Draft:Autoimmune retinopathy

Autoimmune retinopathy (AIR) is a rare and poorly understood immunological disease in which proteins in the retina are attacked by the patients immune system, leading to loss of vision. AIR is related to molecular mimicry, in which foreign antigens and self antigens have a similar sequence, eliciting an immune response. The disease can be characterized into paraneoplastic (PAIR) or non-paraneoplastic (nPAIR). The non-paraneoplastic division can be subdivided into cancer-associated retinopathy (CAR) and melanoma-associated retinopathy (MAR).

Pathophysiology

The pathogenesis of AIR is likely linked to antiretinal antibodies (ARAs), which target retinal antigens. ARAs can be retina-specific or found in nonretinal tissues. Molecular mimicry also plays a large role. In nPAIR, the molecular mimicry occurs between retinal proteins and viral/bacterial antigens, while in PAIR, it occurs between tumor antigens and retinal proteins. The most common antibodies found in CAR and nPAIR, respectively, are against recoverin (23 kDa) and alpha-enolase. Presence of these particular antibodies is related to symptoms and diagnosis of AIR in patients. Since AIR is an autoimmune disease, it is likely related to a family history of autoimmune disease.

Symptoms

Symptoms of AIR vary depending on the type, but tend to be overall consistent. The disease is characterized symptoms including progressive vision loss, rod and cone dysfunction, scotomas, and decreased night vision.

Diagnosis

Unfortunately, there is no standardized way of diagnosis for Autoimmune retinopathy. Additionally, AIR is very underdiagnosed or misdiagnosed as diseases with overlapping symptoms, such as Retinitis pigmentosa. Diagnosis is largely based on symptoms, but demonstration of serum antiretinal antibodies has proven important. Detection of these antibodies can be done using Western blot, immunohistochemistry (IHC), or enzyme-linked immunosorbent assay (ELISA). Diagnosis is typical in patients >60 years of age, however, AIR can present in younger patients as well.

Treatment

The difficulty in diagnosis of AIR presents major challenges for its treatment. In PAIR, treatment of cancerous bodies are typically used such as tumor removal, chemotherapy, or radiation. For nPAIR, treatment is more experimental with the use of systemic or local corticosteroids. The overall goal of this treatment however, is not to reverse the damage done by AIR, but to inhibit progression of patient vision loss. Future research in AIR and treatment possibilities is crucial to identifying appropriate and effective treatment.