实测与理论瞳孔直径下全角膜与前角膜球面像差的差异性分析

Discrepancies between Total and Anterior Corneal Spherical Aberrations Calculated on the Basis of the Measured and Theoretical Pupil Diameters

摘要: 【目的】观察不同年龄段人群实测与6.0 mm瞳孔直径下全角膜和前角膜球面像差的差异。【方法】观察不同年龄段(20~29, 30~39, 40~49, 50~59, 60~69, 70~79)共100例受试者，通过Sirius眼前节分析系统检测不同瞳孔直径下(2.0 mm, 2.5 mm, 3.0 mm, 3.5 mm, 4.0 mm, 4.5 mm, 5.0 mm, 5.5 mm, 6.0 mm, 6.5 mm, 7.0 mm)全角膜和前角膜球面像差及暗环境下实测瞳孔直径，通过数学拟合曲线计算出该实测瞳孔直径下全角膜和前角膜的球面像差值，分别比较其与6.0 mm瞳孔直径下全角膜与前角膜球面像差之间的差异。【结果】实测瞳孔直径与年龄呈负相关(P < 0.05)。全角膜和前角膜实测球面像差与年龄均呈负相关(P < 0.05)，6.0 mm瞳孔直径下前角膜球面像差与年龄呈正相关(P < 0.05)，而全角膜球面像差则与年龄无关(P > 0.05)。在60~69，70~79年龄段，实测全角膜和前角膜球面像差均显著低于6.0 mm瞳孔直径下对应参数(P < 0.05)。在20~29，30~39，70~79年龄段，实测全角膜与前角膜球面像差间有显著性差异(P < 0.05)；在6.0 mm瞳孔直径下，全角膜球面像差值在30~39，40~49，60~69年龄段显著低于前角膜对应值(P < 0.05)。【结论】老年人群中实测瞳孔直径下全和前角膜球面像差均显著小于6.0 mm瞳孔直径下对应参数，此差异与老年人群实际平均瞳孔直径较小有关。在实测和6.0 mm瞳孔直径下，全与前角膜球面像差在部分年龄段存在差异，两者有显著性差异的年龄段分布不同。所测前角膜球面像差不能完全代替全角膜球面像差，建议以实测全角膜球面像差值作为白内障手术选择消球差人工晶状体类型的依据。

Abstract: Objective: To compare the difference between total and anterior corneal spherical aberrations calculated on the basis of the pupil diameters of 6.0 mm and the actual measurements in different age groups. Methods: A total of 100 subjects in different age groups (20 - 29 years old, 30 - 39 years old, 40 - 49 years old, 50 - 59 years old, 60 - 69 years old, 70 - 79 years old) were examined using Sirius anterior segment analytic system. Their total corneal spherical aberrations (TCSA) and anterior corneal spherical aberrations(ACSA) were detected on the basis of different machine-provided pupil diameters (2.0 mm, 2.5 mm, 3.0 mm, 3.5 mm, 4.0 mm, 4.5 mm, 5.0 mm, 5.5 mm, 6.0 mm, 6.5 mm, 7.0 mm) and the scotopic pupil diameters were recorded as measured pupil diameters in the dark room. TCSA and ACSA based on the machine-measured pupil diameter was calculated through fitting curves, and compared to the TCSA and ACSA at a theoretical 6-mm pupil diameter. Results: The measured pupil diameter was negatively correlated with age (P < 0.05). TCSA and ACSA based on measured pupil diameter were both negatively correlated with age (P < 0.05). At 6-mm pupil diameter, ACSA was positively correlated with age (P < 0.05), while there was no obvious correlation between TCSA and age. In 60 - 69 and 70 - 79 years old groups, their TCSA and ACSA at the measured pupil diameters were significantly lower than those at 6-mm pupil diameter (P < 0.05). In 20 - 29, 30 - 39 and 70 - 79 years old groups, TCSA were significantly different from ACSA at the measured pupil diameters (P < 0.05). In 30 - 39, 40 - 49 and 60 - 69 years old groups, TCSA were significantly lower than ACSA at 6-mm pupil diameter (P < 0.05). Conclusions: TCSA and ACSA at the measured pupil diameters in the old subjects are significantly lower than those at 6-mm pupil diameter, which could be ascribed to their relatively small actual mean pupil sizes. At either the measured pupil diameters or 6-mm pupil diameter, TCSA significantly different from ACSA in some age groups. Our study suggested that the TCSA, rather than ACSA, at measured pupil diameter should be used for the selection of aplanatic intraocular lens for cataract patients.