CN115016146A - Method and try-on set for scleral contact lens fitting - Google Patents

Abstract

The present invention relates to a method and set of trial lenses for fitting a scleral contact lens to a subject, the scleral contact lens comprising an optical zone disposed at the center of the lens, the optical zone having a base curve radius of curvature BCR, a transition zone surrounding the optical zone, the transition zone having a transition zone radius of curvature TZR, and a landing zone disposed at the periphery of the lens, the landing zone having a landing zone radius of curvature LZR, wherein TZR is BCR dependent but LZR is independent of BCR. The method comprises the following steps: measuring corneal morphology of the subject to obtain a Flat K (FK) value and a corneal eccentricity e value corresponding to the FK value of the cornea of the subject; selecting a first try-on piece of the scleral contact lens for the subject based on the FK value and the e value. The set of fitting sheets includes at least two subgroups having different LZR, each subgroup containing a plurality of fitting sheets having different BCR. The method and the trial wearing plate set are simple and easy to operate, and the time for the fitting of the scleral contact lens can be greatly shortened.

Description

Method and try-on set for scleral contact lens fitting

technical field

The present invention relates to the field of contact lenses, in particular to a method for fitting a scleral contact lens and a try-on set.

Background technique

A scleral contact lens is a large-diameter, rigid, gas-permeable contact lens that is typically worn during the day. In contrast to conventional rigid oxygen permeable contact lenses (RGPs), scleral contact lenses land on the sclera and arch over the entire cornea and at the corneal/scleral junction known as the corneoscleral limbus, thus allowing contact with the lens at the back surface. A gap is formed between the cornea and the anterior surface of the corneoscleral limbus, the posterior lens clearance. The posterior tear space includes the corneal space and the corneoscleral limbus space. This gap is used as a liquid reservoir, which can be filled with tears, normal saline or functional solutions such as medicinal liquids, etc., which can create an ideal ocular surface environment, which is useful for protecting the cornea and limbal tissue, improving dry eyes, and correcting irregular corneal astigmatism. , reduce high-order aberration, etc., with the incomparable advantages of contact lenses.

Scleral contact lenses typically include an optic zone, a transition zone, and a landing zone. The optical zone is located in the center of the lens and is mainly used for vision correction. The landing zone is the outermost area of the scleral contact lens and is the weight-bearing area of the entire lens. The transition zone connects the optic zone and the landing zone and is usually arched above the corneoscleral limbus.

The fitting of scleral contact lenses requires consideration of many factors, including ensuring that the lens has an appropriate posterior tear gap when worn on the human eye, does not come into contact with the cornea and corneal limbus, does not have large air bubbles, and does not compress blood vessels, Comfortable to wear, etc. To improve comfort, most scleral contact lens fittings require the measurement of multiple ocular surface parameters, and their design often involves multiple lens parameters in order to adjust the posterior surface of the scleral contact lens according to the subject's ocular surface topography, especially is the shape of the rear surface of the landing zone in order to maximize the fit of the eyeglasses. Therefore, the fitting procedure of most scleral contact lenses is cumbersome and complicated, and it usually needs to be evaluated at 20 to 30 minutes, 2 hours and 4 hours of wearing the lens, which takes a long time.

Therefore, there remains a need for a scleral contact lens that is simple to design, simple to fit, and easy to wear.

SUMMARY OF THE INVENTION

The present invention relates to a method for fitting a subject with a scleral contact lens, the scleral contact lens comprising an optical zone disposed in the center of the lens, a transition zone surrounding the optical zone, and a landing zone disposed at the periphery of the lens, the the optical zone has a base arc radius of curvature BCR, the transition zone has a transition zone radius of curvature TZR, and the landing zone has a landing zone radius of curvature LZR, where TZR is dependent on BCR but LZR is independent of BCR, the method comprising: measuring the corneal morphology of the subject to obtain a flat K (FK) value of the subject's cornea and a corneal eccentricity e value corresponding to the FK value; and based on the FK value and the e value A first trial of the scleral contact lens is selected for the subject, the first trial having an optic zone with a first base arc radius of curvature BCR ₁ and a landing zone with a first landing zone radius of curvature LZR ₁ .

In some embodiments, the step of selecting the first trial piece includes: calculating the lens sag according to the FK value, the e value and the target initial vertex gap; calculating the theoretical basis according to the lens sag and base arc eccentricity and the first base arc curvature radius BCR ₁ is obtained by subtracting the correction parameter C from the calculated theoretical base arc curvature radius, wherein the target initial vertex gap is selected from 40 to 200 μm, and the base arc eccentricity is selected from From 0.30 to 1.10, the correction parameter C is selected from 0.2 to 0.5.

In some embodiments, the BCR is selected from 5.0 to 14.0 mm; and/or the TZR is 0.0 to 2.0 mm larger than the BCR; and/or the LZR is larger than the BCR and is independently selected from 8.5 to 15.0 mm.

In some embodiments, the method further comprises: performing a fit assessment on the first try-on 20-30 minutes after the subject wears the first try-on, wherein if the If the first trial piece fits well, then customize the scleral contact lens with the BCR ₁ and LZR ₁ for the subject; if the first trial piece does not fit well, it is the subject Pick a second trial piece with a second base arc radius of curvature BCR ₂ and/or a second landing zone curvature radius LZR ₂ , and reapply after the subject wears the second trial piece for 20 to 30 minutes A fit assessment was performed where BCR ₂ was different from BCR ₁ and LZR ₂ was different from LZR ₁ .

In some embodiments, the fit assessment includes measuring the vertex clearance and/or the corneoscleral limbus clearance.

In some embodiments, measuring the subject's corneal morphology is by corneal topography, and preferably, the method includes taking a plurality of corneal topography measurements.

The present invention also relates to a try-on set for scleral contact lens fitting, the try-on lens being a scleral contact lens and comprising an optic zone arranged in the center of the lens, a transition zone surrounding the optic zone, and an optic zone arranged on the lens A peripheral landing zone, the optical zone has a base arc radius of curvature BCR, the transition zone has a transition zone radius of curvature TZR, and the landing zone has a landing zone radius of curvature LZR, where TZR is dependent on BCR, but LZR is independent of BCR , the try-on sheet group includes: a high-side warping subgroup containing a plurality of first try-on sheets and a low-side warp subgroup containing a plurality of second try-on sheets, the landing of the plurality of first try-on sheets The curvature radii of the zones are all the first landing zone curvature radii LZR ₁ , and the landing zone curvature radii of the plurality of second try-on sheets are all the second landing zone curvature radii LZR ₂ , wherein LZR ₁ is greater than LZR ₂ , and LZR ₁ and LZR ₂ is each independently selected from 8.5˜15.0 mm; and wherein the plurality of first trial pieces have respective different base arc curvature radii, and the plurality of second trial pieces have respective different base arc curvatures Radius, the base arc curvature radii of the first try-on sheet and the second try-on sheet are all selected from the same base arc curvature radius set, and the base arc curvature radius set includes a plurality of Preset base arc curvature radius from 5.0 to 14.0mm.

In some embodiments, the number of the first try-on pieces and the number of the second try-on pieces are the same.

In some embodiments, the number of the preset base arc curvature radii is the same as the number of the first trial pieces and/or the number of the second trial pieces.

In some embodiments, the trial set also includes other subgroups with LZRs other than LZR ₁ and LZR ₂ .

Description of drawings

Figure 1 schematically shows a cross-sectional view of a scleral contact lens according to the present invention placed on a human eye.

2 is a schematic structural diagram of a scleral contact lens according to an embodiment of the present invention. The left image is a bottom view of the scleral contact lens; the right image is a cross-sectional view of the left image along line A-A.

Figure 3 is a fluorescein image obtained by evaluation of a diffuse light source under cobalt blue light from a slit lamp.

Figure 4 is a schematic diagram of the edge warping evaluation of the landing zone.

5 is a flow chart of a method for fitting a scleral contact lens according to the present invention.

Reference number:

OZ: Optical Zone; TZ: Transition Zone; LZ: Landing Zone; TD: Overall Lens Diameter; AC: Apex Clearance; LSH: Lens Sagittal Height; ESH: Eye Sagittal Height; Junction point; J2: junction of the transition zone and posterior surface of the landing zone; 1: cornea; 2: bulbar conjunctiva.

Detailed ways

The specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Numerous specific details are set forth in the following description, only so that this disclosure will be thorough and complete, and will fully convey the concept of the present invention to those skilled in the art. With regard to the drawings, the relative proportions and proportions of features in the drawings may be exaggerated or reduced in size for the sake of clarity and convenience. Such arbitrary ratios are merely illustrative and do not limit the invention in any way. Unless otherwise defined, terms used in this application have the meanings commonly understood by those skilled in the art.

When describing contact lenses in this application, the "front surface" refers to the side close to the inner surface of the eyelid when worn, or the convex surface of the lens; the "back surface" refers to the side of the lens facing the cornea when worn, or the The concave surface of the lens.

A scleral contact lens

The present invention relates to a scleral contact lens with a simple design, as shown in FIG. 1 , the scleral contact lens includes an optical zone (OZ), a transition zone (TZ) and a landing zone (LZ), and the optical zone has a base arc curvature Radius BCR, the transition zone has a transition zone radius of curvature TZR, and the landing zone has a landing zone radius of curvature LZR, where TZR is dependent on BCR but LZR is independent of BCR. The optic zone is located in the center of the lens and is usually larger in diameter than the horizontally visible iris, and is mainly used for vision correction. The landing zone is the outermost area of the scleral contact lens and is the area where the scleral contact lens contacts or lands on the ocular surface. The transition zone connects the optic zone and the landing zone and is usually arched above the corneoscleral limbus. In the scleral contact lens of the present invention, the radius of curvature of the transition zone is linked with the radius of curvature of the base arc. By measuring the corneal shape of the subject, the target radius of curvature of the base arc can be selected and the corresponding radius of curvature of the transition zone can be determined at the same time. The adaptation of the landing zone can be adjusted by adjusting the curvature radius of the landing zone to select suitable lens parameters.

The scleral contact lenses of the present invention are open or non-closed scleral contact lenses. As used in the present invention, a "non-closed" or "open" scleral contact lens means that the posterior surface of the landing zone of the scleral contact lens is not designed or tailored to the corresponding ocular surface shape of its wearer The appearance is completely or as complementary or fit as possible, as opposed to traditional closed or semi-closed scleral contact lenses.

Since a perfect fit with the ocular surface (the bulbar conjunctiva portion) is not sought, the scleral contact lens of the present invention, especially its landing zone, is simple in design, wherein the posterior surface of the scleral contact lens is rotationally symmetric. In some embodiments, the rear surface of the landing zone is a rotationally symmetric aspheric surface. In some embodiments, the eccentricity of the aspheric surface is between 0.05 and 1.00, preferably between 0.05 and 0.60.

Other features of the scleral contact lens of the present invention also include: high ocular surface mobility, thin tear gap behind the lens, etc., which will be described in detail below.

(I) lens movement (movement)

The landing zone is the outermost area of the scleral contact lens, and it is also the load-bearing area of the entire lens. In order to improve comfort, avoid conjunctival compression and disperse the weight of the lens as much as possible, the rear surface of the landing zone is usually required to fit the corresponding ocular surface shape as much as possible. to have a larger contact area. Studies have shown that the shape of the anterior surface of the sclera (between 15.0mm and 20.0mm in diameter) is tangential in most subjects, with a convex shape in less than a third of subjects , a very small fraction of the subjects were concave in shape. Furthermore, it is known in the art that the shape of the anterior surface of the sclera is progressively asymmetric beyond 13.0 mm in diameter. Therefore, in order to achieve good fit and lens stability, most scleral contact lenses are designed to have a tangential rear surface profile of the landing zone with little or no curvature, and many attempts to place the sclera Contact lenses are divided into multiple zones or quadrants to facilitate adjustment of parameters and designs within each zone of the scleral contact lens according to the subject's ocular surface topography.

Because of this, most scleral contact lenses are closed or semi-closed with little or no tear exchange and lens movement. In most cases, without mechanical manipulation, an ideally fitted conventional scleral contact lens will not exhibit any clinically significant tear exchange. Complications prone to closed scleral contact lenses include (but are not limited to) daytime fogging from tear pool debris, visual fluctuations from lens settling, higher-order aberrations from decentering, high lipid concentrations, Inflammatory factor accumulation, corneal hypoxic stress, etc. In addition, because traditional scleral contact lenses have no or only a very small amount of tear exchange, the reservoir behind the lens cannot be filled after wearing, resulting in the formation of air bubbles, etc. Add a suitable liquid to the sclera, keep your head basically parallel to the ground, and place the scleral contact lens filled with the liquid into the eye with one hand. If the amount of liquid added is insufficient or the wearing is not skilled, it may cause air bubbles between the lens and the ocular surface, so the lens needs to be removed and re-fitted, because air bubbles can cause eye discomfort, blurred vision and corneal staining, which is the contact of the sclera. Glasses need to be avoided both while wearing glasses and while wearing them.

Therefore, in the embodiments of the present invention, the inventors solve the problems of traditional closed/semi-closed scleral contact lenses by providing a non-closed or open scleral contact lens. As used in the present invention, a "non-closed" or "open" scleral contact lens means that the posterior surface of the landing zone of the scleral contact lens is not designed or tailored to the corresponding ocular surface shape of its wearer Appearances are completely or as complementary or fit as possible.

Because the perfect fit with the ocular surface topography is not pursued, the scleral contact lens of the present invention has higher ocular surface mobility compared with similar products. The higher the lens movement, the higher the tear exchange rate. The scleral contact lenses of the present invention have been shown to provide continuous dynamic tear exchange, as demonstrated by, for example, after instillation of fluorescein outside the lens, the fluorescein can be observed to fill the back of the lens after 5-10 blinks. However, mobility that is too high or too low can reduce comfort, so in some embodiments, the scleral contact lenses of the present invention are configured to move between 0.4 mm and 1.2 mm, preferably 0.5 mm, on the surface of the eye during use Between mm and 1.0 mm, eg, about 0.5, 0.6, 0.7, 0.8, 0.9, 1.0, 1.1 mm, and any value therebetween, preferably less than 1.0 mm, more preferably about equal to 0.5 mm (eg, 0.5±0.05 mm). The movement is measured by slit lamp illumination (0.5-2.0 mm width) and a scale line of known length of the slit lamp or the beam width of the slit lamp illumination, and the movement of the lens is assessed using the direct focus method.

In some embodiments, the posterior surface of the landing zone of the scleral contact lens of the present invention is rotationally symmetric about the optical axis of the scleral contact lens, so that when the lens is placed on a sclera with an asymmetric anterior surface topography, there is no will fit it perfectly, but will likely have only a few points or locations of contact, resulting in higher mobility and better microscopic tear exchange. In yet other embodiments, the rear surface of the landing zone is a rotationally symmetric aspheric surface.

In yet other embodiments, the vertical distance from the junction of the posterior surface of the landing zone to the posterior surface of the transition zone (ie, the starting point of the landing zone, J2) from the lens axis of the scleral contact lens Between 6.0mm and 7.0mm, preferably between 6.0mm and 6.8mm, such as 6.0, 6.1, 6.2, 6.3, 6.4, 6.5, 6.6, 6.7mm and any value in between, to fully utilize sclera with diameters other than 13.0mm Asymmetry of the front surface.

Without wishing to be bound by any theory, the inventors believe that the scleral contact lens of the present invention effectively avoids proteins, lipids, viscous fluids in the tear layer between the cornea and the posterior surface of the lens by achieving sufficient exchange between the tear fluid below the scleral contact lens and the tear fluid outside the lens. The accumulation of proteins and inflammatory factors thus solves the problems existing in the prior art.

As mentioned above, conventional scleral contact lenses are typically designed as closed or semi-closed reservoirs and are therefore particularly suitable for dry eye patients. However, the biggest problem with closed or semi-closed scleral contact lenses is the accumulation of various chemicals and debris in the tear layer under the lens, and midday fogging is one of the most representative manifestations, which makes the The test subjects had to remove the lenses for cleaning during the day's wearing to maintain good vision. The scleral contact lens of the present invention does not fit perfectly with the ocular surface in the landing zone, has relatively high mobility, and can realize the filling of the tear pool behind the lens and the continuous exchange and renewal of tears with the help of the subject's blinking action. Beneficial to corneal health, allowing lenses to be worn comfortably throughout the day without any problems.

Therefore, the scleral contact lens according to the present invention not only requires no instillation of physiological saline before wearing, and is easy to wear, but also has no fogging phenomenon during the day, and is safe and convenient to remove.

(II) Corneal space

When the scleral contact lens of the present invention is placed on the eyeball, neither the posterior surfaces of the optic zone nor the transition zone are in contact with the subject's anterior surface of the eyeball, thereby forming a fluid storage space. The space between the posterior surface of the optic zone and the anterior surface of the cornea is called the corneal space, and the space between the posterior surface of the transition zone and the anterior surface of the corneal limbus is called the corneal limbus space. Corneal clearance can be characterized by central clearance or apical clearance (AC (apical clearance)). The central gap is the distance between the center of the posterior surface of the scleral contact lens and the anterior surface of the cornea; the apex gap is the distance between the highest point of the anterior corneal surface and the posterior surface of the scleral contact lens. Since the anterior corneal surface morphology is often irregular, especially in patients with keratoconus, corneal trauma, or postoperative corneal surgery, the apex space is used in the present invention to determine the appropriateness of scleral contact lens arching over the cornea. Vertex clearance is related to the lens sagittal height (LSH) (ie, the vertical distance between the geometric center of the rear surface of the lens and the plane of the edge of the lens).

The corneal space cannot be too large or too small. When the corneal gap is too large, the thickness of the tear layer increases, which affects the transmission of oxygen from the outer surface of the lens to the cornea, which easily leads to corneal hypoxia, and at the same time, it is easy to cause various ocular debris (such as mucus debris, eyelid debris) Aggregation of meibomian debris, lacrimal debris). When the corneal space is insufficient, due to the sedimentation effect of the scleral contact lens, it is possible for the subject to contact the posterior surface of the scleral contact lens with the anterior surface of the cornea several hours after wearing the lens, resulting in damage to the corneal epithelium. In addition, some scholars believe that even if no corneal load bearing occurs, a thinner (under 100 microns) tear layer is disadvantageous because the film adhesion it produces in the enclosed space increases the adsorption between the scleral contact lens and the ocular surface , which makes it difficult to remove the lens, especially after the ocular surface secretions, metabolites, etc. make the tears more viscous after wearing the lens for a long time. Of course, there is no consensus in the art on how much is the ideal corneal gap, but it is generally believed that at least 250 microns of corneal gap should be guaranteed during the initial lens fitting.

The inventor found that, in the closed scleral contact lens of the present invention, the apex gap of the scleral contact lens is set to be no more than 200 microns, which not only does not cause the problem of difficulty in removing the lens, but also unexpectedly reduces the degree of lens settlement. Even at apex clearances as low as 40 microns, there was no corneal weight bearing and damage after prolonged wear by the subjects. As used herein, the term "initial apex clearance" refers to the point at which the highest point of the anterior surface of the cornea is in contact with the sclera as measured by optical coherence tomography (OCT) or fluorescein staining 20 to 30 minutes after the subject wears the glasses The distance between the rear surfaces of the mirrors. The initial apex gap according to the present invention is also one of the important parameters used by the optician to judge whether the selected trial lens is suitable when fitting the scleral contact lens of the present invention.

Thus, the initial apex gap between the posterior surface of the optic zone of the scleral contact lens according to the invention and the apex of the eyeball is below 200 μm, eg, less than 200 μm, less than 190 μm, less than 180 μm, less than 170 μm, less than 160 μm, less than 150 μm , less than 140μm, less than 130μm, less than 120μm, less than 110μm, less than 100μm, less than 90μm, less than 80μm, less than 70μm. Apex gaps higher than 200 microns are undesirable because in the non-enclosed scleral contact lenses of the present invention, excessive apex gaps tend to cause air bubbles to follow from where the landing zone does not fit the ocular surface during wearing. With the movement of the lens and tears into the space behind the lens.

In a preferred embodiment, the initial vertex gap is greater than 40 μm, such as more than 40 μm, more than 50 μm, more than 60 μm, more than 70 μm, for example, the initial vertex gap is 55, 65, 75, 80, 85, 90, 95, 100, 105, 110, 115, 120, 125, 130, 135, 140, 145, 160, 165, 170, 175, 180, 185, 190, 195 μm or any value in between. Apex clearances below 40 microns are disadvantageous because the irregular shape of the sclera and the rotation of the eye in different directions of gaze may cause the lens to move close to the cornea, potentially risking damage.

Since the scleral contact lens according to the present invention has a thin posterior tear gap under ideal fitting conditions, in which the tear lens is formed with a thin tear lens thickness, the resulting tear lens thickness variation is almost negligible even if the lens movement is high. It is negligible and will not cause fluctuations in the subject's vision.

In some embodiments of the invention, the transition region of the scleral contact lens is configured to be located above the corneoscleral limbus of the eyeball when the scleral contact lens is placed on the eyeball. The corneoscleral limbus is the cornea-sclera junction, an area that contains stem cells that are critical to eye health. If the scleral contact lens is in contact with the corneal limbus, it will cause damage to the stem cells in it; similarly, if the scleral contact lens is arched too high in this area, it may affect the oxygen supply of the corneal limbal stem cells. Accordingly, in some embodiments of the present invention, the scleral contact lens is further configured to provide a corneoscleral limbal clearance of between 75-150 microns.

Apical space and corneoscleral limbal space after wearing glasses can be quantitatively measured by optical coherence tomography (OCT) or assessed using fluorescein staining, both statically and dynamically.

(III) Edge warping

In some embodiments, the ends of the landing zone are provided with edge warps. As used in the present invention, "edge lift" refers to the end of the landing zone not in contact with the ocular surface, edge lift is sometimes referred to as edge lift or edge lift, and "edge lift height" refers to the end of the landing zone The distance from the bulbar conjunctiva where the chord length of the eye is equal to the diameter portion of the scleral contact lens (Figure 1).

In general, due to the large size of the scleral lens, the side warping is not liked by the subjects, because the side warping is more likely to make the subject feel the presence of the lens (foreign body sensation), and the upper side warping may also exacerbate the macropapillary Conjunctivitis (GPC). During the fitting process of scleral lenses, the ideal situation generally accepted in the art is that the landing zone fits perfectly with the sclera (bulbar conjunctiva), with no edge warping, no compression, and no blanching of the conjunctiva.

However, the present invention utilizes the effect of promoting tear fluid exchange brought about by the edge warp. Setting the edge warp at the end of the landing zone makes the post-lens tear exchange effect of the scleral contact lens of the present invention more excellent.

In addition, the inventors also found that by setting the radius of curvature r1 at the connection point (J2) of the posterior surface of the landing zone and the posterior surface of the transition zone of the scleral contact lens of the present invention and the radius of curvature of the end of the posterior surface of the landing zone r2 (Fig. 2), and set the radius of curvature of the part of the rear surface of the landing zone between the above two points to increase gradually (continuously or in stages) radially outward, so that the rear surface of the landing zone can be The face shape is individually controlled to create a gently raised side warp and reduce the subject's foreign body sensation. The radius of curvature r1 at the connection point J2 is also the radius of curvature of the landing zone LZR. In some embodiments, the radius of curvature r1 at the connection point (J2) between the rear surface of the landing zone and the rear surface of the transition zone is between 8.5 and 15.0 mm, such as 9.0, 10.0, 11.0, 12.0, 13.0, 14.0, 15.0mm or any value in between. The curvature radius r2 of the end of the rear surface of the landing zone is between 8.65 and 20.0 mm, preferably between 10.0 and 15.0 mm. Changing r1(LZR) can result in a change in the position of the lens landing on the conjunctiva, an overall change in the sag of the lens and the fit with the anterior surface of the cornea. Part B of Fig. 2 shows the change of the landing zone caused by the change of r1.

In some embodiments, the sag S at J2 is set according to the curvature radius r1 at J2, where S represents the vertical distance from the connection point J2 to the lens edge plane; the larger r1 is, the smaller S is, and the higher the edge warp is. wherein S(r1)=(A+B×r1+C×r1 ² +D×r1 ³ ) ^-1 , and A is selected from -2 to -150, B is selected from 0.5 to 5, and C is selected from -0.06 to - 0.6, D is selected from 0.003～0.03. For example A is -10, B is 2.5, C is -0.28 and D is 0.017. As an example, a suitable sag height S is selected from 0.6 to 3.2 mm, preferably 1.0 to 2.2 mm, more preferably 1.2 to 1.7 mm. The inventors have found that varying the landing zone of the scleral contact lens within this range can provide a side warp with a suitable height to create a balance between tear exchange and subjective perceived comfort of the subject.

(IV) Other lens features

In some embodiments, the scleral contact lens of the present invention further comprises a fenestration and/or a pocket, the fenestration and/or pocket being provided in the optical zone and/or of the scleral contact lens transition zone (Figure 2). Through holes are small holes drilled in the scleral lens to help improve tear exchange under the lens and/or provide more available oxygen through the lens. The horizontal cross section of the through hole has a maximum dimension selected from 0.2 to 1.0 mm. Unlike through holes, pockets are non-penetrating structures with openings on the rear surface of the lens. Pockets suitable for use in the present invention can have various profiles. The concave pockets can reduce the average thickness of the lens and increase the oxygen permeability of the lens. Therefore, in some embodiments, the scleral contact lenses of the present invention are provided with a plurality of concave pockets on the rear surface. In some embodiments, the recessed pocket is configured to capture and confine air bubbles that may enter the rear mirror gap through the through hole, such as described in CN112666723A. The patent documents are hereby incorporated by reference in their entirety.

In still other embodiments, the optical zone diameter φ _a0 of the scleral contact lens of the present invention is between 5.00 and 12.00 mm. The central thickness of the optical zone is between 0.15 and 0.55 mm, so as to provide sufficient lens strength and at the same time good lens oxygen permeability. In various embodiments, the rear surface of the optical zone may be spherical, aspherical, or toric. In various embodiments, the posterior surface of the optic zone may have a radius of curvature greater or less than the radius of curvature of the cornea. In some embodiments, the radius of curvature r0 of the posterior surface of the optical zone (that is, the base arc radius of curvature (BCR) of the scleral contact lens) is between 5.0 and 14.0 mm, such as between 5.5 and 12.0 mm, such as 6.0, 6.5, 7.0, 7.5, 8.0, 8.5, 9.0, 9.5, 10.0, 10.5, 11.0, 11.5 and any value in between.

In various embodiments, the width of the transition region of the scleral contact lenses of the present invention (ie, half the difference between φ _a1 and φ _a0 ) is between 0.8 and 1.8 mm, preferably between 1.0 and 1.5 mm. In various embodiments, the radius of curvature (ie, the radius of curvature of the transition zone) at the junction (J1) of the rear surface of the transition zone and the rear surface of the optical zone (ie, at the starting point of the transition zone) (TZR)) is greater than or equal to the radius of curvature of the base arc, for example, 0.1-2.0mm larger than the radius of curvature of the base arc, such as 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1.0, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9mm and any value in between. Thus, in various embodiments of the present invention, the radii of curvature of the optic zone rear surface and the transition zone rear surface are linked.

In various embodiments, the radius of curvature of the landing zone of the scleral contact lenses of the present invention does not depend on the BCR setting, but rather on the desired edge warp height, as long as it is greater than the BCR.

In various embodiments, the scleral contact lenses of the present invention have a diameter of 14.0 to 25.0 mm, preferably 14.0 to 18.0 mm.

Table 1. Exemplary scleral contact lenses of the invention

2. Fitting of scleral contact lenses

The fitting of scleral contact lenses includes pre-fit inspection, fit assessment, parameter adjustment and ordering custom lenses.

Pre-matching examinations include medical history collection, eye health examination, measurement of eye parameters, and subjective and objective optometry. The measurement of eye parameters includes corneal curvature, corneal morphological parameters, corneal diameter, pupil diameter measurement, etc. Knowing the corneal morphology is the basis for choosing the base arc of the trial film. Corneal curvature can be measured using a keratometer and corneal topography. Because corneal topography can more completely reflect the overall appearance of the cornea, it is more widely used in practice.

According to the results of the pre-matching examination, the optician will select the first trial film for the subject for fit evaluation. Good scleral contact lens fitting includes three basic aspects: proper corneal space, corneal limbal space, and scleral fit. Therefore, the fit assessment includes evaluation checks of the optic zone, transition zone, and landing zone, such as a penlight or slit lamp after 5 minutes of wearing to roughly assess whether there is corneal contact or air bubbles in the central zone, whether the landing zone has lift, blood vessels compression, etc., while asking subjects for comfort. If the first piece is positioned in the center, without contact, without large bubbles, and without obvious discomfort, the slit lamp fluorescein evaluation shall be used after continuing to wear for 20 minutes; otherwise, the trial piece shall be replaced and re-evaluated. The fitting of traditional scleral contact lenses usually requires evaluation at 20 to 30 minutes, 2 hours, and 4 hours of wearing the lens, which is time-consuming. The criteria for successful fitting of scleral contact lenses include good dynamic and static assessment (no air bubbles, no contact, including no contact between the cornea and the limbus), improved visual acuity corrected by on-chip refraction, and good subject comfort.

If the fitting of the trial piece is not good, the optician needs to select a trial piece with other parameters for the subject according to the situation, until a good fit is obtained, and then the optician can give the subject a trial piece according to the parameters of the trial piece. Order the corresponding product. Scleral contact lenses designed by different manufacturers usually require opticians to adjust different lens parameters and provide corresponding fitting guidelines. Some scleral contact lenses have complex designs, many adjustable parameters, and complicated fitting.

The scleral contact lens according to the present invention is simple in design, so fitting is relatively simple. Therefore, in some embodiments, the present invention also provides a method of fitting a scleral contact lens. As shown in FIG. 5, the method includes measuring the corneal morphology of a subject, eg, using corneal topography, to obtain a flat K value (FK) of the subject's cornea and a corneal eccentricity e value ( Step 110); Based on the FK value and the e value, the experimenter selects the first trial piece of the scleral contact lens, and the optical zone of the first trial piece has the first base arc radius of curvature BCR ₁ And its landing zone has a first landing zone curvature radius LZR ₁ (step 120 ).

The step of selecting the first trial piece includes: calculating the appropriate lens sag according to the FK, e value and the target initial vertex gap (40-200 μm), and according to the lens sag and base arc eccentricity (0.30-1.10, preferably 0.5～0.99) to calculate the radius of curvature of the base arc; subtract a correction parameter C in the range of 0.2～0.5 from the calculated radius of curvature of the base arc to obtain the radius of curvature of the base arc of the first trial piece. The calculation formula required for each step belongs to the common knowledge in the art, for example, see Contact lens optics and lens design, ISBN 978-0-7506-8879-6, Chapter 4aspherical surfaces (Contact lens optics and lens design, ISBN 978-0-7506- 8879-6, Chapter 4 Aspheric Surfaces). In a preferred embodiment, the correction parameter is 0.3.

The method of the present invention also includes performing a fitting evaluation (step 130) after wearing the lenses for 20 to 30 minutes, for example, by adding fluorescein sodium dropwise to evaluate, and the evaluation contents include: whether the lens is positioned in the center, the degree of movement; Large air bubbles, with or without contact; whether there are air bubbles or compression in the peripheral part of the lens (transition area); whether there are air bubbles and compression in the periphery of the lens (landing area). Figure 3 shows several situations that may occur in lens fitting, among which flat fitting means that the gap behind the mirror is too thin or there is contact in the center; steep fitting means that there are large bubbles in the center; perfect fitting shows that the fluorescent layer is uniform after visible mirrors distributed. In the case of both flat and steep fits, it is necessary to adjust the parameters of the try-in, such as the BC radius of curvature or edge warping. In the field of fitting of contact lenses, especially hard lenses (such as RGP, orthokeratology lenses and scleral contact lenses), it is a conventional technical means in the art to adjust the corresponding lens parameters according to the fitting evaluation results of the trial lenses. As a simple example, for example, in the method of the present invention, if the compression of the optical zone is observed, or the apex gap is less than 40 μm, the steeper BC (smaller BCR) can be adjusted to increase the sagittal height of the lens and move away from the cornea; Large air bubbles or the apex gap is larger than 200 μm, and/or the limbal gap is too large or there are air bubbles, then replace with a trial film with a larger BCR. If there is pressure in the landing area, you can relax the edge warp and choose a larger r1 (ie LZR); if there are air bubbles in the landing area, choose a smaller r1 to reduce the edge warp. Figure 4 shows several cases of poor lens edge warping fit.

In some embodiments, the methods of the present invention further comprise measuring the vertex gap and/or the corneoscleral limbal gap, eg, by OCT.

Further, the method of the present invention also includes customizing or ordering a scleral contact lens with said parameters for the subject according to the ideal BCR and side warp height (characterized by LZR) obtained by the fit assessment and the subject's diopter (step 140). Those skilled in the art can understand that the order parameters may also include other special instructions, such as adjusting the diameter of the lens, polishing the lens well, and so on. However, in various embodiments, the method does not include the step of measuring the topography of the sclera of the subject, and the ordering parameters do not include parameters related to the scleral topography.

In yet other embodiments, the methods of the present invention further comprise performing multiple corneal topography measurements to ensure data consistency and accuracy.

Since the scleral contact lens of the present invention has dynamic tear exchange with no or only slight subsidence, there is no need to wait for up to 4 hours of evaluation time when the lens is fitted, and the ideal fit can be found only by adjusting the BC and edge warping of the lens , which greatly shortens and simplifies the lens fitting process.

Therefore, according to yet another embodiment, the present invention also provides a try-on set for scleral contact lens fitting that provides different combinations of lenses BCR and LZR for selection by the optician. Specifically, the try-on sheet group includes: a high-side warp subgroup containing a plurality of first try-on sheets and a low-side warp subgroup containing a plurality of second try-on sheets, the plurality of first try-on sheets The landing zone curvature radii of the sheets are all LZR1, and the landing zone curvature radii of the plurality of second try-on sheets are all LZR2, wherein LZR1 is greater than LZR2 and is independently selected from 8.5 to 15.0 mm; and wherein the plurality of Each of the first try-on sheets has a different base arc radius of curvature, the plurality of second try-on sheets each have a different base arc radius of curvature, and the base arcs of the first try-on sheet and the second try-on sheet have different base arc radii. The curvature radii are all selected from the same base arc curvature radius set, and the base arc curvature radius set includes a plurality of equal steps (for example, selected from steps of 0.2 to 1.0 mm, for example, steps of 0.5 mm) distributed, selected from 5.0～14.0mm preset base arc curvature radius.

In some embodiments, the number of the first try-on pieces and the number of the second try-on pieces are the same. In still other embodiments, the number of the preset base arc curvature radii is the same as the number of the first try-on pieces and/or the number of the second try-on pieces. In some embodiments, the trial set also includes other subgroups having LZRs other than LZR ₁ and LZR ₂ , the other subgroups also comprising a plurality of trials. For example, the trial-wearing sheet group further includes a mid-edge warping subgroup including a plurality of third trial-wearing sheets, and the landing zone curvature radii of the plurality of third trial-wearing sheets are all LZR3, and LZR1>LZR3>LZR2.

As an example, the present invention provides a scleral contact lens try-on set, the try-on set includes: (1) a high-edge warped subgroup with 14 first try-on lenses and LZR1 of 13.0 mm, (2) ) contains 14 second trial pieces, LZR2 is 10.0mm low side warp subgroup, and (3) contains 14 third trial pieces, LZR3 is 11.5mm middle side warp subgroup, where the radius of curvature of the base arc The set contains the following 14 preset base arc radii of curvature 6.0, 6.2, 6.4, 6.6, 6.8, 7.0, 7.2, 7.4, 7.6, 7.8, 8.0, 8.2, 8.4, 8.6mm.

3. Indications of the scleral contact lens of the present invention

The scleral contact lens according to the present invention is suitable for (1) patients with irregular corneal astigmatism, such as keratoconus, corneal limbal degenerative disease and astigmatism after corneal transplantation, etc.; (2) treatment of ocular surface diseases, such as dry eye, corneal nerve pain, GVHD graft-versus-host reaction, severe ocular surface disease (eg, persistent non-healing epithelial defect (PED)), as well as with medications (eg, lubricants, rush, cyclosporine eye drops) and other ophthalmic procedures (eg, Amniotic membrane transplantation, eyelid margin surgery) combined treatment; (3) non-emmetropic eyes, such as refractive error, presbyopia.

Example

Example 1

Patient A: 30 years old, male, visual acuity decreased for 3 years after chemical injury of left eye

Basic eye information: uncorrected visual acuity 0.05, subjective optometry OS-0.75/-2.25*150, best corrected visual acuity 0.4

The patient's corneal flatness K value was 8.46 and e value was 0.94 measured by corneal topography

The first trial film: BC 8.6mm, moderate side warp (sagittal height S=1.47mm at the junction), slit-lamp examination after 20 minutes of wearing the lens: the tear layer behind the central keratoscope is thin, about 20μm thick; the tear layer behind the peripheral lens Thin, about 40μm thick; the nasal conjunctiva is albino, the lens is well centered, and there is no lens movement in the natural blinking state.

Adjusted to high side warp (the sagittal height S=1.40mm at the junction), and a trial film with a steep BC of 8.2mm was selected. After 20 minutes of wearing the lenses, the central and peripheral corneas were examined by slit lamp. After the tear layer was filled to 100 μm, the landing zone was The fit is good, the conjunctival blood flow is not blocked in dynamic and static assessments, the lens is well positioned in the center, and there is a slight movement of about 0.5mm in the natural blinking state. Complaint of no foreign body sensation.

Review after wearing glasses for one month, the subjective refraction of wearing glasses was -0.75/-0.50*180, and the visual acuity of wearing glasses was 0.8.

Example 2

Patient B: 22 years old, male, 2 years after corneal cross-linking for left eye keratoconus

Basic eye information: uncorrected visual acuity 0.15, subjective optometry OS-4.00/-3.75*80, best corrected visual acuity 0.3

The patient's corneal flatness K value measured by corneal topography was 8.39, and e value was 0.21

The first trial film: BC 7.2mm, moderate side warp (sagittal height S = 1.47mm at the junction), slit lamp examination after 20 minutes of wearing the lens: central corneal contact; peripheral bubble behind the lens; good fit in the landing zone, dynamic and static Conjunctival blood flow was not blocked, the lens was well centered, and there was a slight movement in the natural blinking state, about 1.0mm.

Adjusted to a steeper BC 7.0mm trial film, with moderate side warpage (sagittal height S = 1.47mm at the junction), slit lamp examination after 20 minutes of wearing the lens: no central corneal contact, posterior tear layer thickness ~ 100μm; peripheral Small mobile bubbles behind the lens; the landing zone fits well, the conjunctival blood flow is not blocked in dynamic and static assessments, the lens is well centered, and has a slight movement of about 0.5mm in the natural blinking state. Complaint of no foreign body sensation.

Review after wearing glasses for one month, the refraction of the protagonist wearing glasses: -0.50/-0.50*145, and the visual acuity of wearing glasses is 0.8.

Example 3

Patient C: 31 years old, female, high myopia in both eyes for 20+ years

Basic eye information: uncorrected visual acuity 0.01, subjective refraction OD-10.75/-3.25*5, best corrected visual acuity 0.8

The patient's corneal flatness K value was 8.11 and e value was 0.78 measured by corneal topography

The first trial film: BC 8.0mm, medium edge warp (sagittal height S=1.47mm at the junction), slit-lamp examination after 20 minutes of wearing the lens: the tear layer behind the central corneal lens is thin, the thickness is <20μm; the tear layer behind the peripheral lens Filling, the thickness is about 100μm; the nasal conjunctiva is albino, the lens is well centered, and the lens movement under the natural blinking body is <0.5mm.

Adjusted to a BC 7.6mm trial film with a high side warp and a steeper angle, the slit-lamp examination after wearing the lens for 20 minutes: the tear layer after the central corneal lens is moderate, about 50 μm; the small mobile bubbles behind the peripheral lens; the landing area is equipped with Good fit, no blockage of conjunctival blood flow in dynamic and static assessment, good central positioning of the lens, and slight movement in the natural blinking state, about 0.5mm. Complaint of no foreign body sensation.

Review after wearing glasses for one month, the refraction of the protagonist wearing glasses: -0.25/-0.50*34, and the visual acuity of wearing glasses is 1.0.

While certain features of the invention have been illustrated and described herein, many modifications, substitutions, changes and equivalents will occur to those skilled in the art. Therefore, it should be understood that this invention is intended to cover all such modifications and variations that fall within the true spirit of this invention.

Claims (10)

1. A method of fitting a subject with a scleral contact lens, the scleral contact lens comprising an optical zone disposed in the center of the lens, a transition zone surrounding the optical zone, and a landing zone disposed at the periphery of the lens, the optical zone The zone has a base arc radius of curvature BCR, the transition zone has a transition zone radius of curvature TZR, and the landing zone has a landing zone radius of curvature LZR, where TZR is dependent on BCR, but LZR is independent of BCR, The method includes: measuring the corneal morphology of the subject to obtain a flat K (FK) value of the subject's cornea and a corneal eccentricity e value corresponding to the FK value; and Based on the FK value and the e value the subject selects a first try-in of the scleral contact lens, the first try-in having an optical zone with a first base arc radius of curvature BCR ₁ and its The landing zone has a first landing zone curvature radius LZR ₁ . 2. The method according to claim 1, wherein the step of selecting the first try-on sheet comprises: Calculate the lens sag according to the FK value, the e value and the target initial vertex clearance; calculating a theoretical base arc radius of curvature from the lens sag and base arc eccentricity; and By subtracting the correction parameter C from the calculated theoretical base arc curvature radius, the first base arc curvature radius BCR ₁ is obtained, The target initial vertex gap is selected from 40 to 200 μm, the base arc eccentricity is selected from 0.30 to 1.10, and the correction parameter C is selected from 0.2 to 0.5. 3. The method of claim 1 or 2, wherein the BCR is selected from 5.0 to 14.0 mm; and/or The TZR is 0.0-2.0 mm larger than the BCR; and/or The LZR is greater than the BCR and is independently selected from 8.5 to 15.0 mm. 4. The method of any preceding claim, wherein the method further comprises: After the subject wears the first try-on sheet for 20 to 30 minutes, a fit assessment is performed on the first try-on sheet, wherein if the first trial piece fits well, customizing a scleral contact lens with the BCR ₁ and LZR ₁ for the subject; If the first trial piece does not fit well, select a second trial piece for the subject with a second base arc radius of curvature BCR ₂ and/or a second landing zone radius of curvature LZR ₂ The subject wears the second try-on sheet for 20-30 minutes and then performs fit assessment again, wherein BCR ₂ is different from BCR ₁ , and LZR ₂ is different from LZR ₁ . 5. The method of claim 4, wherein the fit assessment comprises measuring vertex clearance and/or corneoscleral limbal clearance. 6. The method of any preceding claim, wherein measuring the subject's corneal morphology is by corneal topography measurement, and preferably the method comprises taking a plurality of corneal topography measurements. 7. A try-in set for scleral contact lens fitting, the try-in lens being a scleral contact lens and comprising an optical zone disposed in the center of the lens, a transition zone surrounding the optical zone, and a landing zone disposed at the periphery of the lens , the optical zone has a base arc radius of curvature BCR, the transition zone has a transition zone radius of curvature TZR, and the landing zone has a landing zone radius of curvature LZR, where TZR is dependent on BCR, but LZR is independent of BCR, The try-on sheet group includes: a high-side warping subgroup containing a plurality of first try-on sheets and a low-side warp subgroup containing a plurality of second try-on sheets, the landing areas of the plurality of first try-on sheets. The curvature radii are all the first landing zone curvature radius LZR ₁ , and the landing zone curvature radii of the plurality of second try-on sheets are all the second landing zone curvature radii LZR ₂ , wherein LZR ₁ is greater than LZR ₂ , and LZR ₁ and LZR ₂ are each independently selected from 8.5 to 15.0 mm; and The plurality of first try-on sheets have different base arc curvature radii, the plurality of second try-on sheets have different base arc curvature radii, the first try-on sheet and the first try-on sheet have different base arc curvature radii. The base arc curvature radii of the two trial pieces are all selected from the same base arc curvature radius set, and the base arc curvature radius set includes a plurality of preset base arc curvature radii distributed in equal steps and selected from 5.0-14.0 mm. 8. The try-on sheet set of claim 7, wherein the number of the first try-on sheets and the number of the second try-on sheets are the same. 9. The try-on sheet set according to claim 7 or 8, wherein the quantity of the preset base arc radius of curvature is identical with the quantity of the first try-on sheet and/or the second try-on sheet . 10. The try-on set of any one of claims 7 to 10, further comprising other subgroups having LZRs other than LZR ₁ and LZR ₂ .

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