Curiosities about
hyaluronic acid

Hyaluronic acid, the substance
everyone’s talking about

Even though it seems to be the very latest in hydration, hyaluronic acid has actually been used in medicine for decades and has certain qualities that are much appreciated by specialists, including ophthalmologists.

The origin of hyaluronic acid

In 1934, Palmer and Myer isolated hyaluronic acid from the vitreous humour of the bovine eye. Its name comes from the Greek hyalos (glass-like) and uronic (for its uronic acid content). In 1942, the first patent was registered for the use of hyaluronic acid as an egg substitute in cake-making, but where hyaluronic acid has really found a place is in medicine and cosmetics.

In the 1960s, it was applied in eye surgery (to temporarily keep the shape of the eyeball during cornea transplants) and started to be used in infiltrations for joint pathologies and also in cosmetics.

The first generation of preparations with hyaluronic acid reached the market in the 1980s. At the start it was extracted from rooster combs. Since 1997, most of the hyaluronic acid in use has been biosynthetic, formed by bacterial fermentation. This procedure avoids allergic reactions to any possible remnants of animal protein.

Hyaluronic acid is also present in the tissues and organs of the human body. The largest amount of hyaluronic acid is found in the skin, bones and intervertebral discs, in intercellular spaces, in the synovial fluid of joints and in the vitreous humour of the eye. The body of a person weighing 70 kg contains about 15 grams of hyaluronic acid, of which about 5 grams degrade and are recovered during the day. As the human body ages, its hyaluronic acid is destroyed faster than it is recovered.

Some applications of hyaluronic acid in medicine

Hyaluronic acid is available in many forms: injections, vials, creams, gel, capsules and drops. It is used today in many applications: from infiltrations to relieve joint pain to preparations to cure mouth ulcers.

Infiltrations in joints

Hyaluronic acid has a lubricating effect, so it can reduce the wear and tear on cartilage caused by rubbing and can relieve pain in pathologies such as osteoarthritis.

Aesthetic medicine

Hyaluronic acid can be injected into the skin and serves to smooth over wrinkles and give volume. Its effect lasts from 6 months to one year, because over time it is reabsorbed and disappears.

Hyaluronic acid is also present in many anti-ageing creams. Its main function is as a humectant to prevent water loss from the skin.

Ophthalmology

Hyaluronic acid is an outstanding humectant that has been used for decades as a component of some artificial tears to relieve the symptoms of dry eye. Today the best results are now being obtained by products that combine hyaluronic acid with other complementary humectants to generate synergies.

The use of hyaluronic acid in eye preparations has many benefits:

  • ● It improves hydration of the cornea. The most important property of hyaluronic acid is its outstanding capacity for retaining water: 1 gram of hyaluronic acid can retain up to 6 litres of water, that is, thousands of times its own weight. Its capacity for retaining water in the eye is much greater than that of other humectants, especially in conditions of low ambient moisture.
  • ● In addition, hyaluronic acid links tear fluid with the cornea and serves almost like a fastener.
  • ● It has regenerating properties. Hyaluronic acid is known to have regenerative and scarring effects on the cornea because it promotes the proliferation of cells in the corneal epithelium.
  • ● It has a very high tolerance level. The use of hyaluronic acid has no known side-effects because it is naturally present in the human body. It is also a biocompatible substance because it is present in the eye of mammals, including humans (in the lens and the vitreous humour). It is therefore very unusual for it to produce allergies or incompatibilities.
  • ● It is viscoelastic. Hyaluronic acid behaves in the same way as tear fluid. It is viscous in the rest phase (when the eye is open between blinking) and fluid during blinking, imitating natural tear film.
  • ● It has a long-term effect. Other hydrating agents in the market remain on the eye surface for a relatively short time (15-20 minutes after instillation). Hyaluronic acid remains in the eye much longer (58 minutes).

Acuaiss Dual Gel has a high content of outstandingly pure hyaluronic acid.

Acuaiss Dual Gel is a tear with a gel-type texture designed to relieve moderate-severe dryness. It contains 0.30% hyaluronic acid and a second humectant, 0.10% hydroxyethylcellulose. This combination makes the product’s viscosity and hydrating capacity greater than those of conventional tears.

In addition, the hyaluronic acid used in Acuaiss Dual Gel is almost 100% pure, guaranteeing very high effectiveness and tolerance.

Sources

● Ahmadian E, Dizaj SM, Eftekhari A, Dalir E, Vahedi P, Hasanzadeh A, Samiei M. The Potential Applications of Hyaluronic Acid Hydrogels in Biomedicine. Drug Res (Stuttg). 2020 Jan;70(1):6-11. doi: 10.1055/a-0991-7585. Epub 2019 Sep 25. PMID: 31556074.


● Jones L, Downie LE, Korb D, Benitez-Del-Castillo JM, Dana R, Deng SX, Dong PN, Geerling G, Hida RY, Liu Y, Seo KY, Tauber J, Wakamatsu TH, Xu J, Wolffsohn JS, Craig JP. TFOS DEWS II Management and Therapy Report. Ocul Surf. 2017 Jul;15(3):575-628. doi: 10.1016/j.jtos.2017.05.006. Epub 2017 Jul 20. PMID: 28736343.


● Knopf-Marques H, Pravda M, Wolfova L, Velebny V, Schaaf P, Vrana NE, Lavalle P. Hyaluronic Acid and Its Derivatives in Coating and Delivery Systems: Applications in Tissue Engineering, Regenerative Medicine and Immunomodulation. Adv Healthc Mater. 2016 Nov;5(22):2841-2855. doi: 10.1002/adhm.201600316. Epub 2016 Oct 6. PMID: 27709832.


● Ollero Lorenzo, Alberto: El origen del ácido hialurónico para tratar el ojo seco. Interview on 22 May 2020. Blog of Dr. Alberto Ollero Lorenzo.


● Salwowska NM, Bebenek KA, Żądło DA, Wcisło-Dziadecka DL. Physiochemical properties and application of hyaluronic acid: a systematic review. J Cosmet Dermatol. 2016 Dec;15(4):520-526. doi: 10.1111/jocd.12237. Epub 2016 Jun 21. PMID: 27324942.


● Sudha PN, Rose MH. Beneficial effects of hyaluronic acid. Adv Food Nutr Res. 2014;72:137-176. doi: 10.1016/B978-0-12-800269-8.00009-9. PMID: 25081082.