Association between Baseline Subfoveal Choroidal Thickness and Anatomical and Functional Outcomes in Geographic...

Area of Science:

• Ophthalmology
• Retinal Diseases
• Medical Imaging

Background:

• Geographic atrophy (GA) is a leading cause of irreversible vision loss.
• Subfoveal choroidal thickness (SFChT) is a key parameter in retinal imaging, but its role in GA progression is not fully understood.
• Investigating factors influencing GA progression is crucial for developing effective treatments.

Purpose of the Study:

• To examine the association between baseline SFChT and visual outcomes and GA growth rate.
• To determine if SFChT mediates the effect of oral metformin on GA progression.

Main Methods:

• Secondary analysis of the METformin for the MINimization of Geographic Atrophy Progression randomized controlled trial.
• Measured baseline SFChT using optical coherence tomography (OCT).
• Calculated GA area growth rate and perimeter-adjusted growth rate, and assessed changes in best-corrected visual acuity (BCVA) and low-luminance visual acuity (LLVA).

Main Results:

• Baseline SFChT was not significantly associated with baseline GA area, BCVA, LLVA, or hyperautofluorescence signals.
• No significant association was found between baseline SFChT and GA growth rate, BCVA decline, or LLVA decline.
• Sensitivity analyses revealed that greater baseline SFChT was associated with a slower rate of BCVA decline in eyes with foveal-involving GA (Spearman ρ = 0.03, P = 0.03).

Conclusions:

• SFChT does not appear to be a significant predictor of overall GA progression or LLVA decline.
• Greater SFChT may be associated with better visual acuity preservation in eyes with foveal-involving GA.
• SFChT did not mediate the treatment effect of oral metformin on GA progression.