KC and Softlenses

[bing]

Hi

I was wondering that if I use soft lens (the lenses which are used normally for cosmetic purposes) than should I expect somewhat better vision as compared to glasses ?

[Andrew MacLean]

bing

There are special soft lenses designed specifically for people with keratoconus, but ordinary soft lenses really give no improvement. The problem is that they follow the contour of the already distorted cornea.

Andrew

[Lynn White]

Hi Bing/Andrew

Well actually its a little more complex than that. It really depends on the level of your KC and position of the cone. It is possible in some cases to get good vision with disposable lenses and the reason they are not used more is that, as Andrew says, its thought they simply will not work. However, it is impossible to say if they would work for you or not as I cannot examine your eyes from here!

However, if you are just wearing spectacles at the moment, it is certainly worth giving it a try. If disposables do not work then the more advanced lathe cut soft lenses may well do so and of course, there are dedicated soft lenses for keratoconus.

Lynn

[bing]

Thanks Lynn & Andrew

I have mild KC just in one eye (\45D) so these lenses might be worth trying

do these lens also have some side effects like the hard lens ? I have read that some doctors actually believe that hard lens can make KC to deteriorate further, hope that it is not the case with the use of normal lens ?

[Lynn White]

Hi Bing,

RGP lenses can compress the cornea and reshape it. Also badly fitted RGP lenses can sometimes cause scarring. Both these effects are due to the rigidity of the lens on an "odd" shaped corneal. As soft lenses flex, they do not cause the same sort of effects.

It does sometimes seem a bit odd that a soft lens that drapes over the cornea can improve vision on a distorted cornea, but reduced vision in KC is slightly more complicated than just the front of the cornea being distorted. Much of the thinning in KC takes place on the back of the cornea and the changes in vision are due to small variations in thickness. Therefore, the extra thickness of a soft lens is sometimes just enough to restore vision.

Lynn

[bing]

Thanks Lynn

but is getting a soft-lens just a hit and trail ? or can the doctor/optician actually recommend you to try a soft-lens based on your scan results ?

[Lynn White]

Bing,

Although scans are very useful for diagnostic purposes, they do not give enough information to say if a soft lens, or indeed any lens, will be suitable for any eye that has keratoconus.

As many practitioners know, a very mild looking keratoconus can prove to be the most tricky to fit with any contact lens and yet a more advanced appearance may be quite easy to fit.

I think I know what you are getting at - can someone tell me just from my topography which lenses will work? The answer is no. This is not because fitting is "hit and miss" it is because successful contact lens wear depends on a great many more factors than just central corneal shape. For example, one has to take into account tear film, lid tightness, sensitivity, spectacle prescription and, for larger lenses of any type, the shape of the sclera surrounding the cornea, which at the moment, topography of any sort does not measure.

So the answer to your question is you need a proper contact lens assessment!

Lynn