Lasik

Presbyopia

Presbyopia is caused by a loss of elasticity in the lens of the eye and in the muscles around the lens. Like other parts of the body, the eyes are subject to wear and tear as they age and they progressively become less able to switch from looking at distance objects to focus on objects close by.   We do this without thinking all day long but the eye finds it more and more difficult to produce sharp images needed for activities like reading, especially in low lighting conditions.

presbyopia

 

 

 

 

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Which one is better? ORTHO-K or LASIK?

Can’t see distant objects clearly? Well, you may have nearsightedness (myopia), in simple words, you need glasses to see. And you may need them for the rest of your life.

LASIK (laser surgery treatment) is a surgical procedure for myopia correction. It has benefited many who find glasses inconvenient. But if you are too young or not interested in a surgery yet still want to see without glasses, you have a new option. A new technology from USA called ORTHO-K is available in Pakistan now.  Let’s have a look of both:

FUNCTION

Myopia occurs curvature of cornea is too steep and image forms in front of the cornea. Both procedures flatten the cornea to allow lights to be refocused on retina.

myopia eye

chart

IS IT SURGICAL?

ORTHO-K is not. It is overnight contact lenses.

LASIK is a surgery.

IS IT REVERSIBLE?

ORTHO-K is reversible. LASIK is not.

FDA APPROVED

ORTHO-K first in 1994 then 2002 (for overnight wear). LASIK in 1998.

PROCEDURE DIFFERENCES

ORTHO-K

BEFORE: Eye Examination and Consultation

DURING THE PROCEDURE: 2 hours contact lens fitting

ORTHO-K patient will try several trial lenses and rest for 20 minutes with eyes closed. If the fit is good and patient can see 6/6 with lenses on, then the parameters of those lenses will be ordered. After the removal of lenses, there should be a noticeable change in vision. 3 weeks later when the order arrives, the ORTHO-k procedure will begin. ORTHO-K users will regularly wear special contact lenses for 8 hours at night which can flatten the cornea. After removal of lenses in the morning, they will not need glasses or any contact lenses during the day or longer.

AFTER THE MAIN PROCEDURE

There will be 8 follow-up appointments after 1 day, 1 week, 1 week, 2 weeks, 2 weeks, 2 weeks, 1 month and 1 month. Refraction and consultation will take place in each appointment. Lenses may be adjusted in these appointments.

LASIK

BEFORE: Eye Examination and Consultation

DURING THE PROCEDURE:10 minutes surgery:

Your eyes will first be numbed with anesthetic drops but you will be awake. A stabilizing device called speculum will keep your eyes open and a suction ring to keep them still. Then an automated microkeratome blade will cut your cornea to create a flap. The flap will be lifted, and laser beam will permanently remove tissues from your cornea. Your cornea will be reshaped and a slice thinner in seconds. Finally corneal flap will be laid back to heal.

AFTER THE MAIN PROCEDURE

You will see your doctor again next day for postoperative examinations. Your eyes may itch, burn or tear but it can improve in the first few days. It is suggested to take a few days off from work. You may also be given eye drops for prevention of infection.

After the surgery, you should not wear eye makeup for at least 2 weeks and no swimming or hot tub for 8 weeks. Regular appointment every 6 months is advised.

LENGTH OF PROCEDURE

ORTHO-K: 8 follow-up appointments in 3-4 months (included in the fee), or 6 months for high myopic patients

LASIK: 10 minutes surgery. (And a re-visit appointment.)

RESULT

ORTHO-K: Rapid improvement can be noticed after wearing for 20 minutes. Vision may fluctuate in the first month.

LASIK: Blurry at first but can improve in 2 days. Vision may fluctuate in the first 3-6 months.

LASTING EFFECT

ORTHO-K: 1 or 2 days after 1 night wear. But permanent as long as using ORTHO-K.

LASIK: Permanent. But myopia may re-progress and glasses may be required.

ADVANTAGE

ORTHO-K: Reversible. If candidate wants to stop using ORTHO-K, he or she can come back to normal glasses or perform Lasik in older age.

LASIK: Permanent, so it saves time.

SIDE EFFECT

ORTHO-K:

Side effect is very rare and preventable in cases of ORTHO-K lenses. The two main causes for any side effect will be whether the practitioner has used trial lenses and conduct a proper evaluation before ordering the customized lenses and whether the patient has followed the hygiene instruction (including using the right solutions) and scheduled appointments.

LASIK:

Not preventable. Dry eyes, hallow, double vision, starbursts, glare, difficulty to drive at night. Vision under-treated or over-treated. In very rare case, blindness.

DISADVANTAGE

ORTHO-K:

Reversible. Vision will return to its original power 1-4 weeks after discontinuing ORTHO-K.

LASIK:

Permanent. If there is occurrence of any side effect, it will also be permanent.

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Who is ORTHO-K for?

There is no age restriction to ortho-k, and it is suitable for a child as young as 7 years old.

In general, you are a good candidate to Ortho-k if you

  • Have motivation of wearing contact lens regularly  at night in order to enjoy the freedom in the day
  • Are compliant to follow-up appointments
  • Have good personal hygiene  (or can supervise your kid for good hygiene)
  • Can sleep for 8 hours
  • Can be satisfied with 6/8 in case of high myopic or flat cornea clients
  • Have healthy cornea ( for example, no post keratoplasty or keratoconus

And it is advised to avoid ortho-k treatment if you

  • Have inflammation or infection of the eye
  • Have any eye disease, injury, post-lasik eyes or abnormality that affects the cornea or surrounding tissue
  • Have any systemic disease that may affect the eye or be worsened by wearing contact lenses
  • Have allergic reactions of the eye, which may be caused or exaggerated by wearing contact lenses or use of contact lens solutions or
  • Have eyes that are red or irritated, or suffer severe dryness
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A Guide to ORTHO-K

Nearsightedness is the most common ocular disorder, and the incidence ranges from 25% in the USA to even 90% in some areas in China. As the lifestyle changes, myopia occurrence also starts at younger age.

Most people choose glasses or contact lenses to correct their vision, but glasses and contact lenses can get in the way of people’s activities. So almost since the beginning of times, people try to get rid of their contact lenses or glasses. Laser surgery is a more commonly known method, but not everyone is ready for a surgery, or a candidate of it.  In this case, is there any other option?

ORTHOKEAROLOGY: AN ALTERNATIVE TO LASIK SURGERY

Orthokeratology (ortho-k) is a non-surgical process which achieves temporary reduction of myopia by gently reshaping the cornea using specially designed reverse geometry gas permeable contact lenses during sleep. The method is to flatten the cornea and reduce the sagittal height, allowing the refocusing of the light rays on the retina (macula) and eliminating refractive errors.

Cornea is estimated to have 540 microns (0.54mm) in thickness, and the epithelial layer (the outer layer) is approximately 50 microns which is similar to the thickness of human hair. Ortho-k only performs on the epithelial layer. The lenses compress corneal tissue and in subsequent the anterior epithelial cells are redistributed from the center towards periphery. The concept is similar to a lasik surgery, except it is reversible.

In short, it is a type of contact lenses worn overnight, and after removal of lenses in the morning, myopia is temporarily reduced for the whole day! The treatment takes 3-4 months in total for most individuals, but there is a noticeable improvement in vision even after the very first night of wearing these lenses! The first month is the adaption period and is needed for your vision to be stabilized. These lenses are also powered so they can be worn in daytime too if the vision has progressed during the adaption period.  90% people can reduce 5 diopters of myopia, and most people require only 1 pair of ortho-k lenses to optimize the corrected vision. However for more complex cases, additional pairs with adjusted parameter may be required. Once the desired corrected vision has been achieved, ortho-k lenses should still be worn in a regular basis though one may only need to wear them on alternative nights.

SAFETY AND VALIDITY

Concept of Ortho-k is not new, Dr. George Jessen invented the first ‘Orthofocus’ lenses in 1960s in the USA. Researcher Robert Morrison also showed in his study of no myopia progression over a two-year period after fitting PMMA rigid lenses to 1,000 teenagers in 1956. Charles May O.D. conducted his research in 1981 in University of California-San Diego and revealed several facts such as no scratch, distortion, reduction of sensitivity or obvious change in thickness of the cornea. Similar research has been done in University of California- Berkeley as well to prove the safety and effectiveness of ortho-k treatment. Dr. Kerns from University of Houston also affirm the finding of myopia control in 1985.

But it wasn’t until the advent of the new technology that allowed the researchers to design specially designed contact lenses that the process has become highly predictable and successful. The invention of overnight wear high gas permeable contact lenses were invented in 1987. In result, such material augmented ortho-k and shortened the treatment time. Stuart Grant O.D. first promoted ortho-k in 1993 for the reason this overnight wear is comfortable, effective and avoids problems face during daytime wear such as dust, sand, pollution and strong lights.

The safety and effectiveness of ortho-k gained approval by FDA in 2002 after strict testing by scientists. Since then, this product has started to gain popularity worldwide and there were 391,000 ortho-k users as of 2009, and every 1 out of 10 people in Netherlands chooses ortho-k for their myopic treatment.  Paragon CRT from Paragon Vision Science and Bausch + Lomb’s Vision Shaping Treatment are currently the two main manufactures of ortho-k.

FOR ATHELETES AND CONTACT LENS WEARER

Ortho-k is ideal for athletes who have concerns about glasses or contact lenses being knocked off during games, and the risk of eye injuries. It also allows more unrestricted peripheral vision which is crucial for games like basketball and baseball.

Though contact lenses are a preferred method for many, the drawbacks are there such as they can quickly dry out especially during intense concentration in the game, or they can move off from the center. There is also more eye allergy or discomfort to contact lens when there is pollen, pollution, dust and sand in the air. Ortho-k on the other hand is worn during the night which avoids all these problems, and poses no more risk of eye infections comparing to soft lenses.

FOR CHILDREN

There is no age restriction to ortho-k candidate, and patient as young as 7 years old can put these lenses in themselves under the supervision of their parents. It is beneficial for kids as ortho-k helps controlling the progression of myopia.

ORTHO-K VS LASIK SURGERY

Laser treatment is certainly a more popular option in Pakistan, and it has its advantage for being a quick and affordable (and perhaps cheaper) treatment. However now that ortho-k is available in many countries including Pakistan, it may be a more suitable option for people who want to avoid the risk and pain. Like any surgery, there is no guaranteed perfect outcome with Lasik or other vision correction procedures, and not everyone gets 6/6 vision after the surgery. Like any surgery, the risks of complications involved with Lasik include dry eye syndrome, glare, double vision and halo. In some cases, loss of vision may occur. In any case, people under 18 years old (or have fluctuating vision) are not candidates for lasik.

On the other hand, ortho-k is safe, totally reversible and no serious incident has ever happened to the user and it is suitable for people of all ages.

Can you imagine wearing these contact lenses at night while gently reshape your eyes, and taking your lenses off and still see? It is now available in Pakistan.

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