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Abstract #66208 Published in IGR 17-3
Lowering of Intraocular Pressure After Phacoemulsification in Primary Open-Angle and Angle-Closure Glaucoma: A Bayesian Analysis
Thomas R; Walland M; Thomas A; Mengersen KAsia-Pacific journal of ophthalmology (Philadelphia, Pa.) 2016; 5: 79-84
Phacoemulsification as treatment for primary open-angle glaucoma (POAG) remains more controversial than for primary angle-closure glaucoma (PACG). If the objective of glaucoma surgery is an additional greater than or equal to 5 to 6 mm Hg reduction of intraocular pressure (IOP), the role of phacoemulsification should be based on the probability of achieving this. A Bayesian analysis of available data was performed to calculate the change in IOP after phacoemulsification in POAG and PACG. Standard meta-analysis formulation with prephacoemulsification and postphacoemulsification IOP-assumed to have normal distributions, with study-specific means and SDs-was used. Absolute and relative change in IOP was calculated using different priors, and sensitivity analyses were performed. The prior that just included a decrease of greater than or equal to 6 mm Hg in the 95% credible interval was identified. The probability of achieving greater than or equal to 5 to 6 mm Hg decrease in IOP (and other levels) was calculated. Depending on the prior, the probability of achieving a greater than or equal to 5 mm Hg reduction in IOP in POAG varied from 0.1% to 3%. Confidence in a greater than or equal to 6 mm Hg decrease required a prior belief that phacoemulsification produces a mean decrease of 7 mm Hg. The probability of a decrease in IOP was greater in PACG: approximately 50% probability of a greater than or equal to 5 mm Hg decrease in PACG uncontrolled on medications. Phacoemulsification in POAG has a high probability of producing a small decrease in IOP that may be useful in early, well-controlled disease. The probability of a clinically significant decrease of greater than or equal to 5 to 6 mm Hg-required for advanced/uncontrolled disease-is low. RESULTS: support the role of phacoemulsification in PACG.
From the *Queensland Eye Institute; †University of Queensland, Brisbane, Queensland; ‡Glaucoma Investigation and Research Unit, Royal Victorian Eye & Ear Institute, Melbourne, Victoria; and §Discipline of Mathematical Sciences, Queensland, University of Technology, Brisbane, Queensland, Australia.
Full articleClassification:
12.12.3 Phacoemulsification (Part of: 12 Surgical treatment > 12.12 Cataract extraction)
