Myopia operation: everything you need to know

The myopia operation consists of laser surgery to reshape the cornea (the transparent part of the eye) by removing tissue (photoablation) to modify the focus of the images we perceive, as José Luis Mendoza, ophthalmologist, explains to CuídatePlus. of Clínica Baviera, in Vigo.

However, there are different techniques in the laser operation for myopia depending on the number of diopters that need to be corrected, according to Ignacio Jiménez-Alfaro Morote, head of the Ophthalmology Service at the Fundación Jiménez Díaz, in Madrid, and professor of Ophthalmology at the Autonomous University of Madrid. “For low and moderate myopia, excimer laser corneal ablation techniques are used to remove corneal tissue with the intention of flattening the cornea, which reduces its curvature and therefore the number of diopters. The surgical techniques in which the excimer laser is used for refractive purposes are PRK and LASIK, the latter being perhaps the most common”, explains Jiménez-Alfaro.

Specifically, LASIK allows the entire intervention to be carried out with laser and is indicated to correct myopia of up to 7 diopters. "In lower graduations, up to 2 and 3 diopters or when the corneal thickness or the state of the ocular surface advise it, the ablation can be performed directly on the cornea after removing the epithelium with the technique called PRK (refractive photokeratectomy)", specifies the head of the Ophthalmology Service of the Jiménez Díaz Foundation. In his experience, the visual results are equivalent with both techniques, although with PRK the discomfort after the operation and the recovery time is somewhat greater than with LASIK. "Above 6 and 7 diopters of myopia, intraocular surgery must be resorted to, implanting intraocular lenses", this ophthalmologist specifies.

So, which patients can undergo myopia surgery? “Patients between the ages of 18 and 60, with myopia in the range of 0 to 8 diopters, with stable prescriptions, and compatible general and ocular examinations can be operated on,” replies the ophthalmologist at Clínica Baviera. For his part, Jiménez-Alfaro considers that, although LASIK and PRK techniques can be applied to patients of any age, a minimum age of 21 years is normally required to guarantee a certain stability of the refractive error. “However, we are flexible with those patients who undergo surgery for professional reasons, lowering this lower limit to 18 years. Above 40 or 45 years of age, it is necessary to always keep in mind the subsequent need for glasses for near vision”, clarifies this specialist.

When is the myopia operation not recommended?

Operación de miopía: todo lo que debes saber

On the contrary, there are cases in which this intervention is contraindicated, mainly in patients with previous corneal diseases or alterations and moderate or severe dry eyes, according to Mendoza. Other situations in which Jiménez-Alfaro does not advise performing refractive laser surgery (myopia operation) are pregnancy, lactation and if there is treatment with drugs to combat acne such as isotretinoin and the like. In his opinion, it is also not recommended in patients with rheumatoid arthritis, lupus, and other collagen diseases.

“At the ophthalmological level, adequate eye health is required: It is not recommended in patients with glaucoma, cataracts and certain corneal diseases, including keratoconus. Individuals with dry eye syndrome are also not good candidates for LASIK, PRK being preferable in these cases”, emphasizes Jiménez-Alfaro.

Likewise, this professor of Ophthalmology at the Autonomous University of Madrid recalls that "the patient must meet a series of criteria in relation to corneal thickness, regularity of the corneal surface and tear function, which are verified in preoperative examinations."

Risks associated with myopia surgery

According to Jiménez-Alfaro, the risks of laser refractory surgery or myopia surgery are minimal because it is a very effective and safe technique, provided that the indication is appropriate and all the criteria required for each technique are met. “However, the possible serious complications that may appear are, as in any surgery, infection and corneal inflammation. These complications are absolutely exceptional”, points out this ophthalmologist and continues: “In some cases, after the intervention, some residual refractive error may persist as a result of the corneal repair process, which can be re-operated on if the conditions of the cornea allow it”.

Along the same lines, Mendoza highlights that “after more than 25 years of experience, these surgeries are very safe in properly selected patients. In general, as mild effects, there is the aggravation of the previous ocular dryness and, at the other extreme, there would be very infrequent infection processes”.

For Jiménez-Alfaro, other complications such as corneal ectasia (weakening and deformation) after LASIK or corneal scarring after PRK are exceptional as long as the required criteria are met and the techniques are performed correctly. “Nowadays, with new technologies, side effects like halos, or difficulty with night vision are rare. Most of these side effects are temporary and disappear within a few days or weeks after surgery, "concludes this expert. In addition, both specialists recommend following all the self-care guidelines indicated by the health professionals after the intervention.