Patient Information


1- Possible Complications and/or side effects of LASIK (Laser ASsisted In situ Keratomileusis).

For the correction of Myopia,  Astigmatism & Hyperopia.

1. There is virtually no central haze or scar formation.
2. Eye drops can usually be discontinued after one or two weeks.
3. Stability occurs fast, usually one to three months.
4. Quick recovery of sight.
5. There is very little pain postoperatively, in the majority of cases.


Serious complications are rare. Possible complications and risks known at this time include the following:

1- Irregular astigmatism.
Irregular astigmatism differs from regular astigmatism in the following way. If one has
astigmatism, one is generally born with it. This is regular astigmatism. This procedure does not normally induce regular astigmatism. Regular astigmatism generally refers to the oval shape of the cornea rather than a sphere. IRregular astigmatism has surface irregularities which can diminish the best corrected visual acuity. Normally, irregular astigmatism does not remain permanently; however, occasionally it can. One must have a perfectly smooth corneal surface in order to have the best corrected visual acuity, especially the smooth surface over the optical center of the eye.
The incidence of significant irregular astigmatism with Excimer Laser could be less than 1%, depending on the degree of attempted correction. The only way to adequately correct the vision would be with a rigid, gas-permeable contact lens.
Most people with irregular astigmatism following this type of surgery improve over time.

2. Incomplete or irregular microkeratome flap or cap resection (uneven cut).
This rarely occurs, but if it does, the surgeon will normally replace the cap or flap down on the bed in its original position and the surgery will be delayed. Normally no harm is done and the vision returns to preop levels in a few days to a few weeks. The surgery can be postponed for 3 to 6 months and then the flap resection with the microkeratome can be repeated in order to achieve an acceptable flap resection. The most common reason for this incomplete microkeratome resection would be poor suction with the suction ring or a break in suction, but this is very rare today with more advanced equipments.

3. Decentration of the Excimer Laser beam
Up to date a decentration is very rare but could occur with the old laser equipments. Today the laser systems have eye trackers  and with them a descentration is impossible. Large decentration  caused  with older equipments could induce amounts of irregular astigmatism, and decrease best corrected visual acuity. We could  fixed them with a second enhancement surgery.

4. Decentration of the corneal flap or disc. (Not commonly occur).
Usually, no harm is done if the day after surgery is observed and fixed.

5. Displaced cap or flap (Not commonly occur).
If the corneal cap or flap is not perfectly aligned at first day after surgery, it will need to be repositioned under topical (drops), anesthesia. A displaced cap may occur from the following
             a-not completely adherent to the corneal bed immediately following surgery
             b- rubbing the eye soon after surgery

6. Subconjunctival Hemorrhage (Bloodshot eye)
May occur secondary to the suction ring vacuum that is placed to hold the eye. This certainly is not a serious condition and merely presents as a bloodshot eye on the first postop day. Will normally clear over the next weeks and is of no visual consequence.

7. Pain
The operation itself is painless. The eyes receive only topical anesthetic drops prior to the procedure. One feels pressure, not pain, while the suction ring is on the eye. One may have a mild to moderate foreign body sensation for a few hours following surgery, but after about 6-8 hours the eye normally feels comfortable. During this period, you may take your appropriately prescribed pain medication. It would probably be a good idea to take a nap following surgery. Normally, when you wake up the discomfort is gone.
Remember, this is one of the least painful of all refractive procedures following surgery.

8. Over or Under correction
The higher the refractive problem, (severe nearsightedness), the less accurate is this procedure. It is more accurate in the lower to moderately than in high myopes. Therefore, if one of these situations occurs, it could be fixed with other surgery (enhancement), 3 to 4 months after the first surgery.

There is a normal overcorrection after the surgery and is self fixed in the first 3 months. 94% of operated patients do not need enhancement surgery.

9. Reoperation (touch-up or enhancement)
6% operated patients need an enhancement in order to fine-tune the vision correction, especially in high myopes. If it is done 3 to 6 months post-op, it will not be necessary to make a new flap with the microkeratome, only lifting the flap. Each patient should be mentally prepared for an enhancement procedure, if necessary. Usually will need only one enhancement surgery but 0.3% will need one more.

10. Use of contact lenses after LASIK.
If you remain partially under or over corrected by any reason, and you choose to wear a contact lens after LASIK, would be possible after 6 months of the surgery.

11. Glare, starburst, contrast sensitivity problems
Significant night glare could occur in a small percentage of the population; however, the glare is usually not any worse than glare prior to surgery, especially when wearing contact lenses. One commonly experiences some night glare and halos immediately following LASIK.
Normally, by 3 to 9 months post-op, night glare is significantly reduced or eliminated.
One may experience glare and star burst without glasses at night following surgery if a

significant residual refractive error remains. The glare can be reduced merely by using a light pair of prescription glasses when driving at night, specially those individuals who have very large and dilated pupils at night will complain more about night glare & halos.

12. Interface Inflammation
Occassionally, one may develop excessive inflammation between the flap and corneal bed. This is usually eliminated with the use of potent and frequent steroid eye drops.

13. Particles in the interface (between the corneal flap, or disc, and corneal bed).
Possibly 2 or 3% of the time, corneal epithelium inflammation or particles may be found to be present in the interface. Mostly inflammation particles disappear with cortisone drops.

14. Mechanical failure of the corneal shaper or Excimer Laser
If either the corneal shaper or the Excimer Laser malfunctioned, surgery would have to be temporarily postponed. We have service and maintenance contracts to assure perfect function and prompt correction of any technical problems and all our equipments have UPS (power supply units), in case of an electric power failure.

15. Infection.
Infection is exceedingly rare after LASIK in general. If one did develop a bacterial infection after LASIK, it most likely could be cured by antibiotic drops. However, if the infection is not discovered until the late stages, one may have to remove the cap or flap and cure the infection. In our experience of more than 8000 procedures, we found no infections up to date. To assure this all patients receive antibiotic drops before surgery.

16. Poor exposure
This is often due to narrow eyelids and/or small orbit with a small eye. Also, deep-set eyes
are not as easily accessible. Therefore, if the eye does not protrude enough for the suction ring, sometimes a lateral canthotomy needs to be done in order to widen palpebral fissure area. This is done with a light injection of anesthetic at the lateral corner of the eyelid. Two tiny snips are carried out on the lateral canthal area (the lateral portion of the corner of the lids where the upper and lower lids meet). This also is rarely done.

17. Close space phobia. (Claustrophobia).
Some patients have this problem, but is not a major concern. On this cases we use less cover sterilized blankets and give the patient a pill to decrease the anxiety.

18. Fluctuation of the vision.
It is normal to have unstable vision during the 3 months after surgery, and will be decreasing and changing to the stabilization with time.

19. Corneal Ectasia (excessive structural weakness of the cornea.)
Very careful calculations and ultrasonic pachymetric measurements are made in order to avoid this complication, so we do not modified the corneal shape more than the necessary thickness.

20. Temporary Glaucoma or increased intraocular pressure.
Temporary glaucoma or increased intraocular pressure has not been a problem with LASIK, especially since corticoid drops are only used for approximately 1 week following surgery.

21. Photophobya.  (Light sensitivity).
Few number of patients have this phenomenon and is usually present only few weeks after surgery. We recommend the use of sunglasses.

22. Dry Eye.
There are a high amount of patients who have undergone LASIK who complain of a dry eye feeling for a few weeks to months following this refractive surgery. We do recommend that these patients use artificial tear drop as often as needed to relieve this sensation.

Any other question or inquiry related to the refractive surgery with Excimer Laser could be answered as needed.

Francisco J. Perdomo, MD.
Specialist in Ophthalmology.
Clinica Cirugia Ocular & Laser.
San Jose, Costa Rica.
-Updated- February 03, 2012..-  ©All rights reserved.


  1. Today is the FIRST day after the LASER EYE SURGERY, and right now, you must use the drops VIGADEXA , one drop   every 8 hours, (three times a day).  In addition, we recommend you apply lubricating drops, (Artificial Tears), SYSTANE ULTRA or  TEARS NATURALE II or others, any time and any amount, as needed, or every time you feel dryness or blurriness due to dry eyes.
  2. The plastic shields must be used every time you go to sleep, to avoid involuntary touching, rubbing or scratching of eyes, during the first eight nights.
  3. Any time you need to take out some secretions from inside the eyes, do so gently  with a “Kleenex” and washed hands (with soap and water), focus your eye to the opposite side where you are touching cleaning to avoid damage to the operated cornea. Women do not use eye make-up for about the first month after surgery.
  4. In the next THREE MONTHS you will feel vision fluctuation, (some days the vision will be very clear and some will be blurred your until eyesight stabilizes).  After this third month, we will reevaluate. In 6% of cases, a second surgery (enhancement) may be needed.
  5. Soon after surgery, in the darkness, twilight or dim light, you may see “haloes” or “star-bursts” for example on car stoplights. These effects will decrease with time, and some patients need many months for this problem to normalize.
  6. The redness on the white part of the eye are small hemorrhages due to capillary venous ruptures resulting from the suction ring vacuum, and will disappear in a few weeks. YOU DO NOT NEED to do anything, because the eyes will absorb the blood.
  7. It avoid any infection or conjunctivitis, during the FIRST MONTH after the surgery, is better not to open the eyes under water while, diving or swimming on in the sea or swimming pools.
  8. Avoid all contact sports such as martial arts, or sports that use balls, such as tennis, baseball etc., during the next FOUR MONTHS. If you do play these sports, do so very carefully; buying and  wearing SPORT PROTECTIVE EYEGLASES, to protect against any hit in the eyes. But sports as jogging, spinning, aerobics, weight lifting, biking with protection are OK.
  9. Avoid being near smokers or smoking areas for ONE WEEK. If you are cigarette smoker, you should smoke outdoors and use many lubricant drops to prevent irritation.
  10. Heaters and air conditioners (in houses, buildings, airports or airplanes), produce eye dryness and, it is recommended that you lubricate your eyes continuously with the lubricating drops.
  11. Use SUNGLASSES with UV PROTECTION if the sunlight is very bright outside.
  12. If you feel some foreign bodies are inside the eyes or increasing irritation that cannot be eliminated with lubricating drops, or if there is a different situation not explained here, please contact us as soon as possible.
  13. To answer questions during office hours; call us at our Clinic phone numbers:  (506) 2232-8420, (506) 2231-7342.
  14. In case of Emergency after work hours, call us through the pager phone number (506) 2283-2626 and leave the message with the operator to be sent to Dr. Francisco Perdomo.
  15. Patients from outside Costa Rica can send us an e-mail explaining the situation.

-Updated- February 03, 2012.-  ©All rights reserved.

Oficentro Plaza Mayor, Rohrmoser 2nd. floor, suite Nº 20.
San José, Costa Rica.
P.O. Box: 112-1230. San José, Costa Rica.
Contact us:

Costa Rica: (506) 2232-8420
Tel./Fax: (506) 2231-7342

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