Corneal Topography in Involutional Ectropion of the Lower Eyelid

Abstract

The shape and position of the eyelids affect corneal topography. This study evaluated preoperative and postoperative corneal topography in involutional ectropion of the lower eyelid. Eighteen patients with unilateral involutional lower eyelid ectropion underwent ophthalmic examinations and corneal topography before surgical correction and at the 6-month postoperative interval. Corneal topographies were evaluated with the Holladay Diagnostic Summary package. The fellow eyes served as controls. Parameters evaluated included the regularity of astigmatism (RA), steep refractive power (SRP), flat refractive power (FRP), and total astigmatism (TA). Preoperatively, RA was found significantly decreased in the eyes with ectropion compared with the fellow eyes, whereas differences in other parameters were statistically nonsignificant. Postoperatively, RA was significantly increased, whereas SRP was significantly reduced. The percentage of eyes with with-the-rule astigmatism (WTRA) was increased postoperatively, although astigmatic axis changes were not systematic. Postoperative topographic changes may be related to either restoration of symmetry in the upper and lower lid apposition on the cornea or to rearrangement of the tear film. Further research will be required to assess whether corneal topographic findings could be used as an index of the severity of eyelid laxity and to evaluate the effects of topographic changes on corneal and total optical aberrations.