Keratoconus Treatments - Hybrid Lenses
For people with the eye condition Keratoconus, contact lenses are often the best way to get vision correction. RGP (Rigid Gas Permeable) contact lenses are the most common for people with the disease but, in some cases, a hybrid lens may be a better option.
Keratoconus is a disease of eye in which the cornea, which is the front part of the eye through which light enters, thins and distorts outwards into an irregular ‘conical' shape.
This distortion of the eye results in reduced vision as the light entering the eye can not be properly focused onto the retina and this causes blurring and ‘ghosting' .
Glasses and soft (or hydrogel) lenses may work for early or mild forms of the disease. Where the condition progresses more then RGP (or Rigid Gas Permeable) contact lenses often work more effectively because they maintains their own shape and trap a layer of fluid between the lens and the cornea. The combination forms and artificial single surface that acts like a regular shape cornea.
Because RGP lenses are so small the edge of the lens can irritate the inner surface of the eyelid and this can make wearing them uncomfortable.
Also the lenses can pop out quite easily, particularly if the cornea of the eye with Keratoconus is quite steeply curved (think about balancing a saucer on the end of a rugby ball).
An alternative that can be considered if this kind of 'edge' irritation occurs is the hybrid contact lens.
If you compare the size of a normal RGP lens and a soft or hydrogel lens then you will see that the RGP is much smaller.
The hybrid lens is basically a bonding of the two materials with the RGP lens at the centre and a soft and flexible 'skirt' of hydrogel material around the outer edge.
Because the centre of the lens, the bit that goes over the cornea, is rigid it will maintain its own shape, trap the layer of fluid and form the single regular surface required for light to pass into the eye without being distorted.
The hard edge of the rigid lens is softened by the hydrogel material and this reduces the sensation of the lens rubbing on the inner surface of the eye lid.
For people who have problems getting used to the feel of a rigid lens in the eye the hybrid solution may be a very good alternative. They also tend to be less prone to popping out and may be more comfortable for people with dry eyes.
They are slightly harder to get in and out than normal RGP lenses, and of course they cost more.
Keratoconus is a disease of eye in which the cornea, which is the front part of the eye through which light enters, thins and distorts outwards into an irregular ‘conical' shape.
This distortion of the eye results in reduced vision as the light entering the eye can not be properly focused onto the retina and this causes blurring and ‘ghosting' .
Glasses and soft (or hydrogel) lenses may work for early or mild forms of the disease. Where the condition progresses more then RGP (or Rigid Gas Permeable) contact lenses often work more effectively because they maintains their own shape and trap a layer of fluid between the lens and the cornea. The combination forms and artificial single surface that acts like a regular shape cornea.
Because RGP lenses are so small the edge of the lens can irritate the inner surface of the eyelid and this can make wearing them uncomfortable.
Also the lenses can pop out quite easily, particularly if the cornea of the eye with Keratoconus is quite steeply curved (think about balancing a saucer on the end of a rugby ball).
An alternative that can be considered if this kind of 'edge' irritation occurs is the hybrid contact lens.
If you compare the size of a normal RGP lens and a soft or hydrogel lens then you will see that the RGP is much smaller.
The hybrid lens is basically a bonding of the two materials with the RGP lens at the centre and a soft and flexible 'skirt' of hydrogel material around the outer edge.
Because the centre of the lens, the bit that goes over the cornea, is rigid it will maintain its own shape, trap the layer of fluid and form the single regular surface required for light to pass into the eye without being distorted.
The hard edge of the rigid lens is softened by the hydrogel material and this reduces the sensation of the lens rubbing on the inner surface of the eye lid.
For people who have problems getting used to the feel of a rigid lens in the eye the hybrid solution may be a very good alternative. They also tend to be less prone to popping out and may be more comfortable for people with dry eyes.
They are slightly harder to get in and out than normal RGP lenses, and of course they cost more.
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