Why Do Certain Artificial Tears Seem to Not Help At All?
There are hundreds of artificial tear options on the market. Which is the best one for you? The answer is that it is hard to tell sometime until a patient tries the product.
Some recent, non-drug company-funded studies, have shown Retaine Non-Preserved Artificial Tear to be superior to other tears, but still I have some patients that feel Retaine does not help either.
Bare in mind that for hundreds of years, eyeMDs and patients have been looking for some permanent relief to dry eyes. In 1872, Georg Ebers, a German Egyptologist, discovered a collection of Egyptian medicinal recipes (“the Ebers Papyrus’) written sometime between 1553 and 1550 B.C.
“If a man’s eyes are affected with dryness, he shall rub an onion, drink it in beer, apply oil to his eyes. Thou shalt disembowel a yellow frog, mix its gal in curd, apply to his eyes.”
— Prescription from Assyro-Babylonian ophthalmology [1. Kraus A. Assyro-Babylonian Ophthalmology. Annals of Medical History 1934;6:42-55.]
Currently, though, there is only 1 FDA approved eye drop on the market (Restasis, Allergan), which seems ridiculous since research on this subject has continued for so many years. Restasis is a wonderful drop for the right patient. For others it causes so much burning that patients cannot stand it. Some report that Restasis does not seem to make any difference even after months & years of treatment (though it is though to prevent worsening of dry eye scores over years). Restasis can also be very expensive over the long term. Still it remain the best drop we have for inflammatory related dry eye, such as Sjögren’s Syndrome, Lupus, Rheumatoid Arthritis.
Part of the reason why other eye drop protocols have failed to show a statistically significant improvement in FDA trials may be due to possible genetic variations in patient’s nerve ending, particular the corneal nerves which are particularly sensitive to tear film instability, and overall systemic (in the body) pain sensitivity.
The below study is of interest in this regard.
Even though an MD or eye surgeon cannot “see” signs of dry eye on the microscope does not necessarily mean that the patient is not having ocular pain. This is frustrating for both patients and physicians. Patients might feel as if no one believes them in their eye pain. And physicians are obliged to document what they see and cannot “imagine pathology,” while at the same time understand that instruments to measure neuropathic ocular pain are in their infancy and very hard to purchase currently.
Thus when patients state that their treatments are not working, I believe them and show them all the tools available currently for dry eye [https://drcremers.com/2015/07/new-innovations-in-dry-eye-treatments.html ] and hope that in the near future we can better understand the hidden issues of neuropathic ocular pain.
Sandra Lora Cremers, MD, FACS
Incomplete response to artificial tears is associated with features of neuropathic ocular pain — Galor et al. — British Journal of Ophthalmology
Abstract
The British Journal of Ophthalmology
September 18, 2015
By Hatim Batawi, Elizabeth R Felix, Anat Galor, Roy C Levitt, Todd P Margolis, Eden R Martin, Konstantinos D Sarantopoulos
Aims Artificial tears are first-line therapy for patients with dry eye symptoms. It is not known, however, which patient factors associate with a positive response to therapy. The purpose of this study was to evaluate whether certain ocular and systemic findings are associated with a differential subjective response to artificial tears.
Methods Cross-sectional study of 118 individuals reporting artificial tears use (hypromellose 0.4%) to treat dry eye-associated ocular pain. An evaluation was performed to assess dry eye symptoms (via the dry eye questionnaire 5 and ocular surface disease index), ocular and systemic (non-ocular) pain complaints and ocular signs (tear osmolarity, tear breakup time, corneal staining, Schirmer testing with anaesthesia, and eyelid and meibomian gland assessment). The main outcome measures were factors associated with differential subjective response to artificial tears.
Results By self-report, 23 patients reported no improvement, 73 partial improvement and 22 complete improvement in ocular pain with artificial tears. Patients who reported no or partial improvement in pain with artificial tears reported higher levels of hot-burning ocular pain and sensitivity to wind compared with those with complete improvement. Patients were also asked to rate the intensity of systemic pain elsewhere in the body (other than the eye). Patients who reported no or incomplete improvement with artificial tears had higher systemic pain scores compared with those with complete improvement.
Conclusions Both ocular and systemic (non-ocular) pain complaints are associated with a differential subjective response to artificial tears.