April 20, 2024

Orthokeratology: Enhancing Visual Acuity through Specialized Lenses

Orthokeratology, also known as ortho-k or corneal reshaping, is a nonsurgical alternative to corrective eyeglasses or contact lenses for the temporary reduction or elimination of nearsightedness. Through the use of specially designed rigid gas permeable contact lenses worn overnight, orthokeratology works by temporarily reshaping the cornea, the clear front cover of the eye.

How does Orthokeratology work?

Orthokeratology works by using rigid gas-permeable contact lenses, also known as orthokeratology lenses, to gently remodel the shape of the cornea while worn overnight during sleep. These special contact lenses have a reverse curve design that apply gentle pressure on specific areas of the cornea, changing its shape. By wearing these lenses for around 8 hours a night, the corneal tissue responds by reshaping itself over the course of weeks.

The lenses move tissue from the central cornea to the peripheral cornea, flattening the optical zone in the central cornea. This has the effect of temporarily reducing or eliminating nearsightedness, also known as myopia. The benefits last for a few hours after the lenses are removed in the morning, gradually wearing off over the course of the day. However, nightly wear ensures ongoing corneal reshaping and vision correction.

Benefits of Orthokeratology

Potential Reversal of Nearsightedness Progression: Early studies show orthokeratology may slow the progression of nearsightedness in children. By controlling the shape of the cornea, ortho-k may reduce rates of nearsightedness progression compared to spectacle wearers.

Independence from Glasses or Contact Lenses: Properly fitted orthokeratology lenses provide clear daytime vision without relying on glasses or contacts during waking hours. This allows for greater freedom and participation in activities like swimming and sports.

Comfort: Unlike hard contact lenses that must be worn during the day, orthokeratology lenses are only worn overnight while sleeping. This alleviates discomfort that can occur from daily contact lens wear.

Potential Cost Savings: While the initial cost of an orthokeratology fitting is higher than glasses, ongoing costs are lower as lenses only need to be replaced every 1-2 years. This provides long-term cost savings compared to continuously replacing glasses prescriptions or contact lenses.

Risks of Orthokeratology

Despite demonstrated benefits, orthokeratology treatment does involve some risks and considerations:

Changes to Corneal Shape: The process of reshaping the cornea, even temporarily, carries risks of inducing irregular astigmatism, infections, or other corneal complications if the lenses are not properly fitted and cared for.

Dependence on Lenses: Vision benefits only occur while wearing the orthokeratology lenses. Vision returns to a nearsighted state upon removal if the lenses are discontinued, requiring continued compliance.

Risk of Infection: Wearing contact lenses overnight increases risks of microbial keratitis or corneal ulcers compared to daily wear lenses. Proper hygiene and handling techniques are critical for safe overnight lens wear.

Patient Compliance: The treatment requires wearing the lenses as prescribed, usually every night, to maintain vision benefits. Missing nights may compromise safety and effects of the treatment.

Who is a Good Candidate?

Those most likely to benefit from orthokeratology include:

– Children 6 years of age or older with low to moderate nearsightedness

– Adults with stable low to moderate nearsightedness

– Those who prefer temporary vision correction without glasses or contacts during the day

– Those active in sports who need alternatives to glasses for safety

– Those wanting potential savings from reduced need for new glasses over time

– Patients highly motivated to comply with the prescribed daily lens wear schedule

Orthokeratology in Summary

In summary, orthokeratology provides a nonsurgical option for temporarily reducing or eliminating nearsightedness through overnight contact lens wear. While not for everyone due to risks and compliance needs, it offers independence from glasses or contacts during waking hours for those who qualify. When performed by an experienced eye care professional using custom-fitted lenses, orthokeratology can successfully reshape the cornea to correct low to moderate near- and farsightedness. While not reversing the underlying refractive error, it does allow clear uncorrected vision temporarily each day through gentle corneal reshaping.

1. Source: Coherent Market Insights, Public sources, Desk research
2. We have leveraged AI tools to mine information and compile it