What is Refractive Error?
In the normal eye, parallel rays of light are brought to a point focus on the retina – the light sensitive layer at the back of the eye. This focusing is done by the Cornea and Lens of the eye. When such a sharp focus is not achieved, a refractive error condition results and the Vision is not clear.
Common Refractive Errors are:
Myopia or Nearsightedness
Myopia is a condition of the eye where the light that comes in does not directly focus on the retina but in front of it, causing blurred vision. In myopia, close objects look clear, but distant objects appear blurred
Hyperopia or Farsightedness
Hyperopia is a vision condition in which distant objects can be seen clearly, but close ones do not come into proper focus.
A normal cornea is round and smooth but a cornea with astigmatism is not perfectly rounded but has a very slight curve and when this curve is too great, or pointing in the wrong direction then astigmatism occurs. It is possible to have astigmatism in combination with myopia or hyperopia.
How is Refractive Error Corrected?
PRK (Photo Refractive Keratotomy) using Excimer Laser
LASIK (Laser Assisted In Situ Keratomileusis) using Excimer Laser
LASEK (Epithelial Laser Keratomileusis)
What is LASIK?
LASIK is a quick and effective procedure to reduce one’s dependence on glasses or contacts by correcting the refractive errors of the eye. The procedure involves creating a thin flap of Cornea, the top layer of the eyes, using either a fine blade or a laser followed by, an Excimer Laser gently reshaping the underlying layers to enhance the visual acuity.
It is one of the safest and most commonly performed procedures across the world with over 30 million eyes allowed to break free from the bonds of corrective eyeglasses.
Am I an Ideal Candidate?
An ideal candidate for LASIK would be one who is:
Above 18 years of age
Has stable cylindrical or spherical powers
Has healthy Retina
Has strong motivation to get rid of glasses/ contact lenses
Pre LASIK Evaluation
Before recommending lasik, a pre LASIK evaluation will be conducted to obtain the accurate eye measurements and hence maximize the post LASIK results.
Points to ponder:
Above 18 years of age
Surgery Days: Wednesday & Friday
Stop wearing contact lenses at least one week prior to the lasik evaluation/ surgery
Latest LASIK Procedures
Blade free (Femto) Lasik
The benchmark procedure for lasik is the Blade Free Femto LASIK. This procedure symbolizes safety and precision by creating an ideal flap using the Femtosecond laser instead of the microkeratome blades used for traditional lasik. This is the only LASIK procedure approved by NASA and the American army that is clinically proven to enable better vision for their workforce. Customized Femtolasik a newer version of Bladefree Lasik goes a step ahead by delivering best possible vision achievable by any laser procedure.
SBK (Sub-Bowman’s Keratomileusis) Lasik is the evolved form of the traditional LASIK that creates an ultra thin corneal flap using modern microkeratome blades. This tissue friendly procedure scores high on safety and accuracy. It is the next best alternative to a bladefree lasik procedure for those looking for a budget option.
Advanced Surface Ablation
Advanced Surface Ablation (ASA) is a laser procedure that effectively corrects nearsightedness, farsightedness and astigmatism in most patients through a unique minimally invasive approach, free of microkeratome blades. Ideal for patients who are not suitable candidates for LASIK but are motivated to get free of their spectacles. Many patients are eligible for this procedure and can achieve clearer vision with reduced dependence on glasses or contact lenses.
I am not eligible for LASIK- What now?
There are still numerous advanced options available, including:
Phakic IOLs/ Implants
People with high refractive errors beyond – 10 and + 4 are advised to opt for Implantable Contact Lens (ICL). A special thin lens is implanted over the natural lens of the eye to allow excellent vision unhindered by glasses. Power upto -20 may be treated by this procedure.
LASIK/ PRK EXTRA
It is a new procedure used for persons with unhealthy cornea, unfit for traditional laser procedures. Here the surgeon combines laser Surface Ablation with Cornea Cross Linking to correct the refractive error & strengthen the cornea as well.
RANGE OF REFRACTIVE ERRORS
Certainly, Femto LASIK is designed to correct the refractive errors till +7 & -14 in most patients. The LASIK procedures are said to be among the safest and most frequently performed surgical procedure on the human body with over 30 million eyes treated worldwide. At Drishti itself over 25,000 eyes have successfully undergone the LASIK procedure in the last 15 years.
Pioneers of LASIK in North India
Internationally trained LASIK surgeons
Advanced LASIK pre-evaluation machines
Specialized Retina Clinic for comprehensive screening
Continuous LASIK technology upgradation
LASIK training centre for surgeons from across the world
Satisfaction rates as high as 99.9%
Over 25,000 satisfied LASIK patients
What are the results of LASIK?
The results of Lasik are absolutely amazing. 99% of the individuals who undergo the Lasik procedure do not have to wear glasses or contact lenses. As the eye is a biological organ, we have to keep in mind that we can correct upto an accuracy of 0.50 Diopt. But this small no. does not need spectacles.
Is Lasik Safe?
The FDA recognizes LASIK as proven, safe and effective. According to guidelines recently released by the Eye Surgery Education Council (ESEC), fewer than 1% of patients who have received LASIK to date have experienced serious, vision threatening problems. With modern instruments the complication rate is negligible. Even if they occur they can be treated successfully. There are no known cases of blindness resulting from LASIK.
Is the LASIK procedure painful?
It is a painless procedure, however some people experience 4-6 hours of mild irritation afterwards
How long does the procedure take?
The laser treatment on the Allegretto Wavelight takes less than 30 seconds, while the entire procedure takes around 10-15 minutes.
When to resume normal activities after LASIK?
People can return to work within 1-3 days following LASIK. Excluding the day of the surgery, one can begin driving as soon as they see well enough. Women can start wearing make-up within 2-3 days of treatment.
Can all Spectacle Nos. be corrected?
Depending on certain factors such as Corneal thickness, pupil size etc we can correct by LASIK:
Myopia upto -12.0 to -14.0D
Hyperopia upto +5.0 to +6.0D
Astigmatism upto 4.0D to 5.0D
Mild discomfort, scratchiness on the 1st day
Small pink or red patches for 2-3 days
Mild dryness of the eye for 2-3 weeks.
What to Expect During LASIK Surgery
Here’s what you can expect from professional and board certified doctors.
If you have chosen LASIK eye surgery, your surgeon will evaluate your sight with similar tests used to prescribe your eyeglasses or contacts. He or she will use this information to help determine how to reshape your cornea to correct your vision and where to direct the laser beam to accomplish that reshaping. If you’ve chosen OptiLASIK® Laser Vision Correction as your procedure, your surgeon will also use highly advanced scanning tools to create a personalized map of your eyes for even more precise results and safety.
Before OptiLASIK® begins, you’ll receive a series of anesthetic drops in each eye. These drops will numb your eyes and help ensure that OptiLASIK® is virtually painless—at most, you may feel some light pressure.
Once the series of drops has been administered and your eyes are numb, you’ll be asked to lie down on a table under the laser equipment.
Throughout the LASIK procedure, you’ll be asked to focus on a small blinking light above you. Don’t worry if your eyes move a tiny bit. The Allegretto Wave® Eye-Q Laser uses sophisticated eye-tracking technology so it can keep up.
Your surgeon will begin OptiLASIK® Laser Vision Correction by pulling back a thin layer of tissue from your cornea, exposing the underlying tissue so your surgeon can more easily reshape it.
From there, your surgeon will apply small, very rapid—billionths of a second—bursts of the laser energy to carefully reshape your cornea, making your eye a more ideal shape for focusing light. Flat parts may be made rounder; curved areas may be flattened, etc.
The personalized map will help guide the laser so you get a precise procedure while maintaining an ideal, natural shape.
Once your eyes have been reshaped—which normally takes less than a minute—your doctor will lay the corneal flap back into place, where it acts like a natural bandage. No stitches are needed.
Many people sit up right after surgery and notice dramatically better vision.* Still, complete recovery can take time—weeks, or months even—and much of the responsibility will be in your hands. So, to get the most out of OptiLASIK® Laser Vision Correction, you need to know what to expect after surgery.
*Results may vary
Most people notice clearer vision right away, sometimes sitting moments after the surgery and finding that their eyes can already focus more accurately.
Others experience a few slight side effects, including watery eyes; a burning, scratchy sensation; or mild discomfort. These symptoms usually pass within the first few days.
Once your doctor confirms that everything is in order, you are ready to go home—just an hour or 2 after you arrived. However, you won't be able to drive yourself immediately following the LASIK procedure, so plan on having someone pick you up.
Make sure you bring dark sunglasses to block the glare of the bright sunlight outside, assuming your doctor hasn’t already mentioned that he will provide them for you. Some do.
Your surgeon may also prescribe medications to reduce swelling, discomfort, and to keep your eyes clean and infection-free. Make sure you fill any prescriptions before you return home.
Use prescription eye drops to prevent infection and reduce any swelling or irritation
Use an over-the-counter lubricant eye drop to keep your eyes moist and comfortable
Wear eye shields, particularly during sleep, to prevent irritation
Wear dark eyeglasses if you experience sensitivity to bright lights
Avoid rubbing your eyes for a few weeks after surgery
You should be able to return to normal activities very quickly, depending on how you feel and your doctor’s instructions.
While many people see clearly by now, in some cases, your vision may seem slightly hazy or blurry. You may be sensitive to bright light, see halos, Halos: A visual effect, in which a circular flare or hazy ring of light may appear around a headlight or other lighted object. or have trouble seeing in low light. Everyone responds differently, but usually, these symptoms clear up within weeks, if not days, as the eye heals. If you experience severe pain or your vision worsens, contact your doctor immediately.
The doctor should schedule a follow-up visit with you shortly after your procedure, typically a week or so later. On recovery visits, your surgeon will test your vision to assess the results and make sure that your eyes are healing properly.
Wait 1 to 3 days before participating in any non-contact sports, but wait at least 1 to 2 months before engaging in strenuous contact or water sports.
Continue gently washing around your eyes with a mild cleanser.
You could experience fluctuations in vision for up to 6 months after surgery. Be patient and talk to your doctor.1 In most cases, patients have excellent results and are not only free of any serious, long-term complications after their LASIK recovery; they're likely to see as well—or in some cases, even better—than they did with their eyeglasses or contact lenses. The only major difference is that they're free of eyeglasses or contacts