Imagine this: You’re sitting at a table with friends but are having trouble distinguishing their faces. Or you’re reading a document and the words are blurry. You reach for your glasses, only to realize you’re already wearing them. They’re not helping.
For people with low vision, scenarios like these are part of everyday life.
“Low vision is defined as compromised vision that can’t be cured with glasses, contact lenses, currently available medicines or surgery,” says Alena Reznichenko, M.D., MSc, MBA, Vice President and Head of Global Medical Affairs of Retina, Johnson & Johnson Innovative Medicine. The condition affects a person’s ability to handle everyday activities, she explains.
“In general, you might notice difficulty with tasks such as reading, driving, recognizing faces, distinguishing colors or watching TV screens clearly,” says Dr. Reznichenko. More specific symptoms depend on the underlying condition.
Johnson & Johnson is currently investigating a gene therapy specifically for X-linked retinitis pigmentosa, with the goal of preserving a patient’s vision by replacing the defective gene.
With some conditions, the degeneration happens over a long period, so it may not be as noticeable. That’s why regular eye exams are essential, notes Dr. Reznichenko.
It’s estimated that more than 7 million Americans live with low vision and 246 million around the world have it, according to the World Health Organization. Due to an aging population and an expected increase in conditions that affect eyesight, the number of people with low vision is expected to double by 2050.
Importantly, low vision doesn’t mean complete blindness. Total blindness is less common. With low vision, a person will still have some sight in one or both eyes; it’s just impaired. That impairment can manifest in various ways, as low vision is a spectrum condition that includes different types.
There are multiple forms of low vision
One type of low vision is central vision loss, which means a person has a dark or blurred area in the center of one or both eyes, causing difficulty with activities like reading or distinguishing faces. Another type, peripheral vision loss, is defined as the inability to see anything to the side or directly above or below eye level.
Night blindness—impaired sight in low-light conditions—and blurred or out-of-focus vision are also part of the low vision spectrum. Some people with low vision have contrast sensitivity, meaning they are less able to perceive sharp and clear outlines of tiny objects, distinguish objects from their background and identify small differences in shadings and patterns.
Low vision can also be the result of glare light sensitivity. This occurs when standard levels of light overwhelm a person’s visual system, producing a washed-out image and/or a glare. People with extreme light sensitivity may suffer pain or discomfort from relatively normal levels of light.
What causes low vision?
A common cause is age-related macular degeneration (AMD), which results in damage to part of the retina and leads to central vision loss. “Estimates show about 200 million people in the world, including 20 million in the U.S., have AMD, making it a leading cause of low vision and blindness among adults,” says Dr. Reznichenko.
Cataracts, glaucoma, diabetic retinopathy, stroke, head injuries and retinal detachment due to eye trauma can also cause low vision.
Inherited retinal diseases (IRDs) like retinitis pigmentosa (RP) are another factor. RP is a group of eye diseases that are passed down in families and cause progressive vision loss. In the United States, RP affects about 1 in 4,000 people. Early symptoms, such as loss of night vision, usually begin in childhood. A person with RP is likely to eventually lose the majority of their vision.
Advances are underway to manage or treat low vision
Management or treatment depends on the underlying cause and the severity of the retinal disorder, says Dr. Reznichenko. Visual aids like magnifying glasses, light-filtering lenses to reduce glare, text-to-speech software and other accessibility aids may help with everyday tasks, she says.
Intraocular injections are available to potentially slow the progression of some conditions, like AMD or glaucoma. However, patients must get frequent eye injections, which can be burdensome.
Currently, there’s no cure for RP. But ongoing research and development could change that. “We believe gene therapy could offer a promising alternative to patients with IRDs,” says Dr. Reznichenko.
More than 250 genes have been linked to IRDs, and some acquired diseases that cause vision loss have an underlying genetic foundation, she explains.
“Johnson & Johnson is currently investigating a gene therapy specifically for X-linked retinitis pigmentosa (XLRP), a severe form of RP, with the goal of preserving a patient’s vision by replacing the defective gene,” says Dr. Reznichenko.
The company is exploring gene therapy research for other eye diseases. “We are committed to restoring and preserving vision globally,” says Dr. Reznichenko.
