Publications (2)1.47 Total impact
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Article: Effects of pterygium surgery on front and back corneal astigmatism.
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ABSTRACT: To evaluate changes in front and back corneal astigmatism after pterygium surgery using the Scheimpflug imaging of Pentacam. Prospective interventional case series. We studied 96 eyes with primary pterygium that underwent surgery. Preoperatively and at 1, 3, and 6 months after surgery, Pentacam (Oculus, Wetzlar, Germany) was used to measure astigmatism at the front and back corneal surfaces. Surgically induced astigmatism (SIA) on the front corneal surface was also calculated, using vector analysis. Of the eyes, 73 completed 6-month postoperative follow-up without developing pterygium recurrence. Front corneal astigmatism decreased from 3.97 ± 4.49 D preoperatively to 1.23 ± 1.88 D at 1 month (p < 0.001). Back corneal astigmatism decreased, but nonsignificantly, from 0.35 ± 0.39 D preoperatively to 0.32 ± 0.2 D at 1 month (p = 0.49). However, although back astigmatism was with-the-rule in 43.8% of patients and against-the-rule in 24.6% of patients preoperatively, these changed to 87.7% and 4.1%, respectively, at 1 month (p = 0.02). Refractive cylinder (52 eyes) reduced from 2.62 ± 2.22 D preoperatively to 1.06 ± 1.57 D at 1 month (p = 0.05). There was no significant change in any parameter after 1 month throughout the 6 months after surgery. SIA was 3.51 ± 2.66 D at 1 month postoperatively, which showed significant correlation with age, preoperative astigmatism, and pterygium length and area, but there was no correlation with gender, pterygium width, preoperative spherical power, or surgical technique. Moreover, higher grades of pterygium morphology had higher SIA postoperatively (p = 0.05). Pterygium surgery was associated with significant changes in front and back corneal surfaces. Eyes with more advanced pterygia achieved higher SIA.Canadian Journal of Ophthalmology 10/2012; 47(5):423-8. · 1.47 Impact Factor -
Article: Effects of pterygium surgery on front and back corneal surfaces and anterior segment parameters.
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ABSTRACT: 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.International Ophthalmology 04/2012; 32(3):251-7.
