Contact Lenses After LASIK

Why post-LASIK corneas are different to fit

A normal cornea is steepest at the center and flattens toward the edge, and every stock lens is designed for that profile. Myopic LASIK flattens the center, leaving a plateau surrounded by steeper untreated cornea. A standard lens placed on that shape bridges the flat center and bears on the steeper periphery, so it can rock, decenter, trap air or blur. Farsighted LASIK does the reverse, steepening the center. Either way, the lens has to be designed for the shape.

Who needs lenses after LASIK

• A small residual prescription in a patient who does not want, or is not suited to, an enhancement
• Presbyopia: reading vision in the forties and fifties, where multifocal or monovision lenses avoid readers
• Regression: a prescription that has drifted over the years
• Night vision symptoms from a small treatment zone or higher order aberrations, which a rigid or scleral lens can improve
• Post-LASIK ectasia, a rare progressive steepening that needs cross-linking and a specialty lens
• Temporary needs, such as a bandage lens during healing

The lens options

For low prescriptions on a regular post-LASIK cornea, daily disposable or custom soft lenses often work, with the fit checked for centration. Where the cornea is irregular or the prescription higher, reverse-geometry rigid gas permeable lenses, whose periphery is steeper than their center, match the LASIK profile and center well. Scleral lenses fit any post-surgical shape and are the choice for ectasia, significant irregularity or dry eye, which LASIK patients are somewhat more prone to. Multifocal versions of each address presbyopia.

Timing and dryness

Lenses are not fitted until the cornea is stable, usually three months after LASIK. Dry eye after LASIK, common in the first months and occasionally persistent, is treated before and alongside fitting, because a dry surface tolerates lenses poorly. Enhancement surgery is discussed as the alternative where the cornea has enough thickness.