Accuracy of Icare Rebound Tonometer and Its Comparison with Goldman Applanation Tonometer

Doi: 10.36351/pjo.v40i1.1709


  • Anila Farid
  • Memoona Arshad
  • Nimra Gul
  • Shabana chaudhary
  • Muhammad Zubair Nazar



Purpose:  To determine accuracy of iCare rebound tonometer (IRT) in terms of agreement with Goldman Applanation Tonometer (GAT) and effect of Central corneal thickness (CCT) on its accuracy.

Study Design:  Comparative cross sectional study.

Place and Duration of Study:  Ophthalmology Department of Ittefaq Hospital Lahore from September 2022 to May 2023.

Methods:  Participants of the study were recruited through non-probability convenient sampling. With Icare PRO® rebound tonometer (IRT), two consecutive sets of measurements with 6 measurements for each set were made, and the averaged values were used for the statistical analyses. After 5 minutes GAT measurement was taken for intraocular pressure (IOP). CCT was measured by ultrasound pachymetry from mean of 2 measurements noted. Data was analyzed by Bland-Altman plots for determining agreement of GAT-IOP and IRT-IOP. Pearson correlation coefficient determined the correlation of GAT-IOP and IRT-IOP with CCT.

Results:  Out of 200 participants there were 76 (38%) males and 124 (62%) females. Mean age of participants was 27.84 ± 6.1 years. Mean IOP with IRT was 16.24 ± 2.02 (range 12.1 – 20.3 mmHg). Mean IOP with GAT was 14.40 ± 1.98 (range 11.00 – 19 mmHg). Mean IOP with adjusted CCT using GAT was 14.40 ± 1.64 (range 11 – 18 mmHg). Mean CCT was 544.81 ± 42.04 (range 615 – 471 um). Mean IOP-GAT & IOP-IRT with adjusted CCT showed normal distribution. Mean difference of IOP-GAT and IOP-IRT with t test was 1.83 ± 1.12 (p = .079).

Conclusion:  There is a strong agreement between IOP-GAT and IOP-IRT. CCT had a strong impact on IOP measurements with both tonometers. However, CCT affected IOP reading of GAT more than IRT.




How to Cite

Farid A, Memoona Arshad, Nimra Gul, Shabana chaudhary, Muhammad Zubair Nazar. Accuracy of Icare Rebound Tonometer and Its Comparison with Goldman Applanation Tonometer: Doi: 10.36351/pjo.v40i1.1709. pak J Ophthalmol [Internet]. 2023 Dec. 4 [cited 2024 Mar. 5];40(1). Available from:



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