Despite identifying 34 trials related to treatments for blepharitis, there is no strong evidence for any of the treatments in terms of curing chronic blepharitis. Commercial products are marketed to consumers and prescribed to patients without substantial evidence of effectiveness. Further research is needed to evaluate the effectiveness of such treatments. Any RCT designed for this purpose should separate participants by type of condition (e.g. staphylococcal blepharitis or MGD) in order to minimize imbalances between groups (type I errors) and to achieve statistical power for analyses (prevent type II errors). Medical interventions and commercial products should be compared with conventional lid hygiene measures, such as warm compresses and eyelid margin washing, to determine effectiveness, as well as head-to-head to show comparative effectiveness between treatments. Outcomes of interest should be patient-centered and measured using validated questionnaires or scales. It is important that participants be followed long-term, at least one year, to assess chronic outcomes properly.
Effect of oral linoleic and gamma-linolenic acid on meibomian gland dysfunction.
To assess the effect of oral linoleic and gamma-linolenic acid, 2 omega-6 essential fatty acids, on meibomian gland dysfunction (MGD).
                Fifty-seven patients with MGD (27 men and 30 women) were randomly divided into 3 groups of 19. Group A received tablets containing linoleic acid (28.5 mg) and gamma-linolenic acid (15 mg) once daily. Group B performed eyelid hygiene once daily. Group C received both treatments. Initially and after 60 and 180 days of therapy, all patients completed a self-evaluation questionnaire on ocular surface disorders and underwent slit-lamp examination. The following signs were evaluated: eyelid edema, eyelid margin hyperemia, meibomian secretion appearance, meibomian gland obstruction, foam collection in the tear meniscus, conjunctival hyperemia, conjunctival papillae, and corneal staining.
                Statistically significant improvement in symptoms occurred in all groups. After 180-day therapy, group A showed significant reduction in secretion turbidity (P = 0.02) and meibomian gland obstruction (P = 0.0001), whereas group B had significant reduction in eyelid edema (P = 0.02), corneal staining (P = 0.01), secretion turbidity (P = 0.01), and meibomian gland obstruction (P = 0.0001). Group C had significant reduction in eyelid edema (P = 0.003), foam collection in the tear meniscus (P = 0.02), corneal staining (P = 0.02), secretion turbidity (P = 0.0001), and meibomian gland obstruction (P = 0.0001).
                Therapy with linoleic and gamma-linolenic acid tablets along with eyelid hygiene improves symptoms and reduces eyelid margin inflammation in MGD more than either omega-6 fatty acids or eyelid hygiene alone.