Apparatus for performing surgery inside the human retina using fluidic internal limiting membrane (ILM) separation (FILMS)

Abstract

A method and apparatus for performing surgery inside the human retina using fluidic internal limiting membrane separation (FILMS) to remove the internal limiting retinal layer from the neural retinal layer at the macula. The method comprises inserting a hollow microcannula between the retinal internal limiting membrane and the neural retinal layer at or near the macula and injecting a sterile fluid, such as sodium hyaluronate, through said microcannula and thereby raising the macular internal limiting membrane retinal layer away from the neural retina such that it can then be removed by conventional means, while simultaneously smoothing the neural retina by localized pressure tamponad. The apparatus comprises a hollow microcannula having a proximal end a distal end and a distal tip. The distal end is shaped to conform tangentially to the surface of the retina. The distal tip is sharply beveled and adapted to discharge a fluid substance and to easily insert under the internal limiting membrane retinal layer and achieve occlusion of the lumen upon minimal insertion, and is sufficiently microscopic as to not substantially injure the neural retina when introduced under the ILM.

Description

[0001] THIS IS A DIVISON OF U.S. Ser. No. 09 / 111,146 FILED Jul. 6, 1998, THE DISCLOSURE OF WHICH IS HEREIN INCORPORPORATED BY REFERENCE.[0002] 1. Field of the Invention[0003] The present invention is directed generally to medical procedures and, more particularly to a medical procedure for removal of the innermost layer of the human retina (internal limiting membrane) from the underlying neural retina at the center of vision (macula).[0004] 2. BACKGROUND ART[0005] The rays of light entering the eye (FIG. 1) and bearing the pattern of the object being looked upon pass through the cornea 32, the aqueous humor, the pupil, the lens 34, and the vitreous humor, then fall upon the retina 26. The retina is the light sensitive film lining the back two-thirds of the eye. Its appearance is similar to that of wet tissue paper. Its layers consist of the internal limiting membrane (ILM), the neurosensory retina, and the retinal pigment epithelium; the ILM, being innermost, is the retinal border w...

AI Technical Summary

Problems solved by technology

This can cause loss of fine vision to the level of legal blindness.

This ILM cellophaning may persist or occur months after seemingly successful removal of EMP, limiting visual recovery.

A macular hole is thought to occur as a result of tangential traction on the retina at the macula, usually leading to legal blindness

This forceps procedure is the most delicate surgical maneuver performed on the human body.

Even minimal ILM surface traction has been increasingly implicated in many forms of maculopathy and often the EMP / ILM layers become, in effect, fused together, not allowing surgical removal of EMP alone.

However, the methods thus far developed for such ILM removal have certain deficiencies.

The method of mechanical pulling tearing away the macular ILM with forceps can cause severe trauma to the macula and the resultant injury can cause ocular damage of equal severity to the problem the surgery is meant to correct.

One problem with the current method of tearing and peeling away the macular ILM is the physical trauma associated with pulling on the ILM until it separates thereby unavoidably stressing the underlying nerve tissue, sometimes causing irreparable nerve damage with worsened vision than may have been present preoperatively.

Accordingly, the surgeon may proceed slowly and carefully but if too slowly the retina may be injured from light toxicity coming from the fiberoptic probe inside the eyeball enabling the surgeon's view.

If the surgeon grasps too shallow then his movements are ineffectual, adding to the time of surgery and the chance of light toxicity.

If the surgeon grasps too deep, permanent nerve damage and hemorrhage results.

The mass of the forceps, although ever so small, often obscures the surgeon's view, further adding to the chance of surgical damage to the retina.

Thus, for some twenty years, the removal of epimacular proliferation so as to restore central vision in the eyes that are approaching legal blindness has remained a vexing problem for vitreoretinal surgeons worldwide.

The potential surgical risks and the uncertain benefits, as well as the high level of skill required to perform such surgery has caused many surgeons to be reluctant to intervene until vision is substantially lost.

This device was introduced and has been substantially used, despite the obvious risk of damage to the neural retina which underlays these thin membranes by rubbing or scraping the retinal surface with an intentionally roughened instrument, as well as the risk of diamond chips dislodging and permanently remaining on the retinal surface within the eye.

Wang, however, did not apply this surgical procedure within the retina itself.

Moreover, the method affords a significant decrease in the surgical skill level needed to treat traction maculopathy and makes visual recovery more rapid, more certain, and more complete.

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