Smartphone direct ophthalmoscope tech helps visualise optic disc

A smartphone direct ophthalmoscope attachment (D-EYE) has proved easy to use and successful in visualising the optic disc compared with the direct ophthalmoscope (DO), according to research presented at the virtual annual meeting of the Canadian Ophthalmological Society. Data from the prospective, randomly assigned, crossover, educational trial involved 44 first-year medical students not familiar with this type of examination, who looked at measurements such as vertical cup-to-disc ratio, fundus matching using an online programme and identifying whether the state of health of the optic nerve was normal or abnormal, according to Dr Rachel Curtis, a fourth-year ophthalmology resident at Queen’s University in Kingston, Ontario, Canada, and the study’s presenting author.

“There is a big push for new technologies and new ways of delivering medical teaching,” Dr Curtis told Ophthalmology Times® during an interview. “The whole concept is finding new technologies to teach medical students [how to examine the optic nerve] and ways to integrate these technologies into practice.”

The smartphone DO attachment lets physicians record the picture or video and show the anatomy, Dr Curtis said. “It can improve continuity of care by documenting serial exams,” she explained. “It also helps students identify what they are seeing on examination. Your student or ophthalmology resident can show it to your preceptor. Another advantage is that the images or a video can be uploaded into an electronic medical record.”

Dr Curtis noted that a competent fundus examination is often part of routine clinical evaluation in family practice, the emergency department and inpatient wards, and is a duty of care in many clinical situations. She added that there has been a decrease in confidence and use of ophthalmoscopy among medical students and physicians.^1,2

“It is a difficult skill to use a direct ophthalmoscope and it is generally not well taught in medical schools,” said Dr Curtis. “This [D-EYE] is a fairly intuitive technology.”

Comparing devices

In the study, a fundus photo matching programme was utilised to compare the performance of the D-EYE with that of the DO. Students were randomised to initiate the examination with the D-EYE or the DO.

The two cohorts studied over 2 consecutive years—one had 26 students and the other had 18—were similar in terms of mean age and gender distribution. Students were given 10 minutes to examine both eyes of one patient, with one eye dilated and one not dilated. They examined multiple patients during the study.

After the examination, students were asked to match the patient’s optic nerve to the fundus photograph that was found in a 9-photo collage that had been randomly generated. They could make multiple attempts and would receive a message under the image telling them whether their choice was correct or incorrect. If it was incorrect, they would receive a message telling them to try again.

Students were asked to complete a form to indicate their perception of “ease of use” of the device and their confidence in using the device. They were also asked to document the vertical cup-to-disc ratio of each eye and to report whether the disc’s state of health overall was normal or abnormal.

Dr Curtis and colleagues found students using the DO needed more attempts (3.57 vs 2.69, P = 0.010) to match the patient’s fundus to the correct photograph and more time (197.00 vs 168.02 seconds, P = 0.043, t test) to correctly choose the proper fundus photograph, when compared with the D-EYE device. These results were discussed at the Canadian Ophthalmological Society annual meeting as part of a paper abstract presentation, which won a third-prize award.

“The difference was both statistically significant and clinically relevant,” said Dr Curtis. “It took 30 seconds more to identify the correct nerve with the DO. Thirty seconds does not seem like a lot, but in a busy ward or clinic, it does make a difference in efficiency. We found that there was not only less time to match the optic nerve, but it took them less matching [fewer attempts] and there was less guessing involved.”

The investigators observed no statistically significant difference in the accuracy of estimating vertical cup-to-disc ratio in either the right or the left eye, which was the primary outcome of the study, using D-EYE vs DO. Medical students reported greater ease of use with the D-EYE (6.40 vs 4.79, P <0.001) as well as overall confidence in the examination (5.65 vs 4.49, P = 0.003).

The technology facilitates examining the optic nerve and is able to distinguish whether its state of health is grossly normal or grossly abnormal, Dr Curtis emphasised. “That is arguably the most clinically relevant outcome,” she said. “If you are going to send [the patient] off for referral or make an appropriate consult, the thing you need to be able to do is to recognise whether or not this nerve needs to be looked at by an ophthalmologist.”

In the time of the COVID-19 pandemic, the use of the smartphone and DO attachment lets clinicians be more physically distant from a patient when performing the examination and adhere to infection-minded prevention. “With the direct ophthalmoscope, you have to be very close to the patient to get a good view,” Dr Curtis concluded. “In an infection-minded environment, you may want a larger buffer between you and the patient. This [smartphone and direct ophthalmoscope attachment] is a good arm’s-length distance between you and the patient’s eye.”

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Rachel Curtis, MD
p: 613-544-3400
Dr Curtis has no financial disclosures related to this content.

References

1. Mackay DD, Garza PS, Bruce BB, Newman NJ, Biousse V. The demise of direct ophthalmoscopy: a modern clinical challenge. Neurol Clin Pract. 2015;5:150-157.
2. Gupta RR, Lam WC. Medical students’ self-confidence in performing direct ophthalmoscopy in clinical training. Can J Ophthalmol. 2006;41:169-174.