If a patient has cystoid macular edema, what test would most likely be ordered?

• A. OCT of macula
• B. Fluorescein angiography
• C. Visual field test
• D. A-scan

Answer: (A)

When cystoid macular edema is suspected, the fastest and most informative way to confirm it is by imaging the macula with Optical Coherence Tomography (OCT). OCT provides high-resolution, cross-sectional views of the retina, allowing you to see fluid-filled cystic spaces within the macular layers and measure retinal thickness precisely. This direct visualization of edema makes OCT the best first-line test for diagnosing CME and for monitoring response to treatment over time.

Fluorescein angiography can show leakage patterns and helps assess vascular status, but it’s more invasive and less direct for confirming the presence and extent of macular edema itself. Visual field testing assesses functional vision and isn’t specific for detecting CME. A-scan ultrasound gives overall ocular dimensions and can help in other contexts, but it doesn’t reveal the macular architecture or cystic changes characteristic of CME.