Retinal translocation and fixation using adhesive material

The present invention relates to a method of displacing an area of the macula of an eye, including the steps of placing a substance below the surface of the retina, folding the retina to form a folded portion of the retina, and affixing the folded portion, so that the folded portion substantially maintains a folded shape.

FIELD OF THE INVENTION

The present invention relates to using retinal translocation to correct vision caused by age related macular degeneration (ARMD). More specifically, the present invention relates to detaching the retina, folding the retina and securing the folded portion, so that the fovea is moved, and thereby correcting the vision in an eye.

BACKGROUND OF THE INVENTION

Age-related macular degeneration (ARMD) is the leading cause of blindness among persons over fifty in the United States and other countries. Two forms of age-related macular degeneration are known: (1) neovascular, also known as exudative, age-related macular degeneration (E-ARMD) and (2) nonneovascular, also known as nonexudative, age-related macular degeneration (NE-ARMD). NE-ARMD is characterized by the presence of drusen, yellow-white lesions of the retinal pigment epithelium within the macula, and by other abnormalities of the retinal pigment epithelium, including retinal cell death.

Although the exact etiology of ARMD is not known, several risk factors seem to be important for the manifestation of this disease. For example, ARMD may be caused by chronic exposure of the retina to light. The presence or absence of certain nutrients in the diet, such as the antioxidant vitamins E and C, also may affect one's predisposition for ARMD. Other conditions, such as hypertension and smoking, are also considered to be important risk factors for the development of this disease.

Several therapeutic methods have been tried. For example, vitamins and dietary supplements have been used for the purpose of delaying the onset of disease. Thalidomide is being investigated to determine if it will slow down or arrest new vessel formation. Laser or radiation has been used to destroy new vessels. However, none of these methods has led to successful results and no definitive treatment for ARMD has been developed to date.

Additionally, retinal translocation has been used to change the position of the fovea. Retinal translocation is a surgical method that involves injecting a fluid, such as saline solution, under the retina to loosen the retina. Gas is then injected into the vitreous to reattach the retina, and a scleral indentation is formed. This procedure results in displacement of the retina inferiority, placing the fovea on normal retinal epithelium.

However, the retinal displacement is generally unpredictable and minimal. For example, the displacement is generally only about 500–1000 microns. Thus, there is little area for subsequent coagulation of the subretinal membrane. Additionally, the displacement does not occur immediately during surgery, but during a recovery process that generally lasts about 24 hours. The displacement occurs due to the position of the head of the patient in a recovery situation. For example, since the head is generally held in an upright manner, the gas injected into the eye rises, thus forcing the retina from the top, moving the retina inferiority with respect to its original position. Furthermore, the retina can generally only be easily moved inferiority since the gas rises up relative to the eye and can only exert pressure to move the retina down.

Additional retinal translocation procedures exist wherein the retina is literally cut 360° and disassembled for translocation relative to the underlying tissue prior to re-assembly of the retina after its rotation. This procedure has 15–30% rate of severe complication and loss of vision.

These procedures are intended to treat conditions wherein the tissue underlying the macular (central vision) portion of the retina becomes diseased. Degenerative conditions of this sort may result in the photoreceptors of the macula portion of the retina adjacent to the underlying diseased tissue becoming non-functional over time. To avoid this result, the above procedures shift the position of the fovea (i.e., the central portion of the macular portion of the retina which is responsible for a person's sharpest vision) relative to the underlying inner surface of the sclera. This allows the fovea then to be reattached to healthier underlying tissue.

To accomplish this result, the Macular Translocation Procedure, which is less radical than the Retinal Translocation procedure, includes the following steps. First, sutures are placed in a horizontal mattress formation in an arc supero-temporally (i.e., just below the attachment of the recti muscle to the sclera) on the outer surface of the sclera. These sutures typically are located in the same position relative to the eye regardless of the exact location of the diseased tissue. Then, at least the macula portion of the retina is intentionally detached from the underlying tissue. This usually is accomplished by performing a 3 port pars plana vitrectomy followed by the use of a subretinal infusion cannula and a balanced salt solution to create the desired retinal detachment. The pre-placed sutures are then tightened and tied off. This results in the creation of an inwardly extending fold in the sclera that effectively “shortens” the scleral diameter. Thereafter, an air bubble is formed inside the eye so that the excess length of the retina relative to the shortened underlying scleral surface is moved. Then, a partial air-fluid exchange is made. The natural fluid removal generated by the pigment epithelium and choroid allow the macula portion of the retina, which has been shifted relative to the underlying tissue by the deformation of the sclera and by the formation of the air bubble, to settle gradually against, and reattach itself to, healthy tissue. Finally, several days after the surgical procedure, the diseased lesion is treated with standard laser photocoagulation.

The placement of the sutures in the macular translocation procedure is time consuming and, therefore, inefficient. It is also difficult to consistently predict when the retina will settle eventually. In some cases, it may not move at all. It is also difficult to predict the distance of scleral shortening that will result upon the tightening and tie off of the sutures. Further, the skill level required to place and to manipulate the sutures without causing extraneous damage to the eye, or surrounding bodily structures, is high.

Therefore, a need exists to improve the vision in an eye that is suffering from age related macular degeneration and make the surgical results predictable and visible immediately during surgery. There is also a need to move the retina superiorly or inferiorly as desired during the surgery.

SUMMARY OF THE INVENTION

An object of the present invention is to improve the vision in an eye suffering from age related macular degeneration and other macular diseases.

A further object of the present invention is to provide a method of moving the retina to a predetermined or predictable location in the eye.

Still a further object of the present invention is to provide a method of moving the retina during the surgical procedure or shortly thereafter.

These objects are basically attained by a method of displacing an area of the macula of an eye, including the steps of placing a substance below the surface of the retina, folding the retina to form a folded portion of the retina, and affixing the folded portion, so that the folded portion substantially maintains a folded shape.

These objects are further attained by a method of forming a fold in an area of the macula of the eye, comprising the steps of forming at least one opening through an external surface of the eye, which allows access to an area of the macula by detaching the retina by injecting a physiologic solution under the retina, inserting a member through the least one opening, contacting the area of the macula with an end of the member, folding the retina to form a folded portion, injecting an adhesive under the fold, at least a portion of the solution being contained with a portion of the folded portion.

DETAILED DESCRIPTION OF THE INVENTION

The eye10generally consists of a cornea11, a lens13, vitreous15, the optic nerve17and a retina14. As illustrated inFIGS. 1–5, the present invention relates to using retinal translocation to correct vision in eye10caused by age related macular degeneration. This is achieved by separating a portion12of the retina14from the choroid16using a substance18and folding the separated retinal portion12to move the fovea20. The folded retinal portion22is then affixed to itself, preferably using a bioadhesive26and folding the macula on itself. The substance18located between the retina14and the choroid16can then be removed by using any method desired, such as air-fluid exchange surgery.

Initially, during this procedure, as shown inFIG. 1, the retina14is detached by inserting or injecting a substance18under the surface28of the retina14to form a separated retinal portion12using a injector29. The substance18preferably is a saline solution and is inserted using a saline injector, as shown inFIG. 1, but can be any desired substance, such as any suitable gas, any suitable oil, or any suitable solid.

Each suitable substance can be inserted in any manner desired and is preferably injected, except a solid substance. When inserting a solid substance, it is preferable to form an incision in the retina and position the solid in the desired position using a grasping or gripping device, similar to device34, described below. The incision in the retina can then be closed, if desired, using any known or conventional method.

An opening30is formed in the outer surface of the eye, which allows access through the eye and into the internal posterior chamber32. As shown inFIG. 2, the separated retinal portion12is grasped using any suitable or desired device or member, such as a clipping or gripping device34, which is inserted through opening30formed in the eye. Using device34, the retina is then gripped or pinched and folded in the desired area. For example, the retina can be folded in the superior or the inferior area of the retina, depending on the desired direction of retinal displacement. A fold in the superior area moves the fovea upward (FIG. 6), and an inferior fold moves the fovea downward (FIG. 7), relative to the rest of the interior of the eye.

It is noted that gripping device34generally has a two handle portions35aand35bthat interact with the two gripping portions37aand37bto squeeze or pinch the retina therebetween. Portions35aand35bare coupled together at junction39, in a conventional manner. However, it is not necessary that the gripping device be constructed in this manner, and can be any type of device that would allow a fold in the retina to be formed. For example, the gripping mechanism can be two separate members that are manipulated to form the fold.

As seen inFIG. 3, once the desired fold is formed, adhesive26is preferably injected under the retinal fold or inside the fold using an adhesive applicator31, and the gripping device or member is removed through the opening30. The adhesive can be applied to the surface of the fold or under the surface of fold to any area desired that affixes the fold to itself or to the surface of the retina. The adhesive is preferably a bioadhesive, such as polydendrimer, but it can be any suitable material. The adhesive applicator is preferably has a tube40that is hollow with a end portion42that allows the adhesive26to be applied therethrough.

The applicator31is generally connected to a reservoir (not shown) that can pump the adhesive through the applicator. However, if desired, the applicator can have a plunger or syringe type device connected thereto, which would allow application of the adhesive.

Furthermore, the adhesive can be a material that can immediately affix the fold to the retina, or a bioadhesive that can be used to activate the adhesive in response to exposure to blue light or an argon laser, which initiates polymerization of the material.

It is noted that the adhesive does not necessarily need to be applied after the fold is created and can be applied at any suitable time. For example, in any process described herein, and particularly when using an adhesive that is activated in response to a laser, the adhesive can be applied at anytime prior to, during or after the formation of the fold.

Furthermore, if desired, the fold can be affixed using any other method or device desired. For example, a clip can be used to affix the fold to the superior or inferior area of the retina, or any combination thereof. Each of these types of mechanical securement methods can be permanent, semi-permanent or temporary. For example, a biodegradable mechanical securement device can be used along with adhesive that is activated post-operatively. The mechanical device would hold the fold in place until the adhesive was activated and then biodegrade over a certain period of time.

Once the fold is fixed in the desired position, the subretinal fluid or solution18is removed or withdrawn using standard air-fluid exchange surgery, wherein air is injected into the vitreous cavity using an air/gas injector41, and the subretinal fluid is removed using a “flute” needle36, as shown inFIG. 4.

Generally, as air or gas is pumped through the injector41and into the posterior chamber32of the eye, pressure is exerted on the folded portion22. This pressure forced the substance18through the flute needle36, and out of the eye.

This removal of the subretinal or saline fluid results in the fovea and/or the macula being moved to a predetermined position and a predetermined distance, as shown inFIG. 5.

When using a solid to reposition the fovea, it is noted that it is not necessary to close the incision made therein, since as with the saline fluid the solid substance is removed after the fold is created. Therefore, it is preferable to have the incision left open for the purpose of removal of the substance. However, the incision can be closed and reopened for removal of the solid substance, if desired.

Furthermore, it is not necessary to close the incision after the solid substance is removed, since the incision will heal on its own. However, if desired, the incision can be closed using an suitable methods, such as bioadhesive or any other desired methods.

The choroidal or the subretinal neovascularization can be coagulated surgically or using a laser, and can be performed either intraoperatively or postoperatively, or at any time or in any suitable manner.

As shown inFIGS. 6 and 7, the macula24has moved from its original position or placement44to a superior position (FIG. 6) or a inferior position (FIG. 7), depending on the location of the retinal fold22.

It is noted that the fold does not necessarily need to be formed only in the inferior (FIG. 7) or superior (FIG. 6) areas. The fold can be formed in any portion of the retina that would allow the macula or the fovea to move in any direction desired. For example, a fold can be formed that would move the fovea up, down, left or right or any combination thereof, relative to the rest of the interior of the eye.

Relative directions, such as up, down, left, right, superiority and inferiority are not meant to limit the invention and are merely used to further describe and explain the present invention.