The safety and efficacy of mass-produced colored contact lenses

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The current results examine the risks, benefits and performance.

When the topic of colored contact lenses arises with a patient, the first thing that comes to mind is to change the color of the eyes.

Aside from cosmetic reasons, there are many ways that colored or tinted contact lenses can help patients, such as decreasing glare or changing color perception for those who are color blind.

Whether for cosmetic or therapeutic purposes, colored contact lenses are generally not something ODs mention to patients. However, once recommended, they are of interest to many patients.

Recommendations can be made from a variety of perspectives. Regardless of how they are provided, it’s important to note that while colored lenses can be of benefit to patients, they come with risks that many are unaware of. Let’s take a look at how colored contact lenses can safely benefit patients.


Related: Five Ways To Stand Out With Specialty Contact Lenses

Colored contact lenses produced in series
Mass-produced colored contact lenses can be found in trial fit kits and are easily accessible for distribution in an office.

Usually these lenses are computer generated. Therefore, ODs cannot change parameters such as saturation, lightness, or coloring alignment.

Mass-produced colored contact lenses can either enhance the natural color of patients’ eyes or change it completely. They fit in a similar fashion to most soft contact lenses used to correct refractive errors.

Therefore, additional usage time is not required compared to mass-produced transparent and soft contact lenses.

Most mass produced colored lenses are available in spherical powers with daily or monthly replacement schedules. The lower cost of the lenses, resulting from mass production, makes it easy to present them to patients as a full-time or temporary wearing option.

Mass-produced colored contact lenses are generally popular for wearing at social events.1 Due to their transparent backing and colorful pigments surrounding the iris, they allow for variation in patterns that can create a natural or bold appearance.

Related: Excessive contact lens wear has short and long term consequences

For example, patients with brown eyes may choose brown or hazel shades to slightly change the color of the iris, or may choose blue or green tints to change the appearance more dramatically.

Despite the ease of adjustment and patient education about the options, these lenses have the highest complication rates among contact lens wearers.2


Complications

While the risks of cosmetic lenses are obvious to ODs who have seen the eye consequences, the general population is often unfamiliar with the threats they pose to eye health.

When Berenson et al asked patients about their knowledge and use of cosmetic contact lenses, the results showed that many patients were unaware of the risks and proper instructions for use.3.4

According to the survey, 1 in 4 patients said they had ever used cosmetic lenses and many had obtained the lenses from unauthorized sources.

When asked about knowledge of contact lenses, the results revealed that many patients were unaware of the proper wearing protocol.3

A majority of patients were unaware that the sale of over-the-counter and non-prescription contact lenses is illegal nationwide. They also didn’t know that contact lenses aren’t one-size-fits-all, that parasites can attach themselves to lenses, and that “anime” lenses aren’t FDA approved.3

Related: Survey Results: What is your biggest frustration with fitting contact lenses?

Of the patients surveyed, 62.3% said they had never learned how to clean their contact lenses.3

While we may be aware of some of these findings, it is important to examine how cosmetic lenses increase the risk of adverse events (AEs) compared to clear contact lenses.


EI

Colored contact lenses have a higher risk of infection and inflammatory events due to their composition. A recent study looked at various cosmetic contact lenses to identify the location of the pigment in the lens layers.5

He found that most of the lenses analyzed contained most of the pigment within 0.4mm of the surface. The extent of the pigment enclosure is not regulated in most countries, but the location affects safety and comfort.5

Another study found that most brands of contact lenses failed the rub test, causing the color pigments to peel off.6

The erase test uses cotton swabs to gently rub the front and back surface of the contact lens for 20 seconds, then measure the amount of color pigment detachment.

Related: Using OCT to Determine Scleral Lens Clearance

Lenses that failed the erasure test showed Pseudomonas aeruginosa adherence, which led to an increase in AEs and more vision-threatening AEs. These pigments contain elements toxic to the tissues of the ocular surface.seven

The presence of any pigment can lead to AEs. Lau et al found that lenses with pigments on the lens surface (front or back) had significantly higher friction values ​​in pigmented areas compared to clear areas.8

The study concluded that cosmetic lenses with exposed pigments have less uniform surfaces, resulting in decreased lubricity and increased surface roughness.

Lubricity and roughness play an essential role in maintaining a stable tear film. Therefore, the disturbance results in unstable visual acuity and decreased comfort of contact lenses.

Acanthamoeba keratitis can occur with all types of contact lenses and this is a risk we discuss with all new wearers. Teaching patients to avoid using water with soft contact lenses is a key part of insertion and removal training when dispensing a lens.

Polyvalent solutions and hydrogen peroxide have helped reduce microbial side effects, but recent studies have shown that lens makeup can affect the likelihood of Acanthamoeba attachment to the lens.9


Related: Try Ortho-K Toric Lenses

Scanning electron microscopy imaging
Using scanning electron microscopy images, Lee et al found that the uncolored surface of cosmetic contact lenses was smoother and flatter than the colored areas.

They also found a greater number of Acanthamoeba trophozoites attached to the colored and rough area compared to the unstained and smoother area.

As the demand for cosmetic contact lenses increases, this is a risk that should be discussed with patients wearing colored lenses.

With newer lens materials, such as silicone hydrogel, most mass-produced contact lenses provide more oxygen permeability than needed.

Oxygen transport is measured through the central optical zone of the lens, leaving oxygen transmission questionable in the periphery.

A study by Galas and Copper used special lenses, specially created with pigment across the central optical zone, to measure oxygen permeability through the pigment.ten

They found that the pigment had no statistical influence on oxygen permeability, thus demonstrating that it does not decrease or impair lens safety.

Related: Experts Offer Tips for Successful Contact Lens Practice


Conclusion

Despite the drawbacks of mass-produced contact lenses, their use has steadily increased. This article aims to help practitioners understand why education is such a vital part of the distribution of colored contact lenses.

Whether cosmetic or therapeutic use, patient education and risk awareness can help reduce unwanted effects and increase the safety of colored contact lenses.

Read more content on contact lenses

The references

1. Rah MJ, Schafer J, Zhang L, Chan O, Roy L, Barr JT. A meta-analysis of studies on cosmetically tinted soft contact lenses. Clin Ophthalmol. 2013; 7: 2037-2042. doi: 10.2147 / OPTH.S51600

2. Ji YW, Cho YJ, Lee CH et al. Comparison of surface roughness and bacterial adhesion between cosmetic contact lenses and conventional contact lenses. Eye contact lens. 2015; 41 (1): 25-33. doi: 10.1097 / ICL.00000000000000054

3. Berenson AB, Hirth JM, Chang M, Merkley KH. Knowledge and use of cosmetic contact lenses in women of childbearing age. J Women’s health (Larchmt). 2019; 28 (3): 403-409. doi: 10.1089 / jwh.2018.7358

4. Berenson AB, Chang M, Hirth JM, Merkley KH. Use and misuse of cosmetic contact lenses among American teens in Southeast Texas. Adolesc Santé Med Ther. 2019; 10: 1-6. doi: 10.2147 / AHMT.S196573

5. Korde V, McDow K, Rollins D, Stinchcomb R, Esposito H. Identification of the pigment enclosure in cosmetic contact lenses. Eye contact lens. 2020; 46 (4): 228-233. doi: 10.1097 / ICL.0000000000000632

6. Chan KY, Cho P, Boost M. Microbial Adhesion to Cosmetic Contact Lenses. Front Eye Cont lens. 2014; 37 (4): 267-272. doi: 10.1016 / j.clae.2013.12.002

7. Hotta F, Eguchi H, Imai S, Miyamoto T, Mitamura-Aizawa S, Mitamura Y. Scanning electron microscopy results with energy dispersive x-ray investigations of cosmetically tinted contact lenses. Eye contact lens. 2015; 41 (5): 291-296. doi: 10.1097 / ICL.00000000000000122

8. Lau C, Tosatti S, Mundorf M, Ebare K, Osborn Lorenz K. Comparison of lubricity and surface roughness of cosmetic contact lenses. Eye contact lens. 2018; 44 Suppl 2 (2): S256-S265. doi: 10.1097 / ICL.0000000000000482

9. Lee SM, Lee JE, Lee DI, Yu HS. Adhesion of Acanthamoeba to cosmetic contact lenses. J Korean Med Sci. 2018; 33 (4): e26. doi: 10.3346 / jkms.2018.33.e26

10. Galas S, Copper LL. Oxygen permeability of the pigmented material used in daily disposable cosmetic contact lenses. Clin Ophthalmol. 2016; 10: 2469-2474. doi: 10.2147 / OPTH.S105222

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