Vision and Eye Symptoms of Lupus

Vision problems are sometimes considered an early symptom of lupus, experienced by over 28% of patients.

Humans in general are very visual – we pay a lot of attention to color, patterns, and movement. Most of society is designed around sight-based communication, including traffic signals, signboards, advertisements, books, and art. While there are accommodations for people who have their sight impaired, such as braille and screen readers, these accommodations are not always enough to navigate a world so targeted to the visual. When lupus interferes with sight, it has a huge effect on everyday life and can be psychologically frustrating for people with lupus. 

Vision problems are sometimes considered an early symptom Systemic Lupus Erythematosus (SLE) have eye-related symptoms. If patients have other telltale symptoms (for example, the malar rash and severe fatigue) that a doctor recognizes, then this can lead to tests such as the antinuclear antibody test. 

Vision loss is often painless, and if caught quickly can potentially be treated with medication. Usually, however, when vision problems appear alone, the priority is to adjust vision with glasses and other external fixes. If you have been diagnosed with lupus and start to have vision problems, however, this is recognized as a sign of increased, severe lupus activity. In fact, Eye disease is often associated with high levels of inflammation, so it’s important to have these issues diagnosed and treated as soon as possible.

How Does Vision Work?

Eyes are specialized organs that detect light and transmit that information to the brain. The brain then interprets the light signals into what we perceive as vision. Humans generally have two eyes, which is important to how we determine depth and dimension. While we can still see with one eye, depth and distance become harder to judge, which can make it dangerous to perform activities that require quick reactions and precision, including driving.

Step 1: Light Enters the Eye

The human eye is a complex organ that works a lot like an analog camera – most of the eye is opaque, protected from dirt and scratches by an outer layer called the cornea, which is kept clean and in good condition by constant moisturizing through tears. The opaqueness of the eye means that extra light is not let in. 

The sclera is the protective outer coating of the eye, which in humans is white and full of blood vessels, and inside the eye, there is a clear fluid called vitreous humor which helps to bend the light and allows the eye to maintain its shape through pressure. This is important, because if the eye shape is off, it can affect how well the eye can focus on details. This is a common cause of near- or far-sightedness.

The first step of vision starts with light travelling through the cornea, a clear, thick, curved area in the front of the eye that bends and focuses the light. The light then enters the eye through an opening called the pupil, and then passes through the lens. The pupil, cornea, and lens allow the eye to focus on details, adapt to different levels of light in the environment, and protect the sensitive cells at the back of the eye from damage. The amount of light let in depends on the environment – in dim light conditions, the pupil is widened (or dilates) to let in more light, while in bright light the pupil contracts to a tiny dot. It is also affected by stress, fear, and other emotions – energetic emotions such as excitement, fear, aggression, or arousal cause dilation, while calmer emotions are associated with constricted, smaller pupils. 

Step 2: Light Receptors in the Retina React

The cells at the back of the eye are special cells that react in response to certain wavelengths of light. There are millions of these cells in the back of the eye, arranged in a two-layered sheet called the retina. The retina consists of color-detecting receptors called cones and light detecting receptors called rods. There are three types of cones, detecting low energy red light, medium energy green light, and high energy blue light. These receptors are triggered in different amounts, which we then interpret as the rainbow of colors around us. Other receptors called ‘rods’ are very good at detecting light and dark. They are able to detect dim light and are responsible for allowing us to see in the dark – though night vision is generally without color.

Step 3: Information is Transferred to the Brain and Processed

These cells transmit their information through a nerve bundle called the optic nerve, the connection from the eye to the visual cortex in the brain. The optic nerve is not the longest nerve in the body, but it still has a long way to carry its information – all the way to a region called the “occipital lobe” which is all the way in the back of the head! There, the information is processed, and our brains categorize what we see into shapes, types of objects, and other classifications. This is both how we see, and how we understand what we see. 

This means that sight is a complicated teamwork between the structures of the eyes, the optic nerve, and the brain. This ‘teamwork’ can degrade with age but also with extreme exposure to powerful light (including long term use of bright screens) and head trauma.

Inflammation caused by lupus can affect any stage of the vision process. When serious, it can cause loss of vision or even blindness if not caught and treated early.

Other Eye Symptoms of Lupus

Although the results are the same – pain, deterioration of vision, or loss of vision – and inflammation is generally the cause, the actual source of the symptoms can vary. 

There are many ways that lupus effects the eyes. Lupus can cause inflammation and damage to the outer layer of the eye (scleritis), the muscles that move the eyes (including the iris itself,) and the iris. It can also affect the nerves that control these muscles. Cutaneous lupus around the skin near the eyes, the eyelid, or the face in general can also effect vision. Keratitis, or inflammation of the cornea, is more direct. It affects the cornea, which is the layer that protects the eye. Inflammation causes the area to become irritated and sensitive, blurring vision both from the inflammation and the increased production of tears.

Lupus retinopathy and dry eye the most common eye related symptoms of lupus.  Retinopathy is when the retina, the back of the eye with all of the receptors, is damaged. The receptor cells die, reducing the amount of light and detail that the eye can detect.

Dry eye is exactly what it sounds like. Lupus that affects the tear glands and tear ducts can also interfere with vision as the eye dries out. Dry eye is a common symptom of lupus and certain other autoimmune diseases such as Sjogren’s Disease. The lack of tears means that the eye can’t clean out dirt and debris as effectively, allowing the eye to be scratched and damaged more easily. The loss of the tear layer also exposes the eye to damage from drying out and to bacteria that are better able to get a foothold in the eye and cause damage of their own. Rarely, lupus affects the eyeball itself.

However, the eyes do have a level of protection from the immune system, much like the brain and reproductive organs. So, the most common cause of vision loss is restricted blood flow due to vasculitis. Vasculitis is when inflammation from lupus constricts the blood vessels providing various parts of the vision system with oxygen. This starves the organ of vital oxygen and makes them unable to do their jobs – even potentially permanently damaging them. The constriction of blood vessels due to lupus is called vasculitis. 

The optic nerve and brain can both also be affected by lupus inflammation or vasculitis, effecting how the information from the eye is transmitted or processed.

Lupus Medications and the Eye

Lupus medications, including steroids and antimalarials are a major part of lupus treatment, but also are known to cause damage to the retina. Steroid medications raise the pressure in the eye and can also lead to cataracts. People on steroid medications, especially hydroxychloroquine (HCQ) should get their eyes checked often.

Alternate treatment options are sometimes used when doctors feel that it’s appropriate.  If someone with lupus starts getting eye-related symptoms, then they should talk to their treatment team about changing their medications to try to avoid the damage.

Other lupus medications are effective though, as are treatments that reduce inflammation overall, such as diet, exercise, and alternative therapies. Other medications for lupus, including the chemotherapy drugs bevacizumab, rituximab, and belimumab, are also useful. Anticoagulants (such as blood thinners) can directly prevent the vasculitis from causing more damage.

A Lupus Warrior’s Takeaway

If you start noticing eye-related symptoms, including sensitivity to light, it’s a good idea to get checked as soon as possible. Case studies have shown that, the sooner these problems are caught, the more likely it is that you can avoid permanent vision loss. 

You can read more about the eye and lupus here.