Opening our eyes to the burden of Uveitis

Uveitis is one of the most common ophthalmological conditions and is associated with visual impairment and decreased quality of life worldwide. It is a form of inflammation in the eyes that can affect the uvea, the middle layer of the eyeball, which includes the iris, ciliary body, and choroid. Uveitis encompasses diverse inflammatory ocular diseases and can affect the lens, retina, optic nerve, and vitreous humor (the gel-like fluid inside the eye). It can be categorized into four types based on its anatomical location: anterior uveitis (involving the anterior chamber of the eye), intermediate uveitis (affecting the vitreous), posterior uveitis (impacting the retina and choroid), and panuveitis. Panuveitis is characterized by inflammation across multiple areas without a specific predominant site, including the anterior chamber, vitreous, retina, and/or choroid.

Typical signs of uveitis include blurred vision accompanied by redness and a feeling of discomfort, heightened sensitivity to light, spots or specks in the field of vision, and the appearance of a white mark on the lower region of the eye. Uveitis may affect one or both eyes. The disease may be caused due to viral, bacterial, fungal, or parasitic infections and conditions such as herpes simplex and tuberculosis. Some noninfectious causes  such as autoimmune or systemic inflammatory diseases, trauma or injury to the eyes may also cause uveitis. Complications such as vision loss, macular edema, cataracts, etc. may occur as a result of uveitis if treatment is delayed.

Uveitis is estimated to cause 5–10% of visual impairment or blindness worldwide. Prevalence varies due to the varying occurrence of infectious and noninfectious entities in different geographies around the world. Although there are some epidemiological studies available, data from the MENA region is generally scarce and almost lacking. Only a few studies have been conducted in this region that determine the pattern of uveitis across countries, including Iran, Saudi Arabia, Turkey, and Tunisia.

• The most recent study conducted was in a Tertiary Hospital in North Jordan from January 2015 to January 2019 to determine the pattern of uveitis and the impact of Behcet’s disease. The study found no actual difference between the prevalence of the disease in men and women. Further, the study revealed that noninfectious uveitis was more common than infectious uveitis (95% vs. 5%, respectively). Among noninfectious uveitis cases, nearly 53% were idiopathic, while nearly 47% were autoimmune-mediated uveitis. Further, the most common cause of autoimmune-mediated uveitis was Behcet’s disease, followed by seronegative spondyloarthropathy and others.
• A study conducted to determine patterns of uveitis in the Middle East and Europe by Nashtaei et al. (2011) concluded that uveitis is commonly seen in the fourth decade of life, with anterior uveitis being the most common anatomical form in the Middle East. Idiopathic cases accounted for the majority of uveitis, followed by Behcet’s disease, toxoplasmosis, Herpes, and others in the Middle East.
• As per the study by Tayel et al. (2015) at Alexandria University, Egypt, Behcet’s disease was the most common identifiable cause of uveitis (24%), followed by Juvenile idiopathic arthritis-associated uveitis (6%) and Vogt–Koyanagi–Harada (5%). Idiopathic anterior uveitis was the most common uveitic entity, representing 32% of cases.
• According to Khairallah and Gargouri (2010), in the MENA countries, uveitis was mostly seen in adults with a peak in the third and fourth decade of their life, and anterior uveitis was the most common anatomic form, but a high rate of posterior uveitis and pan uveitis was reported. Moreover, herpetic anterior uveitis, toxoplasmosis, and tuberculosis (Saudi Arabia) were identified as the common infectious entities, while Behçet’s disease and Vogt–Koyanagi–Harada disease were the most common noninfectious entities.
• A systematic review to determine the pattern of uveitis conducted in Iran concluded that anterior uveitis was the most common anatomical subtype while the prevalence of the other three types of uveitis, including middle, posterior, and pan-uveitis, were almost equal. Further, the study revealed that idiopathic uveitis, toxoplasmosis, Behcet’s syndrome, and Fuchs heterochromic iridocyclitis were the most common etiologies of uveitis.
• A study conducted in Tunisia in 2006 to determine patterns in child-onset uveitis in referral centers revealed that the mean age at the onset of uveitis was 12.4 years, and the male-to-female ratio was 0.68. Idiopathic termediate uveitis was the leading cause of uveitis in the study, followed by idiopathic anterior uveitis and toxoplasmosis.

Although epidemiology studies are the basis for proper management of any condition, they are lacking for uveitis in the MENA region. At present, no study determines the true prevalence of the disease, and most studies are outdated, making it difficult to rely on them as significant changes may have occurred in the past decade. Moreover, population-based studies are lacking; most studies stem from referral centers or hospitals representing only the severe cases of uveitis.

With the disease having a variable presentation, diagnosis and management has been challenging. A prompt diagnosis, with the correct diagnostic approach and assessment of appropriate treatment, is crucial for minimizing inflammation and achieving full recovery, thereby mitigating or avoiding ocular complications, permanent cumulative damage, and long-term vision loss. A thorough eye exam is needed to diagnose uveitis. The clinical diagnosis is often based on spillover inflammation (i.e., cells and protein flare) observed with a slit lamp in the aqueous or vitreous humor. Blood tests and x-rays may also identify potential systemic disorders contributing to the condition.

The disease is critically underserved in terms of treatment in the MENA region. Further, it is a broad disease that encompasses an ocular sequel and a large spectrum of associated systemic diseases, making treatment more challenging. The treatment aims to obtain the disease’s quiescence by treating the infectious agent or the immune condition. Corticosteroid is often considered the initial therapy which acts to reduce inflammation. Apart from corticosteroid immunosuppressant therapy, antibiotics or antiviral, biologics, and other medications are also used.

As per Alawneh et al. (2023), the majority of uveitis patients (94%) in a tertiary Hospital in North Jordan were treated with ophthalmic eye drops, cDMARDs (46%), biologics (n = 33, 15%), and colchicine (14%). The study by Tayel et al. (2015), conducted at Alexandria University, Egypt, revealed that most patients with uveitis needed combined therapy, including intra-ocular, topical, and systemic steroids, together with other synthetic or biological DMARDs. Commonly used biological DMARDS included infliximab and adalimumab.

The treatment strategy must consider multiple factors like etiology, the extent of uveitis and associated inflammation, and systemic disease. Hence, there is need for large cohort and population-based studies around the MENA region that shed light on these important factors, and the resulting data can hold considerable value for clinical and research applications, aiding in the development of tailored treatment protocols at a community level.

Like many other medical conditions, uveitis presents unique challenges and unmet needs in the MENA region. Given the difference in etiologies and patterns of uveitis in different regions, it is imperative to conduct more studies to understand the presentation and prevalence of uveitis in the MENA region. Apart from epidemiology studies, various factors, including healthcare infrastructure, access to care, socio-economic conditions, and the prevalence of certain diseases, need attention to overcome the growing burden of uveitis in the MENA region.