DRY EYE DISEASE (DED) is the most prevalent ophthalmic disease affecting an estimated 5% to 50% of the adult population (Craig et al 2017; Mittal et al, 2021). It is a multifactorial disease of the ocular surface in which tear film instability, hyperosmolarity, ocular surface inflammation, and neurosensory abnormalities play etiological roles.

When patients do not experience adequate relief with traditional dry eye treatments, alternative approaches, such as topical biologics, neurostimulation, and intense pulsed light therapy (IPL), should be considered (Mittal et al, 2021).

TOPICAL BIOLOGICS

Serum eye drops (SEDs) are human-derived biologics that contain growth factors and vitamins that mimic the biochemical properties of inherent basal tears. These drops contain natural anti-fibrotic, antimicrobial, anti-inflammatory, and anti-angiogenic components that have been recognized to promote wound healing and support corneal epithelization (Liu et al, 2006; Shtein et al, 2020).

SEDs are blood-derived, where blood is extracted and centrifuged, then serum is separated and diluted with sterile saline. The drops are stable for up to six months frozen and should be used within one week in refrigeration (Shtein et al, 2020; Pan et al, 2017). Serum concentration can range from 20% to 100% and typically are dosed two to eight times a day (Pan et al, 2017). These drops can be obtained through select compounding pharmacies.

It should be noted that SEDs are not pharmaceuticals and thus not regulated by the U.S. Food and Drug Administration. Currently, there is no universal protocol for the use and preparation of these topical biologics (Pan et al, 2017).

NEUROSTIMULATION

Neurostimulation focuses on enhancing basal tear production by activating the trigeminal parasympathetic pathway responsible for regulating the lacrimal functional unit, which encompasses the meibomian glands, lacrimal glands, and goblet cells. Current treatment options to increase basal tear production include a portable extranasal tear stimulator and an intranasal spray (Erdinest et al, 2022; Ji et al, 2020; Wirta et al, 2022).

A novel portable tear stimulator may temporarily increase acute tear production via extranasal mechanical stimulation. When applied externally to the nose for 30 seconds, sonic frequency activates the trigeminal parasympathetic pathway (Ji et al, 2020). Their clinical studies demonstrated statistically significant improvement in dry eye indicators, accompanied by minimal adverse events, following a minimum of twice-daily dosing for 30 days (Ji et al, 2020).

Varenicline is a preservative-free intranasal spray designed for twice-daily use. It is believed to act as a nicotinic acetylcholine receptor agonist that activates the trigeminal parasympathetic pathway in the nose, stimulating basal tear film production (Ji et al, 2020). The ONSET-1 Phase 2b trial demonstrated that the nasal spray was well tolerated and showed meaningful improvements in signs and symptoms of DED after 28 days (Wirta et al, 2022).

INTENSE PULSED LIGHT THERAPY

IPL therapy is a safe and useful approach for treating DED secondary to meibomian gland dysfunction and ocular rosacea (Toyos et al, 2022; Cote et al, 2020). It is suggested that these short wavelengths of light administered from IPL prompt closure of abnormal telangiectatic blood vessels that prevents the release of inflammatory mediators into the surrounding tissue (Toyos et al, 2022; Cote et al, 2020). IPL might also create localized warming of the skin, improving meibomian gland structure and facilitating the release of obstructed meibum (Tashbayev et al, 2020). It has also been found to decrease Demodexmites, consequently reducing inflammation in DED (Cote et al, 2020; Tashbayev et al, 2020).

Topical biologics, neurostimulation, and IPL have all been studied with promising results. These therapies give us new ways to approach dry eye treatment, especially for those who have exhausted traditional options. CLS

References

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