Excimer laser

Excimer laser

It is posssible to correct nearsightness(myopia) , farsightness(hyperopia) and astigmatism with excimer laser .The procedure is made with topical anesthesia (with drops) and takes around 15 minutes.

It is posssible to correct nearsightness(myopia) , farsightness(hyperopia) and astigmatism with excimer laser .The procedure is made with topical anesthesia (with drops) and takes around 15 minutes. Excimer laser gives a new shape to the cornea with high precision .So that , the refractive error is corrected in seconds. The laser beem does not penetrate the cornea.There is an eye tracker integrated to the laser ,so if the patient moves his eyes during the treatment, the system follows eye movements preventing any misalignments.It possible to correct up to 10 dioptres of myopia, 4 dioptres of hyperopia and 6 dioptres of astigmatism.  

Who are suitable candidates for this treatment?

-Age should be between 21 and 60 .

- The prescription should be stable at least for one year.

- The patient should not have glaucoma, uveitis, corneal disase like keratoconus or retinal pathology.

- Patients with thin corneas and dry eye sydrome are not good candidates.

-The ones with uncontrolled diabetes and romatoid disease are not suitable for the treatment. Also , we don't recommend the treatment to pregnant and breast feeding women.

What are the treatment options ?


PRK: the uppermost thin cell layer is removed from the cornea. Laser is applied . The removed cell layer is replaced by the cornea with a new one in three days' time.


-The cornea is not cut. It is a superficial treatment (surface ablation).

- It can be applied to relatively thin corneas.

-It can be applied to corneas with surface irregularities.

- It can be applied to people who may have eye trauma due to their occupation.


-The procedure is pain free. However ,the patient may have excessive tearing , burning sensation and pain in the following 3 days.

- The recovery is slow when compared to lasik and the patient can go back to work after 4-5 days.

- Unwanted corneal haze can develop after the operation in patients with high refractive errors(above 5 dioptres) .To prevent this complication it is either be made to less than 5 dioptres or an adjuvant (mitomicin c ) is applied for 20 seconds to the cornea after the treatment.

LASEK:It is same as prk. The only difference is that ,the uppermost cells that are lifted in the beginning of the precedure are put back to their original place after the laser treatment .

Advantages and disadvantages are almost the same as prk . The only difference is that , according to some publications the risk of haze is lower in lasek than prk.

2: İ-LASİK:This is the most widely used technique in the world. A thin (100 microns) layer of tissue (flap) is lifted with hinge from the cornea.This flap is lifted with femtosecond laser(İfs intralase)(bladeless lasik) . Lifting the flap with femtosecond laser is more precise and with much less rate of complications when compared with normal lasik with blades. Then, the excimer laser beem is applied for seconds.There is an eye-tracker integrated to the system ,so if the patient moves his eyes during the procedure ,the system follows it a increasing the sucess rate. The lifted corneal flap is then put back to its original place after the laser.This procudure is pain free both during and after the operation . The patient may have some watering and burning sensation for a few hours.

ADVANTAGES of i-LASIK (intralasik) :

-It is more comfortable and safe than other techniques ..

- The recovery is very fast . The patient can go back to work the next day.

- There is no risk of haze. It can be made to high dioptres .


- It can not be made to thin corneas.

- The ones with cornea surface irregularities and dry eye sydrome are not suitable for lasik.

-The dryness of the cornea is much more in the post-op months when compared to lasek and prk.The partient has to use artificial tear drops for prolonged periods of time.

3:SMILE: Cornea is cut in two layers with laser.Then , the cut tissue is dissected and removed from a small pocket.


- The recovery period is faster than prk and lasek but slower than lasik.

- No risk of haze.

-Can be made to relatively thin corneas.


- It can not be applied to hyperopia (farsightness).

-It's success is limited in astigmatism.

- It can not be applied to low myopia(nearsihtness).

-It is not possible to make wavefront treatment(customised ablation) with this technique(possible with prk ,lasek and lasik) .

- It is not possible to make enhancement treatment with this technique if a small residual refractive error is present(possible with prk,lasek and lasik ).

- The patient may end up with a worse sight than before if the lenticule is not removed completely.

- There is not an eye tracker in the system that can compansate for the cyclotorsion of the eye during the treatment. This can cause a decrease in the quality of sight.

What kind of exams & scans are we making before the procedure ?

- Orbscan measurement (a detailed scan of the cornea )

- Corneal topography

-Wavefront scan

-Corneal pachimetry(thickness measuent)

-Complete eye exam with and without dilating drops.

-Pupillometry(measuring pupil diameter) .

The patient has to stop wearing soft contact lenses for two weeks and hard contact lenses for 3 weeks before the examination.

What is wavefront treatment?

Each patients' optic system is unique. Many people have imperfections in the optical system. These imperfections cause night vision disturbances (interfere with the quality of sight) . The wavefront device measures these unwanted imperfections before the operation. Thus, if they are above a certain limit , we recommend ' wavefront treatment to the patient . The wavefront device gives a map of sight for each individual. We transfer this map to the excimer laser system(customised treatment). In this way, we not only correct refractive error,but also we manage to increase the quality of vision. We are using the IFS femtosecond laser and VISX S4 excimer laser system in our hospital. It is one of the most popular devices in United States of America.The wavefront system is the first to get FDA approval .

What are the risks of the laser treatment?

As with every operation ,this operation has some complications. But the rate of complication is very low with the developed technology. Most of the complications can be handled with a second procedure.

This treatment is made worldwide for many years. It has been approved by FDA since 1996. According to the study conducted by the Society of American Cataract and Refractive Surgery , the rate of success was found to be %96. The most common complications are undertreatment, overtreatment(residual refractive error) and dry eye sydrome.


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