dry eye dx and tx
Sjögren's Syndrome: Beyond Dry Eyes
BY WILLIAM TOWNSEND, OD, FAAO
In 1930, Henrik Sjögren published a description of five patients who had marked dryness of the eyes and mouth, which he referred to in his doctoral dissertation as “keratitis sicca.” Subsequent histological evaluation revealed that Sjögren's syndrome (SS) results from chronic lymphocytic infiltration and destruction of the lacrimal and parotid glands, resulting in dry eye and dry mouth. It may also affect exocrine glandular cells, i.e. the pancreas, bronchial tree, and gastrointestinal tract. This relatively common systemic autoimmune disorder affects 2 to 3 percent of adults and may occur in isolation (primary) or in association with other connective tissue diseases (secondary), most commonly rheumatoid arthritis, systemic sclerosis, or systemic lupus erythematosus.
For almost 80 years, SS has been recognized as a leading cause of severe or even extreme dry eye, but we often fail to recognize that its effects extend beyond the realm of ocular/oral dryness to involve other body systems.
In conjunction with the well-recognized exocrine effects, SS may manifest as arthralgia or polyarthropathy; 25 percent of individuals who have rheumatoid arthritis (RA) have SS, and 50 percent of individuals who have SS have RA. Myopathy (muscle injury) and myalgia (muscle pain) are also manifestations of SS; sedimentation rate, electromyography, and muscle biopsy are helpful in differentiating the cause of these symptoms.
SS may present as various forms of neuropathy that affect both sensory and motor function and typically precede the onset of sicca syndrome. Sensory changes may include numbness, tingling, burning, ataxia, and loss of vibratory or nocioceptive perception. Motor involvement may present as weakness secondary to neuritis.
Motor and sensory changes in the central nervous system (CNS) secondary to SS are well recognized and affect both the brain and spinal cord. They include hemiparesis, aphasia, dysarthria, seizures, movement disorders, and cerebellar syndrome. Encephalopathy, aseptic meningitis, alterations in cognitive function, dementia, and psychiatric abnormalities are also potential CNS manifestations of SS. The pathophysiology of CNS changes is believed to be lymphocytic infiltration of the meninges and/or vasculopathy, leading to microinfarcts and microhemorrhages.
Therapy for SS-related CNS disease focuses on treating the vasculitis. When signs of autoimmune activity or progression are detected through MRI or cerebrospinal fluid evaluation, it may be necessary to initiate aggressive treatment with corticosteroids and subsequent intravenous cyclophosphamide. SS-related CNS changes often herald the onset of other complications. Up to 75 percent of patients who have SS and active CNS disease have concomitant active peripheral vasculitis affecting the skin, muscles, and nerves.
Individuals who have CNS and/or systemic effects secondary to SS frequently have no idea that their symptoms are even remotely associated with SS. Inquiring about and eliciting a history of these conditions allows eyecare practitioners to refer these patients to appropriate providers such as immunologists or neurologists who can manage the non-ocular components of SS. The result is often an overall improvement in quality of life for these individuals. CLS
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Dr. Townsend practices in Canyon, Texas and is an adjunct faculty member at UHCO. E-mail him at firstname.lastname@example.org.