‘Phantom’ Eye Pain
Eye pain that is often described as dryness but that is unresponsive to traditional therapies and that presents without obvious signs of dry eye is now being defined as ocular neuropathic pain. Normal pain sensation is a warning of imminent or actual tissue damage, whereas neuropathic pain is caused by a dysfunction, disease or damage to the pain alarm system itself.
A small percentage of patients that suffer from severe eye pain often have little to no signs of dryness. Most have eye sensitivity to wind, light and changing temperatures. A few also feel aches or pains around the face, neck and jaw. Their eyes look normal, and these patients are often dismissed by doctors because they can’t find anything wrong.
One cause for this “phantom pain” may be that the main sensory nerve system of the face (Trigeminal nerve) is somehow damaged, making the whole area hypersensitive to any stimulus. The nerve endings of the cornea send messages to the brain that are misinterpreted – indicating that the tear film is thinner than it really is. The result is false dry eye symptoms.
A way for a practitioner to test if this is a problem of the main nerve system is to instill topical anesthetic drops – if the pain remains unchanged, the problem is likely due to the main sensory nerve and brain – and not the eye surface. If the drops help a little but not completely, the issue may include some eye surface nerve hypersensitivity as well. This surface nerve sensitization in the cornea is often triggered by trauma, LASIK or other eye surgeries, but it may occur spontaneously.
In addition to oral and topical pain medications, anti-depressives and anti-anxiety drugs work well to suppress the discomfort. Depression and anxiety are correlated with the main nerve/brain-oriented hypersensitivity – very similar to fibroneuralgia. Repurposing of certain anti-convulsive drugs such as Gabapentin is also effective with this neuropathic pain in many cases.
For corneal surface hypersensitivity, therapies include topical non-steroidal anti-inflammatory drops and large hard contact lenses to protect the ocular surface from any significant evaporation. Pharmacy-compounded serum eye drops that are produced from the patient’s own blood can serve to soothe and quiet the sensitive corneal nerve endings.
Contact us today to schedule an appointment and find options to help relieve your “phantom pain” symptoms.