A deductive approach to binocular vision anomalies

Professor Bruce Evans, director of research at the Institute of Optometry, delivered a session focused on interactive binocular vision (BV) at the AOP’s Locum clinical skills conference last year (27 November).

Introducing his session, Evans told attendees: “At least one in 20 of your patients has a BV problem. Every couple of days you will see a BV patient, so you cannot be an optometrist without knowing some orthoptics.”

During the session, hosted at the ABDO National Resource Centre in Birmingham, Evans presented real cases of binocular vision anomalies he had seen in community optometric practice settings.

“I think it has always been the case that there are many optometrists who are anxious about binocular vision anomalies,” Evans told OT. He added: “When they see a patient with a prism, or longstanding BV problem, maybe their stress levels rise and they start thinking, ‘this is going to be a difficult patient.’

“What I’m trying to get across in these talks is that, often, they are not. Often there is a very logical, sequential, deductive approach to investigating, and nearly all of these cases can be managed,” he said.

Evans added: “The most important take-home message always is: what do you need to refer? When do you need to refer? How urgently do you need to refer?”

During the presentation, Evans led delegates through the case of a 50-year-old female with a history of incomitant deviation that had recently started to decompensate.

The challenge was to work out why this was occurring; whether it could be caused by an optical intervention, or pathology and so require referral.

Evans outlined a grading system for the cover test, developed at the Institute of Optometry, and asked attendees to vote on which tests they would complete, what the diagnosis was, and whether they would refer or manage.

The professor highlighted that while occasionally the patient’s symptoms might indicate a BV anomaly, “more often than not, it is the routine testing that we do of a patient. Every eye exam will include cover testing, near point of convergence, and often those will detect a BV anomaly.”

He emphasised the importance of routine motility testing in children, sharing: “If children have congenital incomitancy, they might not report it and the parents might not even have noticed it, but it is something we would see on motility.

“In those cases, there may be a patient who doesn’t present with any suspicious symptoms and the parents don’t describe any suspicious history, but on testing we find something that we discover needs further investigation,” he said.

The AOP’s Locum clinical skills conference was run in partnership with Johnson & Johnson MedTech.

Following the success of the first Locum clinical skills conference, the AOP has confirmed that it will host two further conferences in 2024.