Goldmann tonometry and a dilated eye exam remain the gold standard methods of intraocular pressure (IOP) measurement and optic nerve head evaluation in glaucoma. While use of portable technology may entail some trade-offs in accuracy, it does offer a viable method of conducting broad-based community screenings that can identify patients who might otherwise have been missed, according to a new study.

Telemedicine screenings for glaucoma that include intraocular pressure (IOP) measurements along with non-mydriatic fundus imaging improve the accuracy of a glaucoma diagnosis at the second visit, according to research in the Journal of Glaucoma.

The study enrolled 902 high-risk individuals who received telemedicine glaucoma screenings at seven primary care practices and four federally qualified health centers. The first screening included fundus photography, IOP measurements by handheld tonometry and family history. The study protocol included monthly site visits by ophthalmic techs and “health educators” to each location to conduct the screenings, rather than ODs or MDs. Following the telemedicine exam, investigators invited those who had suspicious nerve findings for glaucoma, an IOP greater than 21mm Hg or other ocular pathologies for a second visit with an ophthalmologist.

 Researchers found 19.6% of patients had IOP greater than 21 mm Hg at the first visit. Also at visit one, 15 patients were found to have an IOP greater than 30mm Hg, including two who had an IOP of more than 40 mm Hg. Among the 347 patients who had a second visit, 10.9% were diagnosed with glaucoma and 7.2% had ocular hypertension. For participants with both suspicious nerve findings and an IOP of more than 21mm Hg compared with those with neither, their odds of being diagnosed with glaucoma were 4.48%. For subjects with suspicious discs and an IOP of 21mm Hg or less, their glaucoma diagnosis odds were only 2.04%.

“The ideal eye screening model would use portable, inexpensive devices that are easy to transport, implement, and interpret, with high sensitivity and specificity,” the authors wrote in their paper. “This study supports incorporating IOP measurements, using a portable tonometer, into vision screening programs in high-risk populations,” the study concludes.

Hark LA, Myers JS, Pasquale, LR, et al. Philadelphia telemedicine glaucoma detection and follow-up study intraocular pressure measurements found in a population at high risk for glaucoma. J Glaucoma. February 11, 2019. [Epub ahead of print].