A posterior chamber phakic intraocular lens and a method for improving its stability and communication capacity

Abstract

The application discloses a posterior chamber type artificial lens with a lens and a method for improving stability and communication capacity of the artificial lens. The artificial lens comprises an optical area and a supporting part, the supporting part is arranged outside the optical area, and a circular central hole is arranged in the center of the optical area; the supporting part comprises a closed haptic and haptic feet arranged outside the closed haptic, a haptic hole is arranged on one side of the closed haptic close to the optical area, an elliptical water guide hole is arranged on the closed haptic close to the haptic feet, the haptic feet are four in number, and positioning holes are arranged on the haptic feet. The elliptical water guide hole close to the haptic feet of the artificial lens can disperse pressure, reduce axial displacement of the artificial lens, keep the position relatively constant, and has high stability; the artificial lens has good communication capacity, the elliptical water guide hole is arranged between an iris and a lens anterior capsule, can make aqueous humor communicate smoothly, reduce contact with the iris and the anterior capsule, and reduce deposition of pigments on the surface of the artificial lens and in the chamber angle. The artificial lens can effectively prevent cataract, pupil block or angle closure glaucoma and the like.

Description

Technical Field

[0001] This invention belongs to the field of intraocular lenses and optical technology, and more specifically, relates to a posterior chamber phakic intraocular lens and a method for improving its stability and communication capabilities. Background Technology

[0002] Normally, newborns are farsighted. As they grow and their eyes develop, the degree of farsightedness gradually decreases, and the refractive state gradually develops towards emmetropia (normal vision). This change is called the "emmetropization process." Newborns typically have 1.0 vision by age 5. After this, the physiological parameters of various parts of the eye enter a relatively slow developmental process, reaching adult size around 12-13 years of age. However, as children enter school age, the increased workload of close-range visual activity gradually increases the burden on their eyes. Furthermore, the use of modern tools such as mobile phones, computers, televisions, and game consoles further increases this burden, leading to adverse consequences such as myopia. According to relevant research, the prevalence of myopia and high myopia among all age groups worldwide will increase year by year from 2000 to 2050. It is estimated that by 2050, the global prevalence of myopia will reach 49.8%, and the global prevalence of high myopia will reach 9.8%. High myopia is characterized by progressive increase in refractive error, continuous elongation of the axial length of the eye, and progressive damage to the contents of the eye and the retina, which leads to visual dysfunction and is one of the main causes of blindness. Therefore, various myopia corrections for myopia patients are becoming increasingly necessary.

[0003] There are many methods for myopia correction, such as eyeglasses, contact lenses, laser eye surgery, and implantable intraocular lenses. Eyeglasses are the most mature and convenient method for myopia correction, offering high safety and affordability. However, they are less aesthetically pleasing, have lower optical quality, and are prone to falling out during exercise. Furthermore, the lenses are fixed, providing optimal vision only when the eye is directly in front; any eye movement restricts the field of vision. Therefore, they are not suitable for all situations and professions. For high myopia, lenses with high refractive power can cause objects to appear smaller and distorted, making eyeglasses generally unacceptable. Compared to eyeglasses, contact lenses offer higher image quality, less visual distortion, and are more aesthetically pleasing, making them suitable for various situations and professions. However, they present challenges in wearing. Because contact lenses are worn in front of the cornea, they easily come into contact with the cornea, tear film, and conjunctiva, leading to friction and requiring meticulous cleaning. Repeated installation and wear of contact lenses can also cause eye health problems. Laser surgery for myopia has become increasingly sophisticated, and its effectiveness, safety, and predictability are widely recognized in clinical practice. However, for patients with high myopia, especially extreme myopia, the unpredictability of corneal biomechanics reduces the predictability of laser surgery correction, potentially leading to a significant increase in parallax and a decline in visual quality. This can result in complications such as keratoconus, corneal opacity, regression of results, dry eye, and poor postoperative visual quality. Furthermore, laser surgery has certain requirements regarding corneal thickness, and the corneal ablation is irreversible.

[0004] To address the shortcomings of the aforementioned technologies, researchers have begun designing and developing implantable intraocular lenses (IOLs) for myopia correction. Posterior chamber phakic IOL implantation involves placing an IOL in the posterior chamber space to correct refractive errors without removing any refractive tissue of the eye (including the cornea and the natural lens). Existing posterior chamber phakic IOLs are implanted in the posterior chamber space between the anterior surface of the natural lens and the posterior surface of the iris, with the haptic or supporting portion fixed in the ciliary sulcus. However, due to the limited space in the posterior chamber, the supporting part of the posterior chamber intraocular lens (IOL) is relatively close to the natural lens and iris. Although existing posterior chamber IOLs contain a central aperture and a haptic aperture, there is still a problem with poor communication of aqueous humor between the two sides of the IOL. This affects the communication of aqueous humor between the anterior and posterior chambers at the pupil, increasing the pressure difference between the anterior and posterior chambers, causing pupillary blockage, narrowing the iris angle, and making the IOL more prone to rubbing against the iris, causing iris pigment loss and deposition on the surface of the IOL and at the iris angle, resulting in a higher incidence of complications such as cataracts and glaucoma. In addition, because the posterior chamber IOL is haptic within the ciliary sulcus, it is prone to axial movement and positional changes due to the influence of the eye's accommodation and the compression of the iris. This may lead to the IOL contacting the anterior capsule of the lens or the corneal endothelium, causing adverse effects on the eye. Therefore, it is urgent to find a way to develop an IOL that can improve its stability and simultaneously solve the problem of poor aqueous humor communication in existing IOLs. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of the prior art and provide a posterior chamber phakic intraocular lens. This lens, by setting an elliptical water-guiding hole at a specific position on the closure loop, avoids the occurrence of cataracts, pupillary block, or angle-closure glaucoma due to poor aqueous humor circulation at the pupil after implantation of existing posterior chamber phakic intraocular lenses, while simultaneously maintaining the fixed position of the intraocular lens. Another objective of this application is to provide a method for improving the stability of posterior chamber phakic intraocular lenses. A further objective of this application is to provide a method for improving the communication ability of posterior chamber phakic intraocular lenses.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] A posterior chamber type phakic intraocular lens includes an optical zone and a support portion. The support portion is disposed outside the optical zone, and the center of the optical zone has a circular central hole. The support portion includes a closure loop and a loop foot disposed outside the closure loop. The closure loop has a loop hole on the side near the optical zone, and the closure loop has an elliptical water guide hole near the loop foot. The loop foot has a positioning hole.

[0008] This posterior chamber type phakic intraocular lens features a haptic aperture on the side of the closure haptic near the optical zone, an elliptical drainage hole on the closure haptic near the haptic foot, and a positioning hole on the haptic foot. These features, along with the central hole, haptic aperture, and the strategically positioned elliptical drainage hole, ensure smooth circulation of aqueous humor between the anterior and posterior chambers of the intraocular lens after implantation. This reduces iris depigmentation and pigment deposition on the lens surface and in the iridocorneal angle, maintains normal intraocular pressure, and prevents cataracts, pupillary block, or angle-closure glaucoma. Furthermore, the elliptical drainage hole near the haptic foot disperses pressure, reduces axial displacement of the intraocular lens, and maintains a relatively constant position of the lens.

[0009] Furthermore, the closest distance between the elliptical water guide hole and the loop foot is 0.4mm-1.0mm.

[0010] Preferably, the closest distance between the elliptical water guide hole and the loop is 0.6 mm.

[0011] Furthermore, the major axis of the elliptical water guide hole is 1.5mm-1.9mm, and the minor axis is 0.3mm-0.7mm.

[0012] Preferably, the major axis of the elliptical water guide hole is 1.7 mm and the minor axis is 0.5 mm.

[0013] Furthermore, the elliptical water guide hole is arranged in a figure-eight shape relative to the optical area.

[0014] Furthermore, there are two positioning holes, which are respectively set on two non-adjacent loops.

[0015] Furthermore, the optical area is circular, and the support portion is inclinedly disposed outside the optical area.

[0016] Furthermore, there are four loops, all on the same plane, and symmetrically arranged at both ends of the closed loop.

[0017] Furthermore, the angle between the plane containing the closed loop and the plane containing the optical zone is 10-60°.

[0018] Preferably, the angle between the plane where the closing loop is located and the plane where the optical zone is located is 35°.

[0019] Furthermore, at least one loop hole is provided on each side of the closed loop near the optical area.

[0020] Furthermore, the distance between the loop and the circumference of the optical area is 0.2mm-0.8mm.

[0021] Preferably, the distance between the loop and the circumference of the optical area is 0.35 mm.

[0022] Furthermore, the optical region is a plano-concave lens with a diameter of 4.5mm-6.0mm and a center thickness of 0.05mm-0.5mm. The diameter and center thickness of the optical region vary with different optical powers.

[0023] Preferably, the diameter of the optical region is 4.9mm-5.85mm and the center thickness is 0.116mm-0.3mm, and the diameter and center thickness of the optical region vary with different optical powers.

[0024] Furthermore, the diameter of the central hole is 0.1mm-0.5mm.

[0025] Preferably, the diameter of the central hole is 0.36 mm.

[0026] Furthermore, the positioning hole is circular with a diameter of 0.1 mm to 0.5 mm.

[0027] Preferably, the diameter of the positioning hole is 0.36 mm.

[0028] Furthermore, both the optical region and the support portion are made of hydrophilic polyacrylate material.

[0029] The hydrophilic polyacrylate material is soft and foldable, with a refractive index between 1.430 and 1.490. The lens is thin and easy to implant in the posterior chamber of the eye.

[0030] Furthermore, after the posterior chamber type phakic intraocular lens is implanted into the eye, it is located between the iris and the natural lens, with the fovea located within the ciliary sulcus.

[0031] The present invention also claims protection for a method for improving the stability and communication ability of the above-mentioned posterior chamber phakic intraocular lens, wherein an elliptical water guide hole is provided on the closure haptic of the posterior chamber phakic intraocular lens at a distance of 0.4 mm-1.0 mm from the haptic foot, the elliptical water guide hole having a major axis of 1.5 mm-1.9 mm and a minor axis of 0.3 mm-0.7 mm.

[0032] Preferably, an elliptical water guide hole is provided on the closure loop of the posterior chamber type phakic intraocular lens at a distance of 0.6 mm from the loop foot. The major axis of the elliptical water guide hole is 1.7 mm and the minor axis is 0.5 mm.

[0033] Compared with the prior art, the present invention has the following beneficial effects:

[0034] (1) The angle between the plane of the closure loop of the phakic intraocular lens and the plane of the optical zone in this posterior chamber type can better fit the posterior chamber space and prevent contact with the anterior capsule of the lens and the posterior surface of the iris;

[0035] (2) The elliptical drainage hole of the intraocular lens in this posterior chamber type is close to the haptic. When the intraocular lens is subjected to force, it can disperse the pressure, reduce the axial displacement of the intraocular lens, keep the position of the intraocular lens relatively constant, and further reduce the probability of the intraocular lens contacting the anterior capsule and iris.

[0036] (3) This posterior chamber type has a central hole, loop foramen and an elliptical aqueduct in a specific position for the intraocular lens, which simultaneously ensures smooth circulation of aqueous humor in front of and behind the intraocular lens after implantation. The elliptical aqueduct is located between the iris and the anterior capsule of the lens. The closest distance between the elliptical aqueduct and the loop is 0.4mm-1.0mm. The major axis of the elliptical aqueduct is 1.5mm-1.9mm and the minor axis is 0.3mm-0.7mm. The elliptical aqueduct within this parameter range can better communicate aqueous humor in front of and behind the intraocular lens, reduce the contact between the intraocular lens support and the iris and anterior capsule of the lens, reduce the impact of the support on the angle structure, and reduce iris depigmentation and pigment deposition on the surface of the intraocular lens and the angle, maintain normal intraocular pressure, and prevent cataracts, pupillary block or angle-closure glaucoma. Attached Figure Description

[0037] Figure 1 This is a front view schematic diagram of the posterior chamber type phakic intraocular lens of the present invention.

[0038] Figure 2 This is a side view schematic diagram of the posterior chamber type phakic intraocular lens of the present invention.

[0039] Figure 3 This is a schematic diagram of the implantation site for the posterior chamber type phakic intraocular lens of the present invention.

[0040] Figure 1-3 The following are the markings: 1 is the haptic foot; 2 is the positioning hole; 3 is the elliptical drainage hole; 4 is the haptic aperture; 5 is the closed haptic; 6 is the central hole; 7 is the support; 8 is the optical zone; 9 is the central axis of the optical zone; 10 is the cornea; 11 is the iris; 12 is the posterior chamber intraocular lens; 13 is the natural lens; 14 is the ciliary sulcus; 15 is the anterior chamber angle; 16 is the anterior capsule of the lens.

[0041] Figure 4 Weight changes in New Zealand white rabbits before surgery, at 1 week, and at 1 month.

[0042] Figure 5 Mean intraocular pressure results after implantation of intraocular lens in posterior chamber phakic eyes.

[0043] Figure 6 Example 3: Pathological section of the implantation site after intraocular lens implantation.

[0044] Figure 7 Example 7: Pathological section of the implantation site after intraocular lens implantation.

[0045] Figure 8 Comparative Example 1: Pathological section of the implantation site after intraocular lens implantation.

[0046] Figure 6-8 The annotations are as follows: LENS CAPSULE refers to the lens capsule of the natural lens in the pathological section; LENSEPITHELIUM refers to the epithelial cells of the natural lens in the pathological section; 25μm is the scale bar; VACUOLATED LENSEPITHELIUM refers to the vacuolation of the epithelial cells of the natural lens in the pathological section; MINERALIZATION refers to the subcapsular mineralization of the lens. Detailed Implementation

[0047] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0048] In the description of the present invention, it should be understood that the orientation or positional relationships indicated by the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. are based on the orientation or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as a limitation to the present invention.

[0049] In the present invention, unless otherwise clearly defined and limited, the terms "mounted", "connected", "coupled", "fixed", etc. shall be construed in a broad sense. For example, it may be a fixed connection, a detachable connection, or integrated; it may be a mechanical connection, an electrical connection, or communicable with each other; it may be directly connected, or indirectly connected through an intermediate medium, and may be the communication inside two elements or the interaction relationship between two elements, unless otherwise clearly defined. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention may be understood according to specific circumstances.

[0050] The "intraocular lens stability" as described in the present invention means that the posterior chamber intraocular lens 12 of the present invention is relatively constant in position with respect to the optical axis 9 of the optical zone and has no displacement change; the "intraocular lens communication ability" means the ability of the posterior chamber phakic intraocular lens 12 of the present invention to exchange aqueous humor in its anterior and posterior chambers. Good communication ability means that the aqueous humor in front of and behind the posterior chamber phakic intraocular lens 12 of the present invention flows smoothly without obstruction. The "figure-eight arrangement" means that the straight line where the long axis of the elliptical water guiding hole 3 is located is distributed in the same way as the two sides of the stroke of the Chinese character "八".

[0051] Unless otherwise specified, the reagents, methods, and equipment used in the present invention are conventional reagents, methods, and equipment in the technical field of the present invention.

[0052] Example 1

[0053] Combined with Figure 1 、 Figure 2 and Figure 3A posterior chamber type phakic intraocular lens includes an optical zone 8 and a support portion 7. Both the optical zone 8 and the support portion 7 are made of hydrophilic polyacrylate material. Hydrophilic polyacrylate material is soft and easily folded, with a refractive index between 1.430 and 1.490, resulting in a thin lens that is easy to implant into the posterior chamber of the eye. The optical zone 8 is circular and is a plano-concave lens. The support portion 7 is obliquely positioned outside the optical zone 8. The optical zone 8 has a circular central hole 6 at its center. The support portion 7 includes a closing loop 5 and loop feet 1 disposed outside the closing loop 5. The loop feet 1 are on the same plane and symmetrically arranged at both ends of the closing loop 5. A loop hole 4 is formed on each side of the closing loop 5 near the optical zone 8. An elliptical water guide hole 3 is provided on the closed loop 5 near the loop foot 1. The elliptical water guide hole 3 is arranged in a figure-eight shape relative to the optical zone 8. The axis of symmetry of the line containing the major axis of the elliptical water guide hole 3 passes through the central axis of the loop foot 1, and is used to disperse the pressure of the intraocular lens at the loop foot 1. There are four loop feet 1, and each loop foot 1 is provided with a positioning hole 2. There are two positioning holes 2, which are respectively provided on two non-adjacent loop feet 1, such as... Figure 1 It is positioned on the lower left and upper right haptic 1. After the posterior chamber type phakic intraocular lens is implanted into the eye, it is located between the iris 11 and the natural lens 13, and the haptic 1 is located within the ciliary sulcus 14.

[0054] Figure 3This shows the position of the posterior chamber intraocular lens 12 implanted in the eye. During implantation, the posterior chamber intraocular lens 12 has a side facing the cornea 10 and a side facing the natural lens 13. The lens plane of the optical zone 8 faces the cornea 10, and the concave surface faces the natural lens 13. When viewed from above, the lens plane of the optical zone 8 faces upwards, the central axis 9 of the optical zone is perpendicular to the lens plane of the optical zone 8, and the positioning hole 2 is located on the lower left and upper right diagonal lines. Two loop holes 4 are opened on the closure loop 5 near the optical zone 8, and an elliptical water-guiding hole 3 is opened on the closure loop 5 near the foot 1. These holes allow aqueous humor to flow between the two sides of the lens, ensuring smooth circulation and preventing cataracts, pupillary block, or comparative glaucoma. After the posterior chamber intraocular lens 12 is implanted into the eye, the haptic 1 is located within the ciliary sulcus 14. The central aperture 6 and the two haptic foramina 4 allow for the flow of aqueous humor between the front and back of the posterior chamber intraocular lens 12 in the central part. The elliptical aqueduct 3, located near the haptic 1, facilitates the flow of aqueous humor in this area, reducing contact between the support portion 7 of the posterior chamber intraocular lens 12 and the iris 11 and the anterior capsule of the natural lens 13. This reduces depigmentation of the iris 11 and pigment deposition on the surface of the posterior chamber intraocular lens 12 and the iridocorneal angle 15. During eye accommodation, the posterior chamber intraocular lens 12 is subjected to force. The elliptical aqueduct 3 disperses the pressure, reducing axial displacement of the posterior chamber intraocular lens 12 and maintaining a relatively constant position. This prevents the posterior chamber intraocular lens 12 from excessively shifting forward to contact the cornea 10 or excessively shifting backward to contact the natural lens 13, thus making the posterior chamber intraocular lens 12 safer. The axial direction of the axial displacement here specifically refers to the direction through the central axis 9 of the optical zone. The elliptical water guide hole 3 is close to the haptic 1. When the posterior chamber intraocular lens 12 is subjected to force, it can disperse the pressure. Here, the pressure refers to the force generated along the central axis 9 of the optical zone when blinking. It reduces the axial displacement of the posterior chamber intraocular lens 12, keeps the position of the posterior chamber intraocular lens 12 relatively constant, and reduces the possibility of the posterior chamber intraocular lens 12 contacting the anterior capsule 16 of the lens.

[0055] Examples 2-4

[0056] Examples 2-4 have the same structure as Example 1, and the specific dimensions of each part are prepared according to Table 1 below to obtain posterior chamber intraocular lenses. Examples 2-4

[0057] Table 1. Specifications of posterior chamber intraocular lenses in Examples 2-4

[0058]

[0059] Note: To simplify the table, in Table 1, "angle" refers to the angle between the plane containing the closed loop and the plane containing the optical zone; "water guide hole" refers to "elliptical water guide hole"; "loop hole distance" refers to the distance between the loop hole and the circumference of the optical zone, that is, the shortest distance between the circumference of the loop hole and the circumference of the optical zone. "Water guide hole distance" refers to the shortest distance between the elliptical water guide hole and loop foot 1, that is, the shortest distance is the line connecting any point on the elliptical circumference of the elliptical water guide hole and any point on the loop foot. The same names in other places in the text have the same meaning as those described in this table, and will not be repeated.

[0060] In the specific implementation process, when implanted into the eye, the posterior chamber intraocular lens 12 has one side facing the cornea 10 and the other side facing the natural lens 13. The lens plane of the optical zone 8 faces the cornea 10, and the concave surface faces the natural lens 13. When viewed from above, the plane of the optical zone 8 faces upward, and the positioning hole 2 is located on the lower left and upper right diagonal lines. The diameter of the positioning hole 2 can be 0.1mm-0.5mm to meet the positioning function; preferably, the diameter of the positioning hole 2 is 0.36mm. The angle between the plane of the support part 7 and the plane of the optical zone 8 is between 10° and 60°; preferably, the angle between the plane of the support part 7 and the plane of the optical zone 8 is 35°, making the lens as a whole spherical shape, which is more suitable for the human eyeball. The transparent optical zone 8 has a diameter of 4.5mm-6.0mm and a center thickness of 0.05mm-0.5mm. Preferably, the optical zone 8 has a diameter of 4.9mm-5.85mm and a center thickness of 0.12mm-0.3mm. The diameter and center thickness of the optical zone 8 vary with the optical power to suit different refractive errors of the human eye. The optical zone 8 has a central hole 6 with a diameter of 0.1mm-0.5mm. Preferably, the central hole 6 has a diameter of 0.36mm. This diameter of the central hole 6 does not affect the imaging quality of the transparent optical zone 8, and the postoperative visual quality is almost identical to that of a lens without a hole. Two loop holes 4 are opened on the closed loop 5 near the optical zone 8, and an elliptical water-guiding hole 3 is opened on the closed loop 5 near the loop foot 1. These holes allow the aqueous humor to flow between the two sides of the lens, ensuring smooth circulation and preventing cataracts, pupillary block, or angle-closure glaucoma.

[0061] Comparative Example 1, Examples 5-9

[0062] Intraocular lenses were prepared according to the dimensions in Table 2. Comparative Examples 1 and Examples 5-9 were prepared by changing some parameters of the elliptical water guide hole 3 based on Example 3, while other parameters remained the same as in Example 4. Comparative Example 1 did not have the elliptical water guide hole 3, but other structures and dimensions were the same as in Example 3.

[0063] Table 2. Specifications of intraocular lenses in Comparative Examples 1 and Examples 5-9

[0064]

[0065] Experiment Example 1: Implantation of Posterior Chamber Phytoscopic Intraocular Lens in Rabbit Eyes

[0066] (1) Experimental methods

[0067] Twenty-seven male New Zealand White rabbits, weighing between 3.2 kg and 3.6 kg and approximately 4.5 months old, were randomly divided into 9 groups of 3 rabbits each. After acclimatization for at least one week, posterior chamber phakic intraocular lenses (IOLs) were implanted into the posterior chamber of the right eye of each New Zealand White rabbit. The left eye served as a control. Changes in the anterior segment of the rabbits were observed after implantation. Animals with unsuccessful implantation were replaced. After implantation of the IOLs from Examples 2-9 and Comparative Example 1 into the right eyes of the New Zealand White rabbits, the rabbits were numbered according to the order of Examples 2-9 and Comparative Example 1, designated as Samples 1-27. The weight change of the rabbits before and after lens implantation was measured to determine the impact of implantation on normal growth. Changes in the rabbit eyes after implantation were observed using a slit lamp. Changes in intraocular pressure and pathophysiological changes in the rabbit eye were also measured to evaluate the impact of posterior chamber IOL implantation on the rabbit eye.

[0068] (2) Experimental results

[0069] a. All rabbit eyes were successfully implanted with posterior chamber phakic intraocular lenses.

[0070] Weight changes in New Zealand white rabbits before and after implantation: preoperative weight, and weights at 1 week and 1 month post-operation are shown below. Figure 4 As shown, by Figure 4 It can be seen that there was no significant change in the weight of the rabbits in Examples 2-9 and Comparative Example 1 before and after the operation. The implantation of artificial lenses into the rabbit eyes did not affect the rabbits' diet and would not cause excessive interference with the rabbits' vision.

[0071] b. Changes in rabbit eyes observed with a slit lamp after implantation are shown in Table 3 below.

[0072] In Examples 2-4, mild corneal opacity was observed at the corneal incision site in New Zealand white rabbits one week post-surgery, which was related to the creation of the surgical incision. This opacity largely subsided by one month, and no corneal decompensation or clouding due to excessive axial displacement of the intraocular lens causing contact with the corneal endothelium was observed. No clouding was observed in the natural lens at one week and one month post-surgery. No pigmentation or flare was observed in the anterior chamber post-surgery, and no abnormalities were observed in the iris, indicating that the intraocular lens did not cause pigmentation or depigmentation of the iris.

[0073] In Comparative Example 1, the corneal incision site of the New Zealand white rabbit showed mild clouding one week after surgery, which was related to the creation of the surgical incision. This clouding largely subsided by one month. In Examples 5-9, the cornea was basically transparent one week after surgery, with some individuals showing mild edema at one month, possibly related to contact between the corneal endothelium and the intraocular lens. At one week, the iris was normal, and no obvious pigmentation was observed in the anterior chamber. At one month, Examples 5, 7-9 showed iris bulging, pigment granules in the anterior chamber, pigmentation in the optical zone of the intraocular lens, and varying degrees of increased intraocular pressure. In Example 6, the iris remained normal at one month, with no pigmentation or flare in the anterior chamber, but some opacity was observed in the natural lens. In Comparative Example 1, corneal edema was more severe, iris bulging was present, pigmentation was visible in the anterior chamber, the natural lens opacity was also more severe, and the degree of increased intraocular pressure was greatest.

[0074] Table 3 Results of rabbit eye changes observed under a crack lamp.

[0075]

[0076] c. Intraocular pressure at different time points after implantation of a phakic intraocular lens in a rabbit eye: Figure 5 .

[0077] Depend on Figure 5 Data on intraocular pressure (IOP) at different times after implantation of a phakic intraocular lens in rabbit eyes showed that IOP did not increase significantly in rabbit eyes in Examples 2-4, while varying degrees of IOP increase were observed in Examples 5 and 7-9, with the highest increase observed in Comparative Example 1. IOP remained normal in Example 6. Therefore, this indicates that the implantation of the intraocular lens in these examples can ensure normal flow of aqueous humor and does not affect the structure of the angle of the anterior chamber.

[0078] d. After all indicators were observed, the rabbits were euthanized, and the operated eyes were taken for pathological examination. The animal handling process complied with the ethical 3R principles.

[0079] Pathological examination results showed no abnormalities in the cornea, conjunctiva, anterior and posterior chambers, iris, ciliary body, anterior chamber angle and trabecular meshwork, lens, vitreous body, retina, choroid, sclera, and optic nerve of the eyes operated on in Examples 2-4. This indicates that the artificial lens is non-toxic to rabbit eye tissues, did not cause iris pigment loss, and the absence of abnormalities in the anterior chamber angle and trabecular meshwork also indicates that the implantation of the artificial lens did not alter the angle structure or aqueous humor flow, and did not cause glaucoma. The absence of lens abnormalities indicates that cataracts did not occur. Specifically, the pathological examination of the rabbit eye lens in Example 3 is as follows... Figure 6 As shown, no abnormalities were observed in the lens capsule and lens epithelial cells of the natural lens in the pathological sections. Figure 7Example 7: In the pathological section of the rabbit eye lens, vacuolation of the epithelial cells of the natural lens was observed, which may be related to factors such as the artificial lens touching the lens capsule; Figure 8 As shown in Comparative Example 1, subcapsular mineralization of the lens occurred, indicating that the intraocular lens in this embodiment is pathologically safe.

[0080] The above experimental examples demonstrate that the angle between the plane containing the closure loop and the plane containing the optical zone in this embodiment better adapts to the posterior chamber space, preventing contact with the anterior capsule and the posterior surface of the iris. The elliptical aqueduct is located close to the loop's foot, which disperses pressure when the intraocular lens (IOL) is under stress, reducing axial displacement and maintaining a relatively constant IOL position, further reducing the probability of contact between the IOL and the anterior capsule and iris. The elliptical aqueduct is located between the iris and the anterior capsule, with a minimum distance of 0.4mm-1.0mm between the elliptical aqueduct and the loop, a major axis of 1.5mm-1.9mm, and a minor axis of 0.3mm-0.7mm. mm; within this parameter range, the elliptical water channel can better connect the aqueous humor in front of and behind the intraocular lens, reduce the contact between the intraocular lens support and the iris and anterior lens capsule, reduce the impact of the support on the angle structure, and reduce iris depigmentation and pigment deposition on the surface of the intraocular lens and the angle, maintain normal intraocular pressure, and prevent cataracts, pupillary block, or angle-closure glaucoma, etc. This indicates that this posterior chamber type phakic intraocular lens has good stability and smooth and unobstructed communication of aqueous humor in front and behind.

[0081] The above embodiments are preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the above embodiments. Any changes, modifications, substitutions, combinations, or simplifications made without departing from the spirit and principle of the present invention shall be equivalent substitutions and shall be included within the protection scope of the present invention.

Claims

1. A posterior chamber type phakic intraocular lens, characterized in that, It includes an optical zone (8) and a support part (7). The support part (7) is located outside the optical zone (8). The center of the optical zone (8) is provided with a circular central hole (6). The support part (7) includes a closing loop (5) and a loop foot (1) located outside the closing loop (5). A loop hole (4) is provided on the side of the closing loop (5) near the optical zone (8). An elliptical water guide hole (3) is provided on the closing loop (5) near the loop foot (1). The elliptical water guide hole (3) is located between the iris and the anterior capsule of the lens. A positioning hole (2) is provided on the loop foot (1). The closest distance between the elliptical water guide hole (3) and the loop (1) is 0.4 mm - 1.0 mm; The major axis of the elliptical water guide hole (3) is 1.5-1.9 mm, and the minor axis is 0.3 mm-0.7 mm. There are four elliptical water guide holes (3). The elliptical water guide holes (3) are arranged in a figure-eight shape relative to the optical area (8). The axis of symmetry of the line containing the major axis of the elliptical water guide hole (3) passes through the central axis of the loop foot (1). There are four loops (1), which are arranged symmetrically on both ends of the closed loop (5) in the same plane; the angle between the plane of the closed loop (5) and the plane of the optical area (8) is 10-60°.

2. The posterior chamber type phakic intraocular lens according to claim 1, characterized in that, There are two positioning holes (2), which are respectively set on two non-adjacent loops (1).

3. The posterior chamber type phakic intraocular lens according to claim 1, characterized in that, At least one loop hole (4) is provided on each side of the closed loop (5) near the optical area (8).

4. The posterior chamber type phakic intraocular lens according to claim 1, characterized in that, After the posterior chamber type phakic intraocular lens is implanted into the eye, it is located between the iris (11) and the natural lens (13), with the fovea (1) located in the ciliary sulcus (14).

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