With so many artificial tears on the market today, it can be tough to know which one to recommend to your patients seeking relief from dry eye symptoms. But researchers from Austria have uncovered findings that might help.  

They evaluated 60 eyes of 30 mild-to-moderate dry eye disease and measured optical quality and ocular surface parameters before and after three months of treatment with either lipid- or sodium hyaluronate-based eye drops.

Both drops led to improvements on the Schirmer test, break-up time, ocular surface staining and symptom score. While the meibomian gland (MG) dropout rate and visual quality—measured as corneal higher-order (HO) root mean square and HO Strehl ratio—showed no significant difference before and after treatment in each group as a whole, breaking it down based on MG loss told a different story.

Those with MG loss in excess of 50% treated with lipid-based artificial tears had a greater increase in their visual quality than those with less advanced MG loss. Patients in the sodium hyaluronate group did not experience the same improvements, as researchers noted no significant changes in visual quality in this group, regardless of MG loss. 

“Based on these findings, we presume that as MGD advances and the lipid layer of the tear film becomes thinner, aqueous therapy alone is not as effective as lipid-containing eye drops in preventing tear evaporation,” the researchers said. “This hypothesis would explain the fact that in more severe forms of MGD, lipid therapy is able to better reduce corneal HO aberrations and improve optical quality.”

That being said, they also admitted lipid-based therapy was poorly tolerated compared with sodium hyaluronate, as patients using lipid-based artificial tears were more likely to complain of ocular irritation and redness.