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Contact lens safety has been in the spotlight even more than usual since the FDA released recommendations on the use and packaging of multipurpose solutions in June.
Contact lens safety has been in the spotlight even more than usual since the FDA released recommendations on the use and packaging of multipurpose solutions in June. The recommendations included the addition of a "discard date" on products and encouragement for contact lens wearers to "rub and rinse" lenses in order to optimize cleaning and disinfection.1
Fifty percent of contact lens wearers may experience some level of ocular dryness symptoms.2 Furthermore, dryness and discomfort are cited as chief patient-reported reasons for contact lens discontinuation.3 Contact lens wearers who experience dryness-related symptoms have the option of using rewetting drops, but may reach for typical ocular lubricants instead.
Forty-five contact lens wearers were enrolled and completed the double-masked, single-site study. Subjects were randomized to the ocular lubricant or rewetting drop and were instructed to instill 1 to 2 drops of the assigned solution in both eyes 15 minutes prior to contact lens insertion (the general rule of thumb for eye drops not labeled for use with lenses)4 , at least 1 drop during contact lens wear, and then immediately after lens removal. Subjects were instructed to follow this treatment regimen daily for 2 weeks, at which time they returned for biomicroscopy, visual acuity, and corneal staining evaluations.
No adverse events were observed in either treatment group. No significant changes from baseline visual acuity were observed in the ocular lubricant treatment group, and a statistically significant-though not clinically significant-improvement in visual acuity was observed for the rewetting drop group (p = 0.0011). Furthermore, mean sum staining (on the National Eye Institute scale) was 0.33 at both the baseline and follow-up visit in the ocular lubricant group, and was 0.43 and 0.55 at baseline and follow-up visits, respectively, in the rewetting drop group. Neither group exhibited significant changes in corneal staining from baseline (p ≥ 0.54), and between-group differences in staining were not statistically significant (p ≥ 0.23).
These results aren't too surprising. The active ingredients in the polyethylene glycol 400/propylene glycol lubricant are used in contact lens care products and have demonstrated good compatibility with the ocular surface in previous ophthalmic applications.5 The data provide increased confidence that contact lens wearers who use ocular lubricants with their contact lenses do not appear to be putting their ocular health at substantial risk. Much of the need for on-lens lubrication stems from the contact lens's interruption of the natural tear film. Viscoelastic properties of eye drops may influence the friction experienced during blinking, and may also affect comfort and drying properties.6
In summary, research emphasizes the need to manage contact lens-related dryness in the growing population of contact lens wearers, and the present study demonstrated comparable safety profiles of ocular lubricant and rewetting drop use by contact lens wearers to minimize symptoms.
David L. Kading OD, FAAO E-mail: firstname.lastname@example.org
Dr. Kading did not indicate a financial interest in the subject.
1. Ensuring safe use of contact lens solution. FDA Web site. http://www.fda.gov/ForConsumers/ConsumerUpdates/ucm164197.htm. Accessed 09 July 2009.
2. Riley C, Young G, Chalmers R. Prevalence of ocular surface symptoms, signs, and uncomfortable hours of wear in contact lens wearers: the effect of refitting with daily-wear silicone hydrogel lenses (senofilcon A). Eye Contact Lens 2006;32:281-6.
3. Richdale K, Sinnott LT, Skadahl E, Nichols JJ. Frequency of and factors associated with contact lens dissatisfaction and discontinuation. Cornea 2007;26:168-74.
4. Restasis product information. Allergan Web site. http://www.allergan.com/assets/pdf/restasis_pi.pdf. Accessed Sept. 11, 2009
5. Christensen MT, Cohen S, Rinehart J, et al. Clinical evaluation of an HP-guar gellable lubricant eye drop for the relief of dryness of the eye. Curr Eye Res 2004;28(1):55-62.
6. Ketelson HA, Davis J, Meadows DL. Characterization of a novel polymeric artificial tear delivery system. Invest Ophthalmol Vis Sci 2008;49:E-abstract 112.