Efficacy Of Propylene Glycol-Hydroxypropyl-Guar Nanoemulsion Lubricant Eye Drops On Evaporative Dry Eye Disease: A 6-Month Clinical Study

This study aimed to assess the relief of dry eye symptoms and changes in meibomian gland function following the use of propylene glycol-hydroxypropyl-guar (PG-HPG) nanoemulsion lubricant eye drops for 6 months in subjects with mild to moderate evaporative dry eye disease (DED).

There is some evidence that PG-HPG nanoemulsion lubricant eye drops may improve the tear film lipid layer more than non-PG-HPG. The improvement of tear film stability after several months of drop use may reduce subclinical inflammation secondary to loss of tear film homeostasis, helping to break the vicious cycle of dry eye disease and promote improved meibomian gland function  

In this prospective, interventional, single-center clinical trial, adult participants (age older than 20 years) with mild to moderate evaporative DED were enrolled, characterized by an Ocular Surface Disease Index (OSDI) score of 13-32, tear film break-up time (TBUT) of 10 seconds or less, corneal staining of 8 spots or fewer on the National Eye Institute scale, a Schirmer I test result of at least 10 mm, and lipid layer thickness (LLT) between 45-73 nm. Participants applied one drop of PG-HPG nanoemulsion lubricant eye drops four times daily for six months. Primary endpoint was the changes of OSDI from the baseline. Secondary endpoints were TBUT, meibomian gland expressibility and quality, blink rate, and LLT. Paired t-test was used. 

Thirty participants (average age 41.97 ± 13.78 years; 93% female) were studied. After six months, OSDI scores decreased significantly from 29.56 ± 7.78 to 14.18 ± 7.79 (mean reduction 15.49 ± 9.32, p<0.01). TBUT showed improvement from 3.24 ± 2.44 seconds to 4.15 ± 3.27 seconds (p=0.03). Meibomian gland expressibility also improved from 0.37 ± 0.58 to 0.15 ± 0.43 (p=0.01). There was a trend toward improved LLT, although this did not reach statistical significance. Other measures, including meibum quality, visual acuity, blink rate, and corneal staining, showed no significant changes.

PG-HPG nanoemulsion lubricant eye drops significantly alleviated both subjective symptoms and objective clinical signs in patients with mild to moderate evaporative DED. The notable improvements in OSDI scores, TBUT, and meibomian gland expressibility highlight the therapeutic potential of this treatment. These findings support the benefits of consistent long-term use of lubricant eye drops. Further research involving larger cohorts and extended follow-up is warranted to validate these results and assess long-term efficacy.