Purchase this article with an account.
Nanar Hovasapian, Sahar Zokaeim, Pinakin Gunvant; Effect Of Corneal Parameters On Measurements Obtained Using Rebound Tonometer, Goldmann Applanation Tonometer And Ocular Response Analyzer. Invest. Ophthalmol. Vis. Sci. 2012;53(14):5032.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
1) To evaluate the effect of corneal parameters on the intraocular pressure (IOP) estimates obtained using the Icare rebound tonometer (IRT) 2) To compare the estimates of IOP obtained by IRT with the clinical gold standard the Goldmann applanation tonometer (GAT) and the Ocular Response Analyzer (ORA)
One hundred and fifty one subjects (mean age 29.7 standard deviation 10.4; 79 males 72 females) were prospectively recruited and IOP was measured using the IRT, GAT and ORA in a random sequence with 2- minute time interval between measurements. Central corneal thickness (CCT) was measured using ultrasound pachymetry and corneal hysteresis (CH) and corneal resistance factor (CRF) values were obtained from ORA. Pearson correlation was utilized to evaluate the effect of CCT on IOP estimates and Altman and Bland Plots were used to evaluate the agreement between IOP measured by various tonometers.
There was a significant correlation between IOP measured using the GAT and the IRT, whereas IOP measured using the ORA was not significantly correlated with CCT (r-square 0.04, 0.20 and 0.01; p =0.02, <0.0001 and 0.14 respectively). It was interesting to note that the IOP measured by IRT did not correlate with CH but was significantly correlated to CRF (r-square 0.01 and 0.39; p = 0.16 and <0.0001 respectively) The 95% limits of agreement of IOP measured using IRT were wide when compared to both the GAT IOP (+4.2 to -5.5) and the ORA IOP (+4.9 to -6.8).
The corneal parameters like CCT impacts the IOP estimates of IRT more that the IOP estimates of GAT. As reported previously by numerous studies CCT does not significantly impact the estimates of ORA IOP. Because the limits of agreement of IRT IOP measurements with the GAT IOP and ORA IOP are wide the IOP measurements by various tonometers cannot be used interchangeably and IRT IOP values should be interpreted cautiously.
This PDF is available to Subscribers Only