Corrected Axial Length and Choroidal Thickness: A Correlation Analysis for Scientific Purposes

Area of Science:

• Ophthalmology
• Biometry
• Medical Imaging

Background:

• Choroidal thickness (ChT) is a key indicator for ocular and systemic health.
• Axial length (AL) influences ChT, but current biometry measurements require correction.
• The reliability of the correlation between corrected AL (ALc) and ChT needs verification.

Purpose of the Study:

• To investigate the persistence of the linear correlation between ChT and ALc.
• To compare the correlation of ChT with both AL and ALc.
• To provide recommendations for ChT studies using corrected biometry data.

Main Methods:

• Spectral domain optical coherence tomography (OCT) with EDI mode was used for ChT measurement.
• IOLMaster was employed for AL measurements, which were then corrected to ALc.
• Pearson correlation coefficient was utilized to analyze the relationship between ChT, AL, and ALc.

Main Results:

• A significant negative linear correlation was observed between ChT and both AL and ALc (r < -0.500, p < 0.050).
• The correlation was strongest between nasal ChT and both AL/ALc (r = -0.581).
• Mean AL was 24.36 ± 1.23 mm and mean ALc was 24.25 ± 1.22 mm.

Conclusions:

• A statistically significant correlation between ALc and ChT persists, comparable to uncorrected AL.
• Population stratification by ALc is recommended for ChT studies due to the persistent linear correlation.
• Cut-off values for ChT studies should be adjusted for systematic errors in optical biometry, evaluating both AL and ChT changes relative to ALc.