This article is more than 5 years old. Information may no longer be current.
High-tech device detects pupillary defects
Click Here to Manage Email Alerts
NEW YORK — An automated pupillographer can help clinicians determine defects in a patient's afferent and efferent pupillary light reflex pathway, according to a speaker here at Vision Expo East.
"Relatively few of us actually perform pupillary reflex testing the way we were trained," Craig Thomas, OD, told attendees at a continuing education session. "I've been practicing 28 years. I started off doing it, but then eased away from it. If patients had pupillary defects, I would see it during the exam."
The RAPDx is an automated pupillographer from Konan Medical (Irvine, Calif.) that assesses differential amplitudes and latencies. "It shows how much it constricts and how fast," Dr. Thomas said. "I got this instrument because I realized my vulnerability in my documentation."
The pupillary light reflex controls the diameter of the pupil in response to the intensity of the light that falls on the retina, Dr. Thomas explained. "The goal in testing is to determine if there's a defect in the afferent or efferent pupillary light reflex pathway," he said. "Now that I have more clinical experience, what I learned 30 years ago is making sense."
Dr. Thomas said a significant percentage of people with glaucoma or nearly any other pathology will have an asymmetric presentation with this test. "By definition, rapid afferent pupillary defect means one eye or visual pathway or nerve is different than the other," he said.
He noted that the RAPDx can pick up a defect in a patient who still has good visual acuity.
Dr. Thomas said he primarily uses the RAPDx for glaucoma in his practice, picking up low-tension or normal-tension glaucoma.
"You get better, more detailed results," he said. "Based on what I've seen, there's no way a human being can see the level of detail this instrument can find. Eighty percent of my patients are black, with dark eyes. It's nearly impossible to see anything.
"I perform the test on as many people as possible between the ages of 18 and 64," he continued.
Most patients younger than 18 have no pathology, and those older than 64 are routinely checked for problems, anyway, he said.
"This test can find low-tension glaucoma in patients you would never suspect otherwise," he said. "I'm making diagnoses earlier."
Dr. Thomas noted that the RAPDx is useful for any type of neurological disease, including multiple sclerosis, brain tumors and infarcts.
"Location is important," he said. "If it's in the back, it won't show up."
In response to a question from an attendee, Dr. Thomas said if he received an abnormal reading on the RAPDx but all other tests were normal, he would order an MRI of the brain with contrast.
He noted that if he sees defects on the RAPDx he will usually see defects with the NOVA-VEP (Diopsys).
"When patients see the RAPDx, they know it's something new," Dr. Thomas said.
He believes the test will lead to enhanced diagnostics, better clinical care, better documentation and increased utilization of traditional diagnostic testing.
- Disclosure: Dr. Thomas has received honoraria from Konan Medical and Diopsys.