Refractive changes after posterior segment surgery.

Retinal surgery can induce significant refractive errors. These errors include spherical changes caused by alterations in axial length after scleral buckle placement, astigmatic changes induced by a scleral buckle or pars plana vitrectomy, and focal alterations in corneal curvature that can significantly limit postoperative visual acuity. The adjunctive use of silicone oil can impose alterations directly, by the oil's interaction with the other refractive elements of the eye, and indirectly, through its effects on intraocular lens power calculations for subsequent cataract surgery.