Saliva as a noninvasive diagnostic for ocular sarcoidosis

Sarcoidosis is a multi-organ granulomatous disorder that predominantly affects the eyes, lungs, and skin. Biopsy, the standard for a definitive sarcoidosis diagnosis, is often impractical for ocular sarcoidosis due to the delicate nature of the eye and risks associated with surgical procedures such as inflammation, infection, retinal detachment, and cataracts. Ocular sarcoidosis is typically treated with steroids and immunosuppressive medications. However, because infectious uveitis exhibits a similar clinical presentation as ocular sarcoidosis, there is an incipient risk of inappropriate treatment without a definitive diagnosis. Failing to prescribe immunosuppressive medications to patients with ocular sarcoidosis can lead to scarring and permanent blindness; conversely, prescribing this treatment to patients with infectious uveitis risks exacerbating the infection and associated pathologies. Saliva is an emerging diagnostic biofluid that is easy to collect, cost-effective, and well-tolerated by patients. Although saliva has been used to identify biomarkers for diseases like cancer and diabetes, its use in diagnosing ocular diseases remains limited. This review provides an overview of sarcoidosis and ocular sarcoidosis, the utility of saliva as a diagnostic tool, and a pilot experiment testing if saliva can be used to diagnose ocular sarcoidosis.