In imaging of macular edema, which test is most commonly used to quantify macular thickness?

• A. Visual field
• B. A-scan
• C. OCT of macula
• D. Ultrasound

Answer: (D)

Quantifying macular thickness relies on imaging that resolves retinal layers with high precision. Optical coherence tomography of the macula provides ultra-high-resolution, cross-sectional images that let you measure the thickness of the retina in microns and create thickness maps across the macula. This enables objective assessment of macular edema, such as central subfield thickness, and allows tracking of treatment response over time.

Ultrasound can estimate tissue depth but lacks the detailed resolution to differentiate retinal layers reliably, so it’s not the preferred method for precise macular thickness quantification. Visual field testing measures function rather than structure, so it doesn’t provide thickness data.