LASIK or Laser-assisted in situ keratomileusis is laser eye surgery used to correct vision problems such as myopia, hyperopia, and astigmatism. It involves reshaping the cornea to correct refractive errors and vision problems.
Invention of spectacles was a great achievement at a time when patients with refractive error were severely handicapped or practically blind. Spectacles enjoyed a high degree of popularity for a long time, but now their disadvantages such as, cosmetic blemish, restricted field of clear vision, aberrations, obstruction in sports and physical discomfort, are apparent. However, this does not mean that spectacles are to be condemned. There are still many situations where spectacles are the only alternative available for restoration of vision and also a respectable visual device.
A question that always haunts the minds of the ophthalmologists and patients alike is “Why should we depend on prosthesis when it is possible to restore natural vision with all its inherent advantages (not just cosmetic)?” The answer to all our doubts and apprehensions lies in LASIK Surgery.
What Is LASIK (Laser Assisted In- Situ Keratomileusis)?
Types of LASIK Eye Surgery
Wave-Front Optimized Or Custom LASIK
Wave-front guided or custom LASIK measures higher order aberrations present in the optical system of the eye and attempts to correct it. Moreover, the lasik treatment maps generated, maintain the natural (prolate) profile of the cornea, there by, preventing induction of any aberrations. All this translates into better contrast and night vision.
Intra LASIK (Femto Second LASIK)
Also called I LASIK or bladeless LASIK or all LASER LASIK or INTRALASE. It is a form of lasik where the corneal flap is raised using femtosecond LASER microkeratome rather than the mechanical microkeratome which uses blade. Thus the only difference is in the way the LASIK flap is created. It is misleading to think there is no cutting – therefore flap related risks are same in laser & blade. The flap thickness may be more predictable in the intralase group & thinner flap can be safer with femtosecond LASER. However the excimer LASER correction of the refractive error on stromal bed is same as in LASIK.
EPI-LASIK Or LASEK/PRK
In patients with thin corneas it may help to lift just a thin epithelial flap as in Epi – LASIK or remove epithelium using alcohol as in LASEK. This leaves behind greater amount of tissue in the corneal bed to achieve higher refractive correction. PRK along with use of Mitomycin – C has the same effect. Although it is possible to correct greater amount of refractive error in these procedures but the recovery is slow & more uncomfortable than in LASIK and there are greater chances of haze developing in the cornea especially with higher correction.
Who is Perfect Candidate for LASIK Operation?
It is extremely important to determine who is a suitable candidate for eye surgery. The important criteria are:
- Refractive error: Myopia between -1 to -12 diopter or Hypermetropia up to 6 diopter
- Astigmatism of up to 6 diopters
- Minimum age 18 to 21 years
- Refraction should have been stable for last 1-2 years
- Presence of keratoconus, thin corneas, corneal inflammatory diseases, herpetic keratitis and autoimmune diseases makes a person unsuitable for LASIK
Preoperative Before the Preparation
- Refraction under cycloplegia
- Corneal topography
- Ultrasonic pachymetry (to measure thickness of cornea)
- Detailed retina examination
- Intraocular pressure examination
- Informed consent procedure
LASIK Surgery Procedure
LASIK is performed under eye drops anaesthesia, so no injection is required. Wavelight Allegretto LASIK machine has a high speed (250 Hz) eye tracker device. This device constantly monitors the position of the eye and realigns the Laser to the exact position on the eye. The steps of lasik eye surgery are:
1. After the anaesthesia, the face of the patient is covered with a drape leaving only the eye exposed. An eyelid speculum is then applied to retract the eyelids and the patient has to look at a blinking green light.
2. A vacuum ring is placed around the cornea, which serves to stabilize the eyeball and also acts as a platform for the microkeratome. When vacuum is activated, the vision becomes hazy and pressure on the eye is felt.
3. The automated Moria Microkeratome dissects through the superficial layers of the cornea and the corneal flap is folded back. During this step the patient hears the sound of a motor in front of the eye.
4. Wavelight Allegretto high speed (200 Hz) Excimer Laser ablates the stromal bed to resurface it to a desired curvature. What makes the Excimer laser so well-suited for corneal ablation is its ability to remove tissue with accuracy of up to 0.25 micron with each pulse. Often, only 50 microns of tissue are removed to achieve the proper amount of correction.
The Exeirner produces a non-thermal light beam that eliminates the possibility of thermal damage to surrounding tissues. This Laser deploys 0.95 mm flying spot with truncated gaussian profile Laser beam to achieve correction of refractive errors, higher order aberrations and fashioning of smooth transition zones. During this step a clicking sound is heard and an odour of ablating tissue (similar to charring hair) is smelt and a flickering light is seen close to the eye. All this while patient needs to concentrate on the entre of the blinking red spot of light.
5. The corneal flap is then repositioned and allowed to dry for a few minutes. The flap self-seals without the need of sutures.
6. Antibiotic and other eye drops are prescribed. The patient is instructed to report back the next day.
Eye Operation Precautions
- Avoid swimming and splashing of water on the eyes for a month
- Avoid rubbing the eyes for a month
- Use sunglasses to avoid bright sun, dust, wind and air pollution
- Avoid excessive viewing of TV or work on computers for a week
- Use medicines regularly as advised
- Consult your eye surgeon in case of any problem
Complications of Laser Treatment for Eyes
No surgical procedure is without any complication, however LASIK is relatively a very safe technique for correction of refractive errors .There is a rare possibility of complications like glare, minor over & under correction, decreased contrast sensitivity, epithelial in growth etc.
Flap related complications on the table are also a rare possibility and most of them can be managed on the table; however, only some need the surgeon to postpone the LASIK surgery to a later date for better management.
- Under or over correction
- Button holing of flap
- Reduced contrast sensitivity
- Corneal perforation
- Central island
- Decentration of ablation
- Corneal infiltration
- Flap damage
- Corneal ulceration
Pain Management in LASIK Operation
What are the Results of Eye Surgery?
How Much Time Laser Cataract Surgery Take?
A typical schedule for LASIK patient is as follows:
- Day 1 - Detailed eye examination
- Day 2 - LASIK Surgery (2-4 hours spent in the centre)
- Day 3 - Review visit for postoperative examination
- Day 7 - Review examination
Patient may travel between days 3 and 7.
Why Choose Max Eye Care For LASIK Surgery?
- State-of-the-art infrastructure with advanced LASER
- Specially designed operation theatre for maximum sterility
- Comprehensive pre-LASIK screening to assess the fitness criterion of the candidate before the surgery.
- Use of advanced corneal topographic system and accurate ultrasonic corneal thickness measuring instruments for accuracy.
- Single use disposable consumables for high precision, accuracy, sterility and safety of the each patient.
- Highly skilled and experienced surgeons, supported by qualified staff
Frequently Asked Questions About Laser Eye Surgery
How Soon Can I Resume My Normal Activities?
The recovery is very fast owing to the simplicity of the procedure. One can resume the normal activities as early as after 24-48 hrs of the surgery with only a few precautions.
Will My Power Come Back After the Surgery?
No, the power never comes back. Only in very cases where the refractive power is very high to begin with, a minimal residual power may remain which can be corrected by what is known as enhancements, (which again can be assessed only after 1-2 months of the operation) depending on the patients need.
Can I Go Blind?
No, there has been no reported case of blindness so far.
Can there Be Any Complications?
The chances of complications happening are rare but in the event of any such complication occurring, our surgeons are very competent to take care of them.
Which Is the Right Age to Get Lasik Done?
stable power of glasses for the last 1-2 years.
Is the Laser Treatment for Eyes Life Long
Yes, the LASIK treatment is designed to last a lifetime. Only after the age of 40 years, does a person require reading glasses.
What is LASIK eye surgery?
LASIK (Laser-Assisted in Situ Keratomileusis) uses a laser to reshape the cornea, correcting common vision problems such as nearsightedness, farsightedness, and astigmatism.
Am I a good candidate for LASIK?
An eye doctor will evaluate various factors, including your overall eye health, prescription stability, corneal thickness, and other considerations, to determine if you're a good candidate for LASIK. A thorough examination is necessary to determine candidacy.
How does LASIK correct vision?
During LASIK surgery, a thin flap is created on the cornea. The surgeon uses a laser to reshape the underlying corneal tissue, correcting its curvature and focusing power. The flap is then placed back in its original position, allowing light to properly focus on the retina, improving vision.
Is LASIK a permanent solution for vision correction?
LASIK is considered a permanent procedure, as it produces long-lasting results for most individuals. However, it does not prevent age-related vision changes, such as presbyopia (difficulty focusing on close objects), which may require additional treatment later in life.
What are the potential risks and complications of LASIK?
While LASIK is generally safe, potential risks and complications may include dry eyes, glare, halos, fluctuating vision, under-correction or overcorrection, infection, corneal flap complications, and reduced night vision.
How long does the LASIK procedure take?
The LASIK procedure itself typically takes around 15 minutes per eye. However, you should plan to spend additional time at the clinic for pre-operative preparations and post-operative instructions.
Does LASIK hurt?
Most LASIK patients experience minimal discomfort during the procedure. Numbing eye drops are applied, and some individuals may feel pressure or a brief sensation. After the surgery, any mild discomfort usually subsides within a day or two.
How soon can I return to work or daily activities after LASIK?
Many patients can resume normal activities, including work, within a day or two after LASIK. However, it's important to follow your surgeon's instructions and avoid strenuous activities or eye irritants during the initial recovery period.
Are both eyes treated during the same LASIK procedure?
Yes, both eyes can be treated during the same LASIK procedure, typically on the same day.
Can LASIK correct astigmatism?
Yes, LASIK can effectively correct astigmatism by reshaping the cornea to create a more symmetrical curvature, thereby improving vision.
Can LASIK treat presbyopia (age-related reading vision problems)?
LASIK is generally not recommended as the primary treatment for presbyopia. However, certain techniques like monovision LASIK or blended vision may be considered to address presbyopia in some cases. Alternative treatments like multifocal intraocular lenses or reading glasses are often recommended.
What is the success rate of LASIK surgery like?
LASIK has a high success rate, with the majority of patients achieving improved vision without the need for glasses or contact lenses. Success rates vary depending on individual factors, such as the severity of the initial vision problems.
How long does it take to recover from LASIK?
The initial recovery period after LASIK can vary, but most patients experience significantly improved vision within a few days to a week. It's important to attend follow-up appointments and follow post-operative care instructions for optimal healing.
Can LASIK surgery be performed on patients with dry eyes?
LASIK can be performed on patients with dry eyes, but it's essential to evaluate and manage dry eye symptoms before proceeding with surgery. Adequate tear production and stability are important for successful healing and visual outcomes.
Are there any age restrictions for LASIK?
LASIK is typically recommended for individuals who have stable vision and are at least 18 years old. Candidates should be mature enough to understand the procedure and have realistic expectations.
Can LASIK correct nearsightedness, farsightedness, and astigmatism simultaneously?
Yes, LASIK can help with nearsightedness, farsightedness, and astigmatism in the same procedure, providing comprehensive vision correction.
What are the alternatives to LASIK surgery?
Alternative vision correction procedures include PRK (Photorefractive Keratectomy), implantable contact lenses, phakic intraocular lenses, and refractive lens exchange.
Will I need glasses or contact lenses after LASIK?
While LASIK can significantly reduce dependence on glasses or contact lenses, some individuals may still require glasses for certain activities or experience minor residual refractive errors. It's important to have realistic expectations and discuss your specific visual needs with your surgeon.
Can LASIK surgery correct vision issues caused by cataracts?
LASIK is not suitable for correcting vision problems caused by cataracts. Cataract surgery removes the cloudy lens and replaces it with an artificial intraocular lens and is the appropriate treatment for cataract-related vision issues.
What pre-operative tests are performed before LASIK?
Before LASIK, various tests are conducted to assess your eye health and suitability for the procedure. These may include conducting a comprehensive eye examination, determining refraction, measuring corneal thickness, assessing corneal topography, and evaluating tear film quality.
Can LASIK surgery be performed on patients with thin corneas?
The thickness of the cornea is an important consideration for LASIK candidacy. If the corneas are too thin, alternative procedures like PRK or implantable contact lenses may be more suitable options.
Are there any long-term side effects of LASIK?
The vast majority of LASIK patients do not experience long-term side effects. However, some individuals may experience dry eyes, glare, halos, or regression of vision over time. These effects are mild and are managed with appropriate treatment.
What is the difference between LASIK and PRK?
LASIK and PRK are both laser vision correction procedures but differ in the way the cornea is accessed. LASIK involves creating a corneal flap, while PRK involves removing the outermost layer of the cornea. Recovery time and post-operative care differ between the two procedures.
Can LASIK surgery be performed on patients with glaucoma?
LASIK may not be recommended for patients with glaucoma or those at risk of developing glaucoma. The eye care professional will assess the individual's condition and discuss suitable treatment options.
Can LASIK treat night vision problems?
LASIK can often improve night vision problems caused by refractive errors. However, certain complications like glare or halos may temporarily affect night vision after LASIK, which should subside as the eyes heal.
Can LASIK surgery be done if I have a history of eye infections?
A history of eye infections can impact LASIK candidacy. It's important to discuss your medical history with the surgeon, who will evaluate the risks and determine if LASIK is appropriate in your case.
What precautions should I take before and after LASIK surgery?
Precautions may include temporarily discontinuing the use of contact lenses, avoiding eye makeup and perfumes before surgery, arranging for transportation on the day of the procedure, and following post-operative care instructions diligently to promote healing.
Can LASIK correct vision problems caused by diabetes?
LASIK can potentially improve vision problems caused by refractive errors, such as nearsightedness or farsightedness. However, individuals with diabetes may also have refractive errors, which can be corrected with LASIK. Still, they need a thorough fundus examination for screening diabetic retinopathy, which can also contribute to visual losses. So, an eye surgeon can advise regarding the possible plan of action.
Are there any restrictions on physical activities after LASIK surgery?
It's generally advised to avoid activities that may strain the eyes or increase the risk of eye injury, such as heavy lifting, swimming, contact sports, or using hot tubs for a few weeks following LASIK.
Can LASIK surgery be performed on patients with corneal scarring?
The presence of corneal scarring may affect LASIK candidacy. Depending on the extent and location of the scarring, alternative procedures like PRK or implantable contact lenses may be more suitable options.
Can LASIK correct vision problems caused by eye injuries?
A thorough evaluation by an eye doctor is necessary to determine suitability.
Are there any limitations for LASIK in treating high prescriptions?
LASIK can effectively treat a wide range of refractive errors, including high prescriptions. However, in some cases, alternative procedures or a combination of LASIK and other treatments may be recommended to achieve the desired outcome.
Can LASIK be performed if I have had previous eye surgery?
Previous eye surgery can impact LASIK candidacy, depending on the specific procedure and its effects on the cornea. It's important to provide a comprehensive medical history to the surgeon for proper evaluation.
Can LASIK surgery be performed on patients with keratoconus?
LASIK is not recommended for patients with keratoconus, as the cornea is already weakened and irregularly shaped. Other treatment options, such as corneal cross-linking or specialized contact lenses, may be more suitable in such cases.
FAQs reviewed by Dr. Meetu Narang Vohra, Senior Consultant, Eye Care / Ophthalmology.