ORTHOKERATOLOGY CONTACT LENS

Abstract

Provided is An orthokeratological contact lens having an inner profile intended to be placed on the corneal surface of an eye and modify the thicknesses of its epithelium to correct refractive defects. The inner profile comprises a disc shaped central curve, at least one annular reverse curve being connected annularly to the central curve and at least one annular outgoing curve tangentially connected to the at least one annular reverse curve at a circumferential connection line, so defining at least one circumferential reshaping area comprising each portion of said annular reverse curve and said annular outgoing curve adjacent to the circumferential connection line, the circumferential reshaping area being suitable for contacting the corneal surface and applying a determined annular pressure on the periphery of the cornea for reshaping the epithelium.

Claims

1. An orthokeratological contact lens having an inner profile intended to be placed on the corneal surface of an eye and modify the thicknesses of its epithelium to correct refractive defects, said inner profile comprising: a disc shaped central curve designed to centrally correct the refractive defect of the eye when placed concentrically with respect to its pupil, an annular reverse curve connected annularly to the central curve, at least a portion of the annular reverse curve having a smaller radius than the central curve, wherein the contact lens comprises an annular outgoing curve tangentially connected to the annular reverse curve at a circumferential connection line, so defining a circumferential reshaping area comprising each portion of said annular reverse curve and said annular outgoing curve adjacent to the circumferential connection line, the circumferential reshaping area being suitable for contacting the corneal surface and applying a determined annular pressure on the periphery of the cornea for reshaping the epithelium.

2. The orthokeratological contact lens according to claim 1, characterised in that the portions of said annular reverse curve and said annular outgoing curve adjacent to the reshaping line comprise a radius of curvature between 0.1 mm and 5 mm.

3. The orthokeratological contact lens according to claim 2, characterised in that the radius of curvature is between 1 mm and 3 mm.

4. The orthokeratological contact lens according to claim 1, characterised in that each portion of said annular reverse curve and said annular outgoing curve adjacent to the reshaping line comprise a different radius of curvature.

5. The orthokeratological contact lens according to claim 1, characterised in that the radius of curvature of any of the portions of said annular reverse curve and said annular outgoing curve adjacent to the reshaping line varies progressively according to a determined sphericity factor defined according to said determined annular pressure on the periphery of the cornea.

6. The orthokeratological contact lens according to claim 1, characterised in that a central portion of said annular reverse curve has an inclination angle α with respect to the tangent plane of the corneal surface between 5° and 85°.

7. The orthokeratological contact lens according to claim 1, characterised in that a central portion of said annular outgoing curve has an inclination angle β with respect the tangent plane of the corneal surface between 5° and 60°.

8. The orthokeratological contact lens according to claim 1, characterised in that it comprises: at least one further annular reverse curve connected annularly to the annular outgoing curve and at least one further annular outgoing curve connected annularly to the at least one further annular reverse curve at a second circumferential connection line, so defining at least one further circumferential reshaping area comprising each portion of said at least one further annular reverse curve and said at least one further annular outgoing curve adjacent to the circumferential connection line, the at least one further circumferential reshaping area being suitable for contacting the corneal surface and applying a determined annular pressure on the periphery of the cornea for reshaping the epithelium.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0035] In order to better understand the description made, a set of drawings has been provided which, schematically and solely by way of non-limiting example, represent a practical case of embodiment.

[0036] FIG. 1 is a schematic view of a symmetrical section of a first embodiment of the present contact lens.

[0037] FIG. 2 is an enlarged view of the inset A of FIG. 1.

[0038] FIG. 3 is a schematic view of a symmetrical section of a second embodiment of the present contact lens.

[0039] FIG. 4 is an enlarged view of the inset A′ of FIG. 3.

DESCRIPTION OF PREFERRED EMBODIMENTS

[0040] Some examples of embodiments of the present contact lens (1, 1′) are described below with reference to lens embodiments sections of FIGS. 1 to 4.

[0041] FIGS. 1 shows a first embodiment of the contact lens (1) having an axially symmetric inner profile intended to be placed on the corneal surface (0) of an eye and modify the thicknesses of its epithelium (0′) to correct refractive defects, said inner profile comprising: [0042] a disc shaped central curve (10) having a diameter (D) between 4 to 7 mm and being designed to centrally correct the refractive defect of the eye when placed concentrically with respect to its pupil, [0043] an annular reverse curve (11a) having a radial width (Wa) between 0.5 to 1.3 mm and being connected annularly to the central curve (10), at least a portion of the annular reverse curve (11a) having a smaller radius than the central curve (10), [0044] an annular outgoing curve (11b) having a radial width (Wb) between 0.5 to 1 mm and being tangentially connected to the annular reverse curve (11a) at a circumferential connection line (11), so defining a circumferential reshaping area comprising each portion of said annular reverse curve (11a) and said annular outgoing curve (11b) adjacent to the circumferential connection line (11), the circumferential connection line (11) being in contact with the corneal surface (0) at a corneal apex distance (D11) between 3 to 4 mm and [0045] a second annular reverse curve (12a) connected annularly to the annular outgoing curve (11b) and [0046] a second annular outgoing curve (12b) connected annularly to the first annular reverse curve (12a) at a second circumferential connection line (12), so defining at least one further circumferential reshaping area comprising each portion of said at least one further annular reverse curve (12a) and said at least one further annular outgoing curve (12b) adjacent to the circumferential connection line (12), the at least one further circumferential reshaping area being suitable for contacting the corneal surface (0) at a corneal apex distance (D12) between 3.70 to 4.2 mm.

[0047] As shown in FIG. 2, the portions (111a, 111b) of said annular reverse curve (11a) and said annular outgoing curve (11b) adjacent to the reshaping line (11) are defined by a single progressive radius of curvature (R), being its magnitude between 0.1 mm and 5 mm and asphericity between 0 and 2. By having a curvature in this range, the contact area defined by said portions (111a, 111b) applies a localised pressure without damaging the epithelium, reshaping it quickly and in an optimal manner. It also can be seen an inclination angle (α) of the annular reverse curve (11a) with respect to the tangent plane (shown in dotted lines) of the corneal surface (0) of about 45°, whereas the inclination angle (β) of the annular outgoing curve (11b) is about 35°.

[0048] FIGS. 3 and 4 show a second embodiment, wherein each portion (111a′, 111b′) of said annular reverse curve (11a) and said annular outgoing curve (11b′) adjacent to the reshaping line (11′) comprise a different radius of curvature (R′, R″); a first radius (R′) of about 0.1 mm, and a second radius (R″) of about 0.7 mm. Also in this embodiment, the annular reverse curve (11a′) has an inclination angle (α′) with respect to the tangent plane of the corneal surface (0) of about 85°, whereas the inclination angle (β′) of the annular outgoing curve (11b′) is about 35°.