Drop viscosity

With orthokeratology treatment, moisturizing drops work like a sort of “cushion” between the lens and the cornea.

A tear with a viscous texture is better equipped to ease the pressure of the contact lens against the cornea, making it more comfortable to wear for longer. However, too much viscosity can also cause trouble as it enhances friction and could prevent the product from spreading evenly across the eye.

Therefore, it is advisable not to use solutions with viscosity values of over 25 cP.

Moisturizing power

In orthokeratology treatment, hydrodynamic forces occur between the contact lens and the cornea. To make this interaction optimal, the corneal epithelium must be kept intact and perfectly hydrated.

Using moisturizing drops with hyaluronic acid, the ultimate humectant, is a safe bet. This substance is capable of retaining up to 6000 times its weight in water and has properties that make it truly unique:

● High water retention capacity

● Guaranteed long-lasting effect

● Corneal epithelization and regeneration

● Bond between the tear film and the corneal epithelium

● Longer tear break-up time

● Viscoelastic properties

It is advisable to choose products with a high concentration of hyaluronic acid (0.30%) when using orthokeratology lenses. This helps to guarantee good hydration and keep the corneal epithelium in optimal condition.

Good tolerability

Designing the ideal formula is a question of balance. As well as choosing the right raw materials, it is crucial to control other parameters such as pH, which should mimic the tear, and osmolarity, which refers to salt concentration.

For moisturizing eye drops that are intended to restore the balance of an unstable (hypertonic) tear film, it is recommendable to use slightly hypotonic solutions. Hyaluronic acid is a biocompatible substance that is found naturally in the human body. Therefore, it poses no risk of allergic reactions or incompatibilities, making it the ideal component to use in eye care formulas.

Acuaiss Dual Gel: the perfect balance

Acuaiss Dual Gel is a tear with the right viscosity (25 cP) and a highly effective double polymer combination: hyaluronic acid at 0.30% and hydroxyethyl cellulose at 0.10%.

The secret to this polymer combination lies in the synergy between its two humectant agents, which enhances the hydrating power and stability of the formula. The result are these liquid-based moisturizing drops with a gel-like texture.

Acuaiss Dual Gel comes in a preservative-free single-dose format to provide the perfect level of hydration and viscosity for users of Ortho-K contact lenses.

Sources

For an overview of how to control myopia and how orthokeratology lenses are adapted, we recommend watching the conference delivered by Joan Pérez Corral during the Contactology Forum in 2018: Strategy on Using Ortho-K in Myopia Management.

● Tomás J, Piñero, D. Overnight Orthokeratology. Legal Implications and Informed Consent. Gaceta Óptica. Junio. 449.