Refractive Surgery: How is the operation? -Oftalvist

Refractive surgery / Myopia, hyperopia and astigmatism surgery

Refractive surgery techniques

At Oftalvist we carry out the following surgical procedures for correcting myopia, hyperopia and/or astigmatism.

Laser eye surgery (FemtoLasik)

Broadly speaking, Lasik, or laser in situ keratomileusis, is the safest and most well-known laser eye surgery technique in the world for correcting myopia, hyperopia and astigmatism, or a combination of myopia or hyperopia with astigmatism.

At Oftalvist we have been pioneers in Spain and Europe since 2004 when it comes to the use of femtosecond technology for the first stage of surgery (of the two stages involved in the procedure), to make the operation as safe and precise as possible.

As such, as opposed to other centres that continue to use a mechanical microkeratome with a blade for Lasik surgery, our centres offer patients a more advanced 100% laser surgery procedure (femtosecond laser + Excimer MEL 90 laser).

Patients should therefore be aware that not all types of Lasik surgery are the same, so they should find out about the technique and technology being used for the eye surgery in question.

How is 100% laser eye surgery performed?

First stage: the surgeon removes a thin layer of the corneal tissue. This process can be carried out with either a mechanical microkeratome with a blade, or with a femtosecond laser. At Oftalvist we use the second option.

At other clinics

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Mechanical microkeratome with blade

At Oftalvist

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Femto-Lasik femtosecond laser

Second stage: we correct the patient’s vision by reshaping the cornea using an Excimer laser (MEL 90). We then put the layer of corneal tissue back in place and reseal it without the need for sutures.

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Advantages of Lasik Surgery with femtosecond laser (FemtoLasik) over Lasik with a blade:

→ 100% laser surgery.

→ World-class technology: the safest and most precise, predictable and consistent surgery.

→ Less increase in intraocular pressure.

→ Suitable for a larger proportion of patients with dry eye.

→ The surgeon has a full view throughout the process.

→ Fast recovery: stronger and more stable scarring.

Intraocular lenses

An ICL is a phakic lens, which means that it can be implanted without the need to remove the transparent crystalline lens from the eye. The surgeon will place it in the posterior chamber behind the pupil, between the iris and the crystalline lens.

This technique is ideal for patients, particularly young people, with high myopia or hyperopia, limited vision or very thin corneas that cannot be treated with the standard Lasik technique. ICL lenses can correct up to 18 dioptres in myopia and 10 in hyperopia. Patients with symptoms of astigmatism and diagnosed as such can also be treated with a different version of this lens, called a toric lens.

PRK

The PRK technique involves separating the epithelium, which is the outer layer of the cornea, using a special alcohol solution (rather than making a corneal flap, as with the Lasik technique).

After removing the corneal epithelium, the surgeon will then use the Excimer laser to adjust the thickness of the cornea to remove the dioptres and resolve the refraction error, whether it be due to myopia, hyperopia and/or astigmatism.

The operation takes around 10 minutes and is performed using topical anaesthetic (eye drops). Patients with very thin corneas are eligible for this procedure, and will be left with good visual acuity afterwards. It is recommended for people who practice contact sports.

Recovery

Complications and/or risks of refractive surgery

Although it’s true that the rates of unforeseeable complications have fallen drastically with the introduction of laser technology, which we use in our centres, we will outline some of the potential side effects that may arise from laser refractive surgery, primarily during recovery:

Dry eye

Patients that regularly wear contact lenses and suffer from dry eye syndrome may experience discomfort due to eye dryness after undergoing laser surgery to correct myopia, hyperopia and/or astigmatism for a few months afterwards, such as irritation or a sensation of having something in their eye.

This can be relieved through the use of artificial tears. However, thanks to femtosecond laser technology, there are now a larger proportion of patients with dry eye that are suitable for this surgery.

Minor residual refractive error

This happens in around 5% of surgeries. In general, this can easily be corrected 12 weeks later with a readjustment procedure.

Infection

This happens very rarely, with an incidence rate of less than 0.4%, as it can be prevented with the right medication. The period of greatest risk is the first 72 hours.

The best way to prevent this complication is to take antibiotics before and after laser surgery. Patients should also attend all their follow-up appoints with the ophthalmologist.

Flap complications (flap dislocation)

This happens with less than 0.5% of patients. It occurs when the flaps are not positioned correctly or when they have to be repositioned after surgery, so they become dislocated from the cornea.

This complication can arise after surgery, which is why we recommend that patients rest properly. The likelihood of this complication is reduced by performing the surgery more quickly, which we are able to achieve thanks to the cutting-edge femtosecond laser technology.

Dislocation of the flap due to injury

This may happen as a result of a knock or an injury up to 7 years after the operation. If this happens, the patient should go to the ophthalmologist straight away.

Eye rubbing

If the patient rubs their eye after the surgery, they could cause the corneal flap to dislocate. This can be easily resolved by going back to the ophthalmologist.

Possible ballooning of the cornea

This will only happen if the cornea is very weak. It is a very rare complication. The ophthalmologist may detect this issue in the preoperative consultation and rule out surgery.

For all these reasons, the initial preoperative consultation is an essential part of the surgery. This is where the ophthalmology specialist will perform myopia, hyperopia and/or astigmatism tests to assess the characteristics of each patient’s eyes and determine the most suitable technique. This will help to avoid any unnecessary risks.

The ophthalmologist may also rule out certain patients who are not eligible to undergo laser refractive eye surgery. Patients may be ruled out if they have scarring on their cornea, if they’ve had an eye infection in the past year, if they have a history of herpes or other disorders, such as Sjögren’s syndrome or lupus, or if they suffer from keratoconus.