Proportion of Non-Responders to Beta-blockers and Prostaglandin Analogs in OHTS, CIGTS, and Enrollees in a United States Managed Care Plan.

Abstract

Purpose: To estimate the proportion of patients diagnosed with ocular hypertension or open angle glaucoma who do/do not respond following initial treatment with either topical beta-blockers (BB) or prostaglandin analogs (PGA).

Methods: We analyzed three datasets - the Ocular Hypertension Treatment Study (OHTS), (1994-1996), the Collaborative Initial Glaucoma Treatment Study (CIGTS), (1993-1997), and the Clinformatics Data Mart Database (2001-2012), a claims database of all eye care recipients in a large managed care network. For patients in OHTS and CIGTS, percent intraocular pressure change (%∆IOP) was calculated by [(treated IOP - baseline IOP)/baseline IOP]*100. Non-response was defined as %∆IOP less than -15%. For the Clinformatics dataset, patients with ocular hypertension / glaucoma were identified by ICD-9-CM codes and we identified newly prescribed BBs or PGAs. Non-response was defined as the addition of another class of ocular hypotensive medication, incisional or laser glaucoma surgery, or cessation of all treatment for glaucoma within 1 year.

Results: The initial treatment for most of the OHTS and CIGTS subjects was BB. In the 741 OHTS subjects started on BB, 27% were non-responders at the 6-month visit. Among the 286 CIGTS subjects started on BB, 17% were non-responders at the 3 month follow up visit. In the Clinformatics dataset, 39% of the 1,392 patients started on a BB were classified as “non-responders.” Of the 12,154 patients started on PGA, 29% were “non-responders.”

Conclusions: Despite differences in OHTS, CIGTS and the Clinformatics database and differences in “non-responder” definition, the proportion of non-responders to BB were surprisingly in a similar range (17-39%) that is consistent with clinical experience. Analysis is underway to assess the economic impact of non-response in the first year of treatment. Understanding the genetic and environmental causes of BB and PGA non-responders will enable an individualized treatment approach.