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目的根据角膜外伤后的散光类型和特点,探寻定量计算散光矫正量的数学公式,使得角膜缘切口矫正角膜散光的手术方法有章可寻,简便易行且安全可靠。方法对22例(22眼)外伤性角膜散光患者,依据测得的角膜散光数值及轴向,在角膜缘后0.5~1.0mm处,通过楔性切除和牵张缝线使平坦的经线变陡峭,矫正远视散光。同时,并依据“偶联效应”矫正近视散光。据Gu llstrand模型眼推导出角膜缘楔形切除宽度的计算公式:DV=(n2-n1/r-χπ)-DA(公式①),并据此计算并调整手术矫正量。结果本组22眼平均裸眼视力术前为0.23±0.12,术后0.62±0.26,矫正视力术前0.8±0.25,术后0.94±0.18,较术前有不同程度的提高,术后3个月复查O rbScan-Ⅱ,模拟角膜镜读数(S imK),SAI及SR I值均较术前明显降低,与术前相比差异有统计学意义(P<0.001)。结论角膜缘成对称楔形切除加牵张缝线术,适用于矫正+4.00D以下的远视散光和混合性散光,及-2.00D以下的近视散光,根据Gu llstrand模型眼,推导出角膜缘楔形切除量的计算公式:公式①,通过计算及试验数据分析发现:角膜缘楔形切除的量与散光矫正的量并非正相关关系。
Objective According to the types and features of astigmatism after corneal trauma, the mathematical formula for quantitative calculation of astigmatism correction is explored, which makes the operation method of corneal incision corrective corneal astigmatism easy to find out, simple, easy and safe. METHODS: Twenty-two patients (22 eyes) with traumatic corneal astigmatism underwent corneal astigmatism and axial direction at 0.5-1.0 mm posterior to the corneal limbus to make the flat warp steepening by wedge resection and stretch suture , Correction hyperopia astigmatism. At the same time, and based on “coupling effect ” correction of myopic astigmatism. According to Gullstrand model eye derived wedge width of the limbal wedge calculation formula: DV = (n2-n1 / r-χ π) -DA (formula ①), and accordingly calculate and adjust the amount of surgical correction. Results The average uncorrected visual acuity of 22 eyes was 0.23 ± 0.12 before surgery, 0.62 ± 0.26 after surgery, 0.8 ± 0.25 before correction, 0.94 ± 0.18 after operation, respectively, which were improved to some extent compared with those before operation, and were reviewed after 3 months O rbScan-Ⅱ, simulated keratometer readings (S imK), SAI and SR I were significantly lower than those before surgery, and the difference was statistically significant (P <0.001). Conclusions The corneal limbus symmetrical wedge resection and stretch suture surgery is suitable for hyperopia astigmatism and mixed astigmatism below + 4.00D and myopia astigmatism below -2.00D. According to the Gullstrand model eye, the wedge resection Amount of formula: Formula ①, calculated and experimental data analysis found: the amount of limbal wedge resection and the amount of astigmatism correction is not a positive correlation.