Contact Lenses for the Elderly Population - Understanding the Issues

Introduction

Eye problems in the elderly population are a major problem. In most cases, these changes are caused by physiological changes due to age. As contact lenses are a popular form of device for curing eye problems, these are extensively used by older people. However, this may cause certain problems.

What Are Contact Lenses?

Contact lenses are made up of plastic-like materials and are placed over the cornea. These materials are used for different pathological conditions like myopia (a vision problem where near objects are visible but not far objects), hyperopia (a vision problem where far objects are visible but near objects appear blurred), astigmatism (blurred vision), and presbyopia (gradual loss of focus on nearby objects). Also, these lenses can be used for cosmetic purposes.

There are four different types of contact lenses based on their use and rigidity:

• Soft Contact Lenses: These lenses are soft and flexible plastic. They allow the passage of oxygen and are usually fabricated using silicone hydrogel. Due to their flexibility, they provide a high level of comfort.

• Rigid Gas Permeable (RGP) Contact Lenses: These lenses are durable, easy to handle, and less likely to break. They are also permeable, allowing oxygen to reach the cornea.

• Extended Wear Contact Lenses: These lenses are designed to be worn for an extended period. They are also made of flexible materials, providing comfort even during prolonged wear.

• Disposable (Replacement Schedule) Contact Lenses: These lenses are intended for single-use purposes. They are discarded after each use, ensuring hygiene and convenience.

What Are the Considerations of Lenses in the Elderly Population?

Elderly people can use contact lenses. However, due to physiological changes in the eye structures, certain considerations are made. These are:

1. Eyelids: Changes in the eyelid are one of the common physiological changes seen in elderly people. Due to age changes in the fat, sagging of the eyelid occur. Also, loss of muscle tone is responsible for the formation of excess skin in the upper eyelid. This is known as dermatochalasis. This condition is responsible for the narrowing of the palpebral apparatus. Also, changes in the lower eyelid cause the formation of wrinkles. However, such changes cause difficulty in lens insertion and removal. Also, abnormalities in the eyelids are associated with difficulty in tear film distribution and blinking.

2. Corneal Changes: Age-related changes in the cornea are very common. This causes a decrease in the corneal cell count and an increase in the variation of the cells. These variations cause structural and functional changes in the corneal cells. As a result, the corneal pump function is altered. This causes less elimination of waste products and an increase in intraocular pressure. Also, these changes cause accumulation of the lipid droplets. Delayed healing is one of the major complications of this problem. Other changes seen in the cornea are reduced oxygen supply to the cornea and increased corneal sensitivity.

3. Tear Film Instability: Eye dryness in an older age group is very common. It is very common in 15 percent of the population above the age of 60. This dryness is caused by a lack of secretion from different glands like the lacrimal gland. Apart from this, a change in tear osmolality is seen in elderly people. Such changes are common in women.

4. Pingueculae: This is one of the age-related changes seen in conjunctiva. It is a benign yellowish or whitish growth of the conjunctiva. This causes difficulty in wearing lenses and hindrance in lens movement.

5. Visual Function: Changes in visual acuity are common in older individuals. This causes problems in low contrast and low luminance conditions. It is associated with a decrease in the contrast sensitivity and an increase in the glare sensitivity. The reductions in visual function are attributed to various factors, including decreased transparency of the lens and cornea, alterations in the retina, and diminished retinal luminance caused by a decrease in pupil size.

What Are the Complications Associated With Lenses in the Elderly?

One of the major problems associated with the use of lens wear in the elderly population is repeated eye infections. One of the major causes of eye infection is improper handling and touching the lens with contaminated hands or keeping the lenses on contaminated surfaces. Also, contamination of lens cases and lens care solutions is one of the major causes of contamination. Hydrogen peroxide is present in the lens surface, which can kill microorganisms, biofilm, and cells. But hydrogen peroxide of the old solutions can be broken down by the action of the catalase enzyme of the microorganisms. The contamination of the microorganisms occurs mainly from the tip of the bottle containing lens care solution. Also, contamination may occur from the biofilm of the lens case and lack of potency in the old solution.

1. Prolonged use of the lenses and nightwear of the lenses increases tissue injury and decreases the upregulation of corneal epithelium.

2. The composition of the lens may cause infections. Hard or rigid lenses are less oxygen-permeable. As a result, these lenses develop a hypoxic condition favorable for the growth of microorganisms. Lenses of polymethyl methacrylate (PMMA) and polyvinyl alcohol (PVA) are less oxygen permeable. Hydroxyethyl methacrylate (HEMA) hydrogel and silicone hydrogel lenses are more oxygen permeable and do not cause hypoxia.

3. Due to changes in the tear film stability, dryness of the eye itching, and redness in the eye can be observed.

4. Prolonged use of the lens may cause difficulty in eye movement or adapting to lighting conditions. Pain in the eyes can be seen.

How to Solve the Complications Associated With Lenses in the Elderly?

Such problems can be solved in the following ways:

1. Regular eye checkups if the person is using the lens. Also, before using the lens eye check-up for corneal and retinal health is important. Assessment of tear film and ocular surface, and measurement of visual acuity is also necessary.

2. Maintaining proper hygiene is important. Also, artificial tears can be used to stabilize the tear films.

3. Soft hydrogel lenses are recommended for elderly people. Rigid gas permeable (RGP) lenses with proper shape and size can also be recommended.

4. Multifocal lenses are good for elderly people.

Conclusion

Contact lenses in elderly individuals are helpful to cure minor corrections. However, physiologic changes are seen in ocular structures due to increased age. The selection of lenses is based on these criteria. Also, patients should maintain and handle the lenses properly. Improper lens selection may cause eye discomfort and repeated eye infections.