Strabismus secondary to implantation of glaucoma drainage device. a. The patient presented with a gradual progressive right hypertropia after insertion of a glaucoma drainage device. b. Downgaze reveals the glaucoma drainage device surrounded by scar tissue, which is creating the restrictive pattern of strabismus. Glaucoma drainage devices may also be associated with strabismus due to mass effect, which would result in a hypotropia.