In early stages,
when the cornea is still regular, corrective prescription glasses or soft contact lenses
can help the patients. As keratoconus
advances the corneal surface becomes increasingly irregular and these options do not help adequately.
In intermediate stage,
there are various treatment options including different type of contact lenses
Rigid Gas Permeable contact lenses
- They are the first choice of treatment when glasses fail to help the patient. They provide a smooth refractive surface replacing the irregular cone like surface of the cornea, thus enabling the patient to see clearly.
Lens fitting in keratoconus
can be a demanding and time consuming process. It requires frequent visits to the eye doctor to get a perfect and comfortable fit. Rigid Gas Permeable lenses (RGP) however may not be as comfortable as soft contact lenses
"Piggybacking" Contact Lenses
- Some eye doctors practice "piggybacking" where a soft contact lens
is first placed on cornea to give it a cushion like effect and over it RGP lens is fitted. Thus, it combines the best features of both lenses in the sense that it makes the wearer comfortable and at the same time gives crisp vision. The fitting should be perfect to ensure good oxygen permeability to the cornea as the patient will be wearing two lenses. However, with newer high oxygen permeable lenses this is not a problem.
Hybrid Contact lenses
- Some manufacturers have come up with this unique design of contact lenses
where the central visual portion is made up of high oxygen permeable rigid material and peripheral anchoring portion is of soft hydrogel material. This also maximizes the best feature of both lenses and improves wearers comfort as well as visual performance in keratoconic eyes with a single contact lens
In the last decade, with newer technological advances in treatment modalities for keratoconus
, INTACS and C3-R have showed promising & encouraging results.
Intacs are plastic insertable devices approved by FDA in 2004 for treatment of keratoconus
of upto 3 dioptres. These semicircular rings of various thickness and diameters are placed within the middle layers of the cornea. Their placement remodels and reinforces the cornea, eliminating all or some of its irregularity caused by keratoconus. At the same time it flattens the cornea, correcting the myopic & astigmatic refractive error to a considerable extent.
Intacs placement is a simple procedure and does not require any tissue removal. They are reversible and cannot be felt by the patient after insertion and healing. They require no maintenance. However, glasses or contact lenses
may be required even after successful intacs implantation. They have been shown to improve vision, thereby saving the patient from requiring corneal transplantation.
C3-R Treatment ( Corneal Collagen Cross Linkage with Riboflavin)
It is a non-invasive and very popular procedure for treatment of keratoconus
. It strengthens the collagen tissue which forms the fabric of cornea. This is simple 60 minutes in-office procedure. Eye drops containing Riboflavin (Vitamin B2) are put on the cornea and then activated by Ultra-violet light(UV-A). This increases the collagen cross linking causing strengthening of cornea thereby stopping it from bulging outwards and arresting keratoconus
In the 3 years results of clinical study in human eyes, C3-R treatment has shown arrest of keratoconus
progression in all treated patients. C3-R procedure changes intrusive bio-chemical properties of the cornea increasing its strength by almost 300%. It is the only procedure currently available to halt the progression of the disease.
It is the last option when all the above methods fail to restore optimum useful vision to the patients. In this procedure, the cornea which forms the transparent outer covering of the eye is replaced by a donor cornea. It is an intra ocular surgery and requires long term healing and consistent follow-up. Even after a successful transplant, glasses or contact lenses
may be required to give useful clear vision.
Another viable option for management of keratoconus is DALK (deep anterior lamellar keratoplasty). In contrast to the previous type of corneal transplant, in this procedure only the outer laters of the cornea are replaced. It is an extra-ocular procedure with lesser complication rates and provides earlier visual rehabilitation for the patient.