The Eyes Have It Too!

Among the many manifestations of psoriatic arthritis that can occur outside the musculoskeletal system, eye involvement is one of the most common inflammatory processes. Often initially mistaken for pink eye due to having a similar appearance, these conditions are eventually identified as manifestations of underlying autoimmune disease.

Anterior uveitis

Anterior refers to the front part of the eye, where the iris and ciliary body are located. The iris surrounds the pupils, and the nearby ciliary body is what makes the fluid that fills the front of the eye. Uveitis refers to inflammation of these structures, resulting in pain and redness of the eye.

Anterior uveitis can affect one or both eyes, usually occurring suddenly and rapidly over a few days. Blurry vision, sensitivity to light, tearing of the eye, and eyelid puffiness can also occur. Men with psoriatic arthritis are more likely to be affected than women.

An eye doctor will use what’s called a slit lamp examination to look at the front of the eye during an episode of anterior uveitis. Inflammatory cells can be found in the anterior chamber of the eye and sometimes behind the lens with the slit lamp.

Understand how uveitis impacts those with PsA

Patients with a positive HLA-B27 status have a higher risk of developing anterior uveitis. Your doctors may do additional lab testing to rule out infectious or other autoimmune etiologies of anterior uveitis to confirm that psoriatic arthritis is indeed the culprit.

Some types of anterior uveitis tend to reoccur, whereas others are self-limited episodes. A typical episode takes about 1-2 months to resolve completely. If inflammation in the eye does not completely resolve with steroid treatment, it’s possible that more extensive therapies may be needed to prevent additional flares.

Anterior uveitis typically has good treatments and a good prognosis. A potential complication is synechiae formation, which is the development of scar tissue and adhesions between the iris and the lens capsule. This can be avoided by treating the underlying inflammatory process of psoriatic arthritis.

Episcleritis

The episcleral structure contains two layers, each with its own network of blood vessels. Inflammation of the episcleral causes redness and visible blood vessels on the “white” part of the eye.

Congestion of the blood vessels also occurs. Usually, only one eye will be affected by redness and eyelid swelling. Sometimes episcleritis can be painless, whereas in other cases, it can cause discomfort and sensitivity to light. Women are affected more often than men are.

Certain eyedrops at the doctor’s office, which blanch blood vessels in the different layers of the eye, can help differentiate episcleritis, scleritis, and conjunctivitis. A slit lamp exam is helpful, with reflections of light being displaced in different directions to help distinguish episcleritis from other conditions.

How is episcleritis diagnosed?

There are two forms of episcleritis—simple and nodular. Nodular episcleritis forms a raised area, is more difficult to treat, and tends to have a more prolonged course. The nodule that forms tend to be freely mobile over the tissue that lies underneath.

Most cases of episcleritis are idiopathic, meaning no underlying trigger or etiology can be found. Around 25-35% of patients can have an underlying inflammatory condition, with psoriatic arthritis being one of the possibilities.