WHEN esotropia appears before age 18 months, the accommodative element is rarely important, and early operation is vital. Internal examination and retinoscopy should be done at the same time. The usual recession of the medial rectus is difficult on the infant, and the buried sutures often cause excessive reaction and consequent limitation of abduction due to excessive scar formation.
I have substituted a marginal myotomy for the recession operation. The exact amount of muscle cut was difficult to gauge at first, and most of the early patients were undercorrected. With the following technique, the exact amount of lengthening can be controlled, and reaction is minimal.
An 8 mm limbal incision is made with scissors and carried back radially for 5 mm above and below the medial rectus muscle. Tenon's capsule is grasped below the muscle edge and undermined to expose the sclera. A muscle hook is passed through
Kennedy JA. Marginal Myotomy of the Medial Rectus. Arch Ophthalmol. 1970;84(5):625-626. doi:10.1001/archopht.1970.00990040627013