Risk of Eye Disorder Seen With Subclinical Cushing’s Syndrome
Subclinical Cushing’s syndrome may be a risk factor for developing central serous chorioretinopathy, an eye disorder wherein fluid accumulates at the back of the eye, according to a recent case report.
The report, “Association of chronic central serous chorioretinopathy with subclinical Cushing’s syndrome,” was published in the American Journal of Ophthalmology Case Reports.
Cushing’s syndrome is characterized by excessive levels of the hormone cortisol. Most cases are caused by high amounts of adrenocorticotropic hormone (ACTH), which stimulates the adrenal glands to produce cortisol due to a tumor in the brain’s pituitary gland. This specific form of the condition is known as Cushing’s disease.
In rare cases, ACTH is produced and released by a hormone-producing tumor outside the pituitary gland.
Often, patients undergo an adrenalectomy, surgery to remove both adrenal glands, which are responsible for producing cortisol.
High cortisol levels can cause fluid to accumulate under the eye’s retina — a region at the back of the eye where light-sensitive photoreceptors send signals to the brain, enabling vision — a condition called central serous chorioretinopathy (CSCR). This can be missed, however, especially in people with mildly elevated cortisol levels that remain under-diagnosed due to a lack of major symptoms. This is referred to as subclinical Cushing’s syndrome.
Researchers in the Wills Eye Hospital and Thomas Jefferson University, in Philadelphia, described the case of a patient who developed CSCR due to subclinical Cushing’s.
The 50-year-old woman had blurred vision with spots in the right eye for several months. She had no family history of eye disease that might be deemed a contributing factor, and her clinical history showed only mild blood pressure for which she was being medicated.
Fluid accumulation under the retina and changes in the retina’s pigment were seen during an eye examination. Optical coherence tomography (OCT), a noninvasive imaging technique that allows sections of the retina to be visualized, confirmed the accumulation and shrinkage (atrophy) in some areas of the retina.
She underwent further exams and was diagnosed with multifocal, chronic CSCR. During an imaging test due to back pain, the patient was later found to have a tumor in her adrenal gland. This type of tumor — found by chance during an examination — is usually referred to as an adrenal incidentaloma.
She was examined by a specialist and blood tests revealed low ACTH and normal cortisol levels. However, cortisol failed to drop after an overnight dexamethasone suppression test (ODST), which can confirm the presence of hypercortisolism (elevated cortisol levels). The test measures cortisol blood levels in the morning after patients take a dexamethasone tablet, a corticosteroid that normally blocks its production.
These findings led to the diagnosis of subclinical hypercortisolism, which likely was the reason for her high blood pressure and chronic CSCR. She began treatment with eplerenone, a medication sold under the brand name Inspra, used to treat high blood pressure.
The woman decided to undergo a minimally-invasive adrenalectomy, following a discussion with her endocrinologist. On her last follow-up, three months after surgery, she no longer took eplerenone and no longer had fluid in the retina.
This case report suggests that “subclinical Cushing’s Syndrome (SCS) may present an underrecognized risk factor for developing chronic CSCR,” the researchers wrote.
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