Title: Four Tonometers and their correlation- A comparative study
Authors: Prasanthi M, Suganya E, Ravikumar R
DOI: https://dx.doi.org/10.18535/jmscr/v7i10.129
Abstract
Background: Early identification of Ocular Hypertension is needed to prevent and control the life threatening glaucoma.
Objectives
- To compare the Intra ocular pressure assessed by using GAT, Schiotz, Tonopen and Non Contact Tonometer (NCT)
- To correlate the Schiotz, Tonopen and NCT tonometers with GAT in measuring the IOP
Materials and Methods: Cross-sectional study conducted in Ophthalmology department of SSSIHMS, Andhra Pradesh for a period of 2 months.112 study participants were included in the study and their IOP was assessed using GAT, Schiotz, Tonopen and NCT tonometers and the readings were compared. Statistical analysis was done using Pearson correlation and p value
Results: The mean age of the participants was 53.20 ± 13.03 years. Most of them are males 66(58.9%), illiterates 50(44.7%) and they belonged to Class I socio-economic status 49(43.7%). The average intra ocular pressure was high in females than males. There was a difference in average IOP between Right eye and Left eye measured using the 4 different tonomters. The mean IOP in left eye was high compared to Right eye, measured using NCT, Tonopen and Schiotz. However the GAT measurement in contrary showed high IOP in Right eye comparing the left eye Pearson correlation showed a moderate positive correlation between the 4 tonometric assessments, having r value of 0.577 and it was statistically significant.
Conclusion: Positive correlation between the tonometric readings gives the future consideration in using various tonometers for IOP measurements.
Keywords: Schiotz tonometer, GAT,NCT, Tonopen, Glaucoma
References
- Gordon MA, Beiser JA, Brandt JA, et al. The Ocular Hypertension treatment Study: baseline factors that predict the onset of primary open-angle glaucoma. Arch Ophthalmol. 2002; 120(6):714-720.
- Bell JA, Roy H: Primary open angle glaucoma. http:/emedicine.medscape.com/article/ 120617-overview (accessed June 2013)
- American Academy of Ophthalmology, BCSC. Section 10. Glaucoma. 2009-10.
- Tonnu PA, Ho T, Sharma K: A comparison of four methods of tonometry: method agreement and inter observer variability. Br J Ophthalmol 2005,89:847–850
- Bandyopadhyay M, Raychaudhuri A: Comparison of Golsmann applanation tonometry with the Tonopen for measuring intraocular pressure in a population-based glaucoma survey in rural West Bengal. Ophthalmic Epidemiol 2002;9:215–224
- Becker-schaffers. Diagnosis and therapy of glaucomas , 8th edition
- Frenkel REP, Hong YJ, Shin DH. Comparison of the Tono-Pen to the Goldmann applanation tonometer. Arch Ophthalmol 1988,106: 750–53.
- Schreiber W etal. A comparison of rebound tonometry (ICare) with TonoPenXL and Goldmann applanation tonometry, ophtahlmology 2007 Apr;104 (4):299-304.
- Hessemer V, Rössler R. comparison of a new hand-held tonometer, Tono-Pen (TP) with the Goldmann tonometer (GM); Klin Monatsbl Augenheilkd 1988; 193(10):420-426.
- Stevens S. How to measure intraocular pressure: Schiötz tonometry. Community Eye Health. 2008;21(66):34.
- Armaly MF, Salamoun SG. Schiotz and Applanation Tonometry. Arch Ophthalmol. 1963;70(5):603–609
- Jonathan SP. Evidence that a gender difference is present from childhood. Ophthalmic and physiological optics. Volume 20, Issue 2, 15 March 2000, Pages 131–136
- Vinayak Bhatia, Harsh Kumar. Comparison of the Goldmann-applanation, Schiotz impression & noncontact tonometers in different glaucoma patients & the effect of central corneal thickness. 10th EGS congress, Copenhagen. JUNE 17-22,2012.
- Rateb M, Abdel-Radi M, Eldaly Z, Elmohamady MN, Noor El Din A. Comparison of IOP Measurement by Goldmann Applanation Tonometer, IC are Rebound Tonometer, and Tono-Pen in Keratoconus Patients after Myo Ring Implantation. Journal of Ophthalmology 2019;2019:7.