Refractive surgery has the aim of eliminating ocular defects such as myopia, hyperopia and astigmatism.
In a normal eye, the image entering the eye from outside is projected over the retina, enabling it to be transmitted to the brain and to be seen clearly, whilst in a eye with a refraction defect, the image is projected in an anomalous way, obtaining as a result a blurred vision.
The treatments used to eliminate refractive defects are:
Excimer and Femtosecond laser
There are several techniques:
Lasik: To perform this technique, a thin superficial layer is raised, named flap, after which the cutting with the Excimer laser is performed that is then replaced. This technique favours the recovery, achieving maximum visual acuity in almost 24-48 hours.
This flap can be performed by means of two techniques: Microkeratome or femtosecond laser (Visumax®):
- The microkeratome is a surgical instrument that has a blade incorporated to the head that enables performing the flap.
- The femptosecond laser performs this flap more precisely, providing a clean cut and enabling the surgeon to control the thickness of the flap more accurately.
At Innova Ocular IOA Madrid the flap is only performed with femtosecond laser, as it is a much safer, exact and accurate technique, which results in higher safety for the patient and a faster recovery.
The Excimer laser used at Innova Ocular IOA Madrid is the Zeiss Platform MEL 80®, a latest-generation laser that uses a beam of only 0.6 mm that considerably reduces the ablation time, thereby contributing to the patient's comfort and to a more efficient planning of the operating time.
The MEL 80 platform has associated the WASCA aberrometry system, that enables determining the optical characteristics of the entire eye, from the cornea to the retina, and the CRS-Master system, that enables performing the cutting or ablation in a personalised way, according to the characteristics of each patient, and it is the most modern and up-to-date system.
Moreover, the eye-tracker system and the iris recognition system enable the surgeon to have total control of the ablation even in the light of small movements by the patient during the process.
PRK: This is a very safe and simple technique in which the first layer of the cornea is removed, the epithelium, and the treatment is applied with the Excimer laser, that models the corneal curvature according to the prescription of the patient to be corrected.
After applying the laser a contact lens is placed that protects the cornea for the first week, until the epithelium of the cornea has completely regenerated.
For the first two days it is normal for the patient to feel discomfort and distorted vision and although the visual recovery is slow (normally using the computer and driving at night is uncomfortable until after 10 days), the final result is very satisfactory for patients, achieving an excellent visual quality.
The ReLEx® Smile concept is as follows: The high precision VisuMax® femtosecond laser creates a small lens (lenticule) inside the intact cornea, the volume and shape of which depends on the visual defect to be corrected. The lenticle is removed accessing the interior of the cornea with a minimally invasive procedure, through a small incision of only a few millimetres. Unlike other older techniques, it is not necessary to remove a corneal flap; there is no cutting of this flap, the incision is minimal and the most external corneal layers remain intact.
In the past years, the minimally invasive treatment and diagnostic methods have set new standards for modern Medicine. This is because minimally invasive usually means a minimum discomfort for the patient. Carl Zeiss, with ReLEx® Smile, has developed a new technique for the minimally invasive correction of the visual defects. This treatment technique offers a wide range of advantages:
- Treatment without flap
- It is not necessary to lift any layer of the cornea.
- The preparation of the lenticle is performed on the intact cornea.
- Minimally invasive access, of only a few millimetres (80 % less than with Lasik Femto-Lasik).
- The external protective layer (epithelium) is preserved almost completely and it is the layer that provides stability to the cornea (Bowman membrane).
- The corneal nerves responsible for producing tears remain almost completely intact.
- There is hardly any pain during and after the procedure.
The entire procedure is performed with the femtosecond laser (all femto):
- Use of femtosecond laser high-precision technology.
- Very high predictability of the results even in cases of high myopia (> -7.00 D, more than 7 dioptres).
- The anatomical design of the contact lens prevents compression of the cornea.
- The patient sees throughout the entire treatment.
- It is a nose and pain-free treatment.
Treatment in one single step:
- The complete correction with laser is performed in one single step.
- The patient does not have to be moved in the middle of the operation.
- Very fast procedure.
The refractive surgery techniques described in the previous sections have advantages and inconveniences. Thus, the PRK is technically very easy and not at all traumatic with the corneal structure, as well as very predictable in myopias and low myopic astigmatisms, achieving excellent results on patients with low prescription. On the contrary, the visual recovery is slower than with ReLEx® Smile and Lasik, and the discomforts in the immediate post-surgery are greater. Lasik enables a fast visual recovery and is the most predictable for hyperopia and high astigmatisms; on the other hand, it requires creating a flap to conduct the surgery, which weakens the cornea more than other techniques and although it is unusual, it produces drier eye on the long-term, which is infrequent with PRK and ReLEx® Smile. ReLEx® Smile is a new technique that enables operating myopia and astigmatisms in a minimally invasive way, enabling to operate higher prescriptions, and is the most accurate in these cases. Furthermore, it enables immediately practicing high intensity physical activities, and is a technique specially indicated for sportsmen and women. The visual recovery is fast, although not as fast as with Lasik.
It is a refractive surgery technique that consists in implanting an extremely fine and malleable lens inside the eye. It is an additive surgery, which means that no tissue is removed from the eye, so it is therefore a reversible procedure. .
The ICL (Intraocular Contact Lens) is the fastest-growing refractive procedure in the past years, with more than 400,000 implants throughout the world.
Although it was initially reserved for high defects, the current trend is to implant them in patients with lower defects and who are attracted by the reversibility nature of the technique.
The procedure is conducted under topical anaesthetic (anaesthetic drops) and lasts a few minutes, and corrects the defect immediately.
The ICL does not require any maintenance and enables performing any activity, such as flying, diving, etc., although a regular annual check-up is recommended.
Innova Ocular IOA Madrid was distinguished at the 2014 European Society of Cataract & refractive Surgeons Congress (ESCRS) in recognition of its global leadership in the implant of toric ICLs.
Refractive lensectomy (transparent lens extraction)
This refractive surgery technique enables correcting cataracts and presbyopia with a multifocal intraocular lens.
As the natural lens is replaced by an intraocular lens, the refractive defects will be eliminated, by selecting the appropriate power of the lens. The calculation of the power of this lens to be implanted must be very accurate, for this reason at Innova Ocular IOA Madrid we use extremely precise and sophisticated calculation formulas of measurement with laser and computerised topography, which lead us to an accuracy of results that would be impossible to achieve with conventional methods.
The procedure consists in performing a microincision in the cornea through which it will be possible to extract the natural lens by means of ultrasounds (phacoemulsification). The intraocular lens is then inserted through the same incision. These lenses are totally biocompatible and can be monofocal, toric or multifocal:
- Monofocal lenses provide an excellent far vision, yet to see close-up, the patient will need glasses to focus at that distance.
- Toric lenses are indicated in patients with astigmatism higher than 1 diopter, achieving an excellent vision without having to perform large incisions to correct that astigmatism. The patient will achieve an optimal far vision yet he/she will need glasses to see close-up.
- Multifocal lenses provide an excellent vision, both far and close-up, and are indicated in patients with astigmatism with less than 1 diopter.
- Toric lenses provide an excellent vision, both far and close-up, and are indicated in patients with astigmatism with more than 1 diopter.
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Myopia is a refraction defect that causes difficulty to see long-distance, in which objects are blurred.Myopia
Hyperopia us a refraction defect or error in the visual focus that causes blurred vision and a certain discomfort when looking a close-up objects.Hyperopia
Astigmatism is an optical defect that causes for the patient to see out of focus, sometimes with double image and even slightly deformed.Astigmatism