Patients with chronic ocular pain may benefit from the use of nerve blocks generally used to treat peripheral neuropathic pain.
Pain disorders can be nociceptive, characterized by pain that arises from actual or threatened damage to non-neural tissue, such as with severe ocular surface disease, band keratopathy, and intraocular inflammation.
They can be neuropathic, as with pain resulting from damage to or changes occurring in the nervous system, such as that caused by a previous cataract, LASIK, or RK surgery; neuralgia associated with the herpes virus; and eye drops containing the preservative benzalkonium chloride, according to Ann V. Quan, MD, an ophthalmology resident, Bascom Palmer Eye Institute, University of Miami Hospital and Clinic, Miami.
Neuropathic pain is a complex process resulting from various receptors. The corneal nociceptors are comprised of polymodal nociceptors that sense chemical, thermal, and endogenous inflammatory mediators, mechanoreceptors that sense mechanical stimuli, and cold thermoreceptors that sense evaporation.
The terminal nerve endings of the corneal nociceptors interact with the external environment and by doing so, they are susceptible to damage during inflammation or repetitive environmental injuries.
RELATED CONTENT: Differentiating ocular pain: Nociceptive or neuropathic
Ann V. Quan, MD
E: [email protected]
Dr. Quan has no financial interest in any aspect of this report.