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Antioxidant eye drops provide another option for cataract patients
Ninety percent of patients in one study showed improvement in best corrected visual acuity.
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The most common cause of blindness worldwide is unoperated cataracts. For some, lack of access to quality cataract surgery has a strong role in the growing backlog of unoperated and untreated cataracts, and increasing numbers of patients are suffering from this condition.
Many of our patients, even with access to care, are still looking for alternatives to delay cataract surgery as long as possible or wanting to avoid surgery all together. Whether they are not a candidate yet, but feel as though they notice a decline in the quality of their vision or notice an increase in the nighttime glare, symptoms of cataracts affect our growing aging population.
The fact that oxidative damage of lens protein is a prominent factor in cataract development has led to speculation that the use of antioxidants may be an effective way to slow their development. An abundance of literature exists with regard to oral antioxidants and is another area to explore. Although the majority of epidemiological studies have shown a positive correlation between higher dietary antioxidant intake and decreased cataract formation, conflicting conclusions exist, and surgeons and ophthalmic corporations have been slow to research and adopt alternative options.
Antioxidant drops used overseas
Antioxidant eye drops have existed on the market for many years. Newer products such as OcluMed (Advanced Scientific), Can-C (N-acetylcarnosine, Profound Products) and Brite Eyes III (Life Extension) have been created based on the initial research of Marc Babizhayev PhD; these formulations were designed to support a failing antioxidant system in the eye.
Carnosine, the primary component in these products, is a protein naturally produced in the body. L-carnosine, a product of N-acetyl L-carnosine, can pass through the aqueous and lipid components of the eye, preventing DNA strand breaks caused by UV damage. Cataracts form with the cross-linking of lens proteins caused by free radicals, which are produced during UV exposure over time. L-carnosine contains a sulphur that helps support the dihydro sulphur bonds in the lens crystallin proteins. In this way, antioxidants such as those listed above serve to protect the lens from denaturing damage, much like the glutathione present in the healthy lens; the prevailing concept is that L-carnosine has the potential to help repair lens transparency.
Eye drop supplement studies
In hopes of demonstrating the benefits of these eye drop supplements, we collected feedback from patients with early cataracts that were willing to use the OcluMed drops, a patented mega formulation, twice a day over a period of 6 months to see if they noticed any improvement in their vision. We elected to use OcluMed, as this product is aimed at supplementing multiple antioxidant systems in the eye including not only N-acetylcarnosine, but also L-carnosine, L-glutathione, cysteine ascorbate and L-cysteine.
Image: Abel Jr. R
We enrolled 24 eyes with moderate cataract density and two blinded independent observers to evaluate the level of visual acuity, glare, contrast sensitivity and subjective response. The patients who received the product noted no adverse effects after taking the drops, and, despite the small sample size, some found the drops soothing, and a few replaced their artificial tear drops because the OcluMed made their eyes feel better for a longer period of time.
Those patients who received the placebo were offered the opportunity to use the active product for a period of 6 months. We found that only minor changes in certain categories demonstrated improvement (one line of glare, one line of visual acuity), but these changes were not able to be placed into a trend. We feel that if a larger controlled study was completed, this may be easier to observe.
In an additional open study that was held for 3 months, three of 12 eyes showed improvement, and two eyes continued to receive the drops for 6 months longer. After discontinuing the drops 2 years ago, their cataracts were found to have stabilized.
In other studies conducted by Francisco Attanasio, the protective effect of carnosine derivatives were explored, and his team demonstrated the ability of carnosine to restore lens transparency on rat lenses exposed to denaturing effects. In other animal studies, OcluVet, (OcluMed formula from PractiVet), an antioxidant eye drop consisting of L-carnosine, N-acetyl L-carnosine and other components, demonstrated a measurable reduction of cataract formation in more than 80% of animal eyes tested. These positive results are important to note, as cataract operations in animals holds major risk and expense as well.
But perhaps most relevant, Marc Babizhayev and his team conducted a study on 49 patients with differing degrees of cataract formation and found that 90% of the eyes treated with N-acetylcarnosine improved in best corrected visual acuity, and more than 88% improved some degree in glare sensitivity. In this study, no treated eyes demonstrated a decrease in vision, nor were adverse effects reported from using two drops twice daily for up to 24 months.
In more recent studies published in Nature, lanosterol was found to have reduced cataract severity by reversing protein aggregation in cataracts. Lanosterol is an amphipathic molecule, meaning it has both hydrophilic and lipophilic properties. It is synthesized by Lanosterol synthase, which is involved in cholesterol synthesis. This study demonstrated that treatment with Lanosterol decreased preformed protein aggregates and further showed improved lens transparency in rabbit cataractous lenses as well as decreased cataract severity in dogs. While, again, more research needs to be conducted, it offers hope of new developments to come.
Cataract surgery still provides our patients with clearer quality of vision. While antioxidant eye drops are not a replacement for this procedure, they present an alternative for that population of patients looking for another option in the meantime and can be considered as an opportunity to offer when we advise our patients to don their sun protection in hopes of delaying cataract progression.
- References:
- Abel R Jr. The Eye Care Revolution. 3rd ed. New York, NY: Kensington Publishing Co; 2014.
- Attanasio F, et al. Biochemistry. 2009;doi:10.1021/bi900343n.
- Babizhayev M, et al. Drugs R D. 2002;3(2):87-103.
- Carey, FA. Organic Chemistry. 6th ed. New York NY: McGraw-Hill Companies Inc; 2006;831.
- Dr. A’s Eye Advisory Web site. http://eyeadvisory.com. Accessed September 78, 2015.
- Grossmann M. N-Acetyl Carnosine Eyedrops and Cataract Management. Natural Eye Care Web site: http://www.naturaleyecare.com/blog/n-acetyl-carnosine-eyedrops-and-cataracts-management. Posted June 7, 2008. Accessed September 8, 2015.
- Williams DL, et al. Vet Ophthalmol. 2006;9(5):311-316.
- Zhao L, et al. Nature. 2015;doi:10.1038/nature 14650.
- For more information:
- Jamie C. Wohlhagen, OD, practices at Delaware Ophthalmology Consultants in Wilmington, Del. She can be reached at: jwohlhagen3@gmail.com.
- Robert Abel Jr., MD, also practices at Delaware Ophthalmology Consultants. He can be reached at abeleyes@gmail.com.
Disclosures: The authors report no relevant disclosures.