title: Topographic analysis of early changes in corneal astigmatism after cataract surgery.
abstract: Using the Topographic Modeling System (TMS), we studied the early changes in anterior corneal curvature following cataract surgery. Thirty patients who had planned extracapsular cataract extraction (p-ECCE) or phacoemulsification were evaluated with TMS at three days, and one, two, three, and five weeks postoperatively. After p-ECCE, the upper part of the cornea which corresponded to the wound and the lower cornea markedly steepened and showed a bow-tie pattern of astigmatism. Eight (57%) of 14 cases showed little reduction in the corneal steepening at five weeks postoperatively. In five cases (36%) the steepening in the lower cornea was less than the minimal change in the upper cornea. After phacoemulsification, corneal steepening was much less than it was after p-ECCE; three cases (17%) showed almost no surgically induced alteration of the cornea. In eight phacoemulsification cases (61%), postoperative corneal steepening decreased rapidly and the corneal shape recovered within five weeks. Our topographic analysis clearly demonstrated that a smaller wound in phacoemulsification surgery produced less corneal steepening and stabilized more rapidly than a larger wound in p-ECCE.
authors.affiliation: Hayashi Eye Hospital, Fukuoka, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Hayashi
authors.forename: F
authors.initials: F
authors.lastname: Nakao
authors.forename: F
authors.initials: F
authors.lastname: Hayashi
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001251:Astigmatism / Q000209:etiology* / Q000473:pathology*; D002387:Cataract Extraction / Q000009:adverse effects*; D003315:Cornea / Q000473:pathology*; D005500:Follow-Up Studies; D006801:Humans; D007091:Image Processing, Computer-Assisted; D007910:Lenses, Intraocular; D008875:Middle Aged; D014792:Visual Acuity