What is Orthokeratology(Ortho-K) lenses?

Orthokeratology, or ortho-k, is the use of specially designed and fitted contact lenses to temporarily reshape the cornea to improve vision. It’s like orthodontics for your eyes and the treatment is often compared to dental braces. Most ortho-k lenses are worn at night to reshape the front surface of the eye while you sleep. Vision improvements are reversible but can be maintained if you keep wearing the lenses as directed.

What is MCT Ortho-K?

MCT technology employs digital orthokeratology, a method based on acquiring individual corneal data and utilizing proprietary design software to create and fit customized rigid gas permeable (RGP) contact lenses. This approach effectively corrects refractive errors such as myopia (nearsightedness), hyperopia (farsightedness), astigmatism, and presbyopia. Furthermore, it addresses post-LASIK complications, aids in the differential diagnosis of subclinical keratoconus, manages the progression of pathological myopia and ocular hypertension, prevents the onset and exacerbation of severe complications, and ultimately reduces the potential for vision loss.

What's the difference between MCT and Ortho-K lenses?

The primary differences between MCT technology and Ortho-K lenses are: 1. No trial wear is required; 2. Minimal lens adjustments are needed; 3. Suitable for high myopia, astigmatism, hyperopia, and presbyopia; 4. Objective measurements are used for follow-up examinations; 5. Simple, efficient, and safe; and 6. Highly predictable outcomes.

Traditional Ortho-K lens follow-ups rely on subjective assessments of wearing effects. Due to insufficient integration of lens design and manufacturing, and less precise fitting of the lens to the cornea, patients wearing the lenses undergo subjective evaluations by doctors using fluorescein staining under a slit lamp. This subjective evaluation makes it difficult to accurately and objectively analyze the causes of any problems encountered during lens wear, leading to frequent lens changes and time-consuming, cumbersome follow-up procedures.

MCT lenses are fully customized based on precise, objective data collected beforehand, providing a more detailed analysis compared to traditional Ortho-K lenses, which rely on data collection and manual assessment. The wearing effects and complication rates of Ortho-K lenses are largely dependent on the quality of manual assessments, while MCT technology virtually eliminates errors caused by subjective human assessments, providing patients with perfectly fitting lenses tailored to their individual corneal shape.

Who is Suitable for MCT Ortho-K Lens Fitting?

Not all myopic patients are suitable for MCT lens fitting. The following conditions must be met for MCT lens fitting: myopia within 600 degrees, no corneal abnormalities (such as inflammation, degeneration, etc.), and no other eye diseases; patients must understand the mechanism of action, potential problems, and limitations of MCT technology, and have good compliance; adolescents are best over 7 years old, have a certain degree of self-care ability, and are supervised by parents; myopia is within 600 degrees, and astigmatism is less than 300 degrees. In addition, a certain financial foundation is required to bear the cost of lenses and other related expenses during treatment, as MCT technology is a relatively expensive correction project. Specifically, the following groups are more suitable:

1.Patients with low myopia who desire good uncorrected visual acuity.

2.No corneal abnormalities, such as inflammation, degeneration, etc., and no other eye diseases.

3.Understanding the mechanism of action of MCT and its potential problems and limitations of correction.

4.Clear motivation and very good compliance.

5.Generally over 7 years old, with a certain degree of self-care ability and parental supervision.

6.Myopia within approximately -0.00 to -6.00D, astigmatism less than -3.00D, both with-the-rule and against-the-rule astigmatism are acceptable.

7.Corneal curvature range of 37.00D~48.00 is preferred (excluding keratoconus); excessively large or small values will increase the difficulty of correction.

8.Children and adolescents with progressive myopia.

9.Those with a certain financial foundation to afford the cost of lenses and other expenses during treatment.

What are the differences between MCT and RGP lenses?

MCT and RGP lenses use similar materials, but MCT lenses have higher oxygen permeability (DK) requirements, typically at least 100 DK.

RGP stands for rigid gas permeable contact lenses. They offer high visual acuity and are considered a more advanced and healthier option for contact lens wearers. RGP lenses are popular in developed countries such as the United States, Japan, and South Korea and are gradually gaining market share in China. Compared to conventional soft contact lenses, RGP lenses offer advantages such as high image quality, correction of high myopia and astigmatism, and control of early keratoconus. They are suitable for long-wear and are less likely to cause dry eye and other eye complications.

In terms of design, MCT lenses use a lens curvature that closely conforms to the cornea, exerting pressure to reshape the corneal curvature and control myopia. The goal is to achieve good uncorrected visual acuity. RGP lenses have a curvature that is parallel to the cornea, leaving a space for tear circulation. This allows for improved corneal peripheral environment during daytime wear due to high oxygen permeability. In terms of efficacy, MCT has a stronger effect on controlling myopia, while RGP has a lower effect on controlling myopia progression (with an annual increase of -0.48D).