- Corneal disorders
Cornea is the anteriormost transparent layer of the eye and play very important role in vision.
So any damage to corena causes defective vision.
Damage in the form of
• Chemical Injury
• Vitamin A deficiency
Most common corneal disorders-
- Corneal abrations
- Corneal foreign body
- Corneal ulcers
- Corneal dystrophy and degenerations
- Fuch’s dystrophy
Any corneal disorder can now be treated. Whereas some conditions can be treated with the help of medications, for others this may not be possible. In such a case, a surgical intervention is the only way out.
Keratoconus (KC) is a thinning disorder of the cornea that causes visual distortion. It causes the cornea to thin & bulge to a cone-like shape, distorting vision.
- Blurring of vision
- Frequent changes in glass prescription
- Increased light sensitivity
- Difficulty in driving in night
- Pain in eyes
• Slit lamp examination- cone like structure seen on slit lamp examination.
• Classic signs of keratoconus –
- Corneal thinning
- Fleischer’s ring (an iron coloured ring surrounding the cone)
- Vogt’s striae (stress lines caused by corneal thinning)
- Apical scarring (scarring at the apex of the cone)
• Investigations- Corneal topography and pentacam – helps for diagnosis earlier and to see the progression
- Spectacles- and contact lenses to correct the refractive errors-
In advance stages of keratoconus- special contact lenses- Rose-K contact lenses are helpful to correct refractive error
- Surgical Intervention- is done to stop progression of keratoconus
Collagen Cross linking- (CXL)- currently the only treatment to stop progression of keratoconus and to avoid corneal transplant. CXL works by increasing collagen crosslink’s which the natural “anchors” within the cornea are.
It has recently received FDA approval for keratoconus.
Intacs are thin plastic, semi-circular rings inserted into the mid layer of the cornea. When inserted in the keratoconus cornea they flatten the cornea, changing the shape and location of the cone. The placement of Intacs remodels and reinforces the cornea, eliminating some or all of the irregularities caused by keratoconus in order to provide improved vision. This can improve uncorrected vision, however, depending on the severity of the KC, glasses or contact lenses may still be needed for functional vision.
Only 15-20% of those with keratoconus ultimately require corneal transplant surgery