- Preoperative ocular pathology: amblyopia, rubella cataract, proliferative diabetic retinopathy, macular edema, retinal detachment, uveitis, history of iritis, iris neovascularization, medically uncontrolled glaucoma, microphthalmus or macrophthalmus, optic nerve atrophy, macular degeneration with visual acuity of less than 20/40, glaucoma with the presence of visual field defects