Cyclic esotropia

Cyclic esotropia is a rare condition in which esotropia alternates with binocular single vision (BSV). A five years old female child presented with the complain of acute onset infrequent squinting of left eye (L/E) for 3 years. Squinting of L/E starts in morning and persists throughout the day. The child becomes completely normal on the following morning without any residual effect. Initially there was 24 hours squinting followed by several months of non-squinting. Gradually interval is lessening. For the last 6 months, she was esotropic for 24 hours and non-esotropic for another 24 hours. She complains of no diplopia during the attack. On examination she is otherwise healthy and hypermetropic by +0.50Dsph on cycloplegic refraction with normal visual acuity (6/6, N5). She was 50 prism diopter esotropic in her left eye on esotropic day both for distant and near fixation and had alternate suppression. Ocular motility is full. Anterior and posterior segment reveals no abnormality. There is BSV with positive stereoscopic vision on Titmus test (40 sec of Arc) on non-esotropic day. This case can be treated surgically either by bilateral medial rectus recession or by recession of medial rectus and resection of lateral rectus of the eye according to the amount of esotropia on the esotropic day.