Purpose
Blepharitis is a generalized inflammation of the eyelid and lid margins, which can include meibomian gland dysfunction (MGD). Meibomian gland dysfunction is characterized by obstruction or a secretion abnormality of the glands that can lead to tear film instability and inflammation and irritation of the lids and ocular surface, in turn changing the corneal reflectivity. The meibomian glands are sebaceous glands found in the lid margins that produce a lipid-rich secretion known as meibum. Excessive bacterial lipase production can alter and degrade meibum, potentially leading to tear instability and dry eye disease. We evaluated the lipase inactivation activity of various commonly used eyelid cleansers including: Cliradex®, Johnson’s® Baby Shampoo, NovaBay® Avenova™ (i-Lid™ Cleanser), OCuSOFT® Lid Scrub® Original, OCuSOFT® Lid Scrub® Plus, and TheraTears® SteriLid®.
Methods
Each eyelid cleanser was added to a solution of 2 mg/mL of Pseudomonas cepacia lipase. After an hour of incubation at 37°C, the lipase-eyelid cleanser solutions were diluted 500-fold into lipase buffer. The lipase activity was determined using the Lipase Activity Assay Kit III (Sigma Aldrich®). A SpectraMax® M5 plate reader was able to continuously incubate the microtiter plate at 37°C and measure the fluorescence (λex/λex = 529/600 nm) every 5 minutes for 1.5 hours after an initial 10-minute incubation period.
Results
In the presence of Cliradex®, Johnson’s® Baby Shampoo, OCuSOFT® Lid Scrub® Original, OCuSOFT® Lid Scrub® Plus, and TheraTears® SteriLid®, bacterial lipase had similar activity to the lipase treated with sterile water, negative control (Figure 1). In the presence of NovaBay® Avenova™, the bacterial lipase activity was completely inactivated, not distinguishable from no added lipase (Figure 1).
Conclusions
Our study compares the inactivation of bacterial lipase by eye care products used to treat blepharitis and MGD. In this in vitro study, NovaBay® Avenova™ completely inactivated bacterial lipase activity while all other products had minimal effect.