Successful Lasik after RK: Factors to Consider
RK
or also known as Radial keratotomy is a surgical procedure
performed to correct myopia and myopic astigmatism in the
1980s. The purpose of RK is to shift the cornea's focus back
onto the retina by reducing the central corneal curvature
through tiny cuts at the edge of the cornea. However, this
procedure is not precise resulting in under or
overcorrection of patients' vision. Due to this reason, many
patients are considering to undergo another eye surgery,
such as Lasik surgery.
It is usually possible for RK
patients to have Lasik or other refractive surgeries but the
success rate will depend on a few factors.
Fluctuation
of weakened corneas
of RK patients make it difficult for glasses fitting.
Unstable corneas are also not suitable to undergo second eye
surgery. It is important to check the cornea stability
before deciding on another cornea surgery.
Hyperopic
shift is also
a difficulty for RK patients. RK patients who were
previously treated for myopia are becoming farsighted
because of the shifting of the weakening cornea.
Presbyopia is a common
vision problem suffered by patients who achieve the age of
40. However, there are currently no safe and reliable ways
to cure this problem with additional eye surgery. If the
patient has both hyperopia and presbyopia, he may consider
correcting his hyperopia provided the cornea is relatively
stable.
Corneal
irregularities will
resulted in irregular astigmatism for patients with previous
RK. It may be quite difficult to perfectly correct this
problem, but it can be improved with various Lasik
surgeries. However, Wavefront-guided ablation may be
impossible if the irregularities are too great.
Advance Surface
Ablation (ASA)
techniques like PRK or LASEK is more suitable for RK
patients. Since RK makes deep radial incisions into the
cornea, there might be risk where the cornea fall into
pieces when the cornea flap is created in Lasik. Intacs is
also a good choice as it could stabilize a fluctuating
cornea. Although Epi-Lasik is also an ASA technique, it
could not be safely performed on RK patients.
Lens Based
Surgeries such as RLE
or P-IOL are better alternatives to resolve some refractive
errors for RK patients whose corneas are weak. However,
these techniques do not overcome the corneal fluctuation
problems.
