A comparative study of the Goldman applanation tonometer with the noncontact autotonometer in myopic and normal subjects of the same age group

Abstract: PURPOSE: Myopia is a prevalent refractive disorder associated with increased risk of ocular complications, including glaucoma. Accurate intraocular pressure (IOP) measurement is vital in myopic and normal eyes for early glaucoma detection. Goldmann applanation tonometry (GAT) remains the gold standard, while noncontact tonometry (NCT) offers a noninvasive alternative. This study aims to compare IOP measurements obtained by GAT and NCT in myopic and normal subjects of the same age group and to assess the reliability of NCT as a screening tool. METHODS: A hospital-based cross-sectional study was conducted from July 2023 to December 2024 at Gajra Raja Medical College and Jaya Arogya Hospital, Gwalior, Madhya Pradesh, India. One hundred and twenty participants aged 20–60 years were enrolled, divided into 60 myopic (6 Diopters) and 60 normal individuals. IOP measurements using GAT and NCT, central corneal thickness (CCT), and axial length (AL) were recorded. Statistical analysis involved independent t -tests, Chi-square tests, correlation coefficients, and Bland–Altman plots. RESULTS: No statistically significant difference was found in IOP readings between myopic and normal groups with both GAT and NCT ( P > 0.05). However, CCT was significantly thinner in myopic eyes ( P < 0.01). Strong positive correlations existed between GAT and NCT readings in both groups. Bland–Altman analysis indicated acceptable agreement between the two tonometers. CONCLUSION: NCT showed good reliability compared to GAT for measuring IOP in both myopic and normal eyes, making it useful for mass screenings. However, variations in CCT, especially in myopic individuals, should be carefully considered when interpreting IOP readings.