Milton M. Hom, OD, FAAO, FACAAI (Sc)
Dr. Hom practices in Azusa, CA. He is a scientific fellow of the American College of Asthma, Allergy, and Immunology. Contact Dr. Hom at firstname.lastname@example.org.
Biocompatibility is the new mantra for the new generation of MPS. No more harsh chemicals.
Peroxide systems revisited
Peroxide perceived as gold standard MPS systems trying to achieve
By Milton M. Hom, OD, FAAO
More than 20 years ago, I anxiously waited for my first peroxide systems to arrive at my office. Back then, we had heat units and -then called- chemical systems, forerunners of multipurpose solutions (MPS). The heat units would bake-on lens protein and require once-a-week enzymatic cleaning. The chemical systems were just that-disinfection chemicals, which sometimes acted too harshly on the ocular surface.
Fast forward to today. The current MPS systems are amazing; much improved over the early days. But peroxide remains pretty much the same with some tweaks on neutralization. When I lecture on contact lenses and care systems, I find that most of us still go to peroxide as our troubleshooter for conditions such as irritation, redness, allergy, discomfort, or other difficulty with MPS (including corneal inflammatory events). Peroxide seems to be perceived as the gold standard MPS systems are still trying to achieve.
Despite all of peroxide’s benefits, there are still disadvantages to consider. In recent years, the disinfection efficacy against Acanthamoeba has come into question. In some systems, the exposure times leave us wanting more. With such short times before neutralization, Acanthamoeba cysts can still remain viable.1-3
Biocompatibility is the new mantra for the new generation of MPS. No more harsh chemicals. Even peroxide’s claim to better end-of-day comfort may have been one-upped by MPS. Recent work has shown patients on peroxide systems still experience discomfort, dryness, and have to rely on using rewetting drops. In a study of 150 soft contact lens wearers in the U.S. who wear their lenses 4 days a week or more and use a hydrogen peroxide solution, 43% reported experiencing discomfort and 25% reported experiencing dry eye while wearing their contact lenses. In addition, approximately one third of lens wearers reported use of rewetting drops in addition to their peroxide care systems once per week or more. Approximately 25% of lens wearers reported use of rewetting drops either every day or several times per week.4
Looking at the current MPS product set, moisture retention is at the forefront. Previously, MPS were disinfection chemicals disguised in saline. Now, we have multiple conditioning agents that are gentle to the eye and greatly enhance comfort. We’ve come a long way, baby.
For those of us in practice, we have to deal with the user-friendliness of peroxide systems. We forget about the long neutralization times (6 hours), leaky cases, and nightmares when traveling. Patients complain the right and left baskets are too difficult to tell apart. Pity the hyperopes and presbyopes. Over the years, I have seen patients drop out of peroxide because it was too much like a chemistry experiment.
The other day I was at a nationwide chain-store pharmacy. I was a little surprised to see a generic peroxide system on the shelf. It looked pretty similar to the real thing. I guess peroxide is no longer immune to the MPS branded vs. private label confusion/drawbacks.
Peroxide still has a place in my practice. But we still need to improve overall lens cleaning, decrease neutralization time, work on comfort, and improve the cases.
Industry, are you listening?ODT
1. Hiti K, Walochnik J, Faschinger C, Haller-Schober EM, Aspock H. One- and two-step hydrogen peroxide contact lens disinfection solutions against Acanthamoeba: how effective are they? Eye (Lond). Dec 2005;19(12):1301-1305.
2. Hiti K, Walochnik J, Haller-Schober EM, Faschinger C, Aspock H. Viability of Acanthamoeba after exposure to a multipurpose disinfecting contact lens solution and two hydrogen peroxide systems. Br J Ophthalmol. Feb 2002;86(2):144-146.
3. Hughes R, Kilvington S. Comparison of hydrogen peroxide contact lens disinfection systems and solutions against Acanthamoeba polyphaga. Antimicrob Agents Chemother. Jul 2001;45(7):2038-2043.
4. Millward Brown Healthcare, market research study conducted online amongst 150 U.S. soft contact lens wearers, all wearing their lenses for at least 4 days a week and using a HP solution, May/June 2011.