Keratoconus is a condition in which the cornea is thinner and more curved. Progression of the process of thinning or increase in curvature reduces vision and may lead to significant impairment of vision. Keratoconus Surgery is the solution we provide at AEILC.
The primary defect lies in the cross links that are present between two fibres of the corneal stromal collagen. In keratoconic eyes, these cross links are known to be fewer in number or strength leading to thinning or change in curvature. This progression may be present only for a limited time period, stabilizing on its own, or may continue to occur leading to an irreversible loss of vision.
Management of keratoconus involves a two pronged approach
- Identification if progressive or not, and treatment of progression if identified
- Ensuring best possible visual correction
IDENTIFICATION OF PROGRESSION
Diagnosis and follow up of keratoconus requires corneal topography, wherein the corneal shape is captured and analysed numerically. This allows serial review of this shape and early identification of progression. A typical topography map is as shown below.
If the corneal thinning is identified to be progressive, either on serial topography or a continuous change in the glasses or contact lens power, corneal collagen cross linking procedure is indicated. This involves treatment of the corneal collagen by UV A light and riboflavin. Goal of the procedure is to arrest the progression of keratoconus. There is no or slight improvement in the visual acuity of the patient. The procedure is painless and patient goes home on the same day. Post operative care includes antibiotics drops for a few days.
TREATMENT OF VISUAL DISTURBANCE
These form the mainstay of correction in the initial stages. However at a point the corneal shape becomes very irregular such that glasses are unable to give the best possible vision.
Contact lenses are able to give very good vision in early cases if the cornea is clear and not scarred. Many options are available to improve vision namely.
- Soft contact lenses
- Rigid Gas Permeable lenses
- Scleral and mini scleral lenses
It is unclear if any particular type of lens has an effect on progression of disease; however, RGP lenses and Scleral /mini scleral lenses offer good clarity of vision. Scleral/ mini sclera lenses have added advantage of increased comfort. Training regarding maintainance and application of lenses is a must.
Depending on the amount of scarring and stage of disease either a full thickness transplant or a deep anterior lamellar keratoplasty is performed in cases where vision does not improve either by glasses or any type of contact lenses. (See section on keratoplasty for details). At Asian Eye Institute, we are well equipped to tackle keratoconus in any of the stages by the latest modalities of management