KR-20260065718-A - Optimized posterior surface for toric contact lenses

KR20260065718AKR 20260065718 AKR20260065718 AKR 20260065718AKR-20260065718-A

Abstract

A method for improving a reference set of soft toric contact lenses, an improved set of toric contact lenses, and an improved toric lens are provided. The method comprises the steps of: identifying geometric characteristics of reference lenses including at least a target spherical power, a radius of curvature of the posterior surface of a peripheral zone, a lens center thickness, a lens material refractive index, an optical zone diameter, and an outer diameter of said transition zone; identifying a reference meridian of a reference set of toric lenses; reducing slope deviations along the reference meridian by adjusting the sag and radius of curvature of the peripheral zone and/or increasing the outer diameter of the transition zone; and creating an improved lens set by applying the adjusted sag and radius of curvature and/or increased outer diameter of the transition zone to all lenses in the improved lens set.

Inventors

게를리간드 피에르 이브
제이날리 샤로크

Assignees

존슨 앤드 존슨 비젼 케어, 인코포레이티드

Dates

Publication Date: 20260511
Application Date: 20240924
Priority Date: 20230927

Claims (20)

As a method for improving a standard set of soft toric contact lenses, each lens in the standard set of lenses is, A front surface and a rear surface positioned opposite the front surface and adapted to be positioned in contact with the user's eye, wherein the front surface and the rear surface meet at the lens edge and define the lens diameter; An optical zone within a central region of the lens having an optical zone diameter surrounding the center of the lens, wherein at least within the optical zone, the rear surface comprises a sphere meridian defining the sphere power for the lens and a cylinder meridian defining the cylinder power for the lens within a predetermined range; A peripheral zone within the peripheral region of the lens extending to the lens edge, and The improvement method comprising a transition zone extending between the optical zone and the external zone, At least the target spherical degree, half the curvature of the rear surface of the surrounding area The diameter, lens center thickness, lens material refractive index, the optical zone diameter, and the transition Geometric shape of the target lens in the reference lens set, including the outer diameter of the zone Step of identifying characteristics; A step of identifying the reference meridian of the reference set of the above-mentioned toric lenses; Adjust the sag and radius of curvature of the surrounding area above and/or the above By increasing the outer diameter of the transition zone, the slope along the reference meridian Steps for reducing deviations; and The above-mentioned adjusted sag and radius of curvature, and/or increased external of the above-mentioned transition zone By applying the mirror to all lenses in the improved lens set, the above-mentioned improved lenses A method including the step of creating a set.
In paragraph 1, the above reference meridian is, A meridian having a circumferential degree corresponding to the middle of the above-determined range of circumferential degrees, A meridian having half of the maximum circumferential degree within the above-determined range of circumferential degrees, or A method selected from a group of meridians having an intermediate radius of curvature between the radius of curvature of the spherical meridian and the radius of curvature of the circumferential meridian for the maximum circumferential degree within the range of circumferential degrees.
A method according to paragraph 2, wherein the total slope deviation range along the rear surface of the improved lens set is reduced compared to the total slope deviation range along the rear surface of the reference lens set.
A method according to paragraph 3, wherein the difference between the magnitude of the negative slope deviation range within the total slope deviation range and the magnitude of the positive slope deviation range within the total slope deviation range is reduced in the improved lens set compared with the reference lens set.
A method according to claim 1, wherein the maximum corneal pressure of the improved lens set is smaller than the maximum corneal pressure of the reference lens set.
A method according to claim 1, wherein the maximum difference in corneal pressure between the low cylindrical lens and the high cylindrical lens in the improved lens set is 0.2 kPa.
The method according to claim 1, wherein the lens diameter is 14.0 to 14.6 mm.
In claim 7, the method wherein the optical zone diameter is approximately 9 mm.
A method according to claim 8, wherein the radius of curvature of the spherical meridian of the reference lens and the target spherical degree are 8.35 to 8.45 mm and -3.0 D, respectively.
In claim 9, the method wherein the refractive index of the reference lens is 1.42.
In paragraph 10, the method wherein the center thickness of the above reference lens is 80 micrometers.
As a set of toric contact lenses for a predetermined range of circumferential powers, Each lens in the above set comprises a front surface and a rear surface positioned opposite the front surface and adapted to be positioned in contact with the user's eye, wherein the front and rear surfaces meet at the lens edge and define the lens diameter, an optical zone within the central region of the lens surrounding the lens center, a peripheral zone within the peripheral region of the lens extending to the lens edge, and a transition zone extending between the optical zone and the peripheral zone, wherein the rear surface comprises a spherical meridian defining the spherical degree for the lens within the optical zone, a circumferential meridian defining the circumferential degree for the lens, and a radius of curvature of the spherical meridian. A set of toric contact lenses, each lens in the set having an outer diameter of 14.0 to 14.6 mm, an outer diameter of the transition zone greater than 13.3 mm, and a sag of the peripheral zone less than 0.70 mm.
A set of toric contact lenses according to claim 12, wherein the maximum difference in corneal pressure for all lenses in the lens set is less than 0.2 kPa.
In claim 12, a set of toric contact lenses, wherein each lens in the set has an optical zone outer diameter of approximately 9 mm.
In claim 12, each lens in the set is a set of toric contact lenses having a posterior radius of curvature of 8.35 to 8.45 mm.
A set of toric contact lenses for a predetermined range of circumferential powers, wherein each lens in the set comprises: an anterior surface; a posterior surface positioned opposite to the anterior surface and adapted to be attached to the user's eye, wherein the anterior and posterior surfaces meet at the lens edge and define the lens diameter; an optical zone within the central region of the lens surrounding the center of the lens; a peripheral zone within the peripheral region of the lens extending to the lens edge; and a transition zone extending between the optical zone and the peripheral zone, wherein the posterior surface comprises a spherical meridian defining the spherical power for the lens within the optical zone and a circumferential meridian defining the circumferential power for the lens, and a radius of curvature of the spherical meridian. A set of toric contact lenses in which the area of the transition zone of the toric contact lens is greater than 46% of the total area of the toric contact lens.
A set of toric contact lenses according to claim 16, wherein the maximum difference in corneal pressure for all lenses in the above lens set is less than 0.2 kPa.
In paragraph 16, a set of toric contact lenses, wherein each lens in the lens set has an optical zone outer diameter of approximately 9 mm.
In claim 16, each lens in the lens set is a set of toric contact lenses having a posterior radius of curvature of 8.35 to 8.45 mm.
A set of toric contact lenses according to claim 16, wherein the area of the transition zone of the toric contact lens is about 46 to 55% of the total area of the toric contact lens.

Description

Optimized posterior surface for toric contact lenses This application relates to the field of ophthalmic lenses for use in patients with astigmatism. More specifically, this application relates to an optimized posterior surface design for a group of astigmatic contact lenses. Myopia or nearsightedness is an optical or refractive defect of the eye in which light rays from an image focus at a point before reaching the retina. Myopia is generally caused by the eye or eyeball being too long or the cornea being too steep. Minus-powered spherical lenses can be used to correct myopia. Hyperopia or farsightedness is an optical or refractive defect of the eye in which light rays from an image focus at a point after reaching the retina or behind the retina. Hyperopia is generally caused by the eye or eyeball being too short or the cornea being too flat. Positive-powered spherical lenses can be used to correct hyperopia. Astigmatism is an optical or refractive defect that causes a person's vision to become blurry because the eye is unable to focus a point object into a focused image on the retina. Corneal astigmatism is caused by the non-rotational symmetric curvature of the cornea. While a normal cornea is spherical, the cornea of a person with corneal astigmatism is not spherical. In other words, the cornea is more curved or steeper in one direction than in others, causing the image to stretch into two line focuses rather than focusing to a single point. Cylindrical lenses can be used to correct astigmatism rather than spherical lenses. Corneal astigmatism can be corrected using hard or rigid gas-permeable contact lenses. In these cases, a fluid or tear lens may exist between the posterior surface of the rigid contact lens and the cornea. This fluid or tear lens follows or adopts the shape of the posterior surface of the contact lens. Because the refractive index of the fluid or tear lens closely matches that of the cornea, the corneal toricity is optically canceled out or reduced. In these cases, a toric lens would not be necessary. However, rigid gas-permeable contact lenses and hard contact lenses are generally less comfortable than soft or hydrogel contact lenses. Since soft or hydrogel contact lenses wrap around the periphery of the cornea, fluid lenses are generally not found, and the tear film is very similar to a thin film. In these cases, a toric lens design is required. A toric lens is an optical element with two different powers in two orientations perpendicular to each other. Essentially, a toric lens has one spherical power to correct myopia or hyperopia and one cylindrical power to correct astigmatism, formed within a single lens. These powers are generated by curvatures oriented at different angles, and these orientations must be maintained relative to the eye. Therefore, toric contact lenses also include a mechanism to keep the contact lens relatively stable on the eye when the wearer blinks or looks around. The maintenance of the rotational orientation of the eye image of a toric contact lens can be achieved by well-known mechanical means such as ballast, peri-ballast, or double stabilization zones, the latter of which is described in U.S. Patent No. 11,281,024, incorporated herein by reference. The anterior surface of a toric lens typically features stabilizing features that provide rotational stability to the lens in the eye. The posterior surface of the lens typically features cylindrical correction. This is a common approach among soft contact lens manufacturers because it offers manufacturing advantages, particularly when the manufacturing process relies on injection molding, and allows for the creation of multiple SKUs with a minimal number of tools. The posterior surface geometry of a contact lens is an important aspect of the lens when it comes into direct contact with the corneoscleral surface of the eye. Therefore, it is desirable to optimize the posterior surface design for the shape of the cornea to minimize contact pressure in order to avoid corneal staining, chafing, abrasion, etc. Beyond optimization for a specific level of cylindrical power correction, what is needed is a posterior surface design for a set of toric contact lenses such that contact pressure in the corneal area is minimized and/or the difference in contact pressure between the lowest and highest cylindrical power lenses is reduced across the entire range of standard commercially available cylindrical power lenses. A method for improving a reference set of soft toric contact lenses is provided herein. Each lens in the reference lens set comprises an anterior surface and a posterior surface positioned opposite the anterior surface and adapted to be attached to the user's eye. The anterior surface and the posterior surface meet at the lens edge and define the lens diameter. Each lens further comprises an optical zone within a central region of the lens that surrounds the lens center and has an optical zone diameter. At le