Antibody-Related Mechanisms in Ocular Diseases: Autoimmunity, Malignancy, and Therapeutic Targeting

Antibodies in ocular disease have heterogeneous biological meanings: they may act as direct pathogenic effectors, systemic diagnostic biomarkers, indicators of B-cell clonality, or therapeutic agents. This distinction is particularly important in the eye, where immune privilege and the blood-ocular barrier restrict tissue access, whereas inflammation may permit entry of immunoglobulins, complement, and immune cells or support local humoral responses. This narrative review integrates antibody and B-cell biology across autoimmune and paraneoplastic retinopathies, aquaporin-4-immunoglobulin G-positive neuromyelitis optica spectrum disorder, myelin oligodendrocyte glycoprotein antibody-associated disease, ocular mucous membrane pemphigoid, ocular myasthenia gravis, thyroid eye disease, systemic autoimmune and fibroinflammatory disorders with ocular involvement, and B-cell malignancies including vitreoretinal and ocular adnexal lymphoma. We distinguish the evidence for direct antibody pathogenicity from disease association and emphasize that a positive result is interpretable only in relation to the ocular phenotype, assay platform, titer, specimen compartment, and orthogonal confirmation. Serum testing, ocular-fluid analysis, electrophysiology, multimodal imaging, cytology, histopathology, immunophenotyping, immunoglobulin clonality, and molecular testing have complementary roles. Therapeutic strategies include B-cell or B-lineage depletion, complement inhibition, cytokine- or receptor-directed monoclonal antibodies, insulin-like growth factor-1 receptor blockade, and emerging FcRn- or plasma-cell-directed approaches; however, regulatory status and ocular-specific evidence vary substantially among diseases. A mechanistically stratified framework may reduce overdiagnosis, improve recognition of malignant masquerade syndromes, and support more precise selection of targeted therapy.