It’s time to look beyond dry eye syndrome’s ability to masquerade as a simple, straightforward irritation, and see that it can be more deep-rooted than suspected.
Given the influx of patients experiencing dry eye syndrome – the condition affects one-in-four people – it’s no surprise that its obvious inconvenience is well-documented. However, its impact also surfaces in less obvious, but hugely disconcerting, forms – such as the condition’s apparent link to chronic pain syndromes.
Shedding light on this particular relationship is research which suggests that some dry eye sufferers have corneal somatosensory pathway dysfunction and would be better described as having neuropathic ocular pain.
With this in mind, perhaps we may start to see a shift in long-term routes of recovery – a change supported by Roy C Levitt, MD, a Neuroanesthesiologist, Pain Specialist, and Geneticist at Bascom Palmer Eye Institute at the University of Miami Miller School of Medicine, and study author, who explained that, ‘A multidisciplinary approach used for chronic pain treatment may also benefit these dry eye patients.’
‘Dry eye patients in our study reported higher levels of ocular and non-ocular pain associated with multiple chronic pain syndromes, and had lower scores on depression and quality-of-life indices consistent with a central sensitivity disorder,’ he continued.
Reflecting on the implications of the findings – and the lessons that we can subsequently learn, Anat Galor, MD, MSPH, a Cornea and Uveitis Specialist and Associate Professor of Clinical Ophthalmology at the Miller School, as well as a fellow author, said, ‘Our highest priority is educating physicians that dry eye represents an overlapping chronic pain condition. Consequently, a multidisciplinary approach should be considered in the diagnosis and pain management of dry eye patients.’
KEY RESEARCH TO KEEP AN EYE ON:
• A team at Stanford University, led by Daniel Palanker, PhD, has developed an implantable device that electrically stimulates the lacrimal gland to produce tears. In addition, it stimulates the nerves linking the brain and sensory neurons in eye, further prompting the lacrimal gland to produce tears. More recently, the team has been able to finetune the content of the tears by stimulating other glands around the eye. Their results produce tears that contain not only water, but lipids and mucins to more closely resemble the consistency of naturally-occurring basal tears
• Defining the molecular composition of the tear lipid layer is another area of research that the National Eye Institute is funding. Ben Glasgow, MD, at the University of California, Los Angeles, is studying the structure and function of lipid binding proteins in tears.