Department of Ophthalmology, Istanbul Medeniyet University Medical Faculty, Umraniye, Istanbul, Turkey.
Cornea. 2013 Sep;32(9):1251-4. doi: 10.1097/ICO.0b013e31829abdb2.
To investigate the effect of accommodation on corneal topography in healthy subjects.
Using a Nidek OPD-Scan ARK-10000, corneal topographic images, images of the iris, and the refraction of 18 eyes of 10 normal subjects with a mean age of 26.3 ± 7.1 years (median, 24 years; range, 19-41 years) were simultaneously obtained before and during fixation of a near target in the Department of Ophthalmology, Istanbul Medeniyet University Medical Faculty, Istanbul, Turkey. At baseline, iris landmarks, such as nevi and crypts, were identified on each iris image that were on opposite sides of the pupil and 180 degrees apart. A line was drawn on the iris images between these 2 landmarks. The same landmarks were identified on the iris images obtained when the eye was fixating at the near target. A line was drawn between the landmarks. The angular rotation of the lines relative to the vertical meridian was measured to assess cyclotorsion of the eyes during accommodation.
At baseline, the mean spherical equivalent refraction of the eyes was -0.78 ± 0.38 diopters (D) (range, -0.25 to -1.67 D) with <0.5 D of astigmatism. During a mean accommodative amplitude of -4.55 ± 2.04 (median, -4.25 D; range, -1.75 D to -8.12 D), there was no apparent difference in corneal topography and no statistical difference in mean keratometry (P = 0.26) or cyclotorsion (P = 0.74).
During accommodation, the cornea does not change curvature and the eye does not appear to significantly cyclotort.
研究调节对健康受试者角膜地形的影响。
在土耳其伊斯坦布尔 Medeniyet 大学医学院眼科，使用 Nidek OPD-Scan ARK-10000 同时获得 10 名正常受试者（18 只眼）的角膜地形图图像、虹膜图像和屈光度。这 10 名受试者的平均年龄为 26.3 ± 7.1 岁（中位数为 24 岁；范围为 19-41 岁）。在获得眼前目标固定时的图像之前，对每只眼的虹膜图像上位于瞳孔两侧且相隔 180 度的虹膜标志（如痣和隐窝）进行识别。在这两个标志之间画一条线。当眼睛固定在近目标时，在虹膜图像上识别相同的标志。在标志之间画一条线。测量这些线相对于垂直子午线的角旋转，以评估眼睛在调节时的旋转性斜视。
在基线时，眼睛的平均等效球镜屈光度为-0.78 ± 0.38 屈光度（D）（范围为-0.25 至-1.67 D），散光<0.5 D。在平均调节幅度为-4.55 ± 2.04（中位数为-4.25 D；范围为-1.75 D 至-8.12 D）时，角膜地形没有明显差异，角膜曲率计平均值也没有统计学差异（P = 0.26）或旋转性斜视（P = 0.74）。
在调节过程中，角膜曲率没有变化，眼睛似乎没有明显的旋转性斜视。
