ABSTRACT
Background: Intraocular pressure (IOP) measurement is essential for diagnosing and managing glaucoma, a leading cause of irreversible blindness. The Goldmann Applanation Tonometer (GAT) is the gold standard for IOP measurement, but alternative methods such as the iCare rebound tonometer and Air-puff (Non-Contact) tonometer (NCT) offer advantages in ease of use and patient comfort. However, variations in IOP readings among these devices raise concerns about their clinical interchangeability. Purpose: This study aimed to evaluate the repeatability and agreement of IOP measurements obtained using GAT, iCare, and Air-puff tonometers. Method: A cross-sectional study was conducted on 81 adult participants. IOP was measured using GAT, iCare, and Air-puff tonometers in a sequential manner. Each measurement was taken three times per device, and the average was recorded. Data were analyzed using paired t-tests and repeated measures ANOVA to assess differences between the devices. Results: The mean IOP values were 16.15 mmHg (GAT), 15.95 mmHg (iCare), and 16.61 mmHg (Air-puff). Statistical analysis showed no significant difference between iCare and GAT (P>0.05), indicating strong agreement. However, Air-puff tonometry showed significantly higher variability, particularly at higher IOP levels, compared to GAT and iCare (P<0.05). Conclusion: iCare tonometry demonstrated strong agreement with GAT and can serve as a reliable alternative for routine IOP measurement, particularly in non-cooperative patients. In contrast, the Air-puff tonometer exhibited greater variability and may be more suitable for preliminary screenings rather than precise glaucoma monitoring. Clinicians should consider these findings when selecting tonometry methods for patient management. Keywords: Intraocular pressure, Goldmann Applanation Tonometer, iCare tonometry, Air-puff tonometry, repeatability, agreement, glaucoma diagnosis.
