Take-home message: The natural triglyceride form of omega-3 is an excellent treatment option for dry eye disease.
By Lynda Charters; Reviewed by Eric D. Donnenfeld, MD
Rockville Centre, NY —
Prescribing a natural oral re-esterified omega-3 nutritional supplement (PRN Dry Eye Omega Benefits, Physician Recommended Nutriceuticals) is an effective treatment for dry eye disease that significantly reduced the tear osmolarity and matrix metalloproteinase-9 (MMP-9) positivity, the Ocular Surface Disease Index (OSDI), and the tear break-up time (TBUT), and increased the Schirmer’s score.
Meibomian gland dysfunction, which is likely the leading cause of dry eye disease around the world, has a high prevalence in ophthalmic and optometric practices, i.e., 37% and 47%, respectively, according to Eric Donnenfeld, MD, who is a founding partner of Ophthalmic Consultants of Long Island and Connecticut, Rockville Centre, NY, clinical professor ophthalmology, New York University Medical Center, New York, and a trustee of Dartmouth Medical School.
These data underscore the need for effective treatments for dry eye disease, he said.
He said the Dry Eye Workshop and the International Workshop on Meibomian Gland Dysfunction both have recommended omega-3 supplementation to treat dry eye disease. However, different types of fish oil preparations have different bioavailability. In the U.S., most fish oil is processed into an artificial ethyl ester not found in nature, which has lower bioavailability than triglyceride oil, the natural form found in fish. A 1995 study of fish oils found that triglyceride oil was absorbed significantly (P=0.001) better compare with ethyl ester oil (Dyerberg et al. Bioavailability of n-3 fatty acid formulation, in: vol. 20 Prevention and Treatment in Vascular Disease. 1995:217-225).
Dr. Donnenfeld and colleagues conducted a double-masked, randomized, placebo-controlled, multicenter study to evaluate the natural triglyceride omega-3 formulation in 105 patients; 75 were female and the average patient age was 56.8 years. Fifty-four patients were randomly assigned to the active treatment group and 51 to the placebo group.
The formulation contained 1,680 mg of eicosapentaenoic acid and 580 mg of docosahexaenoic acid. The patients took four capsules once daily for 12 weeks or four placebo capsules. All patients were evaluated at baseline and 6 and 12 weeks after treatment onset. At each visit, the investigators evaluated the tear osmolarity, MMP-9, fluorescein corneal staining, Schirmer’s testing, and OSDI. At the screening examination and the week 12 evaluation, the omega index was tested.
The study primary end point was to determine the effect of 2,240 mg of the triglyceride-based omega-3 on the tear osmolarity. The secondary end points were the effects of the therapy on the OSDI symptoms, TBUT, corneal staining, lipid layer thickness, Schirmer’s test, MMP-9, and omega-3 index score.
Dr. Donnenfeld reported that the tear osmolarity decreased significantly (P=0.042 and P=0.004, respectively) in the treatment group at week 6 (309 mOsm/L) and week 12 (307 mOsm/L) time points compared with placebo.
The MMP-9 values decreased by 23% at 12 weeks in the treatment group compared with a 2% decrease in the placebo group, which was clinically significant.
The OSDI score decreased at week 12 by 17 points in the treatment group compared with five points in the placebo group, a difference that reached significance (P=0.0002).
The TBUT increased significantly (P=0.002) in the treatment group, from 4.78 seconds to 8.25 seconds at week 12 compared with the placebo group in which the baseline value of 4.61 seconds and those at week 6 (5.55 seconds) and week 12 (5.81 seconds) remained stable.
Finally, the investigators also saw a significant (P<0.001) change in the omega index in the treatment group with a 3% increase at week 12 compared with the placebo group in which the change was 0.24%.
Dr. Donnenfeld underscored the importance of using natural preparations of omega-3 because of the superior absorption (higher omega-3 index) compared with synthetic products.
“The natural triglyceride form of omega-3 supplementation administered orally is an effective treatment for dry eye disease. The study results showed that the formulation significantly improves tear osmolarity, MMP-9 levels, the TBUT, the OSDI, and increases the omega-3 index,” he concluded.
Eric D. Donnenfeld, MD
E: [email protected]
Dr. Donnenfeld is a consultant for Physician Recommended Nutriceuticals.