Medical mystery: Man goes blind in one eye
A middle-age man in excellent health awoke one morning, turned to check the time on his bedside clock - and realized that overnight, he had gone blind in one eye.
A middle-age man in excellent health awoke one morning, turned to check the time on his bedside clock - and realized that overnight, he had gone blind in one eye.
In a panic, he took himself to the emergency room of a nearby hospital, where he was told he had probably suffered a stroke that had blocked the artery leading to his retina.
His doctors were perplexed.
The patient had no history of vascular disease or heart problems, and had been religiously taking a daily low-dose aspirin for years.
Twenty years earlier, he learned he was HIV positive, but he had been diagnosed early and immediately began a series of highly effective antiretroviral medicines. For decades, his T-cell count consistently remained in a normal range and his viral load was undetectable - meaning his immune system was practically normal.
With his current therapy, the HIV virus was subdued, hibernating in a variety of cells throughout the body but not replicating.
The eye doctors ordered a sophisticated battery of vascular studies and the results seemed to indicate the retinal embolus. But an ultrasound of his carotid and intracranial arteries showed no problems.
They wondered whether the source of the problem might be a clot in his heart valve, but, faced with a long list of diagnostic possibilities, they referred him back to his HIV physician.
In that doctor's care, the patient underwent a series of tests to see whether he had a hypercoagulable condition that would have predisposed him to develop a clot, or perhaps an inflammation of his arteries - a condition called vasculitis. And even though the patient had not been sexually active in more than six months, several tests for sexually transmitted diseases were also done for the sake of thoroughness.
The initial test results all came back normal.
His heart valves and cholesterol levels were fine, he was not hypercoagulable, and there was no evidence of any inflammation of the arteries.
But 48 hours later, an STI (sexually transmitted illness) test returned with a surprising result. His rapid plasma reagin (RPR) - a marker for syphilis - was strongly positive. A subsequent test confirmed the finding.
Normally, syphilis does not attack the retina until the late stages of the disease - usually many years after the initial infection. And this patient had not shown any of the early symptoms - no genital ulcers, no rashes.
How did this bacterial infection sneak up on him like that? And why did the eye doctors think he had a stroke due to an embolus?
Solution
Left untreated, syphilis normally does not affect the brain and eyes for decades. But in patients who are HIV positive and controlling their illness assiduously with medication, syphilis can develop at a strangely accelerated rate, presenting itself in the retina and meninges in only a few months.
The reason for this accelerated form of syphilis in HIV patients is not well understood. Fortunately, it is a very rare complication.
Given how unusual the case was, it is not surprising the eye doctors thought the patient had suffered a stroke. Syphilis is angioinvasive, meaning the bacterium can penetrate arteries and, in doing so, mechanically block or occlude the flow of blood into very small arteries and arterioles. This blockage can closely resemble a stroke.
The patient responded very well to treatment. After two weeks of intravenous penicillin, his vision returned to nearly normal.