Intracorneal ring and procedure to place same

• US 20060212115A1
• Filed: 03/17/2006
• Published: 09/21/2006
• Est. Priority Date: 03/18/2005
• Status: Abandoned Application

• Current Assignee: Arturo Maldonado Bas
• Original Assignee: Arturo Maldonado Bas
• Inventors: Maldonado Bas, Arturo
• Application Number:
  US11/378,814
• Publication Number:
  US 20060212115A1
• Time in Patent Office: Days
• US Class Current: 623/5.120
• CPC Class Codes: A61F 2/147 Implants to be inserted in the stroma for refractive correction, e.g. ring-like implants

Abstract

The intracorneal ring is made up of a suitable material deformable with compression and with an appropriate molecular memory so that, being at rest, it can take the shape of a ring. The ring has an outside diameter between 5 and 7 mm, a wall thickness between 0.25 and 0.4 mm, and an inner diameter of about 4.5 to 6.2 mm. When dealing with the keratoconus treatment, the ring is placed in a concentric position with respect to the cone apex and inside the thickest area of the cornea. In the astigmatism correction, it is placed in a pocket done in the corneal stroma, thus behaving as a curvature modifier of the cornea anterior face.

Claims

1. Intracorneal ring made up of a biocompatible material comprising a suitable material deformable with compression and with an appropriate molecular memory so that while at rest the material can take the shape of a ring, said ring having an outside diameter between 5 and 7 mm, a wall thickness between 0.25 and 0.4 mm, and an inner diameter about 4.5 to 6.2 mm, wherein, in keratoconus treatment, said ring is placed in a concentric position with respect to a cone apex and in a thickest area of the cornea, and wherein in astigmatism correction, said ring is placed in a pocket done in a corneal stroma, thus behaving as a curvature modifier of a cornea anterior face.

2. The intracorneal ring according to claim 1, wherein said ring is made of an heterologous and biocompatible material.

3. The intracorneal ring according to claim 1, wherein said ring is made of polymethylmethacrylate.

4. A procedure to place an intracorneal ring made up of a biocompatible material comprising a suitable material deformable with compression and with an appropriate molecular memory so that while at rest the material can take the shape of a ring, said ring having an outside diameter between 5 and 7 mm, a wall thickness between 0.25 and 0.4 mm, and an inner diameter about 4.5 to 6.2 mm, implying an incision and a subsequent suture, comprising:

a first step to mark a visual axis and an apex of a keratoconus and a selection of one of those axes so that, centering with a cone or a papillary axis, an external mark can be made with gentian violet over a corneal epithelium as a guide to determine a dissection area of a pocket to hold the ring;

a second step to determine a corneal thickness and keratoconus location;

a third step to make a limbal incision between 5 and 5.5 mm with a depth 80% less that a corneal apex pachometry, dissection and formation of a pocket in the cornea following lamellas of parallel faces until reaching a central area;

a fourth step to dissect the pocket formed in the previous step;

a fifth step in which, in a first stage the intracorneal ring is held with pincers appropriate to blend flexible intraocular lens, in a second stage the ring is pressed and deformed in order to get it oval shaped, in a third stage the ring is introduced in the dissected pocket and in a fourth stage the pincers are opened so that the ring regaining its original shape can unfold inside the corneal stroma and in a sixth step, the intracorneal ring is placed in a desired position in relation to pocket borders.

5. The procedure according to claim 4, wherein in the second step the corneal thickness is determined by means of a pachometric map and the location of the keratoconus by means of mydriasis retro lighting.

6. The procedure according to claim 4, wherein in the third step the dissection is carried out with a crescent bevel up.

7. The procedure according to claim 4, wherein in the fourth step a dissector with a concave inferior surface is used in order to dissect a pocket of a slightly bigger diameter than the intracorneal ring to be placed.

8. The procedure according to claim 4, wherein in the sixth step the intracorneal ring is placed in the desired position while thrusting the ring softly with an instrument.