Miyata Kazunori, Minami Keiichiro, Otani Atsushi, Tokunaga Tadatoshi, Tokuda Shouta, Amano Shiro
*Miyata Eye Hospital, Miyazaki, Japan; †Kagoshima Miyata Eye Clinic, Kagoshima, Japan; ‡Tomey Corporation, Nagoya, Japan; and §Inouye Eye Hospital, Tokyo, Japan.
Cornea. 2017 Jul;36(7):834-840. doi: 10.1097/ICO.0000000000001193.
To propose a grading system of pterygium severity based on corneal higher-order irregularity (HOI) and to evaluate postoperative changes in corneal irregularity of the graded pterygia.
In 268 eyes of 226 patients undergoing excision surgery of primary nasal pterygium, Placido corneal topography images were taken before and until 6 months after surgery. The best-corrected visual acuity (BCVA) and pterygium size with respect to the corneal diameter were also measured. HOI components within 1.0-, 3.0-, and 5.0-mm diameters were obtained using Fourier harmonic analysis of corneal topography data. With threshold levels when the HOIs for 3 diameters steeply increased, 4 levels of grading from 0 (mild) to 3 (severe) were determined. Associations of the grades with the preoperative surface regularity index (SRI), irregular components (IRRs) obtained from the 3.0-mm diameter Fourier analysis, and BCVA were examined. Time-course changes in the indexes after surgery were evaluated for each grade.
There were 62, 65, 41, and 100 eyes in grades 0 to 3, respectively. Preoperatively, the SRI in grade 3 was significantly higher than in the other grades (P < 0.001), and the IRR and BCVA varied with the grade (P < 0.001). Between 1 and 6 months postoperatively, grade 3 pterygia showed significant changes in the SRI and IRR (P = 0.013 and 0.017, respectively), whereas there was no change after 3 months postoperatively in the SRI, IRR, and BCVA for all other grades.
The proposed grading effectively classified the severity of pterygia and evaluated postoperative restoration of corneal irregularity. Using corneal topographic data allowed for objective evaluation of pterygium severity.
基于角膜高阶不规则度（HOI）提出一种翼状胬肉严重程度分级系统，并评估分级翼状胬肉术后角膜不规则度的变化。
对226例接受原发性鼻侧翼状胬肉切除手术的患者的268只眼，在手术前及术后6个月内拍摄角膜地形图图像。还测量了最佳矫正视力（BCVA）和相对于角膜直径的翼状胬肉大小。使用角膜地形图数据的傅里叶谐波分析获得直径1.0、3.0和5.0毫米范围内的HOI分量。当3个直径的HOI急剧增加时，根据阈值水平确定了从0（轻度）到3（重度）的4个分级水平。检查分级与术前表面规则指数（SRI）、从3.0毫米直径傅里叶分析获得的不规则分量（IRR）以及BCVA之间的关联。对每个分级评估术后指标的时间进程变化。
0至3级分别有62、65、41和100只眼。术前，3级的SRI显著高于其他分级（P < 0.001），IRR和BCVA随分级而变化（P < 0.001）。术后1至6个月，3级翼状胬肉的SRI和IRR有显著变化（分别为P = 0.013和0.017），而所有其他分级在术后3个月后SRI、IRR和BCVA均无变化。
所提出的分级有效地对翼状胬肉的严重程度进行了分类，并评估了术后角膜不规则度的恢复情况。使用角膜地形图数据可对翼状胬肉的严重程度进行客观评估。
