Intraocular Pressure Following Prerandomization Glaucoma Medication Washout in the HORIZON and COMPASS Trials

Area of Science:

• Ophthalmology
• Glaucoma Research
• Pharmacology

Background:

• Open-angle glaucoma (OAG) is a leading cause of irreversible blindness.
• Topical ocular hypotensive medications are a cornerstone of OAG management.
• Understanding medication effectiveness and factors influencing intraocular pressure (IOP) is crucial.

Purpose of the Study:

• To evaluate the efficacy of topical ocular hypotensive treatments in OAG patients.
• To identify predictors of intraocular pressure (IOP) elevation after medication cessation.

Main Methods:

• Secondary analysis of prerandomization data from two prospective, multicenter randomized clinical trials (HORIZON and COMPASS).
• 1,400 patients with OAG on 0-4 classes of topical IOP-lowering medication underwent IOP measurement before and after a washout period.
• Goldmann applanation tonometry was used for IOP assessment.

Main Results:

• A dose-dependent increase in IOP was observed after medication washout, with patients on more medications experiencing greater IOP elevation.
• Factors associated with increased postwashout IOP included a higher number of glaucoma medications, elevated unmedicated IOP, thinner central corneal thickness (CCT), lack of prior selective laser trabeculoplasty (SLT), and male sex.
• Postwashout IOP changes were consistent between the HORIZON and COMPASS cohorts.

Conclusions:

• Discontinuation of glaucoma medications leads to a predictable, dose-dependent rise in IOP in OAG patients.
• Standardized washout methodology in clinical trials can estimate real-world medication effectiveness.
• Thicker CCT and a history of SLT may indicate a reduced need for IOP-lowering medications.