How Do Different Eye Drops Work?


14/09/2024 09:43
Person using an eye drop

Eye drops are amazing at providing symptomatic relief for dry and gritty eyes resulting from a variety of issues. With so many types of drops on the market, it’s difficult to know which drops would be most suitable for you. It's a good idea to get a comprehensive health check from your optometrist for a personalized dry eye treatment recommendation. In the meantime, here's a brief guide to learn about different eye drops.

Preservative vs. Non-Preservative

Preservatives are used in eye drops to keep them sterile, which extends the shelf life of the product. This increases cost-effectiveness and convenience, as a single multi-use bottle can last several months. This option is best for infrequent users who experience very mild and occasional symptoms of dryness and grittiness.

Non-preservative eye drops are recommended as preservatives may sometimes cause irritation or exacerbate dryness, especially with frequent use. Non-preservative eye drops come in single-dose units or multi-dose bottles but with a shorter shelf life. This option is best for sensitive eyes that require frequent use of drops. These generally can be used while wearing contact lenses.

Important Ingredients

Hyaluronic Acid

Hyaluronic acid is a powerful ingredient that attracts and conserves moisture, providing long-lasting relief. It is known for:

  • Moisture retention
  • High viscosity to create a long-lasting film over the cornea
  • Increasing the healing properties of the cornea
  • Being a naturally occurring substance causing less irritation

Examples of these eye drops include: Hyloforte, Blink Tears.

Phospholipids

Phospholipids are fat molecules that the eyes naturally produce to prevent the evaporation of the tear film that sits in front of the eyes. They are known for:

  • Being the ideal option for patients diagnosed with Evaporative Dry Eye disease, usually caused by a lack of naturally occurring lipids in the eyes from conditions like Meibomian Gland Disorder
  • Better compatibility with natural tears as they contain components similar to those found in natural tears
  • Longer-lasting lubrication

Examples of these eye drops include: Systane Complete, Novatears.

Cyclosporine

In some countries, cyclosporine is an ingredient in eye drops that can be purchased over the counter. It is an immunosuppressant that causes an increase in tear production in patients whose tear production is presumed to be reduced due to ocular inflammation. These work differently from lubricating drops as they tackle the root cause of the problem and increase the eye’s natural production of hydration.

Examples of these eye drops include: Restasis.

Mode

Liquid

Most eye drops are liquid and are instilled through a dropper form. These are often quite easy to use and can provide immediate relief of symptoms. This is the most common form of lubrication used for the eyes. The only drawback to using these drops is that they may require more frequent reapplication compared to other forms, and there is some potential for blurry vision after installation, which tends to recover quickly.

Gel

Gel is a thicker, more viscous consistency than liquid drops, usually dispensed from a tube or bottle. The thicker consistency provides extended lubrication and stays on the eye longer, reducing the need for frequent application. They’re suitable for severe dry eye conditions or even overnight protection. The main detractor is that they cause more noticeable temporary blurriness due to their thicker consistency.

Spray

Spray eye drops are dispensed as a fine mist or spray. Application usually involves spraying the product onto closed eyelids, then blinking or directly into the open eye. They provide an even distribution and are especially beneficial for patients who have difficulty keeping their eyes open for the dropper form. A disadvantage is that it may be harder to control the exact amount applied, leading to potential wastage or uneven distribution.

References

  1. NIH, Hyaluronic Acid in the Treatment of Dry Eye Disease
  2. NIH, Lipid-based Eye Drops
  3. Restasis

Patrisha is a licensed optometrist who writes about the latest developments in vision and eye health. Drawing from her professional experience, she shares insights and practical advice to help readers better understand their eye care options and stay informed about new trends in the field.