Dopamine receptors in ocular surface biology: Current evidence and future directions.

Dopamine, a classical catecholamine neurotransmitter, exerts diverse regulatory functions in the central nervous system, retina, and intraocular signaling. Recent research has highlighted its emerging role in ocular surface biology, which includes the cornea, conjunctiva, tear film, and lacrimal glands. The ocular surface serves as a neuroepithelialimmune interface where neuromodulators such as dopamine influence epithelial homeostasis, wound repair, inflammation, and sensory signaling. Molecular and functional studies have confirmed the expression of dopamine receptor subtypes (DRD1-DRD5) and dopaminergic enzymes in ocular surface cells including corneal and conjunctival epithelial cells, stromal keratocytes, and lacrimal glands, suggesting local dopaminergic regulation. Activation of D₁-like receptors enhances corneal epithelial regeneration and suppresses NLRP3 inflammasome activation, while D₂-like receptor stimulation reduces lacrimal gland inflammation in experimental dryeye models. Dopamine is an important mediator linking the central nervous system, immune system, and peripheral cells function at the ocular surface. By modulating ion transport, immune signaling, and regenerative activity, dopamine plays a crucial role in maintaining ocular surface homeostasis and tissue resilience. In this review, we demonstrated the expression of dopamine receptors in human scleral cells, conjunctival and corneal epithelail cells. Further, the review consolidates current evidence on dopamine receptor expression and function across ocular surface tissues, explores mechanistic insights into dopaminergic regulation, and highlights the translational potential of dopamine based interventions in ocular surface disorders, wound healing, and neuronal inflammation.