Overview

Eye health is an important factor in our daily lives. Our sight is one of our main ways of maneuvering around the world, and we need to keep it in good shape and understand some pathologies that can affect it. In this article, we will talk about cataracts, autoimmune diseases, and how they can be related to each other.

So, let us delve into what a cataract is. It is an eye condition where the clear lens in the eyes has a cloudy area and has calcified.¹ This causes the light to be obstructed from the eye, which can progress with age.¹ This will gradually lead to vision loss and blindness.¹ Cataract is a significant contributor to blindness worldwide, and it can affect people in any age group, ranging from infants to the elderly; however, it is more common in older people.¹

There are different treatment options for cataracts, such as refractive glasses in early stages or surgery, which has seen quite a success.¹

Multiple factors are responsible for cataracts, such as:¹

• Senile: age-related cataract is the most common type
• Congenital: this can be uni/bilateral and can be from infections or low oxygenation (e.g., placental bleeding)
• Cortical: involved with the cortex, where opacification of the lens occurs and affects the cortical hydration. This type of opacity is accompanied by glare and photophobia
• Christmas tree: this form has a low incidence of occurrence and is presented as a polychromatic needle-like appearance deep within the cortex and nucleus
• Traumatic: injury can be a common cause of unilateral cataract in younger patients; this includes blunt trauma, electric shock, UV radiation, or even chemical injuries such as galactose and lactose
• Endocrine diseases: illnesses such as diabetes can influence the eyesight and risk of cataract; for example, diabetes is characterised by high levels of sugar in the blood. This high amount will diffuse into the lens and cause accumulation inside and overhydration of the lens. This causes the refractive index of the eye to change and, with time, can lead to cataracts.
  Other endocrine illnesses can have an effect, but diabetes is one of the many examples out there.
• Drugs, e.g., corticosteroids
• Bad diet and nutrition, with a lack of vitamins and antioxidants
• Alcohol and smoking

Even though cataracts are quite treatable, they still pose an economic burden on some countries, especially developing ones, with senile cataracts affecting 17% of the population worldwide.² Multiple factors increase the risk of cataracts, such as aging, high blood pressure, or diabetes.² It is interesting enough to note that autoimmune illnesses can also play a role in this case. For example, around 3 to 5% of the population suffers from a type of autoimmune disease, and this can include type 1 diabetes.² Hence, contributing to the risk of cataracts.

So, in this article, we want to elaborate on the risk factors of cataracts in patients who have autoimmune diseases.

Overview of autoimmune diseases and eye health

So, to start, we need to define autoimmune diseases. They are a group of illnesses that affect one’s immune system and defenses.² When the body’s immune system malfunctions and does not recognize self from foreign bodies, proteins, and such, this can lead to the formation of autoimmune diseases where our immune cells attack our own body.² This reaction will lead to inflammation and a weakened body and can potentially lead to life-threatening situations.³

There are many types of autoimmune diseases in the world, and some can be associated with a risk of developing cataracts. Some of the examples include:

Rheumatoid Arthritis (RA)

RA is a common inflammatory autoimmune disease that affects our joints.⁴ It is described as long-term inflammation in the joints all over the body due to an immune response that leads to the destruction of the bone and cartilage and damage to the joints.⁴ RA can affect a wide range of organs, such as the heart, lungs, and eyes.⁴ It was documented that patients with rheumatoid arthritis are at higher risk of developing cataracts due to extended inflammation and damage to the eye tissue.⁴

Systemic Lupus Erythematosus (SLE)

SLE is one of the autoimmune diseases out there and affects any organ in the body.⁵ It has a wide range of symptoms and severity, ranging from mild appearances like rashes to more serious complications such as lupus nephritis.⁵ Lupus is predominantly seen to affect the kidneys and central nervous system, but it can also affect the eyes.⁵ Due to the inflammation and multiorgan involvement, this causes the body to be weaker and more sensitive sensitive injuries—in this case, the eyes are more susceptible to inflammation and damage and can lead to the development of eye injuries and this can include cataracts.⁵

Sjögren's Syndrome (SS)

SS is another autoimmune disease that affects the salivary and tear glands in our bodies, usually causing mouth and eye dryness.⁶ Due to the dryness of the eyes, irritation and inflammation will occur and cause eye damage.⁶ Furthermore, the eyes in this case are more susceptible to infection and ulceration, as well as opacification, which can then lead to cataracts and visual degradation and potentially blindness.⁶

Multiple Sclerosis (MS)

MS is an autoimmune disease that affects the central nervous system, leading to inflammation and neuronal loss.⁷ It is a chronic condition that can result in multiple symptoms, and one of them includes visual impairment.⁷ Due to the nature of MS and the neurodegenerative aspect of the disease, it can lead to inflammation in the eyes and potentially lead to cataracts.⁷ 

Psoriasis

Psoriasis is a chronic inflammatory disease of unknown causes; however, it is classified as an autoimmune disease that is controlled through T cells.⁸ This disease has flare-ups and affects the joints and eyes, with around 10% of the patients showing eye-related symptoms.⁸ Due to inflammation and possible damage to the eyes, the risk of cataracts and visual impairments can increase.⁸

Primary risk factors for cataracts

There are multiple risk factors for cataracts in people who have autoimmune diseases. These include:^6,7,9,10

• Chronic inflammation can be a cause of eye damage, as seen in psoriasis and SS diseases. The constant eye damage from inflammation can lead to opacification of the lens and development of cataracts
• Use of steroids can affect the eyes and lead to the development of cataracts; this is because steroids are given to lower immune response and inflammation, however, steroids are seen to be linked to the development of cataracts, but its mechanism is still elusive, proposed to be due to the formation of non-enzymatic Schiff base intermediates
• Immunosuppressants can be used to treat autoimmune diseases such as SS. However, due to lowered immunity in these patients, they become more susceptible to infection, which can then, in turn, result in an increased risk of cataract. Some of these medications include methotrexate and azathioprine
• Age and genetics can have a role in increasing the risk of cataracts. This includes a family history of cataract, natural aging along with the lowered immunity that is accompanied with it, and even sex—females (assigned at birth) are at higher rates of autoimmune diseases

There are additional factors that can influence the risk of cataracts, such as:^1,6,9

• Exposure to sunlight and UV rays
• Smoking and drinking habits
• Dietary conditions—a poor diet is associated with more stress on the body and a risk for cataract development
• Presence of underlying conditions such as diabetes

Prevention and recommendations

There are multiple steps that we can take to protect our eyes and reduce the risk of cataracts:¹⁰

• Having regular eye checkups to check on their health. This is even more important for people with autoimmune diseases, which allows for early detection and intervention
• Protecting the eyes from the sun and UV exposure by wearing sunglasses or a hat
• Lifestyle adjustments such as quitting smoking and exercising
• Having a better diet, such as eating nutritional foods and having plenty of fruits, vegetables and whole grains
• Avoiding or decreasing the use of steroids where possible, as they are associated with an increased cataract risk. In cases of RA, the use of alternative therapies can be an option to avoid long-term steroid use. However, these choices need to be discussed with a healthcare provider before making any decision

Summary

Patients who suffer from autoimmune diseases are at a higher risk of illnesses than others. This includes damage to their vision and the development of cataracts. Due to the stress, the inflammation, and the immune system's impact on the body in case of autoimmunity, the inflammation can lead to damage to the eye lens and opacification. However, other factors can influence this development, such as life choices, such as smoking, a bad diet, a lack of exercise, and the use of immunosuppressants or steroids. There are multiple steps that we can take to avoid developing cataracts and protect our eyes from damage. They can be as simple as wearing sunglasses to a more invasive intervention such as surgery.