Dry Eye Symptoms Relieved With Hydroxypropyl-Guar Nanoemulsion Treatment

Woman using eye drops, close-up
Researchers compare hydroxypropyl-guar nanoemulsion treatment with saline drops to assess its efficacy in relieving dry eye symptomatology.

Hydroxypropyl-guar nanoemulsion (HP-Guar nanoemulsion) provides greater short and long term relief than saline drops for patients with dry eye, according to a study  published in Contact Lens and Anterior Eye.

Researchers enrolled 20 participants with dry eye disease (15 women, mean age, 46.9±14.4 years) in the prospective, crossover study and randomized them to treatment with either HP-Guar nanoemulsion or saline eye drops. Ocular symptoms, lipid layer thickness, tear evaporation, tear osmolarity and non-invasive break-up time were measured at baseline, at 1 and 2 hours after eye drop instillation, and after 4 weeks of 4-times daily drop use. Investigators were masked to treatment methods. Patients reported the intensity of their symptoms through a visual analogue scale between 0 and 100 (0 worst, intolerable, 100 best, perfect).

Participants treated with HP-Guar nanoemulsion reported less grittiness, burning, and stinging 1 hour after eye drop instillation compared with baseline (79.5±23.3 vs 66.8±27.7; P =.02), less dryness 1 and 2 hours post eye drop instillation compared with baseline (77.8±23.0 and 76.2±23.7 vs 61.0±27.1, respectively; P <.01 for both), and greater satisfaction both 1 hour post drop instillation and after 4 weeks of daily use compared with baseline (80.4±21.6 and 83.4±16.6 vs 68.6±26.0, respectively; P ≤.011 for both). Participants in the saline treatment group also reported less dryness after 4 weeks of daily use compared with baseline (74.2±23.8 vs 60.2±24.0, P <.01). 

The average lipid layer thickness was significantly thicker 2 hours post drop-instillation (79.5±21.7 nanometers (nm)) compared with baseline (63.7±18.9 nm) and 4-week assessment (62.4±23.1 nm; P <.01 for both) for patients treated with HP-Guar nanoemulsion. The average lipid layer thickness was significantly thicker at 1 and 2 hours post eye drop instillation (76.0±23.8 nm and 80.4±24.8 nm) compared with baseline (61.0±15.6 nm; P <.01 for both) for participants treated with saline. 

No significant differences were noted in tear evaporation rate (P =.08), tear osmolarity (P =.35) or non-invasive keratograph break-up time (P =.64) between the 2 groups.

“The results of this study show that both eye drops were effective at increasing tear film lipid layer thickness in the short-term only, but greater symptomatic relief was obtained with HP-Guar nanoemulsion compared to saline in both the short- and long-term,” according to the researchers. 

Study limitations include the inability to mask participants, and the potential for geographic and volunteer bias.

Disclosure: This research was supported by Alcon Research, LLC. Please see the original reference for a full list of disclosures. 


Markoulli M, Wong K, Jia T, Siddireddy JS, Briggs N, Tan J. The effect of hydroxypropyl-guar nanoemulsion on signs and symptoms of dry eye. Cont Lens Anterior Eye. Published online July 12, 2022. doi:10.1016/j.clae.2022.101736