WHAT ARE REFRACTIVE ERRORS?

In a normal eye the refractive of focusing power of the cornea (putil), the lens(motia), and the length of the eye are finely Co-ordinated to form a perfect image on the light sensitive layer called retina(parda), thereby producing clear vision.In a normal eye the cornea usually provides about two-third and the lense provides the remaining one-third of the refractive power of the eye.The light rays may get focused in front of the retina causing short sight or 'Myopia' (minus number correction) or behind the retina causing long sight or 'Hyperopia'(plus number correction). Distorted foccusing due to 'Astigmatism' is corrected by cylinder lenses and it may be combined with either Myopia or Hyperopia.

HOW DO LASIK AND EXCIMER LASER WORK?

The invisible ultraviolet rays emitted by the excimer laser machine permanently changes the curvature or contour (and thereby the power)of the cornea and hence correct the natural foccusing of the eye.No artificial lenses and no injections are used.Being 100% computer controlled the latest fourth generation fully integrated LASIK and EXCIMER LASER machine uses a special beam delivery technology which is highly accurate,safe and more technologically advanced than other systems.The doctor feeds in the accuartely measured data for each patient into the laser computer and modifies certain parameters as per experience and the LASER machine itself does the rest by controlling the power and duration of the laser rays emmitted.The two main laser procedures for spectacle removal are LASIK and Excimer Laser PRK (or photo-refractive keratectomy).LASIK is the more techmologically advanced procedure and also the most preferred.The difference between the two is expained later.

ARE YOU A SUITABLE CANDIDATE?

• First of all you should be above 18 years of age with a stable spectacle power between -1.0 to -25.0 or +1.0 to +8.0 and cylinder from +/-0.5 to 6.0.
• There is no upper age limit but generally only distance vision or constant use numbers are recommended to be corrected.People needing only near or reading glasses(presbyopia) are not suitable.
• If you have significant post operative refractive error following I.O.L.,cataract surgery or keratoplasty.
• Provided that you do not suffer from corneal surface disorder,keratoconus,dry eyes,unoperated cataract,glaucoma,significant retinal pathology,diabetes,connective tissue disorder etc.
• CONTACT LENSE USERS ARE ADVISED TO DISCONTINUE LENSES BEFORE CHECK UP.It is preferable to wait for at least 1 week in case of soft contact lenses while RGP(semi soft) and hard lens users are advised to wait for 2 and 3 weeks respectively.

ACCURATE PRE-LASER ARE IMPORTANT

Your general medical & eye records are reviewed .Your complete eye check-up including testing of spectacle number,detailed examination of the retina,ultrasonic pachymetry and computerized corneal topography test will be done to determine your suitability for various laser treatement procedures.The strict adherence to scientific guidelines at Grover Laser Vision Center along with the detailed and accurate pre-laser tests and technological expertise and experience make our laser vision correction results comparable to the best centers in the world.The doctors at this center always keep it in mind that an accurate data input plays a very important role in a successful outcome of treatment, the effect of which is going to last a lifetime.

THE LASIK PROCEDURE

LASER is acronym for Laser Assisted In Situ Keratomileusis.It is basically a modification of the Excimer Laser technique in which an additional instrument called the automated microkeratome is used to create a thin flap or cap of superficial corneal tissue.This protective flap is folded up and then the excimer laser works deep in the tissue rather than on the surface of the cornea as in excimer laser PRK.At the end of the procedure which lasts for less than 5 to 10 minutes of which laser time is of few seconds only the flap is folded back and it sticks to its base without the need of stitches.There is no pain during the procedure as the eye is numbed with eye drops,a feeling of slight discomfort or pressure may be felt by some patients for a short while.

The U.S. - F.D.A. approved LASIK laser and latest superior hinge or top flap technique of LASIK followed here is one currently most favoured in Canada & U.S.A. We are using the latest and most advanced variable hinge micro keratome at our center.

WHAT TO EXPECT AFTER LASIK LASER

During the first few hours there is a feeling of irritation and watering from eyes which usually disappears within 12 to 24 hours.Patients are advised strictly not to rub or wipe their eyes and to avoid dusty environment or splashing water in their eyes for about two weeks.The improvement in distance vision is almost immediately appreciated by patients of high numbers while people with low numbers realise the change within 12 to 24 hours ; near vision takes somewhat longer to recover.Most normal activities can be resumed within 1 to 2 days of laser treatment,eye drops are usually prescribed for 2 to 3 weeks.As opposed to excimer laser PRK there is no need to bandage the eyes and chances of regression or corneal haze are almost nil.Patients with very high minus numbers or thin cornea before laser may at times have light glare at night.

IS ANY RISK OR SIDE EFFECT INVOLVED?

More than 6,000,000(six million) human eyes around the world, mostly in countries like Canada, U.S.A. ,Japan, U.K. ,Germany and Australia are a testimony to the success of this spectacular technology.This number is increasing by approximately 1,000,000(one million) every year. Though being one of the safest methods for the permanent removal of glasses , there may be a few instances of over or under correction,infection, irritation, corneal haze and glare. The reasons for these problems are generally not technical but are due to different healing responses which vary from person to person. Most of these problems are transient and respond well to eye drops.No serious complications like loss of eye have been reported with the newer models of laser machines and automated microkeratomes.Once stabilised, the correction is life long and your spectacle number never comes back and only rare cases need retreatment for residual refractive errors.With the advent of LASIK laser treatment the side effects of prolonged steroid eye drops use are also not seen now .In old age when cataract surgery may be needed,laser treated eyes carry no additional risk as compared to a normal eye.However, as also with contact lenses,people of about 40 years of age or above and those with high refractive error may need corrective glasses for driving or fine work after laser treatment.

Advantages of LASIK over Excimer Laser PRK

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No.	Difference	Excimer Laser PRK	LASIK Laser
1	Range of correction recommended	Low to moderate 1 to 6 diopters usually	Low to High 1 to 25 diopters except in case of thin corneas
2	Laser Depth, site of laser ablation	Surface laser ablation/treatment	Deep/intra-stromal laser ablation,below the corneal flap
3	Pain during laser treatment (Intra-operative pain)	None	None or mild discomfort due to suction ring
4	Post-operative pain	Moderate Pain for 24 to 72 hours	Slight watering or irritation for 12 hours
5	Post-operative Mediaction	Usually 3 to 6 months	Usually 2 to 3 weeks
6	Prolonged steroid eye drop use	Needed	Not Needed
7	Fuctional Visual Recovery	3 to 5 days Bandage for 48 hours.	12 to 24 hours.No bandage required
8	Maximum Visual Recovery	3 weeks to several months	Usually 1 to 4 weeks
9	Return to work	3 to 5 days	1 day
10	Surgeon Skill	Less surgeon dependent	More skill and experience required.
11	Risk of central corneal haze/scar	2% to 5%	less than 1%
12	Regression of Laser Effect	May occur in some (though uncommon)	Almost never seen (extremely rare)