Deciphering the Action of Perfluorohexyloctane Eye Drops to Reduce Ocular Discomfort and Pain

Abstract

Perfluorohexyloctane (F6H8) eyedrops have been recently introduced in Europe as a product to treat dry eye disease, based on its ability to reduce tear film instability in Meibomian gland dysfunction and evaporative dry eye disease, although its mechanism of action is still unknown. In the present pilot study, we evaluated the effects of the ocular instillation of a single drop of commercial F6H8 eyedrops in 20 healthy humans (9 women/11 men), measuring: (a) Corneal surface temperature (CST) from infrared video images; (b) tear volume using phenol red threads; (c) blinking frequency; and (d) ocular surface sensations (cold, dryness, pricking, foreign body, burning, itching, gritty, eye fatigue, watering eyes, and light-evoked discomfort sensations; scored using 10 cm Visual Analog Scales), before and 5–60 min after F6H8 or saline treatment. CST decreased and tearing and blinking frequency increased significantly after F6H8 but not after saline solution. When applied unilaterally, CST decreased only in the F6H8-treated eye. No sensations were evoked after F6H8 or saline. The corneal surface temperature reduction produced by topical F6H8 does not evoke conscious ocular sensations but is sufficient to increase the activity of corneal cold thermoreceptors, leading to an increased reflex lacrimation and blinking that may relieve dry eye condition thus reducing ocular discomfort and pain.

Influence of perfluorohexyloctane (Evotears®) on higher order aberrations

“…We demonstrated higher repeatability of HOA measurements after application of F6H8 than in untreated eyes, which is in accordance with the results of previously mentioned works. Several studies have proven the efficacy of F6H8 in the treatment of dry eye symptoms [ 28 – 30 ]. In a preclinical trial, Agarwal et al [ 31 ] showed a beneficial effect of F6H8 by immediately fusing with the precorneal tear film and compensating for surface irregularities.…”

Ductal Hyperkeratinization and Acinar Renewal Abnormality: New Concepts on Pathogenesis of Meibomian Gland Dysfunction

“…Numerous studies have demonstrated the efficiency of topical antibiotics [ 84 , 85 ], with the latest evidence indicating that the act is nonpersistent [ 86 ]. In the past few years, perfluorohexyloctane has gained popularity and been widely used in developed countries as an alternative therapy for MGD-EDE [ 87 , 88 , 89 ]. The possible pharmacological mechanism is that it can serve as a surfactant, forming monolayers at the water/air interphase and preventing the evaporation of the tear film [ 89 ].…”

“…In the past few years, perfluorohexyloctane has gained popularity and been widely used in developed countries as an alternative therapy for MGD-EDE [ 87 , 88 , 89 ]. The possible pharmacological mechanism is that it can serve as a surfactant, forming monolayers at the water/air interphase and preventing the evaporation of the tear film [ 89 ]. AZR-MD-001 is currently being studied to evaluate the safety, efficacy, and tolerability in patients with MGD.…”

Management of Dry Eye Disease in Asia: A Review

“…Perfluorohexyloctane is thought to create an occlusion layer and reduce eyelid shear force upon blinking, thereby avoiding the increase in vaporization resulting in DED, as it increased tear film breakup time and lipid layer thickening in patients with DED [99]. It has also been shown to provide a long-lasting cooling effect on the ocular surface [100].…”