Intraocular pressure response to medication in a clinical setting: the Marshfield Clinic Personalized Medicine Research Project.

PURPOSE

To estimate glaucoma and ocular hypertension prevalence and to describe temporal trends in prescribing patterns and intraocular pressure (IOP) response to topical medications used in glaucoma and ocular hypertension.

MATERIALS AND METHODS

The medical records of adult subjects enrolled in the population-based Marshfield Clinic Personalized Medicine Research Project were searched to identify participants who had been diagnosed with ocular hypertension or glaucoma and prescribed agent(s) to lower IOP. All IOPs before and after prescription of the IOP agents were recorded.

RESULTS

As of December 31, 2005, 18,773 adults were enrolled in the Personalized Medicine Research Project, 57.1% were female, and their mean age was 50.3 years (range, 18 to 101 y). The overall rate of definite glaucoma in subjects aged 50 years and above was 2.1% (95% confidence interval=1.2, 2.4) and the rate of treated ocular hypertension was 1.4% (95% confidence interval=1.2, 1.7). Topical beta-blockers were the agents prescribed for the majority of subjects until the year 2000, when prostaglandins, first used in 1995, became the primary agent prescribed. In 2005, 75% of subjects used prostaglandin analogs and 46% used topical beta-blockers. The largest relative reduction in IOP in the first 3 months after prescription was observed for prostaglandin analogs (21.4% mean relative reduction), followed by beta-blockers (20.9% mean relative reduction). There has been a significant decrease over time in mean IOP before initiating medical therapy (linear regression beta coefficient=-0.30, P<0.0001, r=0.09).

CONCLUSIONS

In this clinic-based setting, we found that treatment of glaucoma has changed over the past 20 years, with ophthalmologists more likely to begin treatment at lower baseline levels of IOP, and prostaglandin analogs the most commonly prescribed and agent to lower IOP.