Jain A K, Saini J S, Gupta R
Department of Ophthalmology, Post-Graduate Institute of Medical Education and Research [PGIMER], Chandigarh, India.
Indian J Ophthalmol. 2000 Mar;48(1):25-32.
Clinical comparison of intraocular pressure (IOP) measured with the Goldmann applanation tonometer (GAT), the ProTon tonometer (PT), and the Schiotz tonometer (ST), in normal eyes, eyes with scarred corneas and postkeratoplasty eyes.
The IOP readings with GAT, PT, and ST were compared in 125 eyes with normal corneas (Group A), 17 eyes with scarred corneas (Group B), and in 21 postkeratoplasty eyes (Group C). The data were statistically analysed at 95% confidence interval; linear regression analysis and paired t-test were done.
The mean differences and their standard deviation [SD] between GAT and PT readings, and GAT and ST readings respectively were: [1] in Group A: -0.23 [SD 2.75] mmHg and +0.24 [SD 3.18] mmHg respectively; [2] in Group B: -1.8 [SD 12.67] mmHg and -4.5 [SD 9.95 mmHg; and [3] in Group C: +0.24 [SD 8.72] mmHg and -0.12 [SD 8.7] mmHg. They were not statistically significant. In Group A the 95% confidence interval between GAT and PT readings was -5.27 mmHg to 5.73 mmHg, and between GAT and ST readings, -6.12 mmHg to 6.59 mmHg. Ninety six [77%] eyes with the PT and 84 [69%] eyes with ST measurements were within 3 mmHg of GAT pressure. The correlation coefficients [r] for PT and ST were 0.93 [P = 0.0000] and 0.88 [P = 0.0000] respectively. In Group B 95% confidence interval between GAT and PT readings was -27.17 mmHg to 23.51 mmHg, and between GAT and ST measurement, -24.37 mmHg to 15.44 mmHg. The correlation coefficients [r] for the PT and ST were 0.112 [P = 0.660] and 0.630 [P = 0.006] respectively. In group C, the 95% confidence interval between GAT and PT measurements was -17.20 mmHg to 17.67 mmHg, and between GAT and ST measurements, -17.51 mmHg to 17.27 mmHg. The correlation coefficients [r] for the PT and the ST were 0.780 [P = 0.0000] and 0.740 [P = 0.0001] respectively.
In clinical practice PT appears to have a higher level of accuracy than ST in normal corneas. In scarred corneas and post-penetrating keratoplasty eyes, because of high SD for mean differences and wide confidence interval of 95%, both PT and ST are inaccurate in measuring IOP as compared to GAT in such eyes.
比较Goldmann压平眼压计（GAT）、ProTon眼压计（PT）和Schiotz眼压计（ST）在正常眼、角膜瘢痕化眼和角膜移植术后眼中测量眼压（IOP）的临床效果。
比较125只正常角膜眼（A组）、17只角膜瘢痕化眼（B组）和21只角膜移植术后眼（C组）使用GAT、PT和ST测量的眼压读数。数据在95%置信区间进行统计学分析；进行线性回归分析和配对t检验。
GAT与PT读数之间以及GAT与ST读数之间的平均差值及其标准差[SD]分别为：[1]A组：分别为-0.23[SD 2.75]mmHg和+0.24[SD 3.18]mmHg；[2]B组：-1.8[SD 12.67]mmHg和-4.5[SD 9.95]mmHg；[3]C组：+0.24[SD 8.72]mmHg和-0.12[SD 8.7]mmHg。差异无统计学意义。在A组中，GAT与PT读数之间的95%置信区间为-5.27 mmHg至5.73 mmHg，GAT与ST读数之间为-6.12 mmHg至6.59 mmHg。96只（77%）使用PT测量眼压的眼和84只（69%）使用ST测量眼压的眼的眼压在GAT测量值的3 mmHg范围内。PT和ST的相关系数[r]分别为0.93[P = 0.0000]和0.88[P = 0.0000]。在B组中，GAT与PT读数之间的95%置信区间为-27.17 mmHg至23.51 mmHg，GAT与ST测量值之间为-24.37 mmHg至15.44 mmHg。PT和ST的相关系数[r]分别为0.112[P = 0.660]和0.630[P = 0.006]。在C组中，GAT与PT测量值之间的95%置信区间为-17.20 mmHg至17.67 mmHg，GAT与ST测量值之间为-17.51 mmHg至17.27 mmHg。PT和ST的相关系数[r]分别为0.780[P = 0.0000]和0.740[P = 0.0001]。
在临床实践中，在正常角膜眼中PT的准确性似乎高于ST。在角膜瘢痕化眼和穿透性角膜移植术后眼中，由于平均差值的标准差较高且95%置信区间较宽，与GAT相比，PT和ST在测量此类眼的眼压时均不准确。
