2Uz.Dr., İstanbul Medipol Üniversitesi, Göz Hastalıkları, Istanbul - TÜRKİYE
3Doç. Dr., İstanbul Medipol Üniversitesi, Göz Hastalıkları, Istanbul - TÜRKİYE
4Prof. Dr., İstanbul Medipol Üniversitesi, Göz Hastalıkları, Istanbul - TÜRKİYE Purpose: The purpose of this study is to evaluate whether IOP measurements by Non-Contact, Goldmann and Schiotz tonometers are affected by central corneal thickness (CCT), and if so, to what extent.
Materials and Methods: CCT determined by ultrasonic pachymetry and IOP was determined with the Non-Contact, Goldmann and Schiotz tonometers, respectively. The correlation between IOP measured by Non-Contact, Goldmann and Schiotz tonometers was determined in thick and thin corneas.
Results: 40 male, 68 female toatal 108 glaucoma suspects were enrolled in the study. Goldman Aplanation Tonometry (GAT) Non Contact Tonometer (NCT) were found strongly correlated. GAT and ST were strongly correlated.In group with CCT >550 NCT-GAT difference was higher than the ST-GAT difference. In Group with CCT ? 550 NCT-GAT difference was not higher than ST-GAT group. This result showed that corneal thickness does not effect the ST results as much as the NCT results. In group with CCT ? 550 NCT-GAT difference was lower then the group with CCT ? 550. CCT ? 550 group results ST-GAT change was lower than CCT ? 550 group.
Conclusion: In the diagnosis and follow up of glaucoma wrong measurements cause serious and irreversible results. The effect of CCT on IOP measurement is a question mark as inaccurate IOP measurements may lead to misdiagnosis. As conclusion statistically all three methods are highly correlated, however in thick corneas the measurements were more affected compared to gold standard Goldman tonometer. Especially measurements with Non-Contact tonometer is more affected in thick corneas when compared with other methods.
Keywords : Schiotz, goldman, non-contact, tonometer, central corneal thickness