Laser Assisted in-situ
range for myopic correction is – 0.5 to –14.00 diopters (-2 to –12
D; Parsons’), with up to 5 diopters of astigmatism
stromal bed thickness should be at least 250 mm
(i.e. total corneal thickness of 550-600mm)
corrections have been approved for +4.00
less than 21 years.
collagen vascular disease (especially in the presence of iritis or
of a pacemaker.
ongoing active inflammation of the external eye (eg, conjunctivitis,
severe dry eye).
error outside the range of laser correction.
SELECTION FOR LASIK (preoperative workup)
lens wear should be discontinued prior to the examination
days for soft contact lens wear
weeks for rigid gas permeable lenses.
complete eye examination
and cycloplegic refraction
fundus examination –Indirect Ophthalmoscopy
estimate of scotopic pupil size is helpful in screening candidates that may be
at risk for postoperative glare
drape, place speculum.
suction ring placed on the eyeball elevates IOP to about 60 mmHg
(temporary blackout of vision occurs).
microkeratome advances and creates an epithelial flap, which is hinged
flap is lifted and laser ablation of stroma done.
LASER is used.
behind residual corneal thickness of at least 250 microns.
bed with saline and close the flap. No sutures. It sticks by itself.
antibiotics and steroid drops for about 1 week.
Enhancement LASIK (i.e. repeat procedure) can be performed
but usually after 3 months of table refraction.
Wavefront technology in LASIK aims to corrct all aberrations
of the eye to give vision beyond 6/6 – super vision.