The Real-World Utility of Ophthalmic Tomography

It is not uncommon for patients with eye and vision concerns to present initially to the emergency department (ED). Unfortunately, effective, reliable, and easy-to-use tools for eye examination are not readily available to the emergency physicians caring for these patients. Direct ophthalmoscopy, once an integral part of the physical examination, has become a dying art in recent decades.1 Yet, the direct ophthalmoscope is the current standard-of-care tool for emergency physicians to examine the posterior eye, including the retina and the optic nerve. For the best view, dilating drops should be used, but dilation takes time and dilating drops are often not available to emergency physicians. Even with dilation, the pupil offers a small viewing window, hence challenging the clinician to control the ophthalmoscope precisely to get a glimpse of the posterior eye. The examination also requires the clinician to get very close to the patient’s face, and the bright light can cause discomfort to patients who are photosensitive.

The difficulty of performing the examination and the difficulty of interpreting the findings together limit the real-world utility of this standard-of-care examination technique. Some emergency physicians have adopted newer methods such as fundus photography and ocular ultrasound, but these techniques take time and practice to master. A method of evaluating the posterior eye which could be reliably interpreted by emergency physicians without necessitating extensive prior training would fill an important practice gap.

A pilot study conducted by Song, et al., potentially offers hope to emergency physicians struggling to evaluate the posterior eye, through the use of a robotic eye-imaging device.2 This device was developed by a collaborative team of clinicians and researchers in biomedical engineering, emergency medicine, and ophthalmology at Duke University, and the robotic eye imaging is based on optical coherence tomography (OCT). OCT is an imaging technique widely used in ophthalmology for high-resolution, cross-sectional imaging of the eye. Historically, the use of OCT has been confined to ophthalmology clinics, as manual OCT image acquisition is a fine skill that requires specialized personnel such as ophthalmic photographers. Now with the help of a robot, emergency physicians may also be able to leverage the power of this state-of-the-art imaging technology to diagnose eye diseases.

Image acquisition with the robotic OCT device is as simple as taking a picture with a digital camera: with the press of a button, the robotic OCT device can find the eye autonomously, track any patient and eye movement in real time, and take an image of the posterior eye. Users can visualize cross-sectional views of the retina and optic nerve easily on a computer (Figure 1). Overall, the need for human operation is minimized. In fact, the study reports that the operator was able to control the system remotely (in a separate room from the patient), suggesting the potential for telehealth capabilities in the future. In a busy emergency department, the robotic OCT device could be used to obtain high-quality images of the posterior eye quickly without requiring dedicated, specially trained staff to operate the device. The telehealth capabilities of the device also raise the possibility that these devices could be deployed to rural or outlying EDs where access to both specialized equipment and personnel for ophthalmic examinations are especially limited.