Fundoscopic exam is a routine part of every doctor’s examination of the eye, not just the ophthalmologist’s. It consists exclusively of inspection. One looks through the ophthalmoscope , which is simply a light with various optical modifications, including lenses. The ophthalmoscope illuminates the retina through the normal iris defect that is the pupil. Light rays forming the image of the retina re-emerge through the pupil. The viewing aperture (window) of the ophthalmoscope contains a lens that modifies light rays to assist the user. In the procedure, one looks at structures lying in the innermost aspect of the globe, collectively known as the eyegrounds: retina, retinal blood vessels, optic nerve head (disk), and to a limited degree, subjacent choroid.
The retina is the only portion of the central nervous system visible from the exterior. Likewise the fundus is the only location where vasculature can be visualized. So much of what we see in internal medicine is vascular related and so viewing the fundus is a great way to get a sense for the patient’s overall vasculature. But the fundoscopic exam can discover pathological process otherwise invisible, examples are plentiful, and include recognizing endocarditis, disseminated candidemia, CMV in an HIV infected patient, and being able to stage both diabetes and hypertension.
Vessels emerge from nasal side of disc. Arteries are narrower than veins.
Pathological Optic Cupping
Note cup-to-disc ratio at least 0.8 (physiologic limit of 0.5).
Optic Disk Edema
The optic disc is elevated and its surface is covered by cotton wool spots (damaged axons) and flame hemorrhages (damaged vessels). Four I’s: increased intracranial pressure (papilledema), infarction, inflammation, infiltration (by cancer).
The first picture below was taken simply by holding smartphone in front of the Panoptic opthalmoscope!
Arterio-Venous (AV) Nicking
Chronic hypertension stiffens and thickens arteries. At AV crossing points (arrow) arteries indent and displace veins
Cotton Wool Spots
Caused by microinfarcts. Exploded ganglion cell axons extrude their axoplasm into retina. Long DDx: hypertension, diabetes, HIV, severe anemia or thrombocytopenia, hypercoagulable states, connective tissue disorders, viruses, and others.
Emboli and Infarcts
Small fleck a ‘Hollenhorst’ plaque caused from platelet/fibrin/cholestorol embolus. Resulting in an infarct (gray area above and right of the plaque).