Antihypertensive medication may temporarily delay glaucoma onset

Patients with high blood pressure appear to be at an increased risk for glaucoma, but antihypertensive medication may temporarily delay the onset of the disease, according to the findings of a study presented at the 12th European Glaucoma Society Congress in Prague, Czech Republic. “Based on the highly significant comorbidity of antihypertensive treatment and glaucoma, we suggest that an eye exam should be considered among patients with hypertension,” said Anna Horwitz MD, who is a PhD fellow at the Department of Neuroscience and Pharmacology and Centre for Healthy Ageing, Copenhagen, Denmark. To investigate if treatment with antihypertensive medication influences the risk of glaucoma, Dr Horwitz and her associates reviewed the clinical records of all Danish citizens for the years from 1996 to 2011. They used the Danish National Prescription Registry to identify all first prescriptions for glaucoma medication and antihypertensive drugs during the study period. They excluded from their analysis all patients diagnosed with glaucoma or hypertension before inclusion in the study. The study did not include data on which antihypertensive medication patients received. HIGHER RISK They found that, overall, those receiving their first prescription of antihypertensive medication during the study period were over four times more likely to later also be prescribed their first anti-glaucomatous treatment than those who did not receive antihypertensive medication (RR = 4.26, p<0.0001). "Overall there is a positive correlation, that means there is a significantly higher risk of glaucoma among patients who have also been prescribed antihypertensive medication, even when you correct for age and gender," she told EuroTimes in an interview. However, following the commencement of antihypertensive treatment, the trend of glaucoma diagnosis was reduced by around one third (p<0.0001) for about two years. Afterwards, the trend seemed to return to its original tendency, noted Dr Horwitz. “Immediately after the onset of antihypertensive medication there was a significant decrease in the risk for glaucoma, so there is a protective effect. Patients with hypertension appear to have a higher risk for glaucoma if they don’t receive antihypertensive medications than if they do receive them,” she said. She noted that, from an epidemiological perspective, the study indicates that hypertension is a risk factor for glaucoma and that antihypertensive medication delays the onset and/or incidence of glaucoma, and that it is the hypertension rather than the antihypertensive medication that raises the risk of glaucoma. In keeping with other epidemiological studies, the study showed increasing age to be a risk factor for both hypertension and glaucoma. The study’s results also suggest that newly diagnosed hypertension patients should routinely undergo a thorough ophthalmological examination when they receive their diagnosis, and that better detection of hypertension could lead to better detection of glaucoma, she said. Anna Horwitz: anna.horwitz@sund.ku.dk

Tags: image contrast, optic nerve, optical coherence tomography