The Predictive Accuracy of the One-Eyed Trial in the Ocular Hypertension Treatment Study (OHTS)

Abstract

 

Purpose:

 

To determine how accurately the intraocular pressure (IOP) response in a one-eyed therapeutic trial in the first eye predicts the IOP response of the second eye in OHTS.

 

Methods:

 

Of 817 participants randomized to medication, we report on 590 participants who completed a one-eyed trial using a topical beta-blocker medication. Baseline IOPs were the untreated IOPs for both eyes prior to randomization. The post-treatment IOP in the first eye was the IOP after approximately 4-6 weeks of treatment. The post-treatment IOP in the second eye was the IOP after approximately 5 months of treatment. A Pearson partial correlation coefficient adjusting for age, central corneal thickness, time on treatment, and other factors, was calculated to determine the association between the IOP response in the first eye and the second eye.

 

Results:

 

Pearson partial correlation coefficient between post-treatment IOPs in the first and second eye is 0.43, (p<0.0001).  

 

Conclusions:

 

Recently, the validity of the therapeutic one-eyed trial in clinical practice has been called into question. The results in OHTS suggest that there is a moderate correlation between the response of the first and second eyes of a patient to topical beta blockers.

 

Clinical Trial:

 

www.clinicaltrials.gov NCT00000125

 

Keywords: clinical (human) or epidemiologic studies: treatment/prevention assessment/controlled clinical trials • clinical (human) or epidemiologic studies: biostatistics/epidemiology methodology