Immediate Effects of Goldmann Applanation Tonometry on Central Corneal Thickness Measurements Using Contact and...

Area of Science:

• Ophthalmology
• Corneal Physiology
• Diagnostic Imaging

Background:

• Intraocular pressure (IOP) measurement is crucial for diagnosing and managing glaucoma.
• Goldmann Applanation Tonometry (GAT) is the gold standard for IOP measurement.
• Central corneal thickness (CCT) influences IOP readings and is vital for accurate diagnosis.

Purpose of the Study:

• To assess the immediate effect of GAT on CCT measurement reliability.
• To compare CCT measurements between contact and non-contact pachymetry methods post-GAT.

Main Methods:

• Fifty-one participants underwent serial CCT measurements using ultrasound pachymetry (USP), optical low-coherence reflectometry (OLCR), and anterior segment optical coherence tomography (AS-OCT).
• Measurements were taken at baseline and after GAT over three days.
• Statistical analysis included ANOVA and paired t-tests to compare mean CCT and standard deviation.

Main Results:

• Mean CCT showed no significant change after GAT across all modalities.
• Contact USP yielded consistently thicker CCT readings than non-contact methods (OLCR, AS-OCT).
• Contact USP demonstrated a significant increase in CCT standard deviation and reduced repeatability post-GAT.

Conclusions:

• Contact IOP measurement techniques like GAT may compromise the reliability and repeatability of CCT measurements.
• Increased CCT standard deviation post-GAT warrants consideration for accurate diagnosis and treatment planning.
• Further research is recommended due to the study's limited sample size.