Late overcorrection after inferior rectus recession.

PURPOSE: Describe characteristics and possible etiology of late overcorrection after inferior rectus recession in patients without Graves disease.

METHODS

Seven adult patients with initial good alignment (< 5 prism diopters) but an overcorrection 1 month after inferior rectus recession were studied.

RESULTS

Two patients had congenital superior oblique paresis, one had traumatic superior oblique paresis, two had orbital 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 patients with late overcorrection after inferior rectus recession underwent repeat surgery of the inferior rectus muscle. All six patients had scarring of the Lockwood ligament but no muscle slippage.

CONCLUSION

Late overcorrection can occur unrelated to Graves ophthalmopathy or a slipped 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, thus slackening the anterior aspect of the muscle. This slackening of the anterior aspect of the inferior rectus muscle would weaken the depression function, thus producing a late overcorrection.