1. Acquired

            A. Thyroid myopathy

            *B. Excessive recession or resection of muscle

            C. Orbital fracture

            D. Retinal detachment operation

            E. Strabismus surgery complicated by adhesions

            F. CPEO

2. Congenital

            A. Congenital fibrous syndrome

            B. Neurogenic paralysis with secondary contracture of antagonist muscle

            C. Duane retraction syndrome

            D. Brown superior oblique tendon sheath syndrome

            E. Strabismus fixus

Harley RD, et al. Congenital fibrosis of the extraocular muscles. Trans Am Ophthal Soc 1978; 76:197.

Wright KW. Pediatric ophthalmology and strabismus. St. Louis: CV Mosby, 1995.