LATE OVERCORRECTION AFTER INFERIOR RECTUS RECESSION

Purpose: Describe characteristics and possible etiology of late overco rrection after inferior rectus recession in patients without Graves di sease. Methods: Seven adult patients with initial good alignment (<5 p rism diopters) but an overcorrection 1 month after inferior rectus rec ession were studied. Results: Two patients had congenital superior obl ique paresis, one had traumatic superior oblique paresis, two had orbi tal fracture, one had strabismus after retinal detachment surgery, and one had hypotropia after cataract surgery, Overcorrection occurred 4 to 6 weeks after surgery, measuring 12 to 25 prism diopters. Six patie nts with late overcorrection after inferior rectus recession underwent repeat surgery of the inferior rectus muscle. All six patients had sc arring of the Lockwood ligament but no muscle slippage. Conclusion: La te overcorrection can occur unrelated to Graves ophthalmopathy or a sl ipped muscle, Postoperative scarring around the Lockwood ligament was identified, which could result in reduced inferior rectus muscle force . It is hypothesized that late scar contracture in the vicinity of the Lockwood ligament could pull the inferior rectus muscle anteriorly, t hus slackening the anterior aspect of the muscle. This slackening of t he anterior aspect of the inferior rectus muscle would weaken the depr ession function, thus producing a late overcorrection.