Effects of pterygium surgery on front and back corneal surfaces and anterior segment parameters.

The purpose of this study was to evaluate the effects of pterygium surgery on front and back corneal surfaces and anterior segment parameters. This prospective study included 96 eyes with primary pterygium that underwent surgery. Preoperatively and at 1, 3, and 6 months postoperatively, Pentacam was used to evaluate front and back corneal surfaces, anterior chamber depth (ACD), anterior chamber angle (ACA) and anterior chamber volume (ACV). Mean simulated keratometry at the front corneal surface increased from 42.73 ± 2.21 D preoperatively to 44.45 ± 2.05 D at 1 month (P < 0.001); it then decreased to 44.32 ± 2.07 D at 3 months (P < 0.001) and 44.19 ± 2.10 D at 6 months (P = 0.01). There was no statistically significant change in mean simulated keratometry at the back corneal surface. Radius of the front corneal best-fit sphere (BFS) decreased from 7.99 ± 0.29 mm preoperatively to 7.77 ± 0.25 mm at 1 month postoperatively (P < 0.001), without further change up to 6 months. Radius of the back corneal BFS increased from 6.42 ± 0.24 mm preoperatively to 6.50 ± 0.24 mm at 1 month (P < 0.001), without further change. Postoperative changes in mean simulated keratometry and radii of BFS had statistically significant positive correlations with pterygium extension onto the cornea and grade of pterygium morphology but, not with the surgical technique. There were no significant changes in ACD, ACA, and ACV values after pterygium surgery. Furthermore, the spherical equivalent of manifest refraction changed from +0.75 ± 1.06 D preoperatively to -0.72 ± 1.33 D at 1 month postoperatively (P = 0.001), with no further significant change. In conclusion, after pterygium surgery there were significant changes in front mean keratometry and front and back corneal radii of BFS. These were correlated with preoperative pterygium size and morphology grade. No significant changes in anterior segment parameters were noted postoperatively.