Macular edema can cause disturbances in the center of vision.
In addition to an eye exam with ophthalmoscopy, macular edema can be diagnosed by an optical coherence tomography (OCT) scan and a dye test: fluorescein angiography (FA).
Large cysts (black spaces) are seen in the retina in this OCT scan image
FA Highlights dye leakage in this macular image of the right eye
Large cysts (black spaces) are seen in the retina in this OCT scan image 