PARIS, July 11 (EDITIONS) –
The high demand for corneal transplants has given rise to much research in the field of “artificial corneas”, made from new materials or the patient’s own tissue; it would thus be possible to manufacture highly biocompatible corneas without resorting to donors.
“Corneal transplants are a common procedure, given the high success rate and volume of donations in our country. In Spain alone, around 5,000 corneal transplants are performed each year.Dr. Carlos Lisa, surgeon at the Cornea and Lens Unit of the Fernández-Vega Institute of Ophthalmology (IOFV), said in an interview with Infosalus: “This is the most common type of transplant common in Spain.
More precisely, This expert recalls that the cornea is the most anterior tissue of the eyeball “it would be like the crystal of the watch”, and a window through which we see, “the first lens that light encounters when it reaches our eye”. The eye bank is responsible for collecting, studying and maintaining donated corneas (from a deceased person) to ensure the suitability of the tissue.
CORNEAL DAMAGE THAT COMPROMISES VISION
According to the doctor, transplantation is indicated when there are corneal lesions that affect the quality or quantity of vision, and cannot be recovered by more conservative techniques. “It is generally due to pathologies that affect its transparency,” he specifies.
Among them, this ophthalmologist indicates that infections secondary to the use of contact lenses or those related to the herpes virus, which cause the appearance of opaque scars, stand out.
“Other common pathologies are keratoconus (excessive curvature of the cornea) and Fuchs dystrophy, which involves accelerated damage to endothelial cells responsible for maintaining transparency. These cells are lost naturally over the years, but can also be damaged following repeated intraocular procedures,” he adds.
TYPES OF CORNEA TRANSPLANTATION
According to Dr. Lisa, There are two types of grafts: the “penetrating or complete graft”, the “penetrating or complete graft” and the “penetrating graft”.which aims to replace the entire cornea with a healthy cornea, including the three main layers of the cornea (epithelium, stroma and endothelium), and is indicated when the disease affects them all; the other option encompasses anterior or posterior lamellar grafts.
“In the latter case, we only replace the diapers that are damaged. Anterior lamellar grafts are indicated, for example, in case of corneal herpes or keratoconus, and posterior lamellar grafts (or endothelial grafts) in case of Fuchs endothelial dystrophy or bullous keratopathy. Lamellar grafts are more effective and safer, facts that translate into faster visual rehabilitation and a lower incidence of complications such as glaucoma, infection or rejection of the graft, ”explains the specialist from the Fernández-Vega Ophthalmology Institute.
WHAT THIS OPERATION CONSIST OF
Today, the surgeon of the Cornea and Lens Unit of the Fernández-Vega Institute of Ophthalmology says that regarding 9 out of 10 operations are partial corneal transplants. ” This surgery involves manually removing the damaged layers of the cornea while preserving the healthy layers. In anterior corneal surgery, we remove 95% of the thickness of the cornea formed by the epithelium and stroma and preserve the endothelium, so there is no need to penetrate the eyeball. We then suture the donor cornea with 16 stitches,” he explains.
In the last ones, he indicates that we access the inside of the eye to extract the endothelium (internal layer of 20 microns) and that we implant, through a small incision of 3 millimeters, a donor endothelium which will remain attached to the rest of the diapers without the need for sutures.
IS SIGHT COMPLETELY RESTORED?
With all this, this ophthalmologist points out that the postoperative period following the transplant is more relaxed since the appearance of lamellar or partial grafts, and requires relative rest for regarding 1-2 months, following which the patient’s return to the labor market can be assessed.
On visual recoverythe expert from the Fernández-Vega Ophthalmological Institute maintains that it is progressive, with an improvement over the previous situation being observed from the first days.
As for whether complications might arise, this doctor acknowledges that “the possibility always exists” and “no matter how sophisticated the surgical techniques”, but he insists that patients know that keratoplasty is a well-established technique with a very high success rate.
In the case of releases, he finds it best to refer to them as “episodes”, since they can be controlled in the vast majority of cases by means of eye drops and it is very rare today, in partial techniques, for rejection to be synonymous with failure. “The rejection rate is between 1 and 9% for laminar techniques, and between 25 and 34% for penetrating techniques,” he specifies. In the latter case, however, he points out that, depending on the pathology, oral immunosuppressants may be necessary.
“To improve the prognosis of these penetrating grafts, we have designed a surgical technique called ‘keratoplasty protected by a pseudo-camera with intercorneal implant’, which avoids perforating the cornea. During the three years that this procedure has been performed at the IOFV, very satisfactory results have been obtained. Corneas that would otherwise have had a very poor prognosis have been advanced. The new implant, which has had CE marking since June 2020, was supported throughout the research process at the Fernández-Vega Institute by the BBVA Foundation and was developed in collaboration with the Spanish company AJL Ophtalmic, specifies the specialist. .
