Eyeworld

30 | EYEWORLD | OCTOBER 2020 N EWS by Liz Hillman Editorial Co-Director I n 2017, the U.S. Department of Health and Human Services declared opioid mis- use a public health emergency. While there are a host of negative health effects related to drug abuse, perhaps not widely recog- nized are ocular effects. "We have been seeing the opioid epidemic affecting the eye as part of the larger issue of polysubstance abuse," said Matilda Chan, MD, and Gerami Seitzman, MD. The main condition these ophthalmologists are seeing related to this drug abuse is severe corneal ulcers. Ocular effects related to opioid epidemic, polysubstance abuse About the doctors Matilda Chan, MD, PhD Associate Professor of Ophthalmology University of California, San Francisco San Francisco, California Gerami Seitzman, MD Medical Director Francis I. Proctor Foundation for Research in Ophthalmology University of California, San Francisco researchers did not see a difference between those who had intact cognition and those with mild cognitive impairment, which is thought to often represent the cognitive stage before Alzheimer's. "We were surprised that we did not see a difference in retinal vessel density between the cognitively healthy controls and those with MCI," she said. Dr. Grewal said it may be nec- essary to study a larger group of individuals to detect a difference in retinal imaging parameters between MCI and controls. From a clinical perspective, additional data to help physicians improve Alzheimer's diag- nostics would be pivotal, Dr. Grewal said. "This helps to address the diagnostic problem because you now have additional data that clinicians can use to try to determine if someone has Alzhei- mer's," he said. Testing for something like blood vessel density could augment the rest of the neurological investigation, Dr. Grewal said. While the eye is likely to play a key role in diagnostics, it's too early to determine the role of ophthalmologists, Dr. Fekrat said. "Perhaps the equipment that we use to predict the like- lihood of someone having Alzheimer's can be stationed in a neurologist's office for screening or as a diagnostic adjunct, or maybe it can be incorporated into the primary care physician's exam as part of Medicare's Annual Wellness Visit," she said. Looking to the future, there is also the possibility that smartphone apps may evaluate patients' self-acquired retinal im- ages through an embedded algorithm that then provides a risk score, she said. Dr. Grewal pointed out that such a risk score would be an additional data point for physicians to assess. "At this time, however, we cannot install retinal imaging machines in CVS, for example, so that anyone can get a scan and receive an output from the machine saying they have Alzheimer's," he said. "That's currently not feasible. Much more work needs to be done and is under- way." Still, testing and evaluating ocular struc- tures have many advantages that cannot be ignored, Dr. Grewal stressed. "It's easy to acquire, the recurring cost is much lower than having the patient undergo an MRI scan, PET imaging, or lumbar puncture every year, and it is an objective measure," he said. "Once we have correlations with structural tests like MRIs and other accept- ed biomarkers, multimodal retinal imaging has the potential to serve as a surrogate marker." As the population grows older, better tools are needed to be able to more efficiently screen and diagnose individuals with MCI or Alzheimer's, with the reason- able cost that examining the eye can allow, he concluded. continued from page 29 Contact Fekrat: sharon.fekrat@duke.edu Grewal: dilraj.grewal@duke.edu Patients with opioid/polysubstance abuse tend to present with a corneal ulcer in the lower half of their cornea. Source: Matilda Chan, MD

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