Refractive surgeries

Definition
Any procedure used to correct the refractive error

Myopia (short-sightedness)
the refractive power of the eye must be decreased either by flattening the cornea or by IOL insertion of appropriate power

Hypermetropia ( Long sightedness )
making the shape of the cornea to be steeper or an appropriate IOL lens is inserted

Astigmatism (refractive power is not same in all meridian )
Cornea must be flatter in the axis where the refractive capacity of the eye is relatively greater or steepened the axis where it is relatively weak or Toric IOL can be used

Presbyopia(reduction of near vision with old age)
Multi focal IOL can be used
Mono vision
Where one eye is corrected for DV ( made emmetropic) other eye is made or left -1.50 D myopic to allow the eye to focus on near objects

Corneal refractive Surgeries
Corneal ablation by excimer laser

LASIK               Laser assisted stromal in-situ keratomilesis)
Epi-LASIK        (epithelial laser - assisted in-situ keratomilueisi)
PRK                  Photo refractive Keratoconus
LASEK             (laser- assisted sub epithelial Keratomiluesis)

LASIK

Laser in-situ keratomileusis (LASIK) involves creating a corneal flap so that midstromal tissue can be ablated directly and reshaped with an excimer laser beam. The procedure allows the ophthalmologist to surgically reshape the cornea in an attempt to obviate the need for corrective lenses

LASIK produces good refractive results for low, moderate, and high myopia Potential complications of LASIK include halos, interface inflammation, haze, and regression. However, significant complications causing a loss of two or more lines of best corrected visual acuity (BCVA) are rare . In addition, with improved instrumentation and increasing surgeon experience, LASIK complication rates continue to fall. The size of the optical zone and the depth and profile of the laser ablation will determine the correction achieved