[Effect of tear film changes on the intraocular pressure measurement by Goldmann applanation tonometer].
OBJECTIVE
To explore the effect of tear film changes on the intraocular pressure (IOP) measurement by Goldmann applanation tonometer.


METHODS
Sixty-eight normal subjects were randomly divided into two groups (Group A and B), 34 in each group. One eye of each subject by random selection was given Dextran (in Group A) and Viscoat (in Group B), respectively. And the fellow eyes were used as controls. IOP was measured in all subjects twice using Goldmann applanation tonometer. And the difference between first and second measurements was compared.


RESULTS
In the control eyes of Group A, the average IOP of first and second measurements were (14.44 +/- 2.68) mmHg (1 mmHg = 0.133 KPa) and (14.47 +/- 2.69) mmHg, there was no difference between the two measurements (t = -0.329, P = 0.744). In eyes given Dextran, the average IOP of two measurements were (14.41 +/- 2.63) mmHg and (12.94 +/- 2.59) mmHg, there was significant difference between the two measurements (t = 13.949, P = 0.000). In control eyes of Group B, the average IOP of first and second measurements were (14.53 +/- 3.13) mmHg and (11.18 +/- 3.07) mmHg, and there was no difference between the two measurements (t = -0.466, P = 0.644). In eyes given Viscoat, the average IOP of two measurements were (14.53 +/- 3.13) mmHg and (11.18 +/- 3.07) mmHg, and there was significant difference between the two measurements (t = 22.126, P = 0.000). After being given Dextran or Viscoat, the IOP values decreased consistently in both Group A and Group B.


CONCLUSIONS
The change of tear film components can affect IOP values by Goldmann applanation tonometer.
Zeng
Yangfa
Y
State Key Laboratory of Ophthlamology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou 510060, China.
Guo
Xinxing
X
Lin
Jun
J
Zeng
Xiangyun
X
Zhong
Yiming
Y
Cai
Xiaoyu
X
Liu
Xing
X
D000328:Adult; D005260:Female; D006801:Humans; D007429:Intraocular Pressure; D008297:Male; D008875:Middle Aged; D013666:Tears; D014065:Tonometry, Ocular / Q000379:methods*