Department of Ophthalmology, Seoul St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, South Korea.
Department of Ophthalmology, Yeouido St. Mary's Hospital, College of Medicine, The Catholic University of Korea Korea, Seoul, South Korea.
BMC Ophthalmol. 2020 Dec 3;20(1):475. doi: 10.1186/s12886-020-01747-9.
To analyze mean corneal powers and astigmatisms on anterior, posterior, and total cornea in patients with keratoconus as calculated according to various keratometric measurements using a Scheimpflug camera.
We examined the left eyes of 64 patients (41 males and 23 females; mean age 29.94 ± 6.63 years) with keratoconus. We measured simulated K (Sim-K), posterior K, true net power (TNP) and four types of total corneal refractive powers (TCRP). We then used the obtained values to analyze mean K, and corneal astigmatism. TCRP were measured at 2.0 ~ 5.0 mm.
Mean corneal powers from Sim K, posterior K, and TNP were 49.12 ± 3.99, - 7.39 ± 0.79, and 47.78 ± 4.09 diopters, respectively. For TCRP centered on the pupil, mean K tended to decrease with measurement area (all p < 0.01). While, both mean K and astigmatism measured using TCRP centered on the apex decreased with measurement area (all p < 0.001). TCRP centered on the apex were greater than those centered on the pupil for mean K values calculated using TCRP (all p < 0.001). The proportion of WTR was greatest on the anterior and total cornea. As the measurement area moved to the periphery, the proportion of WTR increased.
Mean corneal powers and astigmatisms on total cornea with keratoconus change depending on calculation methods and measurement areas.
使用 Scheimpflug 相机分析角膜混浊患者的各种角膜曲率计测量值计算的前、后和总角膜平均角膜力和散光。
我们检查了 64 例（41 名男性和 23 名女性；平均年龄 29.94±6.63 岁）圆锥角膜患者的左眼。我们测量了模拟 K（Sim-K）、后 K、真实净力（TNP）和四种总角膜屈光力（TCRP）。然后，我们使用获得的值来分析平均 K 和角膜散光。TCRP 在 2.0 至 5.0 毫米处进行测量。
Sim-K、后 K 和 TNP 的平均角膜力分别为 49.12±3.99、-7.39±0.79 和 47.78±4.09 屈光度。对于以瞳孔为中心的 TCRP，平均 K 随着测量区域的增加而降低（均 p<0.01）。而以顶点为中心的 TCRP 测量的平均 K 和散光均随测量区域的增加而降低（均 p<0.001）。以顶点为中心的 TCRP 计算的平均 K 值大于以瞳孔为中心的 TCRP（均 p<0.001）。以角膜顶点为中心的 TCRP 的 WTR 比例在前部和总角膜中最高。随着测量区域向周边移动，WTR 的比例增加。
圆锥角膜患者总角膜的平均角膜力和散光随计算方法和测量区域的不同而变化。
