Trans-lid tonometer may be useful for glaucoma screening

A tonometer that works with the subject’s eyelid closed may be helpful as a glaucoma screening tool when Goldmann applanation tonometry is not applicable, a study suggests.

Dirk Sandner and colleagues at the University of Dresden performed a study to evaluate the accuracy of a transpalpebral tonometer in comparison with Goldmann tonometry. They measured the IOPs of 199 eyes of 103 subjects with normal corneas using the transpalpebral tonometer and Goldmann applanation tonometry within 5 minutes of each other, in random order.

The mean difference between trans-lid tonometry and Goldmann applanation tonometry was 0.71 mm Hg. IOP readings taken with the trans-lid tonometer were within 2 mm Hg of Goldmann readings in 66.4% of cases, and 81% were within 3 mm Hg.

Trans-lid tonometry correlated sufficiently with Goldmann tonometry, the authors concluded, “but in more than 10% of the measurements, the IOP readings differed by more than 3 mm Hg.” They suggested that the instrument might be helpful as a screening tool in eyes with irregular corneal surfaces not amenable to Goldmann tonometry.

The study is published in Graefe’s Archive for Clinical and Experimental Ophthalmology.