Orthokeratology

Temporary molding the anterior corneal surface by wearing specially designed rigid gas permeable contact lenses overnight, to correct the vision for the next all day.

The construction and fitting of the first successful contact lens with negative power to correct myopia was done by German ophthalmologist Adolf Gaston Eugen Fick in 1888.

The first corneal contact lens was developed in 1949 and was much smaller and more comfortable than the previous scleral lens designs. The small corneal contact lens rested on the central cornea, instead of across the entire visible ocular surface.

The development of Orthokeratology (Ortho-k) contact lens to temporary mold (reshape) the very anterior corneal surface to correct vision was since 1960. Until 1990 the modern reverse geometry design Ortho-k contact lenses with highly breathable materials were developed for use only while sleep at night and improved vision in the day without the need to wear eyeglass or regular contact lens.

The mechanism of Ortho-k lens

 

Unlike regular contact lenses have a perfectly round dome shape. An Ortho-k lens uses a reverse geometrical design in which the central area of the lens is flattened. The hydraulic forces applied to the tear film induce pressure to the corneal epithelium centre.

As the epithelial cells are interconnected, the intracellular fluid can move around between cells. When pressure is applied to the central epithelial cells, the fluid moves to the peripheral cells. As a result, the central part of the epithelium becomes thinner, and the periphery thickens. The epithelium are not squished or damaged. The central cells simply undergo dehydration.

Ortho-k is a non-surgical treatment option for vision correction involve the use of computer-guided individually customzied micro precise constructed contact lenses from data captured from your cornea. These lenses are worn overnight to temporary reshape or mold the superficial corneal curvature resulting in clear vision during the day without the need for glasses or regular contact lenses.

From the day Ortho-k treatment started by wearing the lenses everynight, your superficial corneal architechtures gradually changing toward the predetermined curvature in one to two weeks, and your corneas are closely monitored by optometrist with the digital equipments to ensure the corneal curvature changes is on path to the targeted treatment outcome and vision correction.

The reshaped superficial corneal curvature alters the manner the light enters the eye to correct the myopia and astigmatism for all day clear vision. At the same time the reshaped cornea bringing the off-axial light focuses in front of the peripheral retina, this peripheral myopic defocus slow down the elongation of eyeball and the progression of myopia.

Just like any medical procedure, the best treatment option may not yield desired treatment result on every patient. Additional visits to tweak treatment strategies with changes of lenses may be needed on certain cases for best therapeutic effect.

 

In the event when the Ortho-k lenses are not worn for a period of time, the epithelial cells gradually return to their original shape and the vision will revert back to its pre-therapy condition.  

Benefits of Ortho-k:

        Myopia control for children

        Freedom from glasses or daytime contact lens

        Stable clear vision during waking hours

        No regular contact lens related dryness or discomfort

        Lifestyle and activities that not suitable for glasses or regular contact lenses.

        None of the risk of laser refractive surgery

 

Ortho-k lenses are for all ages requiring vision correction and especially beneficial for children. 

Extensive studies have shown Ortho-k lenses significantly reduce the speed of myopic progression in children. Ocular axial length elongation is also markedly retarded when compared with children vision corrected with normal glasses and regular contact lenses. 

The elongation of eyeball greatly increased the risks of irreversible sight threatening retinal diseases, cataract, and glaucoma.


Call 64669398 / 64621567 / 82182180 to make appointment for Ortho-K therapy