Cataract surgery for a keratoconus patient does require some additional testing and consideration for the best visual outcomes. Choosing the appropriate lens and lens power can be more challenging with keratoconus. The length of the eye and the shape of the cornea are important factors when calculating an intraocular lens (IOL).
If you are wearing a contact lens it is important that the lens be discontinued prior to your eye exam. At Price Vision Group we recommend discontinuing rigid gas permeable contact lenses for 2 weeks and soft contact lenses for 1 week prior to your cataract exam. This will allow the cornea to return to its natural shape in order to accurately evaluate the degree of corneal astigmatism and eye length. Regular astigmatism is linear and can be corrected with glasses and irregular is not linear and cannot be corrected with glasses correction. A rigid gas permeable contact lens can correct irregular astigmatism.
The correct IOL is very important for the keratoconus patient. The monofocal IOL is the “standard” IOL. This IOL is covered by most insurance plans and works well for low amounts of regular astigmatism or irregular astigmatism. If a patient has irregular astigmatism a rigid gas permeable contact lens may still be indicated after cataract surgery to correct the irregular astigmatism.
A toric IOL can be a good option to correct higher amounts of regular astigmatism in keratoconus cataract patients. These lenses can improve your uncorrected visual acuity and significantly reduce your dependency on glasses post cataract surgery. It can be more difficult to fit contact lenses with a toric IOL, so this should be considered prior to a toric IOL selection. Glasses can be worn post operatively, if needed, to correct any residual refractive error. A toric IOL is considered a “premium” IOL and is not covered by insurance.
A multifocal IOL is not a good option for most keratoconus patients. The multifocal IOLs are best when the cornea is pristine and obviously if you have keratoconus your cornea has irregularities. The multifocal IOL is not a good option for those with keratoconus.
When you are ready for cataract surgery accurate pre op testing and IOL selection are key to the best visual results.