Diplopia and Strabismus after Retinal and Glaucoma Surgery

Abstract

Strabismus after retina surgery and glaucoma surgery involving drainage explants is associated with secondary strabismus. The most frequent causes of strabismus after retina surgery include scarring and fat adherence, a large segmental explant directly under a rectus muscle, and inadvertent displacement of an oblique muscle or tendon by an encircling band. Retinal encircling elements such as 240 bands that indent the sclera do not, by themselves, cause strabismus. Glaucoma explants such as Molteno tubes, as well as Krupin and Baerveldt implants may also produce strabismus. The cause of strabismus is related to the size of the bleb. The larger the bleb, the higher the incidence of strabismus. Superior nasal filtering blebs may cause a Brown syndrome, while superior temporal filtering blebs tend to produce esotropia and hypotropia. The newer fenestrated Baerveldt glaucoma implant reduces the bleb size and may reduce the incidence of strabismus.

• diplopia
• strabismus
• retinal surgery
• glaucoma surgery
• Baerveldt explant
• Krupin explant
• Molteno explant
• Brown's syndrome