Elevated IOP may increase nuclear cataract risk

Patients with an elevated IOP may have an increased risk of developing nuclear cataracts, but not other types of cataract, according to an Australian study.

Sujatha Chandrasekaran, MBBS, MPH, and colleagues at the University of Sydney analyzed data from 2,532 participants in the Blue Mountains Eye Study, a population-based study whose members were at least 50 years old at baseline. For the purposes of this analysis, IOPs of more than 21 mm Hg were considered elevated. Subjects without open-angle glaucoma or secondary or angle-closure glaucoma with IOPs of more than 21 mm Hg in either eye were classified as having ocular hypertension, as were non-open-angle glaucoma participants with IOPs under 22 mm Hg but who used glaucoma medications.

The 5-year incidence of nuclear cataract was 23.4% (592 patients), which fell only slightly to 23.1% (574 patients) after excluding those on glaucoma medication. The association between elevated IOP or ocular hypertension and nuclear cataract was significant. Use of glaucoma medications was associated with non-significantly increased adjusted odds for incident nuclear cataract. The researchers found no association between elevated IOP and incident cortical cataract or posterior subcapsular cataract.

The study is published in the March issue of Ophthalmology.