Abstract
Abstract: :
Purpose: To investigate whether the human amniotic membrane can decrease the induced astigmatism of laser corneal refractive surgery. Methods: PARK (-3D of astigmatism 1800) was performed on both eyes of 10 albino rabbits, which were divided into 2 groups, each 10 eyes. Immediate after PARK, group A received amniotic membrane graft and group B received polyethylen film graft on cornea. The degree of astigmatism was measured with topography and cycloplegic refraction at preoperative and 4, 8, 12 weeks postoperatively and evaluated by vector analysis. Results: Topography data showed that mean preoperative average keratometry and corneal astigmatism had no significant difference in both groups. After 3 months, mean change of the corneal astigmatism was 1.440.86D in the group A, compared with 2.590.30D in the group B. This change of astigmatism showed significant difference, as well as the axis of astigmatism (p<0.05). The surgically induced astigmatism was 0.130.86D in the group A, compared with 1.000.30D in the group B at 3 months (p<0.01). The cycloplegic refraction showed that the change of astigmatism had no difference in both group at all period. But surgically induced astigmatism was significantly less in the group A (1.240.52D) than the group B (2.171.02D) at 1 month postoperatively (p<0.01). Conclusion: The amniotic membrane eliminated PARK-induced astigmatism as well as prevented surgically induced astigmatism. We suggest that amniotic membrane could be a useful tool for controlling the astigmatism induced by laser refractive surgery. Further clinical study is needed to verify our experimental finding.
Keywords: 325 astigmatism • 549 refractive surgery: other technologies • 543 refractive error development