1种转位角膜自体移植片最适大小与位置的简化数学模型  

Optimal size and location for corneal rotational autografts:A simplified mathematical model

作　　者：Afshari N.A. Duncan S.M. Tanhehco T.Y. Azar D.T. 桑延智 

机构地区：[1]Duke University Eye Center,Duke University Medical Center,Box 3802,Durham,NC 27710,United States Dr.

出　　处：《世界核心医学期刊文摘（眼科学分册）》2006年第9期26-27,共2页Digest of the World Core Medical Journals:Ophthalmology

摘　　要：Objective:To calculate clinical guidelines for the optimal location and size of a rotational autokeratoplasty.Methods:The ideal graft size and trephine decentration for a rotational autograft were calculated based on scar location using geometric models.Mathematical variables were set to maximize postoperative visual acuity and for generalization of the geometric model.This model was used in a rotational autokeratoplasty of a patient with a history of a corneal scar and diplopia.An 8-mm autograft was decentered 0.5mmsuperiorly and rotated 180° to relocate the scar to the superior aspect of the cornea,out of the patient’ s vision.Results:For cases that satisfy the given variables,a graft diameter of 8 mm with a decentration of 0.5 mm balances maximization of scar removal and scar movement superiorly,with minimization of discrepancy in corneal thickness after rotation.For scars that are α ° from horizontal,the graft should be rotated 180-α °.By using these calculations,the autograft in this case successfully resolved the diplopia and improved visual acuity.Conclusions:A rotational autograft can be an effective alternative to standard penetrating keratoplasty for some patients with corneal scars.We establish a mathematical model for most clinical instances of a rotational autograft,in which an 8-mm graft with a decentration of 0.5mm best satisfies the goals of surgery.Objective： To calculate clinical guidelines for the optimal location and size of a rotational autokeratoplasty. Methods： The ideal graft size and trephine decentration for a rotational autograft were calculated based on scar location using geometric models. Mathematical variables were set to maximize postoperative visual acuity and for generalization of the geometric model. This model was used in a rotational autokeratoplasty of a patient with a history of a corneal scar and diplopia. An 8- mm autograft was decentered 0.5mmsuperiorly and rotated 180° to relocate the scar to the superior aspect of the cornea, out of the patient＇s vision. Results： For cases that satisfy the given variables, a graft diameter of 8 mm with a decentration of 0.5 mm balances maximization of scar removal and scar movement superiorly, with minimization of discrepancy in corneal thickness after rotation. For scars that are α° from horizontal, the graft should be rotated 180 - α°. By using these calculations, the autograft in this case successfully resolved the diplopia and improved visual acuity. Conclusions： A rotational autograft can be an effective alternative to standard penetrating keratoplasty, for some patients with corneal scars. We establish a mathematical model for most clinical instances of a rotational autograft, in which an 8 -mm graft with a decentration of 0.5mm best satisfies the goals of surgery.

关 键 词：自体移植片 角膜移植片 转位移植 数学模型 角膜疤痕 术后视力 自体移植术 角膜移植术 

分 类 号：R779.65[医药卫生—眼科]