CN115016145A - Defocused sclera contact lens - Google Patents

Abstract

The invention discloses a defocused scleral contact lens, which relates to the technical field of ophthalmology and includes a base arc area, a defocused area, a transition area and a seating area. The front surface of the scleral contact lens is an optical area. The focal zone, the transition zone and the seating zone are arranged concentrically from the center to the edge of the rear surface of the scleral contact lens in turn, the base arc zone is located on the rear surface of the scleral contact lens, and is spherically rotationally symmetrical, and the transition zone is located above the scleral limbus. , is a rotationally symmetric aspherical design and does not contact the corneal and scleral limbus, the seating area, located on the back surface of the scleral contact lens, is rotationally symmetric on a spherical surface, conforming to the sclera morphology of the contact area, and is in contact with the sclera. Through the cooperation of the above structures, the present invention realizes that the contact lens can retain the therapeutic effect of traditional scleral lenses on dry eye and keratoconus, and provide induced defocusing around the retina, thereby delaying the development speed of the wearer's myopia.

Description

A defocused scleral contact lens

technical field

The invention relates to the technical field of ophthalmology, in particular to a defocused scleral contact lens.

Background technique

The first scleral lens appeared in the late 19th century by glass blowing. For more than 100 years, with the continuous improvement of design level, material research and development, and processing level, scleral lens has developed into a new design, new A high-end product formed by the intersection of technology, high oxygen permeability material and diagnostic fitting technology.

The usual method of correcting vision is to wear frame lenses and contact lenses. Among them, the commonly used hard contact lenses directly contact the cornea and wear it on the cornea, but there are more sensory nerve cells on the cornea, which are more sensitive to contact objects. Sensitive, when rigid contact lenses are worn directly on the cornea, patients with corneal diseases (eg, keratoconus, dry eye) are at risk of aggravating foreign body sensation or other uncomfortable symptoms.

For the above problems, the prior art proposes a scleral lens that does not contact the cornea and land on the sclera outside the limbus. Specifically, the diameter of the contact lens is increased to make the lens larger than the entire cornea, so that all the lenses are in contact with the ocular surface. The touch point was changed from the cornea to the less sensitive sclera to reduce the risk of damage to the pathological cornea and the presence of foreign body sensation.

When the problems brought about by hard contact lenses are solved by scleral lenses, the optical performance becomes the focus. The human eyeball can actively adjust emmetropia through the contraction of the lens driven by the ciliary muscle, and the growth of the eyeball depends on the focusing of the peripheral parts of the retina. When shortsighted patients wear ordinary frame glasses for vision correction, because ordinary frame glasses only correct the central vision the clearest, the lens design itself is to gradually increase or irregularly increase the degree of power in areas other than the central luminosity. In this case, after correction, The visual light is projected to the fovea to ensure clear vision, but the image received by the peripheral retina is not exactly on the retina, but is imaged on the back of the retina, forming what we now think of as hyperopic defocus, thereby inducing the eyeball It grows backward and promotes an increase in the degree of myopia.

There are many patients with myopia caused by eye diseases such as severe dry eye syndrome and keratoconus, and these patients are not suitable for using defocusing frame lenses. Ordinary scleral lenses cannot achieve the effect of myopia prevention and control, so we propose a defocused scleral contact lens.

SUMMARY OF THE INVENTION

The purpose of the present invention is to provide a defocused scleral contact lens, which can retain the therapeutic effect of traditional scleral lenses on dry eye and keratoconus, and induce defocusing around the retina, thereby delaying the wearer's myopia. The speed of development solves the problems raised in the above background technology.

In order to achieve the above object, the present invention provides the following technical solutions: a defocused scleral contact lens, comprising a base arc area, a defocused area, a transition area, and a seating area, and the front surface of the scleral contact lens is an optical area, and the base arc area, The defocus area, the transition area, and the seating area are arranged concentrically from the center to the edge of the rear surface of the scleral contact lens in turn;

The base arc region is located on the rear surface of the scleral contact lens, and is spherically rotationally symmetrical;

The transition area above the corneoscleral limbus area is rotationally symmetrical aspherical design and does not contact the corneal and scleral limbus. In contact with the sclera, it can position the scleral contact lens and provide uniform support, and ensure that the base arc area, the defocus area, and the transition area will form a tear layer between the cornea and the lens;

The optical zone spans the area above the cornea and is located on the front surface of the scleral contact lens, and is used to focus the final image of the transmitted light through the tear layer formed by the base arc zone and the transition zone on the retina;

The defocal zone is located on the back surface of the scleral contact lens, between the base arc and the transition arc, and is used to image the transmitted light through the tear layer formed by the base arc zone and the transition zone in front of the retina.

Preferably, the diameter of the scleral contact lens is 14.5 mm˜17 mm.

Preferably, the base of the posterior surface of the scleral contact lens is designed as a continuous curved surface with a predetermined shape, and the sagittal height of the posterior surface decreases gradually from the center of the base arc region to the seating region.

Preferably, the transition area of the scleral contact lens is designed by the limbus state, and the sagittal height of the posterior surface of the transition area is greater than the sagittal depth of the corneal peripheral area of the eyeball.

Preferably, the sagittal height of the optical zone matches the sagittal depth of the central corneal region of the eyeball, the sagittal height of the transition zone matches the sagittal depth of the peripheral corneal region of the eyeball, and the sagittal height of the limbus landing zone matches the corneal limbus of the eyeball The sagittal depth of the scleral landing zone matches the sagittal depth of the sclera of the eyeball, the sagittal height of the posterior surface of the optical zone is greater than the sagittal depth of the central corneal zone of the eyeball, and the sagittal height of the posterior surface of the transition zone is greater than Sagittal depth of the peripheral corneal region of the eyeball. Thereby, a gap can exist between the scleral contact lens and the cornea, and a tear layer that is not easily evaporated can be formed, thereby forming a tear lens.

Preferably, the diameter of the optical zone is set to be 7.2mm to 7.8mm, the width of the defocus zone is set to be 1.2mm to 1.8mm, the width of the base arc zone is set to 10mm, and the radius of curvature of the base arc zone is set to 6mm to 9mm, the diameter of the transition zone is set to 12mm to 14mm, the diameter of the seat zone is set to 14.5 to 17mm, and the radius of curvature is 10.5mm to 13.5mm.

Preferably, the thickness of the tear lens formed by the tear layer of the scleral contact lens ranges from 100 μm to 300 μm.

Preferably, the coupling between the central optical zone and the defocus zone is gradually flat, and the coupling between the defocus zone and the edge of the lens is gradually steeper.

Preferably, the optical zone is set to be a concave lens sheet, and the degree of the optical zone is set to be -20.00DS～0.00DS.

Preferably, the center thickness of the scleral contact lens is 0.1 mm˜2 mm.

Preferably, the out-of-focus area is set as a convex lens sheet, and its degree is set to be +1.00D～+20.00D.

Compared with the prior art, the beneficial effects of the present invention are: the defocused scleral contact lens of the present invention is convenient for the wearer to use, friendly to patients with dry eye and keratoconus, and can induce the peripheral defocus of the retina to delay the wearer's myopia The development speed of the wearer can stabilize the vision of the wearer and avoid the problem of corneal damage.

Description of drawings

In order to illustrate the technical solutions of the embodiments of the present invention more clearly, the following briefly introduces the accompanying drawings used in the description of the embodiments. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can also be obtained from these drawings without any creative effort.

Fig. 1 is the structural representation of the present invention;

Fig. 2 is the contrast diagram of Fig. 1 of the present invention;

Fig. 3 is the schematic diagram that the scleral contact lens of the present invention is worn and on the eyeball;

FIG. 4 is a schematic diagram of imaging on the retina of light passing through a defocused scleral contact lens provided by the present invention.

In the figure: 1. Base arc area; 2. Defocus area; 3. Transition area; 4. Sitting area; 5. Optical area.

Detailed ways

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, but not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

1 to 4, the present invention provides a technical solution: a defocused scleral contact lens, comprising a base arc area 1, a defocus area 2, a transition area 3, a seating area 4, and an optical area 5, wherein the base arc area Zone 1, defocus zone 2, transition zone 3, and seat zone 4 are arranged in order from the center to the edge of the rear surface of the scleral contact lens, and the structure is a concentric circle structure, and the base arc zone 1 is located on the rear surface of the scleral contact lens and is a spherical rotation Symmetrical, conforming to the corneal geometry, it does not contact the cornea, preserves the proper tear gap, provides good visual quality, and does not irritate the cornea.

Transition zone 3 above the corneoscleral limbus, rotationally symmetrical aspherical design, no contact with the corneal and scleral limbus, there is very little tear gap, reducing the pressure of the scleral contact lens on the tissue, the seat zone 4 is located on the rear surface of the lens, spherical rotational symmetry , which conforms to the sclera shape of the contact area, is in contact with the sclera, can position the lens and provide uniform support, and ensure that the base arc area 1, the defocus area 2, and the transition area 3 will form a tear layer between the cornea and the lens.

Optical zone 5 spans the area above the cornea, covers the base arc zone 1 and the defocus zone 2, and is located on the front surface of the scleral contact lens, and is used to focus the transmitted light through the tear layer formed by the base arc zone 1 and the transition zone 3 for final imaging on the retina.

The defocused area 2 is located on the posterior surface, between the base arc and the transition arc, and is used to image the transmitted light through the tear layer formed by the base arc area 1 and the transition area 3 in front of the retina.

In order to ensure reliable contact between the seating area 4 and the sclera, there is no pressure on the sclera. The diameter of the seating area 4 is set to be 14.5mm to 17mm, the width is set to be 2.5mm to 3.5mm, and the radius of curvature is set to be 10.5mm to 13.5mm.

In order for the wearer to see clearly, the optical zone 5 needs to cover the base arc zone 1 and the defocus zone 2, so the diameter of the optical zone 5 is 8.2 mm˜9.8 mm. The optical zone 5 on the front surface is connected to the edge of the lens through a connecting arc, and the connecting arc is required to ensure that the thinnest area of the lens is greater than 0.16mm and less than 2mm.

In order to make the wearer see clearly, the width of the base arc area 1 is set to 7.6 mm, the radius of curvature of the base arc area 1 is set to 6 mm to 9 mm, and the width of the defocus area 2 is set to 1.2 mm to 2.2 mm.

In order to solve the problem of dry eye in patients, the base arc area 1, the defocus area 2, and the transition area 3 form a tear layer, and the thickness of the tear layer should be 100-300 μm.

The optical zone 5 is set as a concave lens sheet, the degree of which is set to be -20.00DS～0.00DS, and the thickness of the center of the lens of the defocused scleral contact lens is 0.1mm～2mm.

The defocused scleral contact lens of the present invention is placed on the front surface of the user's eyeball when in use, contacts the sclera, and forms a tear layer on the cornea and the limbus of the cornea. Since the optical zone 5 and the defocused zone 2 have different focal points, the defocused effect is produced. , after the light passes through the optical zone 5, the image is focused on the retina, and after the light passes through the defocus zone 2, the image is focused in front of the retina to achieve myopia and defocusing. The base arc zone 1 and the defocus zone 2 do not contact the cornea, so they are relatively flat , the transition area 3 plays the role of erecting the base arc area 1 and the defocus area 2, so it is steeper than the base arc area 1. Because of its steepness, it cannot be extended in parallel with the sclera. Therefore, the sitting area 4 is compared with the transition area 3. Flatter, so that the lens is in parallel contact with the cornea.

The tear layer of the defocused scleral contact lens of the present invention can bring a continuous water bath effect to patients with dry eye, thereby alleviating the pain caused by dry eye. Its defocus zone 2 can be used to delay the development of myopia.

The defocus area 22 is set as a convex lens sheet, and its power is set to +1.00D～+20.00D according to the individual difference of the wearer.

The main feature of the defocused scleral contact lens of the present invention is that its seating area 4 is in contact with the cornea, and there is a gap between the transition area 3, the defocused area 2, and the base arc area 1 and the cornea to form a tear layer, and the cornea can be continuously bathed in water. The optical area 5 cooperates with the base arc area 1, which can effectively correct vision, and the optical area 5 cooperates with the defocus area 2, so that the area of the retina corresponding to the positive tear mirror can produce peripheral myopia and defocus.

Manufacturing example of defocus scleral lens

The corneal curvature of the patient was 7.62 mm, the corneal diameter was 8.4 mm, and the scleral curvature was 11.44 mm by corneal topography. The myopia of the patient was -250 degrees obtained by the computer refractometer. That is, the design index is, the total diameter is 16mm, the width of the transition zone is 3mm, the width of the defocus zone is 2.4mm, and the diameter of the base arc zone is 7.6mm. The refractive power is -2.5D, the defocus area +1.0D lens, and the refractive index of the lens material is 1.43.

Design of the seat area: The seat area should conform to the sclera shape of the contact area, so the radius of curvature of the seat area is 11.44mm and its width is 3mm

Base arc design: The base arc should fit the corneal geometry, so the radius of curvature of the base arc is 7.62mm, and its diameter is 7.6mm

Optical zone design: the known base arc is 7.6mm, and the lens power is -2.5D. by formula

F=(n-1)(1/R1-1/R2)

In the formula: F is the power of the lens, n is the refractive index of the material, R1 is the radius of curvature of the optical zone, and R2 is the radius of curvature of the base arc.

It can be concluded that the radius of curvature of the optical zone is 7.97mm.

Design of the out-of-focus area: the radius of curvature of the known optical area is 7.97, and the optical power of the out-of-focus area is +1.0D. by formula

F=(n-1)(1/R1-1/R3)

In the formula: F is the power of the lens, n is the refractive index of the material, R1 is the radius of curvature of the optical zone, and R3 is the radius of curvature of the defocus zone.

It can be concluded that the radius of curvature of the defocal zone is 8.12mm

Design of transition zone: the width of the transition zone is 3mm, and the single or multiple arcs with different curvature radii forming the surface of the transition zone are defined as ⌒n, and the endpoints on both sides of the ⌒n are Pn and Pn+ respectively 1. A two-dimensional coordinate system XY is established with the center of curvature of the cornea as the origin. In the two-dimensional coordinate system, the coordinates of the endpoints on both sides of ⌒n are Pn(Xn, Yn) and Pn+1(Xn+1, Yn+1), the angles between the endpoints Pn and Pn+1 and the center of curvature of the cornea are Tn and Tn+1, respectively, and the information of the endpoints Pn and Pn+1 of ⌒n can be obtained by calculation Pn(Xn, Yn, Tn ), P n+1(Xn+1, Yn+1, Tn+1), based on this, single or multiple arcs with different curvature radii can be obtained ⌒n+1, ⌒n+2, ⌒n+3… , the endpoints are Pn+1, Pn+2, Pn+2, Pn+3, Pn+3, Pn+4…, the endpoint coordinates are Pn+1(Xn+1, Yn+1), Pn+2(Xn+ 2, Yn+2), Pn+2 (Xn+2, Yn+2), Pn+3 (Xn+3, Yn+3), Pn+3 (Xn+3, Yn+3), Pn+4 ( Xn+4, Yn+4)..., and the angle between the endpoint and the center of curvature of the cornea is Tn+1, Tn+2, Tn+2, Tn+3, Tn+3, Tn+4..., then ⌒n , ⌒n+1, ⌒n+2, ⌒n+3… The curvature radius satisfies the following relationship:

Based on the above formula, substitute the endpoints of ⌒n into the formula to obtain Rn' and Rn", and take the average value of Rn' and Rn" to obtain the radius of curvature Rn of ⌒n. Similarly, ⌒n+1, Radius of curvature Rn+1, Rn+2, Rn+3… of ⌒n+2, ⌒n+3…;

Input the above simulation parameters into the optical design software Code.v, design the optical system, and carry out item-by-item optimization. The curved surface of the obtained defocus scleral lens is rotationally symmetric about the center. It is output to a single point diamond lathe for machining.

Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, and substitutions can be made in these embodiments without departing from the principle and spirit of the invention and modifications, the scope of the present invention is defined by the appended claims and their equivalents.

Claims (10)

1. An out-of-focus scleral contact lens, comprising: the sclera contact lens comprises a base arc area, an out-of-focus area, a transition area and a seating area, wherein the front surface of the sclera contact lens is an optical area, and the base arc area, the out-of-focus area, the transition area and the seating area are sequentially concentrically arranged from the center to the edge of the back surface of the sclera contact lens;

the base arc area is positioned on the rear surface of the scleral contact lens and is in spherical rotational symmetry;

the sitting area is positioned on the rear surface of the sclera contact lens, is in spherical rotational symmetry, conforms to the shape of a sclera of the contact area, is in contact with the sclera, can position the sclera contact lens and provide uniform supporting force, and ensures that a basal arc area, an out-of-focus area and a transition area can form a tear liquid layer between a cornea and the lens;

the optical area spans the area above the cornea and is positioned on the front surface of the scleral contact lens and is used for finally imaging and focusing the transmitted light on the retina through a tear layer formed by the base arc area and the transition area;

the defocusing area is positioned on the rear surface of the scleral contact lens and is positioned between the base arc and the transition arc, and the defocusing area is used for imaging and focusing the transmitted light in front of the retina through a lacrimal fluid layer formed by the base arc area and the transition area.

2. A through-focus scleral contact lens as claimed in claim 1, wherein: the diameter of the defocused scleral contact lens is 14.5-17 mm.

3. A through-focus scleral contact lens as claimed in claim 1, wherein: the diameter of the optical area is set to be 8.2-9.8 mm, the width of the out-of-focus area is set to be 1.2-2.2 mm, the width of the base arc area is set to be 7.6mm, the curvature radius of the base arc area is set to be 6-9 mm, the diameter of the transition area is set to be 12-14 mm, the diameter of the sitting area is set to be 14.5-17 mm, and the curvature radius is 10.5-13.5 mm.

4. A through-focus scleral contact lens as claimed in claim 1, wherein: the optical area is provided with a concave lens sheet, and the power of the concave lens sheet is set to be-20.00 DS-0.00 DS.

5. A through-focus scleral contact lens as claimed in claim 1, wherein: the central thickness of the scleral contact lens is 0.1 mm-2 mm.

6. A through-focus scleral contact lens as claimed in claim 1, wherein: the defocusing area is arranged as a convex lens sheet, and the power of the convex lens sheet is set to be +1.00D to + 20.00D.

7. A through-focus scleral contact lens as claimed in claim 1, wherein: the optical area of the scleral mirror covers the base arc area and the out-of-focus area.

8. A through-focus scleral contact lens as claimed in claim 1, wherein: the sclera contact lens adopts siloxane-based fluoro-methyl acrylate copolymer, and the material is high oxygen permeability material with Dk value more than 120.

9. A through-focus scleral contact lens as claimed in claim 1, wherein: the tear layer thickness of the scleral contact lens is 100-300 mu m.

10. A through-focus scleral contact lens as claimed in claim 1, wherein: when the sclera contact lens is worn on an eyeball, a seating area of the sclera contact with the sclera of the eyeball, a transition area is connected with a base arc area to form a circular arch shape to cross over a cornea and a corneoscleral edge, tear is filled in the middle of the sclera contact lens to form the lachrymal lens, and the lachrymal lens is matched with a front surface optical area and a defocusing area to achieve the visual light correction effect.

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