By Linda Conlin, Pro to Pro Managing Editor

September is Sickle Cell Awareness Month, but what does that have to do with eyes? Sickle Cell Disease is an inherited blood disorder in which hemoglobin, the protein in red blood cells that carries oxygen to tissues, is abnormal. This causes the normally disk-shaped red blood cells to take the shape of the letter C, or a sickle. These cells are stiff and sticky, interfering with oxygen getting to tissues and forming clots. What’s more, the sickled cells live for only two to three weeks, while normal red blood cells live up to nearly four months.

Sickle Cell can affect both the anterior and posterior chambers of the eye. In the anterior chamber, blood vessels become shorter, and intraocular pressure may increase, leading to glaucoma. In the posterior chamber, retinal blood vessels can be affected by the sickled cells. To compensate for reduced oxygen, new blood vessels fan out into the retina. The new vessels are weak and can leak, in addition to pulling on the retina, possibly detaching it.

Proliferative sickle cell retinopathy (PSR) is the most frequent threat to vision, resulting in vision impairment for 10-20% of patients. In PSR, the blood vessels become blocked, and rather than reforming normally, they divert away from the retina. Without nutrients, the retina starves and can become damaged or die, leading to vision loss. Unfortunately, there are few preventive treatments for PSR at this time, although surgical procedures may resolve a later stage retinal detachment.

What can be done? Eye exams for sickle cell patients should always include a test of intraocular pressure to monitor for glaucoma. Dilation allows the doctor to see the blood vessels of the eye, some of the retina and to identify abnormalities. Fluorescein angiography, in which fluorescent dye is injected into the blood vessels in the eye, can identify areas of the retina lacking blood supply. Dilated eye exams should begin with children because sickle cell retinopathy can start at about age 10. Exams should be at least once every two years to age 20, when annual exams should begin.

Sickle Cell Disease affects approximately 100,000 people in the United States, primarily African-Americans. Sadly, sickle cell funding pales in comparison to other diseases. Cystic fibrosis, which affects 30,000 people in the U.S., for example, gets seven to 11 times more funding per patient than sickle cell disease, according to a 2013 study in the journal Blood.  The ALS challenge in 2014 raised $115 million for approximately 20,000 patients in the U.S. While patients, doctors and organizations fight for funding, ECP awareness of the signs and symptoms of sickle cell’s effects on the eye can help patients get treatment sooner.  Learn more about the impact of glaucoma and retinal disease on vision with our CE, An Introduction to Low Vision, at www.2020mag.com/ce.