ES2211366A1 - Ablation platform for laser-assisted in position of keratomileusis, has handle which is attached to lower end to ring, where fixing unit is provided in lower end to convex-shaped platform - Google Patents

Abstract

The ablation platform has a handle which is attached to the lower end to a ring. A fixing unit is provided in the lower end to a convex-shaped platform. A corneal disk is also provided, where a platform is surrounded by a clamping ring. The platform has a convex curvature that is similar to the convex curvature of average human cornea.

Description

Posterior ablation platform for lasik.

Technical sector

The present invention relates to a surgical instrument that facilitates the application of the excimer laser, a laser that is used for the correction of ocular refractive defects (myopia, farsightedness and astigmatism), on the posterior aspect of the corneal disc that usually partially separates during the surgical technique called LASIK (laser in situ keratomileusis).

State of the art

The usual way to proceed in LASIK surgical interventions, both primary and re-treatments, consists in the application of the laser excimer on the anterior stromal face of the cornea that appears after the passage of an apparatus that separates a thickness of approximately one third of the cornea, portion of cornea that rises, of the two thirds remaining of it. To this anterior stromal face of the corneal tissue that does not lift is also called `` bed stromal. '' On some occasions, the thickness of the cornea that remains in the stromal bed, which is the one that provides structural integrity to the eyeball at this point, it is so thin that it can lead to the cornea bulges or ectasie yielding to intraocular pressure by result a layer too weak.

In order to structurally preserve the stromal bed as much as possible, the holder of the present invention, Dr. Miguel José Maldonado López, described for the first time in the scientific article published in 2002 in the magazine of the American Academy of Ophthalmology titled `` Undersurface ablation of the flap for LASIK retreatment. Ophthalmology 2002; 109: 1453-1464 '' a technique that allows correction of small amounts of myopia and astigmatism by the application of the excimer laser not on the stromal bed, as it is custom, but on the back of the corneal disc that separates during LASIK. In this way the laser ablates tissue corneal in a location that does not structurally influence the integrity of the eyeball, which prevents weaken the cornea and thus prevent ectasia or bulging of the same with time, which would associate myopia and / or astigmatism growing and difficult solution.

This technique of ablation of the back of the corneal disc has proven effective for the correction of ocular refractive defects mentioned above. However, the Surgical practice finds two great difficulties in it: 1) keep the patient's eye fixed in a deviated gaze position that matches the center of the corneal disc with the laser beam excimer, and 2) the ablation surface that is generated when extending the corneal disc on the surface of the eye (limbus corneal-scleral) is sub-optimal, when presenting with frequency undulations resulting from the disparity between the normal curvature of the cornea and limbus adjacent corneal-scleral, which is flatter, what which conditions a slower visual recovery for the patient.

So far there is no instrument surgical that can help solve these challenges that technique Surgical poses simultaneously, since they exist in the market different fixing rings, but none have a platform Convex support so that the corneal disc can be extended and exposed on its back properly.

Explanation

The posterior ablation platform for LASIK it comes to overcome the limitations of the technique outlined in the previous heading with the specific advantages of facilitating simultaneously: 1) an easier laser application, by maintaining the fixed eye in a deviated position, and 2) a visual recovery faster, by providing a surface of the rear face of the less irregular corneal disc, and therefore, a treatment of higher quality

This new instrument that is constituted by a handle that forks at its lower limb to configure a fork at the end of which two terminals of the fixation ring-platform set, so that it can have mobility in one direction while being able to be fixed to the eyeball with the pressure transmitted by the hand of the surgeon through said handle.

The fork of the mango is continued through the terminals or lateral projections of the fixing ring with it. The fixing ring consists of a circular structure from which protruding blunt projections on its lower edge with which is intended to fix the instrument on the globe eyepiece is firm and at the same time comfortable for the eye of the patient, an eye that usually previously receives anesthesia in drops form.

The ring has an anterior opening so that It is incomplete in its approximately 90 ° to 120 ° above. This anterior opening serves to adapt the ring assembly of fixing-platform to the hinge that joins the disk corneal that rises during these interventions with the rest of cornea, and that has a rectilinear arrangement.

The ring continues inside with the platform, structure designed to extend the disk corneal which, after rising, will be reflected back supporting its epithelial or superficial face on said platform, thus exposing up your stromal or internal face. This platform is not flat. but adopts the dome shape of a sphere with a radius similar to the one on average that shows the human cornea in its appearance central, so that the adaptation between the corneal disc raised and the surface on which it extends is greater and by therefore the above mentioned undulations do not appear in the Heading `` state of the art ''.

The platform, like the ring of fixation, is truncated in its anterior part to be able to adapt to the rectilinear configuration of the disc hinge corneal that rises and in which the instrument will fit.

The surface of the instrument is convenient that show poor reflectivity, so intense lighting The surgical microscope does not cause undesirable reflexes. Originally both the handle and the ring set fixation-platform of the instrument are made of stainless steel, although they could be made with other materials Metallic (such as titanium) or non-metallic.

Description of the drawings

Figure 1 shows an overview of the instrument in which you can see the configuration of the handle and of the fixation ring-platform set. How shown in figure 1, the handle is stylized and forks in its lower part to be able to embrace the external appearance of the ring fixation.

In window 1 you can see the detail of the union of the two pieces, the handle and the ring set of platform fixing. The lateral projections of the ring that are set on the lower end of the fork of the handle allow the ring set of platform fixing has sufficient mobility as to adapt to the position of the deviated eye.

In window 2 the ring set of platform fixation from a lower perspective which allows to observe the projections as small spikes of the fixing ring

Windows 1 and 2 also show the convex configuration of the platform that is set in the ring of fixation truncating both in its previous aspect to allow its adaptation to the anatomy of the corneal disc and its hinge during LASIK intervention.

Description of an embodiment

The instrument in question consists of a handle that It has a straight section of 71.79 mm in length and 4 mm in diameter, which continues with an angle of 165 ° with another section of 18.21 mm (millimeters) in length and a progressively larger diameter thin (3 mm in diameter decreasing to 2 mm), which is continued at its lower end with an angle of 222 ° with a fork 16.79 mm in length and an opening of 13 mm. These angulations They are designed with the purpose of saving anatomical reliefs of the bony flanges of the orbit while allowing a good display of the platform regardless of the position of the surgeon's hand, be it upper, nasal or oblique

The fixing ring has a height of 1 mm, an external diameter of 13 mm and an internal diameter of 12 mm with a opening in its anterior portion of 120 °. From the lower edge of the ring split 15 lower projections, equidistant from each other, 0.33 mm high and 0.15 mm long.

The platform occupies all the space it leaves inside the inner diameter of the fixing ring and has a 0.4 mm thickness. The platform adopts a dome shape spherical 7.68 mm radius that is truncated in its previous aspect with an extension of 120 ° coinciding with the opening of the ring of fixation.

The matter with which the instrument is stainless steel of a greater hardness in the set fixing ring-platform than in the handle. The Instrument finish offers a sparsely surface reflective to allow more comfortable work under the lights of the surgical microscope.

Industrial application

This device can be manufactured by the Surgical instrument manufacturing industry. Your end use it is obvious that it concerns the scope of surgical treatment, especially eye refractive defects by technique LASIK, either in primary interventions or in re-treatments

Claims (3)

1. The object of the invention is a new instrument for eye surgery that is constituted by a handle that is attached at its lower end to a fixing ring that contains a convex platform inside, truncating both the fixing ring as the platform in its previous aspect, so that it can be applied on the eye in the context of LASIK-type eye surgery allowing the laser to be released on the posterior aspect of the corneal disc in a stable position and without irregularities. This instrument is characterized by containing a platform surrounded by a fixing ring, both cut at a perimeter equal to or greater than 90 ° in its anterior part, and which is attached at its back to a handle that facilitates its handling. 2. An instrument for eye surgery according to claim 1, characterized in that the platform it contains has a diameter equal to or greater than 6 mm. 3. An instrument for eye surgery, according to the preceding claims, characterized in that the platform it contains is not flat, but convex, presenting a curvature similar to that of the average human cornea (equivalent to a radius of approximately 7.68 mm ) and because the surface finish is poorly reflective.