Dry Eye Dx and Tx
MRE in Dry Eye Therapy
By Katherine M. Mastrota, MS, OD, FAAO
The acronym MRE typically stands for Meal, Ready-to-Eat, a self-contained, individual field ration in lightweight packaging bought by the United States military for its service members for use in combat or in other field conditions where organized food facilities are not available.
But for clinicians managing dry eye, MRE stands for moisture-retaining eyewear. Such eyewear (moisture chambers/barrier products) dampens the evaporative, destabilizing effects of air moving across the ocular surface; protects the ocular surface from environmental pollutants, allergens, and temperature extremes; and simultaneously allows for increased humidity behind the glasses/goggles/sunglasses. MRE can be particularly useful for wear during sleep when tear production is reduced or for patients who demonstrate lagophthalmos/nocturnal lagophthalmos.
What's Available in MRE
Most barrier products are constructed with fixed or removable silicone or porous foam moisture shields that line the frame/goggle/mask, which effectively surrounds the ocular adnexa and creates a protective environment around it. Some MRE have snap-in humidifying cartridges. MRE can fit over conventional spectacles or can be made with a patient's prescription. Plastic side shields fitted to a patient's existing frame or sports-type goggles, e.g., motorcycle, swimming, or snow-sport goggles, can serve as MRE. Conventional safety goggles can also second as MRE. Remember that press-on prescription lenses (plus/minus/adds) can always be affixed to customize any frame/goggle used as MRE.
When recommending an MRE product to your patient, a number of considerations come into play: comfort, cost, stability, simplicity, single versus multiuse, aesthetics, frame colors, tinted versus transparent lenses, indoor versus outdoor use, option for prescription lenses, type of attachment (temple versus band or strap), overall fit, adjustability of fit, seal material, ± humidifying unit, ± insertable moisture pads, ± insertable heating element, amount of eye vault versus ability to hold the lids closed, sizing (child versus adult), ease of care, durability, and availability/necessity of replacement parts. Decisions made on many of these factors depend on whether the MRE is for day or sleep wear.
When prescribing for protection during sleep, sleep posture (side sleepers versus stomach sleepers) and CPAP (Continuous Positive Airway Pressure—a respiratory ventilator used primarily in the treatment of sleep apnea that employs a face mask and head straps) compatibility must be addressed. It is not uncommon to extract a history of CPAP use in dry eye patients, especially those diagnosed with Floppy Eyelid Syndrome.
Applications for MRE
MRE is an excellent adjunct to the palliative or therapeutic management of dry eye. Such devices can support management of blepharitis (anterior or posterior), lid apposition abnormalities (e.g., trauma, palsies, post-blepharoplasty, proptosis/exophthalmos), or corneal-based disease (e.g., recurrent corneal erosion, basement membrane dystrophies).
Finally, more conventionally designed eyewear has been developed with computer users in mind. Manufacturers of such eyewear report that the highly wrapped configuration (increased face form) of these frames and lenses creates an ocular microclimate that traps in humidity and blocks out evaporative air currents.
Eyewear/MRE serves as an effective indoor/outdoor dry eye treatment. Thoughtful consideration to the personalization of “eyewear therapy” will reap rewards for both you and your patients. CLS
Special thanks to Rebecca Petris (The Dry Eye Zone) for her contribution to this article.
Dr. Mastrota is secretary of the Ocular Surface Society of Optometry (OSSO). She is center director at the New York Office of Omni Eye Services and is a consultant to Allergan, B+L, Noble Vision, Ista Pharmaceuticals, and Ocusoft, Inc. You can reach her at firstname.lastname@example.org.