top of page
Search
  • Writer's pictureDr. Zimski

Neuropathic Eye Pain in Dry Eye Patients

Updated: Apr 30


Ocular surface pain can have a tremendous impact on quality of life.


But what is it? What causes it? And how are our Denver-area dry eye patients affected?


First, some definitions. Pain is defined by the International Association for the Study of Pain as an “unpleasant sensory and emotional experience associated with, or resembling that associated with, actual or potential tissue damage.”


Patients use various descriptors to characterize their eye pain that include dryness, burning, grittiness, itching, tenderness, and aching. Pain can be unprovoked or it can be triggered by stimuli such as light, wind, or temperature changes. Traditionally, eye pain has been lumped under the diagnosis of dry eye, and while dry eye is certainly one cause of eye pain, it is now understood that factors beyond dryness contribute to pain.  


Neuropathic Eye Pain: Woman smiling


For example, it is common for patients with migraines and fibromyalgia to have neuropathic eye pain.  


Pain can be divided into two broad categories: pain due to tissue damage of the ocular surface (termed nociceptive pain) and pain caused by nerve dysfunction (neuropathic pain) defined as pain caused by disease of the peripheral and central nerves that connect the ocular surface to the brain. Sometimes nerve receptors get a bit too sensitive and fire signals inappropriately and then the more your brain tunes into these signals, creating a feedback loop that is hard to break. 


It would be nice if every patient could be put into one of these categories, but in reality, dry eye is a complex disease and often eye pain often results from a combination of these issues.  


Fortunately, there have been advances in the diagnosis and management of eye pain with a focus on treatments for neuropathic eye pain


Welcome to the world of neuropathic eye pain. Let’s look at what it is and (if you’re suffering from it) how our Denver-area dry eye office can give you the relief you need. 


What is Neuropathic Eye Pain?


Neuropathic eye pain, also known as ocular surface pain, can be classified into central, peripheral or mixed. Common features include sensitivity to light and wind. Sometimes there is  an inciting event such as “pink eye” (viral conjunctivitis) or eye surgery (such as LASIK or cataract surgery), and sometimes it’s the result of a long history of dry eye.  


And while there's still much to learn about neuropathic pain and dry eye, ongoing research and advancements in treatment offer hope for those struggling with this complex condition. By understanding the unique challenges each patient faces, we can tailor our approach to provide personalized care that targets the root cause of their discomfort.


How to Approach Diagnosing Eye Pain



Dr. Lauren Zimski: Dry Eye Pain and Neuropathic Eye Pain

The first step is always diagnosing and treating the ocular surface as aqueous tear deficiency, evaporative tear deficiency, and other abnormalities of the ocular surface all cause eye pain. 


The first step is taking a thorough medical history and asking patients to fill out a questionnaire to better understand the most bothersome symptoms a patient is experiencing.  Systemic conditions including skin conditions, autoimmune diseases, sleep apnea and medications can all affect the ocular surface. 


There are many standardized questionnaires for dry eye, some are time consuming and were designed for research studies and some have been designed to quickly assess dry eye symptoms, how frequently they occur and can be used to track the progression of dry eye symptoms over time. The SPEED questionnaire is a valuable tool and I administer to all my new patients and use it to follow patients after initiating new treatments. (Take the questionnaire now).

Neuropathic Eye Pain: woman in chair

Inflammadry is done to look for the presence of ocular surface inflammation.  Inflammatory mediators can interfere with nerve activity, triggering a cascade of pain signals and if inflammation is present, treating it effectively often significantly improves pain.  


Next, the evaluation continues with examining eyelid position, periocular health, and looking for skin conditions such as rosacea or seborrheic dermatitis. At the slit lamp, the eyelid margin is further evaluated looking for dilated blood vessels (telangiectasias), collarettes at the base of the lashes (which is associated with demodex mites), and blinking patterns. Then dye is instilled and special filters are used to look for conjunctival and corneal staining, tear break-up time, and tear height. Meibography is used to look for meibomian gland loss and then expression is used to assess the amount and quality of the oil. 


Once these conditions are identified and treated, most patients have significant improvement of their eye pain, but a small number of patients have persistent eye pain after their ocular surface improves.  And sometimes patients have significant eye pain, with a healthy ocular surface, and have been told that nothing is wrong. These patients often become frustrated and depressed, as they feel like there is no hope.


For interesting images of this condition, check out the scientific paper: Corneal confocal microscopy detects small nerve fibre damage in patients with painful diabetic neuropathy.


Treatments for Neuropathic Eye Pain Starts With Identification


There are two steps in evaluating neuropathic eye pain. 


The first is checking corneal sensation with a wisp of a cotton tip in four quadrants of the cornea.  Abnormalities in corneal sensation are a clue that a patient may have neuropathic eye pain.  


Next, an “anesthetic challenge” is done by placing a numbing drop. Patients are asked to rate their pain before the drop is instilled and one minute afterwards.  Pain that completely resolves is peripheral pain and pain that does not resolve is central neuropathic pain. This test is only helpful when patients report pain before installation.  


Next week we will explore treatment options for neuropathic eye pain.  Stay tuned!

Comments


bottom of page