This case, and the representative images are a wonderful example of how remote illness can affect the eye. It is also a nice reminder that every once in a while, an ophthalmologist may need to dust off the stethoscope.1) The above color fundus photos of a patient's righ
t eye shows an area of retinal whitening in the temporal region of the macula, sparing the fovea. This whitening represents nerve fiber layer (NFL) ischemia and edema. Hypoxia impairs axonoplasmic flow, which is what leads to the swelling of nerve fibers in this ischemic state. Notice how the fovea remains spared, just as in the "cherry red spot." The image is characteristic of branch retinal artery occlusion (BRAO). The emboli are strikingly seen at approximately the same location along both the superior and inferior temporal arcades. The main clue is that the patient is just now being treated for strep sepsis. From this picture, one must be extremely concerned that an endocarditis has developed and valve vegetations provide the source for these emboli. In fact, we can see that microabscesses have formed at the sites where the bacterial plaque came to rest.
The FA shows the emboli as blockages to arterial filling. Also, areas of diffuse hypoperfusion can be seen corresponding to the area of NFL ischemia.
Here are a couple of views you might see through a direct ophthalmoscope. The top right would represent the "cherry red spot" that would come into view if you asked the patient to fixate on the light. This should prompt you to trace along the arcades to try to find emboli, shown in the other two simulated views.:
2) In the case of any CRAO or BRAO, a stethoscope could be used to listen for carotid bruits or hear murmurs. In this case, the high index of suspicion for septic emboli, a transesophageal ultrasound to look at the heart valves is of the utmost importance. While patients with this picture are usually very sick, it is possible that the first dose of antibiotics has already reduced the bacteremia, thus improving the patient's systemic symptoms.
In this case, the patient was found to have a murmur, and was sent for ultrasound. Aortic valve vegetation was discovered and the patient underwent surgery for replacement of the valve.
More reading:
http://www.ncbi.nlm.nih.gov/pubmed/10409855
http://www.merckmanuals.com/professional/cardiovascular_disorders/endocarditis/infective_endocarditis.html
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