Fundus photos created on smartphones have helped make the fundus exam affordable and portable, especially for patients in rural areas. However, according to newly published research, you shouldn’t consider it a pocket-sized exam lane just yet. German investigators looked at 54 eyes of 27 participants to assess the impact of pupil dilation on image quality in optic nerve head (ONH) imaging and vertical cup-to-disc ratio evaluation. Patients with glaucoma—and glaucoma suspects—were imaged while undilated and after dilation, monoscopically, using both conventional digital fundus photography and smartphone images.

Although they found that smartphones could successfully capture a fundus image without dilation approximately 74% of the time, the researchers discovered that, even with dilation, smartphone images led to more frequent errors in mean cup-to-disc ratio evaluations than conventional digital fundus photography. Additionally, “disc pallor was underestimated on undilated smartphone-based fundus photography,” reads the report. “This highlights the need for dilation in order to ascertain good quality ONH evaluation using smartphone-based fundus photography.” Even when dilated, however, conventional digital imaging still outperformed the smartphones.