It is a common practice among scleral lens fitters to use unit dose 0.9% sodium chloride inhalation/irrigation vials to rinse and fill the bowl of scleral lenses prior to insertion. These vials are comprised of a 0.9% sodium chloride and 99.1% water solution. They are sterile 3ml or 5ml vials and contain no preservatives or buffers. The Material Safety Data Sheet (MSDA) for 0.9% sodium chloride solution states that it is non-corrosive to the skin, eyes or lungs.1
At the recent Global Speciality Lens Symposium, I spoke with some members of the Scleral Lens Education Society (www.sclerallens.org) who have observed that the best results are achieved with normal saline. Upon insertion, scleral lenses trap solution behind the lens—especially the larger, true scleral lenses that do not allow for fluid exchange. The solution may stay under the lens, and in contact with the cornea, for the duration of the lens wear. Some multi-purpose contact lens solutions, gas-permeable cleaners and buffers have been implicated in causing corneal staining, debris build up and general red eyes.2-4
Although saline solution has been used in contact lens wear for decades, the question arises: Is solution packaged for inhalation or irrigation considered off-label when used in the eye and/or with contact lenses?
Off-label prescribing is defined as any prescription drug used for indications that are not approved by the Food and Drug Administration (FDA) and is common in clinical practice across the United States. Off-label prescribing occurs whenever drugs are used at different doses, via different routes of administration or in patient populations other than those specified by FDA-approved labeling. Off-label prescribing is legal and the FDA states, “Good medical practice and the best interests of the patient require that physicians use legally available drugs, biologics and devices according to their best knowledge and judgment. If physicians use a product for an indication not in the approved labeling, they have the responsibility to be well informed about the product, to base its use on firm scientific rationale and on sound medical evidence, and to maintain records of the product’s use and effects.”5
Although the FDA does not restrict physician prescribing for off-label indications, current law regulates and prohibits manufacturer promotion for unapproved uses.6 The 0.9% non-preserved, buffer free sodium chloride has a pH between 5 and 7. Low pH solutions have the potential to alter the shape of soft contact lenses and have been reported to cause tightening of soft contact lenses.7 Therefore, doctors should weigh the risks and benefits and monitor for untoward events.
Personally, I have been using 0.9% sodium chloride inhalation vials for rinsing and inserting contact lenses for the past 15 years—not only for my scleral lenses patients, but also for infants and those with solution sensitivities.3 My patients find the unit dose vials convenient and readily available through most pharmacies and online distributors.
Technically, they are over-the-counter agents, but I always write a prescription for easy communication with the pharmacist and to ensure compensation from the patient’s insurance/flex spending account. Additionally, I take the time to counsel my patients that although the vials are labeled for inhalation use, we are using them in an off-label fashion. They are instructed to clean and disinfect contact lenses with approved contact lens solutions.
If you want a non-preservative, non-buffer saline solution for rinsing and inserting lenses, 0.9% sodium chloride inhalation vials are the only product on the market. It is reasonable to prescribe this off-label use for this product.
1. Baxter. Material Safety Data Sheet. 2009 Oct. Available at:
www.vwrsp.com/msds/10/681/68100-028.pdf (Accessed February 2011).
2. Schrage NF, Frentz M, Reim M. Changing the composition of buffered eye-drops prevents undesired side effects. Br J Ophthalmol. 2010 Nov;94(11):1519-22.
3. Epstein SP, Ahdoot M, Marcus E, Asbell PA. Comparative toxicity of preservatives on immortalized corneal and conjunctival epithelial cells. J Ocul Pharmacol Ther. 2009 Apr;25(2):113-9.
4. Gorbet MB, Tanti NC, Jones L, Sheardown H. Corneal epithelial cell biocompatibility to silicone hydrogel and conventional hydrogel contact lens packaging solutions. Mol Vis. 2010 Feb;16:272-82.
5. U.S. Food and Drug Administration. “Off-Label” and Investigational Use Of Marketed Drugs, Biologics, and Medical Devices. 2010 Oct. Available at: www.fda.gov/RegulatoryInformation/Guidances/ucm126486.htm (Accessed February 2011).
6. U.S. Food and Drug Administration. “Prescription Drug Advertising: Questions and Answers. 2009 Jul. Available at: www.fda.gov/Drugs/ResourcesForYou/Consumers/PrescriptionDrugAdvertising/UCM076768.htm#law_violation_how (Accessed February 2011).
7. Lum E, Perera I, Ho A. Osmolarity and buffering agents in soft contact lens packaging solutions. CL Ant Eye. 2004 Mar;27(1):21-6.