title: The effect of pterygium surgery on corneal topography.
abstract: OBJECTIVE
  The aim of this prospective randomized clinical study was to evaluate the effect of pterygium surgery on the corneal topography using a computerized corneal topography system.
  
  
  METHODS
  Computerized corneal topography was performed on 27 patients with primary pterygium before and after pterygium excision surgery. The topographical changes that occurred following surgery were evaluated using paired and unpaired two-tailed t-test and Pearson coefficient of correlation analyses. Simulated keratometric astigmatism at the central 3 mm and the total mean refractive powers of the whole cornea were measured before and after surgery. Following surgery, flattened or steepened corneal areas were determined.
  
  
  RESULTS
  Simulated keratometric astigmatism at 3 mm was found to be 2.30 +/- 2.08 D (0.2 - 7.63) preoperatively and 0.82 +/- 0.74 D (0.06 - 2.79) postoperatively. The difference between these two values was statistically significant (t = -3.46, P = 0.002). Total mean refractive power of the whole cornea was found to be 42.26 +/- 0.63 (40.80 - 43.64) preoperatively and 43.69 +/- 0.88 (41.50 - 44.90) postoperatively and the difference was 1.42 +/- 0.87. There was a statistically significant high difference (t = 28.36, P < 0.001). When preoperative and postoperative corneal topographies were compared, the whole cornea was found steeper at the postoperative period except a little region in the superior nasal quadrant.
  
  
  CONCLUSIONS
  We believe that corneal topographical changes caused by the pterygium are almost reversible after surgical treatment, and postoperatively the cornea becomes steeper.
authors.affiliation: Yüzüncü Yil University Medical Faculty, Department of Ophthalmology, Van, Turkey. acinal65@hotmail.com
authors.forename: A
authors.initials: A
authors.lastname: Cinal
authors.forename: T
authors.initials: T
authors.lastname: Yasar
authors.forename: A
authors.initials: A
authors.lastname: Demirok
authors.forename: H
authors.initials: H
authors.lastname: Topuz
mesh_terms: D003315:Cornea / Q000503:physiopathology*; D019781:Corneal Topography; D006801:Humans; D008875:Middle Aged; D013508:Ophthalmologic Surgical Procedures; D011446:Prospective Studies; D011625:Pterygium / Q000503:physiopathology / Q000601:surgery*; D012029:Refraction, Ocular; D014792:Visual Acuity