[Clinical analysis of the diplopia and strabismus after ophthalmic surgeries]

To explore the mechanism and therapy of strabismus secondary to ophthalmic surgeries.

79 cases of postoperative secondary strabismus were examined for eye position, eyeball movement, diplopia and ocular muscle traction test. Strabotomies were performed in some of the cases. Their involved extrocular muscle conditions were examined during the surgery.

The cases of strabismus in the series were secondary to surgery of retinal detachment (38.0%), cataract extraction (31.7%), orbital surgery (13.9%), and other ophthalmic surgeries such as glaucoma, pterygium and blephatoptosis. Some cases secondary to surgery of retinal detachment and cataract extraction didn't recover in more than 6 months after surgery. The traction tests of involved muscles in some cases were positive. Fibrosis of the involved ocular muscles and adhesion of involved ocular muscles to conjunctiva, sclera and explants were found during strabotomies. Strabismus secondary to orbital surgery mainly showed impeding movement of eyeball. Strabismus secondary to pterygium mainly related to injury of the medial rectus operations. Strabismus secondary to glaucoma surgery recovered spontaneously in 2 - 14 days after operations.

Intraocular or external ophthalmic surgeries can cause secondary strabismus. The mechanism is primarily due to direct injury of the extraocular muscles, impeding movement and mechanical compression to the eyeball. Surgeons should pay more attention for those side effects, and take effective therapy to prevent and treat iatrogenic strabismus.