Comparative evaluation of Goldman applanation tonometer, Perkins tonometer, and Non-contact tonometers in a tertiary care hospital

Abstract

Measurement of intraocular pressure (IOP) is basic investigation in a general ophthalmic workup. We attempt to determine the agreement in the measurement of IOP obtained by Goldman applanation tonometer, Perkin’s applanation tonometer, Non-contact tonometer in patients attending general ophthalmology OPD in a tertiary care centre in South India and its use in a community ophthalmology settingA cross-sectional analytical study in which IOP was measured in patients using the three tonometers. Central corneal thickness (CCT) was measured using Ultrasonic pachymetry. Bland Altman analysis was done to evaluate the agreement between instruments. 800 eyes of 400 patients were included in the study. By Bland Altman method, Perkin’s tonometer was found to have better correlation to IOP obtained by Goldman applanation tonometer. Perkin’s tonometer was found to be most accurate when CCT was in the range of 501–550 microns and noncontact tonometer was found to be least accurate when CCT was greater than 600 microns. On comparing correlation at different age groups, both the methods had better correlation at <40 years age group.Both the tonometers showed a significant correlation with the gold standard technique GAT over a range of IOP and CCT with the Perkin’s tonometer better than the NCT. This study proves that Perkin’s tonometer can be recommended as a reliable screening tool in community outreach ophthalmology services. The twin advantages of portability and availability make the Perkin’s tonometer a popular choice among ophthalmology trainees and optometrists in a developing country like India.