CN218446262U - Trial wearing sheet set for scleral contact lens fitting - Google Patents

Abstract

The utility model relates to a try on piece group for scleral contact lens is tested and is joined in marriage, scleral contact lens is including setting up at the optics district of lens central authorities, encircleing the transition zone in optics district and setting up at the peripheral landing zone of lens, optics district has base arc radius of curvature BCR, the transition zone has transition zone radius of curvature TZR, and the landing zone has landing zone radius of curvature LZR, and wherein TZR relies on BCR, but LZR is independent of BCR. The set of fitting sheets includes at least two subgroups of different LZR, each subgroup containing a plurality of fitting sheets having different BCR. The utility model discloses a try on piece group and simply easily operate, can shorten sclera contact lens greatly and examine the time of joining in marriage.

Description

Trial wearing sheet set for scleral contact lens fitting

Technical Field

The utility model relates to a contact lens field especially relates to a try on piece group that is used for sclera contact lens to examine the preparation.

Background

Scleral contact lenses are large diameter rigid gas permeable contact lenses commonly used for daytime wear. In contrast to conventional rigid oxygen permeable contact lenses (RGPs), scleral lenses land on the sclera and arch across the cornea and at the corneal/scleral junction, known as the limbus, thus enabling the formation of a gap between the posterior surface of the lens and the anterior surface of the cornea and the limbus, the posterior lachrymal space (posteror lens clear). The retrospecularly-isolated tear space includes the corneal space and the corneoscleral limbus space. The gap is used as a liquid storage, which can be filled with tears, physiological saline or functional solution such as liquid medicine and the like, can create an ideal ocular surface environment, and has incomparable advantages for protecting cornea and corneoscleral marginal tissues, improving dry eye, correcting irregular corneal astigmatism, reducing high-order aberration and the like.

Scleral contact lenses typically include an optical zone, a transition zone, and a landing zone. The optical zone is located in the center of the lens and is primarily used for vision correction. The landing zone is the outermost peripheral region of the scleral contact lens and is also the weight bearing area of the entire lens. The transition zone connects the optical zone and the landing zone, typically arching above the corneoscleral rim.

The fitting of scleral contact lenses requires consideration of a number of factors, including ensuring that the lens has a proper post-lens tear clearance when worn on a human eye, does not contact the cornea and the corneal limbus, does not have large bubbles, does not compress blood vessels, is comfortable to wear, and the like. Most scleral contact lens formulations require the measurement of a variety of ocular parameters for comfort and are typically designed with a variety of lens parameters to adjust the shape of the posterior surface of the scleral contact lens, particularly the posterior surface of the landing zone, to the eye topography of the subject in order to maximize the fit of the lens eye. Therefore, most scleral contact lenses are complicated to fit and require a long time to evaluate when the lens is worn for 20-30 minutes, 2 hours, and 4 hours.

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

SUMMERY OF THE UTILITY MODEL

The utility model relates to a try on piece group for scleral contact lens is checked and matched, try on the piece be the scleral contact lens and including setting up in the optics district of lens central authorities, encircle the transition district in optics district and the landing district of setting at the lens periphery, optics district has the base arc curvatureA radius BCR, the transition zone having a transition zone radius of curvature TZR, and the landing zone having a landing zone radius of curvature LZR, wherein TZR is BCR dependent, but LZR is independent of BCR, the set of trial pieces comprising: the high-edge warping subgroup containing a plurality of first test wearing pieces and the low-edge warping subgroup containing a plurality of second test wearing pieces, wherein the curvature radiuses of the landing areas of the first test wearing pieces are the first curvature radiuses LZR of the landing areas ₁ And the curvature radiuses of the landing areas of the plurality of second try-on pieces are all the second curvature radiuses LZR of the landing areas ₂ Wherein LZR ₁ Greater than LZR ₂ And LZR ₁ And LZR ₂ Each independently selected from 8.5 to 15.0mm; and the plurality of first try-on pieces have different base arc curvature radiuses, the plurality of second try-on pieces have different base arc curvature radiuses, the base arc curvature radiuses of the first try-on pieces and the second try-on pieces are all selected from the same base arc curvature radius set, and the base arc curvature radius set comprises a plurality of preset base arc curvature radiuses which are distributed in an equal step mode and are selected from 5.0-14.0 mm.

In some embodiments, the number of the first try-on pieces is the same as the number of the second try-on pieces.

In some 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 set of try-on pieces further comprises a material having a composition other than LZR ₁ And LZR ₂ Other subgroups of LZR.

In some embodiments, the TZR is 0.0 to 2.0mm greater than the BCR.

In some embodiments, the posterior surface of the landing zone is a rotationally symmetric aspheric surface having an eccentricity between 0.05 and 1.00.

In some embodiments, the scleral contact lens is configured to have a degree of movement between 0.4 and 1.2mm at the surface of the eyeball during use.

In some embodiments, the scleral contact lens is configured such that, during use, a vertex gap between a posterior surface of the optical zone and a vertex of the eyeball is no more than 200 microns.

In some embodiments, the landing zone tip is provided with an edge warp.

In some embodiments, the junction of the posterior surface of the landing zone and the posterior surface of the transition zone is a perpendicular distance from the lens axis of the scleral contact lens of between 6.0 and 7.0 mm.

Drawings

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

Fig. 2 is a schematic diagram of a scleral contact lens according to an embodiment of the present invention. The left figure is a bottom view of the scleral contact lens; the right drawing isbase:Sub>A sectional view of the left drawing taken along the line A-A.

FIG. 3 is a fluorescence pixel rendering image evaluated using a slit-lamp cobalt blue diffuse light source.

FIG. 4 is a schematic diagram of landing zone edge lift evaluation.

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

Reference numerals:

OZ: an optical zone; TZ: a transition zone; and (3) LZ: a landing zone; TD: the total lens diameter; AC: a vertex gap; LSH: the rise of the lens; ESH: eye rise; EL: edge warping; j1: the optical zone and transition zone rear surface junction; j2: a transition zone and landing zone rear surface junction; 1: a cornea; 2: the bulbar conjunctiva.

Detailed Description

The following detailed description of the embodiments of the present invention will be made with reference to the accompanying drawings. Numerous specific details are set forth in the following description in order to provide a thorough and complete disclosure of the present invention and to fully convey the concept of the invention to those skilled in the art. With respect 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 proportions are merely illustrative and do not limit the invention in any way. Unless defined otherwise, terms used in the present application have meanings commonly understood by those skilled in the art.

As used herein in connection with contact lenses, "anterior surface" refers to the surface that is proximate to the inner surface of the eyelid when worn, or the convex surface of the lens; "posterior surface" refers to the side of the lens that faces the cornea when worn, or the concave surface of the lens.

1. Scleral contact lens

The utility model relates to a scleral contact lens of simple design, as shown in fig. 1, scleral contact lens includes optics district (OZ), transition district (TZ) and Landing Zone (LZ), optics district has base arc radius of curvature BCR, the transition district has transition district radius of curvature TZR, and the landing zone has landing zone radius of curvature LZR, and wherein TZR relies on BCR, but LZR is independent of BCR. The optic zone is centered in the lens and is generally larger in diameter than the horizontal visible iris diameter and is used primarily for vision correction. The landing zone is the outermost peripheral region of the scleral contact lens, which is the region where the scleral contact lens contacts or lands on the ocular surface. The transition zone connects the optical zone and the landing zone, typically arching over the corneoscleral rim. The utility model discloses an among the scleral contact lens, transition district curvature radius and base arc curvature radius linkage through the cornea form of measuring the testee, can elect target base arc curvature radius and confirm the transition district curvature radius that corresponds simultaneously, and the condition of fitting is joined in marriage through the landing zone again, adjusts landing zone curvature radius, can elect suitable lens parameter.

The sclera contact lens of the utility model is an open or non-closed sclera contact lens. As used herein, "non-enclosed" or "open" scleral contact lenses means that the posterior surface of the scleral contact lens' landing zone is not designed or customized to be fully or as complementary or conform to the corresponding ocular surface topography of its wearer, as opposed to conventional enclosed or semi-enclosed scleral contact lenses.

Because perfect fit to the ocular surface (bulbar conjunctiva portion) is not sought, the scleral contact lens of the present invention, and in particular 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 rotationally symmetric aspheric. In some embodiments, the aspheric surface has an eccentricity of between 0.05 and 1.00, preferably between 0.05 and 0.60.

Other features of the scleral contact lens of the present invention include: higher ocular surface mobility, thin posterior tear space, and the like, as will be described in more detail below.

(I) Lens moving (movement)

The landing zone is the outermost peripheral region of the scleral contact lens and is also the load bearing area of the entire lens, and in order to improve comfort, avoid conjunctival compression and distribute the weight of the lens as much as possible, it is generally required that the posterior surface of the landing zone conforms to the corresponding ocular surface shape as much as possible to have a larger area of contact area. Studies have shown that the shape of the anterior scleral surface (between 15.0mm to 20.0mm diameter) is tangential in most subjects, takes on a convex shape in less than one third of the subjects, and a very small percentage of subjects are concave. Furthermore, it is known in the art that the shape of the anterior surface of the sclera increases in asymmetry in areas other than 13.0mm in diameter. Thus, to achieve good fit and lens stability, most scleral contact lenses are designed with a tangential posterior surface profile with little or no curvature, and many have attempted to divide the scleral contact lens into multiple zones or quadrants to facilitate adjustment of the parameters and design of the scleral contact lens in each zone based on the ocular surface topography of the subject.

Because of this, most scleral contact lenses are closed or semi-closed with little or no tear exchange and lens mobility. In most cases, an ideally suited conventional scleral contact lens would not exhibit any clinically significant tear exchange without mechanical manipulation. Complications that may be readily induced by closed scleral contact lenses include, but are not limited to, daytime fogging caused by tear pool debris, visual fluctuations caused by lens sedimentation, off-center induced higher order aberrations, high lipid concentrations, inflammatory factor accumulation, corneal hypoxic stress, and the like. In addition, because conventional scleral contact lenses have no or only minimal tear fluid exchange, the reservoir of the lens cannot be filled, resulting in the formation of air bubbles, etc., after wearing, and thus, during wearing, the wearer is required to add a suitable liquid to the concave surface of the lens in advance, lower the head substantially parallel to the ground, and then place the scleral contact lens with the liquid in the eye with one hand. If insufficient fluid is added or the wearing is not skilled, air bubbles may be present between the lens and the ocular surface, and therefore the lens needs to be removed and reapplied because air bubbles can cause eye discomfort, blurred vision and corneal staining, which is avoided with scleral contact lenses both during and while the lens is being worn.

Thus, in embodiments of the present invention, a person solves the problems associated with conventional closed/semi-closed scleral contact lenses by providing an open or closed scleral contact lens. As used herein, "non-enclosed" or "open" scleral contact lenses means that the posterior surface of the scleral contact lens 'landing zone is not designed or customized to be completely or as much complementary or fit to its wearer's corresponding ocular surface topography.

Because perfect fit with the ocular surface topography is not pursued, the scleral contact lens of the present invention has a higher degree of ocular surface movement than similar products. The higher the lens mobility, the higher the tear exchange rate. It has been demonstrated that the scleral contact lenses of the present invention provide sustained dynamic tear exchange, which is manifested, for example, by the observation that, after a drop of fluorescein is applied to the outside of the lens, the fluorescein fills the back of the lens after 5 to 10 blinks. However, movement that is too high or too low can reduce comfort, and thus in some embodiments, the scleral contact lenses of the present invention are configured to move between 0.4mm and 1.2mm, preferably between 0.5mm and 1.0mm, such as about 0.5, 0.6, 0.7, 0.8, 0.9, 1.0, 1.1mm and any value therebetween, preferably less than 1.0mm, and more preferably about equal to 0.5mm (e.g., 0.5 ± 0.05 mm), at the surface of the eyeball during use. The degree of movement is measured by slit lamp illumination (0.5-2.0 mm width) and a graduation line of known length of the slit lamp or slit lamp illumination beam width, and the movement of the lens is evaluated 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 around the optical axis of the scleral contact lens, so when the lens is placed on the sclera with an asymmetric front surface topography, it will not fit perfectly with it, but will likely have only a few contact points or positions, so that the mobility is higher, more facilitating the exchange of tears under the lens. In still other embodiments, the rear surface of the landing zone is rotationally symmetric aspheric.

In still other embodiments, the perpendicular distance of the junction of the posterior surface of the landing zone and the posterior surface of the transition zone (i.e., the starting point of the landing zone, J2) from the lens axis of the scleral contact lens is 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 therebetween, to take full advantage of the asymmetry of the anterior surface of the sclera beyond 13.0mm in diameter.

Without wishing to be bound by any theory, the inventors believe that the scleral contact lens of the present invention solves the problems of the prior art by effectively avoiding the accumulation of proteins, lipids, mucins and inflammatory factors within the tear layer between the cornea and the back surface of the lens by achieving sufficient exchange of tears beneath the scleral contact lens with tears outside the lens.

As mentioned above, conventional scleral contact lenses are typically designed to be closed or semi-closed reservoirs, and thus are also particularly suitable for dry eye patients. However, the biggest problem of closed or semi-closed scleral contact lenses is the accumulation of various chemicals and debris in the tear layer under the lens, and daytime fogging (midday fogging) is one of the most representative manifestations, so that the subject has to take off the lens for cleaning during the course of one day to maintain good vision. The utility model discloses a sclera contact lens is not laminated with the ocular surface is perfect in the landing zone, has the mobility of relative height, and the action of blinking with the help of the experimenter can realize the abundant and tear of tear pond behind the lens and the continuity exchange and the renewal of tear, is favorable to the cornea healthy for the lens can be comfortable wear a whole day and do not have any problem.

Therefore, the sclera contact lens of the utility model not only does not need to drip normal saline before wearing, but also has simple wearing, no fogging phenomenon in the daytime and safe and convenient picking.

(II)Corneal space

When the sclera contact lens is placed on the eyeball, the back surfaces of the optical area and the transition area of the sclera contact lens are not contacted with the front surface of the eyeball of the testee, thereby forming a liquid storage space. The gap between the optical zone back surface and the corneal anterior surface is called the corneal gap, and the gap between the transition zone back surface and the corneal limbus anterior surface is called the corneal limbus gap. The corneal space may be characterized by a central space or an apical space (AC). The central space is the distance between the center of the posterior surface of the scleral contact lens and the anterior surface of the cornea; apex gap refers to the distance between the highest point of the anterior surface of the cornea and the posterior surface of the scleral contact lens. Since the anterior corneal topography is generally irregular, particularly for keratoconus patients, corneal trauma or post-corneal surgery patients, the apex gap is used in the present invention to determine whether the scleral contact lens vault over the cornea is appropriate. The apex gap is related to the Lens Sagittal Height (LSH) (i.e., the perpendicular distance between the geometric center of the lens back surface and the plane of the lens edge).

The corneal space must not be too large nor too small. When the corneal space is too large, the tear layer therein increases in thickness, affecting the transmission of oxygen from the outer surface of the lens to the cornea, easily resulting in hypoxia of the cornea and, at the same time, accumulation of various ocular debris (e.g., mucosal debris (mucosis), meibomian gland debris (meibomian debris), lacrimal debris). In the case of insufficient corneal space, due to the sedimentation effect of the scleral contact lens, it is possible that the contact of the posterior surface of the scleral contact lens with the anterior surface of the cornea occurs after the subject wears the lens for several hours, causing damage to the corneal epithelium. Furthermore, even if corneal weight bearing does not occur, the relatively thin (100 micron or less) tear layer is considered by scholars to be disadvantageous because it creates a thin film adhesion in the enclosed space that increases the absorption between the scleral contact lens and the ocular surface, resulting in difficulty in lens removal, particularly after prolonged lens wear, where tear fluid therein is more viscous due to ocular surface secretions, metabolites, etc. Of course, there is no determination in the art as to how much of the corneal space is ideal, but it is currently believed that at least a 250 micron corneal space should be guaranteed during initial lens prescription.

The inventor finds that in the closed scleral contact lens of the present invention, by setting the suitable apex clearance of the scleral contact lens to not more than 200 microns, not only does not cause the problem of difficulty in lens removal, but also unexpectedly reduces the lens sedimentation degree, and even when the apex clearance is as low as 40 microns, corneal load and damage do not occur after the subject wears the closed scleral contact lens for a long time. As used herein, the term "initial apex gap" refers to the distance between the peak of the anterior surface of the cornea and the posterior surface of the scleral contact lens as measured by Optical Coherence Tomography (OCT) or fluorescein staining after a subject wears the lens for 20 to 30 minutes. If the utility model discloses an initial summit clearance also be the utility model discloses a sclera contact lens is when the inspection, whether the optician is used for judging the selected piece of trying on and is joined in marriage one of suitable important parameter.

Thus, the initial apex gap between the posterior surface of the optical zone of the scleral contact lens according to the present invention and the apex of the eyeball is below 200 microns, e.g., 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 140 μm, less than 130 μm, less than 120 μm, less than 110 μm, less than 100 μm, less than 90 μm, less than 80 μm, less than 70 μm. A vertex gap above 200 microns is undesirable because in the present unconfined scleral contact lenses, too high a vertex gap tends to cause air bubbles to enter the lens back space from where the landing zone does not conform to the ocular surface as the lens moves and tears move during wear.

In a preferred embodiment, the initial apex gap is above 40 microns, such as greater than 40 μm, greater than 50 μm, greater than 60 μm, greater than 70 μm, for example the initial apex 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 therebetween. An apex gap of less than 40 microns is disadvantageous because the irregular shape of the sclera, and the rotation of the eye in different gaze directions, can cause the lens to be in close proximity to the cornea during movement, with the potential for damage.

Because according to the utility model discloses a sclera contact lens has thinner tear clearance behind the mirror under the circumstances of fitting the ideal, and wherein the tear thickness that the tear formed is thin, so even the lens mobility is high, the change of tear thickness that leads to by it also can be neglected almost, can not lead to the visual fluctuation of experimenter.

In some embodiments of the present invention, the transition region of the scleral contact lens is configured to be located above the corneal limbus of the eyeball when the scleral contact lens is placed on the eyeball. The corneoscleral limbus is the cornea-sclera junction, which contains stem cells critical to the health of the eye. If the scleral contact lens is in contact with the limbus, damage to stem cells therein may occur; also, if the scleral contact lens arch is too high in this region, it may affect the oxygenation of the corneoscleral limbal stem cells. Thus, in some embodiments of the present invention, the scleral contact lens is further configured to provide a corneoscleral limbus gap of between 75-150 microns.

The specular apex and corneoscleral margin can be quantitatively measured by Optical Coherence Tomography (OCT) and can be assessed both statically and dynamically using fluorescein staining.

(III) edge warping

In some embodiments, the tip of the landing zone is provided with an edge warp. As used herein, "edge lift" refers to the landing zone tip not contacting the ocular surface, edge lift is sometimes referred to as edge lift or edge tilt, and "edge tilt height" refers to the distance from the landing zone tip to the bulbar conjunctiva where the chord length of the eyeball is equal to the diameter of the scleral contact lens (fig. 1).

Generally, because of the larger size of the scleral lens, edge warping is not preferred by the subject because it is more likely that the subject will perceive the presence of the lens (foreign body sensation), and the upper edge warping may also exacerbate Giant Papillary Conjunctivitis (GPC). During the fitting process of the scleral mirror, the ideal situation generally accepted in the field is perfect fit of the landing zone to the sclera (bulbar conjunctiva), no edge tilting, no compression, and no conjunctival whitening (blanching).

However, the utility model utilizes the tear exchange promoting effect brought by the edge upwarping. Set up the limit perk at the landing zone end and make the utility model discloses a tear exchange effect is outstanding behind sclera contact lens's mirror.

Furthermore, the inventor also found that by setting the curvature radius r1 at the connection point (J2) of the rear surface of the landing zone and the rear surface of the transition zone of the scleral contact lens of the present invention and the curvature radius r2 (fig. 2) of the end of the rear surface of the landing zone, and setting the curvature radius of the portion of the rear surface of the landing zone between the two points to be gradually (continuously or stepwise) increased radially outward, the rear surface profile of the landing zone can be controlled individually, the gently raised edge warp is constructed, and the foreign body sensation of the subject is reduced. Where the radius of curvature at the junction J2, r1, is the landing zone radius of curvature LZR. In some embodiments, the radius of curvature r1 at the junction (J2) of the landing zone rear surface and the transition zone rear surface is between 8.5 and 15.0mm, such as 9.0, 10.0, 11.0, 12.0, 13.0, 14.0, 15.0mm or any value therebetween. The radius of curvature r2 of the end of the rear surface of the landing zone is between 8.65 and 20.0mm, preferably between 10.0 and 15.0 mm. Changing r1 (LZR) can result in changes in the position of the lens landing on the conjunctiva, changing the sagittal height of the lens as a whole and fitting to the anterior surface of the cornea. Part B of fig. 2 shows the landing zone change caused by the r1 change.

In some embodiments, the sagittal height S at J2, S representing the perpendicular distance of the junction point J2 from the lens edge plane, is set according to the radius of curvature r1 at J2; the larger r1, the smaller S, and the higher the edge warp. Wherein S (r 1) = (a + B × r1+ C × r 1) ² +D×r1 ³ ) ^-1 And A is selected from-2 to-150, B is selected from-0.5 to 5, C is selected from-0.06 to-0.6, and D is selected from 0.003 to 0.03. For example, A is-10, B is-2.5, C is-0.28, and D is 0.017. Suitable rise S is, by way of example, selected from 0.6 to 3.2mm, preferably 1.0 to 2.2mm, more preferably 1.2 to 1.7mm. The inventors have found that varying the landing zone of a scleral contact lens within this range provides a lip lift of suitable height for tear exchange and testingA balance is established between the subjective perception of comfort of the person.

(IV) other lens characteristics

In some embodiments, the scleral contact lens of the present invention further comprises a through-hole (perforation) and/or pocket (pocket) disposed in the optical zone and/or transition zone of the scleral contact lens (fig. 2). The 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 the range of 0.2 to 1.0mm. The pockets, unlike the through holes, are non-through structures having an opening on the rear surface of the lens. The pocket suitable for the utility model can have various profiles. The pockets can reduce the average thickness of the lens, increasing the oxygen permeability of the lens, and thus, in some embodiments, the scleral contact lens of the present invention is provided with a plurality of pockets on the back surface. In some embodiments, the pocket is configured to trap and restrict air bubbles that may enter the retroscopic space through the through-hole, such as described in CN 112666723A. The patent documents are incorporated by reference herein in their entirety.

In still other embodiments, the scleral contact lens of the present invention has an optical zone diameter phi _a0 Between 5.00 and 12.00 mm. The optical zone has a central thickness of between 0.15 and 0.55mm to provide sufficient lens strength while allowing good oxygen transmission through the lens. In various embodiments, the posterior surface of the optical zone can be spherical, aspherical, or toric. In various embodiments, the optical zone posterior surface can have a radius of curvature that is greater or less than the corneal radius of curvature. In some embodiments, the radius of curvature r0 of the posterior surface of the optical zone (i.e., the base curve radius of curvature (BCR) of the scleral contact lens) is between 5.0mm and 14.0mm, such as between 5.5 mm and 12.0mm, such as between 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 therebetween.

In various embodiments, the width of the transition zone (i.e., #) of the scleral contact lens of the present invention _a1 Phi and phi _a0 Difference of differenceHalf of) between 0.8 and 1.8mm, preferably between 1.0 and 1.5 mm. In various embodiments, the radius of curvature at the junction (J1) of the posterior surface of the transition zone with the posterior surface of the optical zone (i.e., the beginning of the transition zone) (i.e., the transition zone radius of curvature (TZR)) is greater than or equal to the base arc radius of curvature, e.g., 0.1 to 2.0mm greater than the base arc radius of curvature, e.g., 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 greater and any value therebetween. Thus, in various embodiments of the present invention, the radii of curvature of the optical zone back surface and the transition zone back surface are linked.

In various embodiments, the radius of curvature of the landing zone of the scleral contact lens of the present invention is not dependent on the BCR setting, but rather on the required rim 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 25.0mm, preferably 14.0 to 18.0mm.

TABLE 1 exemplary scleral contact lenses of the present invention

2. Fitting of scleral contact lenses

Fitting of scleral contact lenses includes pre-fitting inspection, fitting evaluation, parameter adjustment, and ordering of custom lenses.

The examination before prescription includes medical history collection, eye health examination, eye parameter measurement, subjective and objective optometry, etc. The eye parameter measurement comprises corneal curvature, corneal morphological parameters, corneal diameter, pupil diameter measurement and the like. Knowledge of corneal morphology is the basis for the selection of trial film base curves. Corneal curvature may be measured using a keratometer and corneal topography. The corneal topography can reflect the complete appearance of the cornea more completely, so the corneal topography has wider application in practice.

Based on the results of the pre-fitting examination, the optician will select the first fitting for the subject to be evaluated for fit. Good scleral contact lens fit includes three basic aspects: suitable corneal space, corneoscleral margin space and scleral fit. Therefore, fitting evaluation includes an evaluation check of the optical zone, transition zone and landing zone, for example, using a pen lamp or slit lamp after wearing for 5 minutes to roughly evaluate whether there is corneal contact or air bubbles in the central zone, whether there is a lifting of the landing zone, vascular compression, etc., while asking the subject for comfort. If the first piece is positioned in the middle, and has no contact, large bubbles and obvious discomfort, the first piece is worn for 20 minutes and then is evaluated by adopting slit lamp fluorescein; otherwise, the test piece is replaced and re-evaluated. The fitting of conventional scleral contact lenses typically requires a long time to evaluate at 20-30 minutes, 2 hours and 4 hours of lens wear. Criteria for successful scleral contact lens fitting include good dynamic and static assessment (no air bubbles, no contact, including no contact at both the corneal and corneal limbus portions), improved vision correction by on-chip optometry, and good subject comfort.

If the fitting of the fitting piece is not good enough, the optician needs to select the fitting piece with other parameters for the subject according to the situation until good fitting is obtained, and then the optician can order the corresponding product for the subject according to the parameters of the fitting piece. Scleral contact lenses designed by different manufacturers typically require the optician to adjust to different lens parameters and provide corresponding fitting guidelines. Some scleral contact lenses have complex design, multiple adjustable parameters and complex fitting.

The sclera contact lens according to the utility model has simple design, so the testing and matching are relatively simple. Accordingly, in some embodiments, the present application further provides a method of fitting a scleral contact lens. As shown in fig. 5, the method includes measuring corneal morphology of a subject, for example, using corneal topography, to obtain a flat K value (FK) and a corneal eccentricity e value corresponding to FK of the cornea of the subject (step 110); selecting a first try-on piece of a scleral contact lens for the subject based on the FK value and the e value, the optical zone of the first try-on piece having a first base arc radius of curvature (BCR) ₁ And its landing zone has a first landing zone radius of curvature LZR ₁ (step 120).

Wherein the step of selecting the first try-on piece comprises: calculating a proper lens rise from the FK, e values and the target initial apex gap (40-200 μm), and calculating a base arc radius of curvature from the lens rise and base arc eccentricity (0.30-1.10, preferably 0.5-0.99); and subtracting a correction parameter C within the range of 0.2-0.5 from the calculated base arc curvature radius to obtain the base arc curvature radius of the first try-on piece. The calculation formulas required for the various steps are well known in the art, see for example those described in Contact lens optics and lens design, ISBN 978-0-7506-8879-6, chapter 4 systematic surfaces (Contact lens optics and lens design, ISBN 978-0-7506-8879-6, chapter 4aspheric surface). In a preferred embodiment, the correction parameter is 0.3.

The method of the present application further comprises performing fitting assessment (step 130) after wearing the lens for 20-30 minutes, such as by instillation of sodium fluorescein, the assessment comprising: whether the lens is positioned in the middle or not and the mobility; whether the center has large bubbles or not and whether the center has contact or not; the middle periphery (transition zone) of the lens is pressed or not; the periphery (landing area) of the lens is pressed or not. FIG. 3 illustrates several situations in which lens fitting may occur, where a flat fit is manifested as a too thin posterior gap or contact at the center; steep fitting represents a large bubble in the center; the fluorescent layers are perfectly matched with the visible mirror and then are uniformly distributed. In both flat and steep fits, it is necessary to adjust the parameters of the fitting, such as BC radius of curvature or edge warping. In the field of fitting contact lenses, particularly hard lenses (e.g., RGP, orthokeratology, and scleral contact lenses), adjusting the corresponding lens parameters according to the fitting evaluation result of the fitting piece is a conventional technical means in the field. As a simple example, for example, in the methods of the present application, if compression of the optical zone is observed, or the apex gap is less than 40 μm, the BC (smaller BCR) can be ramped up, increasing the lens sagittal height, away from the cornea; if the optical zone has a large bleb or a tip gap greater than 200 μm, and/or the limbal gap is too large or bleb, then the trial is replaced with a larger BCR. If the landing zone is pressed, the edge can be relaxed and tilted, and a larger r1 (namely LZR) is selected; if the landing area has bubbles, a smaller r1 is selected to reduce edge warping. Fig. 4 shows several cases of poor edge lift fit of the lens.

In some embodiments, the methods of the present application further comprise measuring the apex gap and/or the corneoscleral margin gap, for example by OCT.

Further, the method of the present application further comprises customizing or ordering a scleral contact lens having the parameters based on the ideal BCR and the edge tilt height (characterized by LZR) obtained from the fitting assessment and the diopter strength of the subject (step 140). Those skilled in the art will appreciate that the order parameters may also include other specific specifications, such as adjusting the lens diameter, polishing the lens well, etc. However, in various embodiments, none of the methods include the step of measuring the morphology of the scleral surface of the subject, nor do the following parameters include sclera morphology related parameters.

In still other embodiments, the methods of the present application further comprise taking multiple corneal topography measurements to ensure consistency and accuracy of the data.

Because the utility model discloses a sclera contact lens has dynamic tear exchange, does not have or only has slight subside, so need not to wait for the evaluation time of 4 hours when the lens is joined in marriage, only can find the lens of joining in marriage the suitable ideal through BC and the limit perk of adjustment lens moreover, shorten greatly and simplified the lens and examined the joining in marriage the flow.

Thus, according to yet another embodiment, the present invention also provides a set of try-on pieces for scleral contact lens fitting that provides different combinations of lenses BCR and LZR for selection by the optician. Specifically, the fitting sheet set includes: the high-side warping subgroup containing a plurality of first test wearing pieces and the low-side warping subgroup containing a plurality of second test wearing pieces, the curvature radiuses of the landing zones of the first test wearing pieces are all LZR1, the curvature radiuses of the landing zones of the second test wearing pieces are all LZR2, wherein the LZR1 is larger than the LZR2 and is respectively and independently selected from 8.5-15.0 mm; and the plurality of first try-on pieces respectively have different base arc curvature radiuses, the plurality of second try-on pieces respectively have different base arc curvature radiuses, the base arc curvature radiuses of the first try-on pieces and the second try-on pieces are all selected from the same base arc curvature radius set, and the base arc curvature radius set comprises a plurality of preset base arc curvature radiuses which are distributed in equal steps (for example, the step is selected from 0.2-1.0 mm, and is for example, the step is 0.5 mm) and are selected from 5.0-14.0 mm.

In some embodiments, the number of the first try-on pieces is the same as the number of the second try-on pieces. In some further 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 set of try-on pieces further comprises a patch having a composition other than LZR ₁ And LZR ₂ Other subsets of the LZR, which likewise comprise a plurality of test strips. For example, the fitting sheet group further comprises a middle edge warping subgroup containing a plurality of third fitting sheets, the landing zone curvature radiuses of the plurality of third fitting sheets are all LZR3, and LZR1>LZR3>LZR2。

As an example, the present invention provides a scleral contact lens try-on sheet set, the try-on sheet set comprising: the high side warp subgroup with LZR1 of 13.0mm containing 14 first test pieces, (2) the low side warp subgroup with LZR2 of 10.0mm containing 14 second test pieces, and (3) the medium side warp subgroup with LZR3 of 11.5mm containing 14 third test pieces, wherein the set of base arc radii of curvature comprises the following 14 preset base arc radii of curvature of 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 for scleral contact lenses of the present invention

The scleral contact lens according to the present invention is suitable for (1) patients with irregular astigmatism of the cornea, such as keratoconus, corneal limbic degenerative diseases, astigmatism after corneal transplantation, etc.; (2) Treatment of ocular surface diseases such as dry eye, corneal neuralgia, GVHD graft-versus-host reactions, severe ocular surface diseases such as persistent epithelial defect non-healing (PED), and combination therapy with drugs such as lubricants, acutely, cyclosporine eye drops, and other ophthalmic procedures such as amniotic membrane transplantation, blepharospinous surgery; and (3) non-emmetropic eyes, such as ametropia and presbyopia.

Examples

Example 1

Patient a:30 years old, male, left eye chemical injury after visual deterioration for 3 years

Basic information of the eye: 0.05 vision with naked eyes, OS-0.75/-2.25 x 150 subjective refraction, 0.4 vision with best correction

The patient's corneal applanation K value was measured by corneal topography as 8.46, and e value as 0.94

First try-on piece: BC 8.6mm, medium edge warped (junction rise S =1.47 mm), examined by slit lamp 20 minutes after wearing the mirror: the central corneal post-lens tear layer is thin, about 20 μm thick; the peripheral postspecular lacrimal fluid layer is thin and about 40 mu m thick; the paranasal conjunctiva is whitened, the lens is centered well, and the lens mobility is absent in a natural blinking state.

The method is adjusted to be high-edge warping (the rise S =1.40mm at the joint), a trial wearing piece with the steep BC of 8.2mm is selected, the lacrimal fluid layer filling of the central and peripheral corneal lenses is checked to be 100 mu m through a slit lamp after the lens is worn for 20 minutes, the landing area is well matched, the conjunctival blood flow is evaluated statically and statically without blocking, the lens is well centered, and the lens has small mobility of about 0.5mm in the natural blinking state. The chief complaint was not foreign body sensation.

The examination is carried out after one month of lens wearing, and the lens wearing is mainly used for optometry: -0.75/-0.50 x 180, with 0.8 lens-wearing vision.

Example 2

Patient B: keratoconus cross-linking operation for male, male and left eye of 22 years old

Basic information of the eye: naked eye vision 0.15, subjective refraction OS-4.00/-3.75 x 80, and best corrected vision 0.3

The patient's corneal applanation K value was measured by corneal topography as 8.39, e value as 0.21

First try-on piece: BC 7.2mm, medium edge warped (junction rise S =1.47 mm), examined by slit lamp 20 minutes after wearing the mirror: a central corneal contact; air bubbles behind the peripheral lens; the landing area is well matched, conjunctiva blood flow is not blocked in dynamic and static evaluation, the lens is well centered, and the lens has small mobility of about 1.0mm in a natural blinking state.

Adjust to a steeper BC 7.0mm trial, medium equilateral tilted (junction rise S =1.47 mm), inspect through a slit lamp 20 minutes after wearing a mirror: the central cornea is not contacted, and the thickness of the lacrimal fluid layer after the mirror is 100 mu m; small mobile bubbles behind the perimeter mirror; the landing area is well matched, conjunctiva blood flow is not blocked in dynamic and static evaluation, the lens is well centered, and the lens has micro mobility of about 0.5mm in a natural blinking state. The chief complaint was not foreign body sensation.

After one month of lens wearing, the examination is carried out, the chief angle of the lens wearing is-0.50/-0.50X 145, and the vision of the lens wearing is 0.8.

Example 3

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

Basic information of the eye: naked eye vision 0.01, subjective refraction OD-10.75/-3.25 x 5, and best corrected vision 0.8

The patient's corneal plateau K value was measured by corneal topography as 8.11, and e value as 0.78

First try-on piece: BC 8.0mm, medium edge warped (junction rise S =1.47 mm), examined by slit lamp 20 minutes after wearing the mirror: the central corneal post-lens tear layer is thin, with a thickness <20 μm; the peripheral retrospecularly lachrymal layer was full, with a thickness of about 100 μm; the paranasal conjunctiva whitens, the lens is well centered, and the lens mobility under the natural blinking corpus is <0.5mm.

Adjusting to a BC 7.6mm trial wearing piece with a high edge tilted and steeper, and inspecting through a crack lamp after wearing a mirror for 20 minutes: the central corneal post-mirror tear layer is moderate, about 50 μm; small mobile bubbles behind the perimeter mirror; the landing area is well matched, conjunctiva blood flow is not blocked in dynamic and static evaluation, the lens is well centered, and the lens has micro mobility of about 0.5mm in a natural blinking state. The chief complaint was not foreign body sensation.

After one month of lens wearing, the examination of the chief angle of the lens wearing is-0.25/-0.50X 34, and the vision of the lens wearing is 1.0.

While certain features of the invention have been illustrated and described herein, many modifications, substitutions, changes, and equivalents may occur to those skilled in the art. It is, therefore, to be understood that the invention is intended to cover all such modifications and changes as fall within the true spirit of the invention.

Claims (10)

1. A set of try-on lenses for use in the fitting of scleral contact lenses, wherein the try-on lens is a scleral contact lens and comprises an optical zone disposed in the center of the lens, a blend zone surrounding the optical zone, the optical zone having a base curve radius BCR, the blend zone having a blend zone radius TZR, and a land zone disposed at the periphery of the lens, the land zone having a land zone radius of curvature LZR, wherein TZR is BCR dependent but LZR is independent of BCR,

the try-on patch set includes: the high-side tilted subgroup containing a plurality of first try-on pieces and the low-side tilted subgroup containing a plurality of second try-on pieces, wherein the curvature radiuses of the landing areas of the plurality of first try-on pieces are the first curvature radiuses LZR of the landing areas ₁ And the curvature radiuses of the landing areas of the plurality of second try-on pieces are all the second curvature radiuses LZR of the landing areas ₂ Wherein LZR ₁ Greater than LZR ₂ And LZR ₁ And LZR ₂ Each independently selected from 8.5 to 15.0mm; and

the first try-on pieces are provided with different base arc curvature radiuses, the second try-on pieces are provided with different base arc curvature radiuses, the base arc curvature radiuses of the first try-on pieces and the second try-on pieces are all selected from the same base arc curvature radius set, and the base arc curvature radius set comprises a plurality of preset base arc curvature radiuses which are distributed in an equal step mode and selected from 5.0-14.0 mm.

2. The set of try-on sheets according to claim 1, wherein the number of the first try-on sheets and the number of the second try-on sheets are the same.

3. The set of try-on sheets according to claim 1 or 2, wherein the number of the preset base arc curvature radii is the same as the number of the first try-on sheets and/or the number of the second try-on sheets.

4. The set of try-on pads according to claim 1 or 2, further comprising a patch having a composition different from LZR ₁ And LZR ₂ Other subgroups of LZR.

5. The set of try-on patches of claim 1 or 2, wherein the TZR is 0.0-2.0 mm larger than the BCR.

6. The set of try-on pads according to claim 1 or 2, wherein the rear surface of the landing zone is a rotationally symmetric aspheric surface with an eccentricity between 0.05 and 1.00.

7. The set of try-on pads according to claim 1 or 2, wherein the scleral contact lens is configured to have a degree of movement between 0.4 and 1.2mm at the surface of the eyeball during use.

8. The set of try-on sheets of claim 1 or 2, wherein the scleral contact lens is configured such that, during use, a vertex gap between a posterior surface of the optical zone and a vertex of a subject's eyeball does not exceed 200 microns.

9. The set of try-on sheets according to claim 1 or 2, wherein the landing zone tip is provided with a bead.

10. The set of try-on sheets according to claim 1 or 2, wherein the junction of the posterior surface of the landing zone and the posterior surface of the transition zone is at a perpendicular distance of between 6.0 and 7.0mm from the lens axis of the scleral contact lens.

Images