Sjögren Syndrome — Detailed Ocular Evaluation (Aqueous-Deficient Dry Eye)

Sjögren syndrome (SS) is a chronic, systemic autoimmune exocrinopathy first described by Henrik Sjögren in 1933, characterized by progressive lymphocytic infiltration of exocrine glands (predominantly lacrimal and salivary), producing the classic sicca symptoms of dry eye (keratoconjunctivitis sicca, KCS) and dry mouth (xerostomia). Prevalence ranges 0.05–4.8 percent of population, female-to-male ratio 9:1, peak incidence fourth-fifth decades. Primary SS occurs in isolation while secondary SS associates with another defined connective tissue disease — most commonly rheumatoid arthritis, systemic lupus erythematosus, or systemic sclerosis.

Pathophysiology involves T- and B-lymphocyte mediated autoimmunity against exocrine epithelial cells, with production of anti-Ro/SSA (60–70 percent) and anti-La/SSB (40 percent) autoantibodies, hypergammaglobulinemia, and elevated rheumatoid factor. HLA-B8, DR3, DRB1*15:01 confer susceptibility. Histopathology shows focal lymphocytic sialadenitis with focus score ≥1 (≥1 focus of ≥50 lymphocytes per 4 mm²) on minor labial salivary gland biopsy — a key 2016 ACR/EULAR classification criterion.

Ocular manifestations: aqueous-deficient dry eye disease (ADDE) with reduced tear volume, increased tear film osmolarity, ocular surface inflammation, corneal and conjunctival epithelial damage. Symptoms include foreign body sensation, burning, photophobia, blurred vision fluctuating with blinking, contact lens intolerance, and decreased visual quality. Severe cases develop filamentary keratitis (corneal filaments composed of degenerated epithelium and mucin), persistent epithelial defects, neurotrophic keratopathy, sterile corneal ulcers, microbial keratitis, and rare perforation requiring tectonic corneal transplantation.

Detailed ocular evaluation: Schirmer test without anesthesia (≤5 mm wetting in 5 minutes is diagnostic; ≤10 mm is supportive), tear break-up time (TBUT) by fluorescein <10 seconds (instability), ocular surface staining grading (Oxford 0–5 scale or van Bijsterveld 0–9), corneal punctate epithelial erosions with sodium fluorescein, conjunctival staining with lissamine green (more sensitive than rose bengal, less irritating), tear meniscus height by Fourier-domain OCT (<0.2 mm), tear film osmolarity (TearLab >308 mOsm/L or inter-eye difference >8 mOsm/L), tear MMP-9 testing (InflammaDry), in vivo confocal microscopy showing reduced corneal sub-basal nerve density and increased dendritic cells, and meibomian gland imaging (meibography) for associated mixed mechanism dry eye.