The randomised double-blind clinical trial, published in Cornea, investigated the effects of supplementation with gamma-linolenic acid (GLA) and omega-3 (n-3) polyunsaturated fatty acids on signs and symptoms of moderate-to-severe keratoconjunctivitis sicca (a tear dysfunction often referred to as dry eye) after the fatty acids were linked to a reduction in the production of inflammatory mediators that are linked to the chronic condition.
Led by Professor John Sheppard from Lee Laboratory for Ocular Pharmacology at Eastern Virginia Medical School, USA, the research team enrolled 38 post-menopausal women with tear dysfunctions to be randomised to receive a proprietary supplemental mix of GLA, omega-3 PUFAs, antioxidants and other nutrients (HydroEye: ScienceBased Health,USA) or placebo for 6 months.
The team reported that the supplement improved ocular irritation symptoms, maintained corneal surface smoothness, and inhibited conjunctival dendritic cell maturation in the women with dry eye.
"Prior to this study, clinical evidence showing that nutritional supplements were beneficial in treating dry eye was scarce," explained Professor Stephen Pflugfelder from the Cullen Eye Institute at the Baylor College of Medicine - who was co-principal investigator of the trial.
"However, within three months, the group treated with HydroEye showed statistically significant improvements in irritation symptoms of dry eye, and no progression of ocular surface inflammation or corneal irregularity," he said. "The placebo group's dry eye symptoms actually worsened over the six-month testing period."
Study details
Sheppard and his colleagues enrolled 38 post-menapausal women suffering from moderate-to-severe keratoconjunctivitis sicca in both eyes in a multi-centre, double-masked placebo-controlled clinical trial. PArticipants were randomised to receive either the supplemental GLA and omega-3 blend or a placebo for 6 months.
Disease parameters, including Ocular Surface Disease Index, Schirmer test, tear breakup time, conjunctival fluorescein and lissamine green staining, and topographic corneal smoothness indexes (surface asymmetry index and surface regularity index). These were assessed at baseline, four, 12, and 24 weeks.
The team found that supplementation with the proprietary HydroEye supplement significantly improved ocular irritation symptoms, suppressed ocular surface inflammation, and maintained corneal surface smoothness.
"While this trial studied post-menopausal women, the largest group of dry eye sufferers, we think the benefits ... should apply to other populations suffering from dry eye since inflammation is believed to be a common thread in dry eye," said Pflugfelder.
Source: Cornea
Published online ahead of print, doi: 10.1097/ICO.0b013e318299549c
"Long-term Supplementation With n-6 and n-3 PUFAs Improves Moderate-to-Severe Keratoconjunctivitis Sicca: A Randomized Double-Blind Clinical Trial"
Sheppard, John D. Jr, Singh, Ruhi, McClellan, Andrew J., et al