Risks of Laser Vision Correction
It is our hope to fully inform you concerning the side effects, limitations and complications of Custom LASIK surgery. We continually strive to give a balanced opinion of the benefits of laser surgery with the known and unknown risks. It is important to understand that it is impossible to perform any form of surgery without the patient accepting a certain degree of risk and responsibility.
Many of our patients are surprised and some are upset by the extent to which we attempt to inform them of the potential for complications. Most of our patients will never encounter any serious complications and the vast majority are pleased with the improvement they achieve. Although the level of risk is close to zero today, it is our intention to accurately outline the associated risks to all candidates so that they may either elect not to accept the risks associated or be better prepared to deal with any unexpected complications or side effects which may arise.
Laser eye surgery is a purely elective procedure, and you may decide not to have this operation at all.
The risks of Custom LASIK revolve around 5 primary areas:
- Post-operative Side Effects, Adverse Effects and Complications
- Refractive Complications
- Corneal Flap Complications
- Corneal Healing Complications
- Other Miscellaneous Complications
As with any surgical procedure Accuwave LASIK has major benefits but also potential risks and side effects. These risks are significantly minimised by the skill of the surgeon and the technology used. At Accuvision we are proud to have leading consultant ophthalmic surgeons with plenty of experience in laser vision correction procedures and a technology platform second to none. It should also be noted that most complications are temporary or manageable with little impact on the long term scenario. Accuvision has also helped many patients with poor outcomes from different treatments at other clinics worldwide.
|Intra-operative||Short flap||4||All eyes successfully retreated|
|Irregular/decentered||2||Retreated at 2 months|
|Post-operative||Shifted/displaced flap||3||Flap repositioned with no effect to visual outcome|
|Poor flap adhesion||0|
|DLK Grade 1 (inflammation)||4||Managed with topical steroid drops or flap rinse|
|DLK Grade 4 (inflammation)||0|
|Epithelial ingrowth||2||Monitored, not visually significant|
|Significant night vision problems||0|
|Loss of 2 or more line of best spectacle vision||0|
|Dry eyes causing symptoms after 3 months||2 patients||Lubricating drops|
|Eyes requiring enhancement||5||2 eyes planned for a 2 stage procedure|
- No patient was left with less than driving standard vision
- No patient lost 2 or more lines of best corrected spectacle vision
- No patients experienced worse night vision
- Please use this information as a guide, risks specific to your eyes will be highlighted during the consultation
Accuvision is a centre for excellence in Laser vision correction where 'minimum standards' do not apply and settling for 'second' best is simply NEVER an option.
1. Post-operative Side Effects, Adverse Effects and Complications
There are several adverse effects which may be encountered early in the post-operative period, including foreign body sensation, pain or discomfort, sensitivity to bright lights, blurred vision, dryness of the eyes, tearing and fluctuation in vision.
The most common long-term side effect is dryness of the eyes which often preceded Custom LASIK but may be exacerbated. The most important long-term side effect is night glare, starbursting, halos or simply reduced visual quality under low light conditions. It is very common to have night glare early during the recovery course and night glare is more common when only one eye has been treated.
Night visual disturbances are typically produced by the pupil size exceeding the laser treatment area. It is more common in near-sighted patients with severe prescriptions and large pupils. Some patients benefit from night driving glasses and most, but not all, patients improve substantially over 6 to 12 months. In a small percentage of patients night glare may be permanent and affect your night driving abilities.
2. Refractive Complications
Refractive problems that may be encountered include too much correction, too little correction, a prescription imbalance between eyes, aggravation of muscle imbalance problems, or a loss of effect from regression. Custom LASIK may result in over corrections and under corrections due to the variability in patient healing patterns and other surgical variables, leaving patients nearsighted, farsighted or with astigmatism. This may or may not require patients to wear spectacles or contact lenses or to undergo further surgery.
Patients may also heal differently between eyes, based upon differences between eyes in pre-operative prescriptions, corneal curvature, variation in healing or other surgical variables. Lastly, depending upon the severity of the original prescription, the individual healing pattern of the patient and other surgical variables, regression may occur, causing the eyes to return toward their original prescription, partially or, very rarely, completely. Further enhancement surgery may be performed when medically stable, if adequate corneal tissue is available and no other medical contraindications are present.
3. Corneal Flap Complications
The primary benefits of Custom LASIK are related to the creation of the protective corneal flap. The corneal flap must be of clinically adequate quality, thickness and size to proceed with laser treatment. Corneal flap complications that occur after the Custom LASIK procedure during the recovery period include displacement and wrinkling of the corneal flap and epithelial ingrowth.
Corneal flap problems include, but are not limited to:
- Corneal flaps of inadequate size, typically too short, preventing laser treatment and requiring the Custom LASIK procedure to be repeated in 3 to 6 months. Typically there is no serious visual disturbance, although glare and shadowing may occasionally be produced.
- Corneal flaps of inadequate thickness may or may not be adequate for laser treatment, and may result in the procedure being aborted and repeated after 3 to 6 months. A thin corneal flap may result in a slow visual recovery over weeks, to months - and possibly permanently blurred vision with or without laser treatment.
- Corneal flaps of inadequate quality or smoothness, include a variety of corneal flap problems which may produce serious permanent corneal irregularities and significant visual blurring. Corneal flap irregularities may be produced because of inadequate suction pressure, inadequate orbital size, inadequate patient co-operation, malfunction or problems with the microkeratome, blade or suction apparatus.
- Corneal flaps are routinely hinged either nasally or superiorly beneath the upper eyelid. A corneal hinge is not required for a good visual result, but a hinged corneal flap is more secure and typically heals faster and more smoothly. Depending upon the corneal shape, the suction ring alignment and the microkeratome, it is possible that a free corneal cap may be produced which is not hinged to the cornea. Although the laser treatment can still be performed, if any irregularities in flap quality or thickness are noted, the corneal disc is immediately replaced and allowed to heal. If the free corneal cap is of excellent quality, then the procedure is completed, but special care must be taken during the first 24 to 48 hours not to displace or lose the corneal cap. Loss of the corneal cap may result in scarring, permanent corneal irregularity and the need for more invasive surgery.
- Corneal perforation is the most serious Custom LASIK complication. Corneal perforation is prevented by the microkeratome depth plate, which is checked before each and every procedure. Some microkeratomes have fixed corneal depth plates. Perforation of the cornea requires corneal suturing and the need for an intraocular lens implant, as the natural lens is usually lost or damaged. It should be appreciated that corneal perforation may also potentially result in infection, the need for a corneal transplant or, rarely, even blindness.
- Corneal flap displacement, partial or complete, occurs during the early post-operative period, typically during the first 12 to 24 hours, but may occur days to weeks later with trauma. Care should be taken to protect the eyes from trauma, as well as to avoid rubbing the eyes or forcefully closing the eyes during the first week following LASIK. Partial displacement of the corneal flap may result in corneal striae or wrinkles, which blurs vision both qualitatively and quantitatively. Most corneal striae are treatable but some may be resistant to treatment, especially in highly nearsighted patients. Complete displacement of the corneal flap is often painful and requires urgent replacement. There is a higher risk of epithelial ingrowth and infection with corneal flap displacement.
- Epithelial ingrowth occurs during the first month following LASIK and is more likely to occur in patients with an abnormal or weakly adherent protective layer, for which age is a factor. Epithelial ingrowth is produced when epithelial surface cells grow underneath the corneal flap during the healing of the corneal flap incision. Epithelial ingrowth is more common with any trauma or breakdown of the epithelium, which is more common in LASIK enhancement procedures and long-term contact lens wearers. Treatment of this condition involves lifting the flap and clearing the cells away. Although most small areas of epithelial ingrowth need only be monitored, untreated large areas of epithelial ingrowth may distort vision and may actually damage the flap integrity if severe and progressive.
4. Corneal Healing Complications
Corneal healing problems with LASIK are more likely to be experienced by patients corrected for higher degrees of near-sightedness, far-sightedness and astigmatism, which may potentially slow visual recovery and increase the need for enhancement procedures for over and under-corrections. Corneal healing may affect not only the speed of visual recovery, but also the smoothness, and may produce visual blurring.
Rarely would corneal scarring be produced with LASIK. The most important aspect of corneal healing following LASIK or any other form of refractive surgery, is the development of corneal irregularities which may permanently affect the quality, crispness and sharpness of the final visual result. Corneal irregularities, or irregular astigmatism, are produced when the cornea heals in an irregular pattern, which may or may not follow a surgical flap complication. Most corneal irregularity improves over 6 to 12 months. Corneal healing is very patient-specific, and plays a critical role not only in how well a patient recovers from a surgical flap complication, but in how rapidly and smoothly all patients recover.
5. Other Miscellaneous Complications
It is important to note that it is impossible to list every conceivable complication that is not listed above. Risks and complications that are considered to be unforeseeable, remote or not commonly known are not discussed. In addition, there may be long-term effects not yet known or anticipated at the present time. The most severe possible complications would necessitate more invasive or repeated corneal surgery, including corneal transplantation, and could potentially produce partial or complete loss of vision.