Incorrect

Incorrect

Incorrect

Correct! You observed the intermittent convergence of the eyes. If you looked closely, you also noticed that the pupils constricted slightly during those movements. This is called “spasm of the near reflex.” The near reflex is a triad of convergence, accommodation, and pupil constriction. All three components are normally activated when you switch gaze from a distant to a near target. In this patient, that triad is being inappropriately activated during distance viewing. (In patients aged under 45 years, you may find accommodation-induced myopia.) Why does this condition happen? Either voluntarily as part of factitious behavior or as part of a habit that escapes from voluntary control. Sometimes that habit can become so ingrained that the convergence becomes persistent. The differential diagnosis includes decompensating esophoria, accommodative esotropia, bilateral horizontal gaze palsies with convergence substitution, and bilateral sixth nerve palsies. Each of these other conditions has distinguishing features. Treatment of spasm of the near reflex is difficult. You can try interrupting binocularity by occluding one eye, but that works only occasionally. If there is a factitious or anxiety component, address that. When spasm of the near reflex becomes persistent, base-out prisms may alleviate diplopia, but may also solidify the misalignment. As tempting as it is to perform surgical weakening of the medial rectus muscles, beware that it can lead to exotropia.