Is it Possible to have a Receded NPC Without CI? That’s not a trick question, though at first it may seem counter-intuitive if not oxymoronic. That is, until you recall from previous blogs (Part 1 and Part 2) that it is possible to experience difficulty with converging even in the presence of measurable esophoria at near. Now, from the American Journal of Ophthalmology (due out in October issue) comes an article supporting the observation that patients having sustained a concussion can have a remote nearpoint of convergence without other signs of convergence insufficiency.
The paper is titled: Postconcussion: Receded Near Point of Convergence is not Diagnostic of Convergence Insufficiency. The lead author is Dr. Aparna Raghuram, an optometrist with a joint appointment in the Department of Ophthalmology at Boston Children’s Hospital and Harvard Medical School. The second author is optometrist Dr. Susan Cotter, a Professor at Ketchum/SCCO and Co-Chair of PEDIG.
Here are the reported results of their study:
“Of the 83 eligible patients, 74 (89%) had receded NPC. Of these, 70 (95%) had oculomotor disorders; 30 (41%) had disorders of accommodation only; 21 (28%) had convergence insufficiency and accommodation deficits; and 6 (8%) had convergence insufficiency only. Six (8%) had a convergence deficit other than convergence insufficiency (all with concurrent accommodative disorders); 4 (5%) had both a nonspecific vergence dysfunction and accommodation deficits; 2 (3%) had convergence excess only; and 1 (1%) had both convergence excess and accommodative deficits.”
So the answer to the question is a firm “yes!”. This helps explain why so many young patients with concussion benefit from plus lenses at near. It is nice to see this information shared in Primary Care Optometry News channels.