Luan Chun-sheng, Chen Xiao-ming, Deng Ying-ping, Wang Lin, Liu Dong-jing, Cui Min, Li Jing
Department of Ophthalmology, West China Hospital of Sichuan University, Chengdu 610041, China.
Zhonghua Yan Ke Za Zhi. 2005 Jul;41(7):642-6.
To investigate the relationship between central corneal thickness (CCT) and Perkins applanation tonometry and establish a mathematic model of correlation between true intraocular pressure (IOP), CCT and Perkins applanation tonometry.
The study included thirty-two new Zealand rabbits. One eye received excimer laser photorefractive keratectomy (PRK), the other eye was used as control. The eye selected randomly according to stochastic digital chart received PRK to thin the central cornea and to generate different central corneal thickness. The Perkins applanation tonometry, CCT, corneal curvature (CC) were measured by Perkins applanation tonometer, ultrasonic pachymetry and keratometer pre- and post-PRK. Direct intracameral IOP readings was measured by IOP transducer. Statistical analyses were performed with the Pearson correlation coefficient and stepwise regression analysis.
There is no difference in the measurement of Perkins applanation tonometry, CCT and CC between experimental and controls. A significant correlation was found between IOP and CCT pre- and post-PRK (r = 0.761, P < 0.05; r = 0.829 P < 0.05). There is correlation between IOP and CC, (r = 0.098, P > 0.05; r = 0.260, P > 0.05). The slope of CCT was 0.066 mm Hg/micron pre-PRK and 0.053 mm Hg/micron post-PRK. However, the change of IOP correlated with CCT. Regression equation for direct intracameral IOP Y = 12.107 + 1.254X(1) - 0.033X(2) (X(1) = Perkins applanation tonometry, X(2) = CCT).
CCT is an important variable in the evaluation of applanation IOP and should be considered when the Perkins applanation tonometry was taken.
探讨中央角膜厚度（CCT）与珀金氏压平眼压计测量值之间的关系，并建立真实眼压（IOP）、CCT与珀金氏压平眼压计测量值之间的相关数学模型。
研究纳入32只新西兰兔。一只眼接受准分子激光屈光性角膜切削术（PRK），另一只眼作为对照。根据随机数字表随机选择一只眼接受PRK以变薄中央角膜并产生不同的中央角膜厚度。在PRK术前和术后，使用珀金氏压平眼压计、超声角膜测厚仪和角膜曲率计分别测量珀金氏压平眼压计测量值、CCT和角膜曲率（CC）。通过眼压传感器直接测量前房内眼压读数。采用Pearson相关系数和逐步回归分析进行统计学分析。
实验组和对照组在珀金氏压平眼压计测量值、CCT和CC的测量上无差异。PRK术前和术后IOP与CCT之间均存在显著相关性（r = 0.761，P < 0.05；r = 0.829，P < 0.05）。IOP与CC之间存在相关性（r = 0.098，P > 0.05；r = 0.260，P > 0.05）。PRK术前CCT的斜率为0.066 mmHg/微米，术后为0.053 mmHg/微米。然而，IOP的变化与CCT相关。前房内直接眼压的回归方程为Y = 12.107 + 1.254X(1) - 0.033X(2)（X(1) = 珀金氏压平眼压计测量值，X(2) = CCT）。
CCT是评估压平眼压时的一个重要变量，在使用珀金氏压平眼压计时应予以考虑。
