

Purpose: To report outcomes and assess the risk factors for failure of trabeculectomy (trab), trabeculectomy with mitomycin-C (trabMMC), and combined trabeculectomy with cataract extraction (CT) in vernal keratoconjunctivitis (VKC) eyes with steroid-induced glaucoma (SIG). Methods: Trab was performed in 45 eyes of 30 subjects, trabMMC in 36 eyes of 25 subjects, and CT in 34 eyes of 27 subjects. Success was complete when intraocular pressure (IOP) was between 6 and 21 mm Hg without anti-glaucoma medications (AGM) and qualified with AGM. Results: Median age (14 vs. 16.3 and 17.4 years) was significantly less in the trab cohort (P = 0.007). Majority (88%–93%) were male (P = 0.78). Preoperatively, median duration of steroid usage was >2 years (P = 0.52), mean IOP (32, 29.4, and 28.4; P = 0.26) and median cup:disc ratio (CDR) (0.9; P = 0.27) were similar in the three groups. Complete success (76%, 71%, and 66% at 5 years; P = 0.91), and qualified success (88%, 97%, and 94% at 5 years; P = 1.0) with trab, trabMMC, and CT, respectively, were similar. Preoperative factors significantly associated with qualified failure (multiple logistic regression) were older children, longer duration of VKC, longer duration and mixed type of steroid use (all P < 0.001) and larger CDR (P < 0.02). At the last follow-up, 38% in trab, 33% in trabMMC, and 50% eyes in CT were blind (visual acuity ≤20/400 and/or visual field ≤10°) due to glaucoma (P = 0.33). Conclusion: The surgical success for all three types of surgery was similar at 5-years. Chronic VKC and long-term steroid use were associated with surgical failure. The majority had advanced disease and a significant proportion were blind due to glaucoma.

Keywords

• allergic eye disease
• steroid-induced glaucoma
• trabeculectomy
• vkc