Tomidokoro A, Oshika T, Amano S, Eguchi K, Eguchi S
Department of Ophthalmology, Omiya Red Cross Hospital, Saitama, Japan.
Cornea. 1999 Jul;18(4):412-5. doi: 10.1097/00003226-199907000-00004.
To quantitatively evaluate the influence of pterygium and its removal surgery on both regular and irregular corneal astigmatism.
In 19 eyes of 19 patients undergoing pterygium surgery, videokeratographic measurements were taken before and 1 month after surgery. Using Fourier harmonic analysis, dioptric data on mire rings were decomposed into spherical, regular astigmatism, and irregular astigmatism (decentration and higher order irregularity) components. The distance between the line of sight and the advancing edge of pterygium was measured, and the eyes were classified into two groups: large pterygium group (the distance <2.0 mm, n = 7) and small pterygium group (> or =2.0 mm, n = 12). Fifteen eyes of 15 subjects served as age-matched normal control eyes.
Before surgery, the magnitudes of regular astigmatism and higher order irregular astigmatism showed significant correlation with the size of pterygium. Regular astigmatism, asymmetry, and higher order irregularity in the large pterygium group were significantly greater than those of normal control eyes. The pterygium removal surgery significantly improved these changes, but regular astigmatism and higher order irregularity in the large pterygium group still remained significantly greater than those in the normal control eyes.
Pterygium induces a significant amount of regular and irregular astigmatism in proportion to its size. The removal surgery can improve these changes, but corneal distortion does not normalize completely in eyes with advanced pterygium.
定量评估翼状胬肉及其切除手术对规则和不规则角膜散光的影响。
对19例行翼状胬肉手术患者的19只眼，在手术前及术后1个月进行角膜地形图测量。采用傅里叶谐波分析，将角膜环的屈光度数据分解为球镜、规则散光和不规则散光（偏心和高阶不规则度）成分。测量视轴与翼状胬肉进展边缘之间的距离，并将眼部分为两组：大翼状胬肉组（距离<2.0mm，n = 7）和小翼状胬肉组（≥2.0mm，n = 12）。15名受试者的15只眼作为年龄匹配的正常对照眼。
手术前，规则散光和高阶不规则散光的程度与翼状胬肉大小呈显著相关性。大翼状胬肉组的规则散光、不对称性和高阶不规则度显著大于正常对照眼。翼状胬肉切除手术显著改善了这些变化，但大翼状胬肉组的规则散光和高阶不规则度仍显著大于正常对照眼。
翼状胬肉会根据其大小诱导显著量的规则和不规则散光。切除手术可改善这些变化，但晚期翼状胬肉患者的角膜变形不能完全恢复正常。
