WO2010002215A2

WO2010002215A2 - Intraocular lens and method of correcting refractive error thereof

Info

Publication number: WO2010002215A2
Application number: PCT/KR2009/003636
Authority: WO
Inventors: Hyun Ho Kim
Original assignee: Hyun Ho Kim
Priority date: 2008-07-04
Filing date: 2009-07-03
Publication date: 2010-01-07
Also published as: KR20100004777A; WO2010002215A3

Abstract

An intraocular lens includes an optic and an optic holder holding the optic in a ring form. The optic is movable in the optic holder parallel to a central axis of the optic. Further, a method of correcting a refractive error of an intraocular lens includes preparing the intraocular lens including an optic and an optic holder holding the optic in a ring form, and moving the optic in the optic holder parallel to a central axis of the optic. Meanwhile, the optic includes at least one first recess or hole in a predetermined area of a front surface thereof, and the optic holder includes at least one second recess or hole in a predetermined area of a front surface thereof. The intraocular lens is supported on a whole through the second recess or hole, and the optic is spirally rotated through the first recess or hole, using surgical hook for each recess or hole.

Description

INTRAOCULAR LENS AND METHOD OF CORRECTING REFRACTIVE ERROR THEREOF

The present invention relates, in general, to an intraocular lens implanted into an eyeball in the event of cataract surgery, and particularly to an intraocular lens capable of safely correcting postoperative refractive error after cataract surgery by a simple procedure, and a method of correcting the refractive error of the intraocular lens.

The human eye is generally very similar in structure and function to a camera, and has a crystalline lens composed of a transparent biconvex lens shaped tissue at the rear of the pupil. This crystalline lens serves as a lens of the camera, becomes opaque and worsens the vision as a result of aging, external injuries, diabetes, side effects of a variety of different medicines, exposure to radioactivity or various harmful electromagnetic waves, and so on. This is called a cataract.

The treatment for cataracts is performed by medicines and operative procedures. Although various medicinal treatments using a variety of medicines are well known, it is difficult to expect these medicinal treatments to be so effective as to replace the operative treatment. Thus, the treatment for cataracts ultimately has no alternative but to have recourse to surgical treatment, and so the development of medical technology is focused on this, the operative treatment.

The operative treatment for cataracts is generally divided into two processes: a first process of removing an opaque crystalline lens, and a second process of implanting an intraocular lens replacing a function of the removed crystalline lens which was to focus light on the retina. The operative treatment for cataracts is generally based on a surgical treatment that extracts an opaque crystalline lens using, for instance, phacoemulsification, and then inserts an intraocular lens having a predetermined shape into the anterior or posterior chamber of the eye.

In this case, most intraocular lenses are adapted to be inserted into a portion called the capsular bag within the posterior chamber in the eyeball or between the capsular bag and the iris.

Meanwhile, the intraocular lenses may be sorted into two types, depending on the position of insertion, wherein one is for insertion into the anterior chamber and the other is for insertion into the posterior chamber. Further, the intraocular lens may be sorted into rigid and soft types according to whether it is able to be folded in half when being inserted. The rigid intraocular lenses generally employ polymethylmethacrylate (PMMA), and the soft intraocular lenses are generally made of silicone or acrylic material.

Among them, most of the intraocular lenses in use at the present time are the posterior chamber insert lenses, particularly the soft intraocular lenses that are foldable up to 3 mm or less so as to be inserted into the eyeball even when the cornea or sclera is incised to about 3 mm during the cataract surgery.

Now, an example of a cataract surgery procedure for implanting a soft intraocular lens like the one illustrated in FIG. 1 will be described below.

FIG. 1 is a top plan view illustrating an example of a conventional soft intraocular lens.

Referring to FIG. 1, an intraocular lens 10 includes an optic 20, which refracts incident light to form the image of an external object on the retina and forms a crystalline lens body, and a pair of fixation members or haptics 30, which are symmetrically connected to predetermined portions of a circumference of the optic 20 in the form of an arm.

The optic 20 of the intraocular lens 10 typically has the shape of a biconvex lens that has a diameter of about 6 mm. Each haptic 30 is generally curved in a “C” or “J” shape by backward bending. An entire diameter of the intraocular lens including the optic and haptics ranges from about 12.0 mm to about 13.0 mm.

A surgical procedure for cataracts which implants a conventional soft intraocular lens is as follows. First, an incision having a width of about 3 mm is made in the cornea or sclera in order to insert the intraocular lens 10 into the capsular bag of the eye.

Then, surgical instruments are inserted through the incision having the length of width 3 mm and a side-port incision having a width of about 1 mm, and then phacoemulsification is performed to cleanly remove opaque crystalline lens material. Then, the intraocular lens is inserted into the capsular bag.

At this time, the intraocular lens is inserted through the incision having the width of about 3 mm in a folded state. After inserted into the eyeball, the folded intraocular lens is unfolded again, and fixed in the eyeball by the haptics.

In modern cataract surgery, the corneal incision wounds are made by 3 mm wide or less. It is because the corneal wound larger than 3 mm width reportedly causes postoperative corneal astigmatism which can aggravate the postoperative quality of vision. The limitation of corneal wound width necessitates the uses of foldable intraocular lens of soft materials.

However, the surgical procedure for cataracts which implants a conventional soft intraocular lens has the following problems.

In order to clearly look at the object after undergoing the cataract surgery, it is important to obtain the emmetropic condition in which the light incident onto the eye is properly refracted by the cornea and crystalline lens and thus is acutely focused on the retina. Consequently, in order to obtain the emmetropic condition, it is important to determine an accurate diopter (or refractive power) of the intraocular lens which is suitable for the eye of an individual patient.

To this end, a corneal curvature and an axial length of the eyeball, these deciding a distance between the crystalline lens and the retina, are measured using ultrasonography (A-scan mode) or laser (partial coherence interferometry) before surgery. The measured values are substituted into an expression in order to calculate the diopter of the intraocular lens, so that the diopter of the intraocular lens may be determined.

This expression which does the calculating is nothing but preoperative mathematical prediction of the desired refractive power required according to a postoperative optical position of the intraocular lens. The method of determining the diopter of the intraocular lens, which has been known up to now, encounters a fundamental limitation in that it fails to completely preclude postoperative refractive error (hyperopia or myopia) from being generated due to measurement errors of the corneal curvature and axial length of the eyeball measured before the surgery or factors related to the surgeon.

Generally, it is known that the measurement error, ±0.3 mm, of the axial length of the eyeball (i.e. the distance between the intraocular lens and the retina) on the basis of the average-sized eyeball having the axial length of the eyeball of 24 mm is involved in ametropia (or refractive error) of about ±1.0D (where D is short for diopter), and that the measurement error of the corneal curvature, ± 1.0D, is literally involved in the refractive error of ±1.0D. It is impossible to accurately predict the factors related to the surgeon(or surgeon factor) before the surgery.

In other words, due to this fundamental limitation, refractive error frequently occurs after cataract surgery using the conventional intraocular lens. The conventional intraocular lens has an invariable refraction index and focal distance. For this reason, when this postoperative refractive error occurs, the intraocular lens that has already been inserted into the eyeball must be removed in order to remove the caused refractive error resulting from the surgery performed to insert the intraocular lens, and then a new intraocular lens correcting the refractive error must be inserted into the eyeball.

Moreover, in the case of a surgery that removes the intraocular lens that has already been inserted into the eyeball and inserts the new intraocular lens again, the procedure of removing and re-inserting the intraocular lens is difficult in the technical aspect, and there is a high possibility of causing a variety of postoperative complications such as intraocular structural damage and hemorrhage, postoperative inflammation, as well as a financial burden resulting from the additional surgery. Especially, intraocular structure damages such as the damage of corneal endothelial cells and iris damages are occasional, but serious and irreversible complications, which make patients and surgeons hesitate on intraocular lens exchange surgery.

As a result, performing the additional surgery is actually difficult. In most case, the patient has no choice but to withstand vision weakening or the inconvenience of wearing eyeglasses due to the refractive error.

Further, in the case of expensive multifocal intraocular lenses that have recently been developed in order to simultaneously correct the cataract and presbyopia, the initially expected presbyopia correcting effect is remarkably lowered when a basic refraction condition of the intraocular lens after insertion is in fact not the condition of emmetropia (i.e. refractive error condition). The only solution to this problem is to remove the intraocular lens that was inserted into the eyeball, and then re-insert a new intraocular lens correcting the refractive error into the eyeball. For this reason, even though the patient is implanted with the expensive multifocal intraocular lens for correcting presbyopia, the refractive error may practically occur to fail to obtain the presbyopia correcting effect which was expected to occur before the surgery. Also in this case, the patient has no choice but to put up with the inconvenience of wearing eyeglasses.

It has recently been reported that a refractive error range caused by an improper diopter of the postoperative intraocular lens has been reduced due to an increase in the accuracy of measuring the corneal curvature and eyeball axial length as well as thanks to an increase in the predictability of various expressions used in its calculation, and thus has fallen within a postoperative refractive power of ±1.0D in 90% or more of surgical cases when the state-of-the-art inspection equipment and calculative expressions have been used. However, this report merely tends to bring one to expect optimal results, whereas the actual refractive error range is generally higher than the reported range. Taking only the myopic refractive error of -1.0D by way of example, a distant vision shows a difference of two to three lines on the Snellen chart, compared to when a postoperative naked vision corresponds to the emmetropia (for example, even a patient who can look at an object with the naked vision of 1.0 under emmetropic conditions can only look at the object with the naked vision between 0.6 and 0.7 due to the myopic refractive error of -1.0D, and thus requires vision correction such as eyeglasses in order to look at the object with the naked vision of 1.0). Particularly, when a hyperopic refractive error occurs after the surgery in lieu of the myopic refractive error (e.g. when a hyperopic refractive error of +1.0D occurs), a patient cannot see both near and distant objects clearly without hyperopia correction eyeglasses (i.e. there is a reduction in near and distant vision). Consequently, there is a serious chance of the patient suffering from severe inconvenience in daily life.

Thus, in many cases, the surgery is performed in the situation wherein more emphasis is placed on reducing the postoperative hyperopic refractive error than on reducing the postoperative myopic refractive error, and a preoperative refraction index aims at the myopia of about -0.5D rather than the emmetropia. As a result, the refractive error leans to the myopia, so that the postoperative myopic refractive error of -1.5D or more occurs occasionally.

Meanwhile, US Patent No. 5,628,798 discloses an adjustable and removable intraocular lens implant. However, in this patent document, multiple complicated parts are separately used for vertical movement of an intraocular lens, so that the intraocular lens becomes too bulky and complicated to stay in a folded state and secure the mechanical integrity in the intraocular space. Thus, application of this other cited patent to modern cataract surgery in which the intraocular lens should be implanted through a small incision having a length of 3 mm or so is in practice difficult.

Further, the cited patent document makes reference to a configuration that allows the intraocular lens to move in a vertical direction, and yet makes no specifications on how the configuration moves the intraocular lens.

The manipulations of intraocular lens are performed in the small intraocular space, so that it is critically important to find the safe method to move the intraocular lens without causing serious complications such as intraocular lens dislocation or intraocular structure injuries. Otherwise, the manipulation in order to move the intraocular lens in the vertical direction can cause serious intraocular structure damages such as corneal endothelial damage, iris damage and lens capsule rupture.

Also, separate devices or components may be required by the cited document configuration, so that the refractive error cannot be corrected in a simple manner.

Consequently, methods capable of completely preventing in advance the refractive error from occurring after the surgery for inserting the intraocular lens are almost nonexistent at present. It is essential to develop a method of correcting the postoperative refractive error in a simple and safe manner and an intraocular lens suitable for this method.

Accordingly, the present invention has been made in an effort to solve the problems occurring in the related art, and the present invention is directed to provide an intraocular lens without complicated components and which can be applied to intraocular lens insertion surgery, and a method of correcting a refractive error of the intraocular lens.

The present invention is also directed to provide a method of using a simple and safe manner to correct a refractive error (hyperopia or myopia) caused after intraocular lens insertion surgery, and an intraocular lens suitable for the method.

In addition, the present invention is directed to provide an intraocular lens configured to obviate that need for surgery to remove an intraocular lens that was previously inserted into the eyeball and re-inserting a new intraocular lens whose refractive error is corrected when the refractive error occurs after intraocular lens insertion surgery, and a method of correcting the refractive error of the intraocular lens.

Moreover, the present invention is directed to provide a method of correcting a refractive error (hyperopia or myopia) in a simple and safe manner by rotating the intraocular lens by a simple procedure when the refractive error occurs after intraocular lens insertion surgery, and an intraocular lens suitable for the method.

In order to achieve the above object, according to one aspect of the present invention, there is provided an intraocular lens including an optic, and an optic holder holding the optic in a ring form, wherein the optic is movable in the optic holder parallel to a central axis of the optic.

Here, the optic holder may include a body forming a body thereof and an optic support extending from the body towards a center thereof. The body may include a sawtooth part having roots on an inner surface thereof, and the optic may be fixedly engaged in one of the roots on an outer circumference thereof.

The optic may include at least one first recess or hole in a predetermined area of a front surface thereof, and the optic holder may include at least one second recess or hole in a predetermined area of a front surface thereof.

The optic may be spirally rotated along the roots of the sawtooth by hooking hook-shaped instruments on the first and second recesses or holes to support the entire intraocular lens through the second recess or hole and to rotate the optic through the first recess or hole, and the optic may be spirally rotated to be movable parallel to the central axis thereof.

The roots may be configured so that the optic moves toward a front surface thereof when the optic is rotated in a clockwise direction and toward a rear surface thereof when the optic is rotated in a counterclockwise direction, or so that the optic moves toward the rear surface thereof when the optic is rotated in the clockwise direction and toward the front surface thereof when the optic is rotated in the counterclockwise direction.

The optic support may support the optic so as to prevent the optic from being separated from the optic holder when the optic moves towards a front or rear surface thereof or when the intraocular lens is folded for intraocular insertion.

The first recesses or hole may be symmetrically located in a pair on a front surface of the optic up and down or left and right.

The second recesses or hole may be symmetrically located in a pair on a front surface of the optic holder up and down or left and right.

The optic holder may include notches that are symmetrically located in predetermined areas of the front surface thereof up and down or left and right.

The sawtooth part may have a length of 0.6 mm or more.

The optic may be configured to correct a refractive error of ±1.0D (where D indicates the diopter) by movement of ±0.3 mm when moving parallel to the central axis thereof by the spiral rotation thereof.

When moving parallel to the central axis thereof by the spiral rotation thereof, the sawtooth part of the optic may include the roots in the form of a helix such that the optic moves toward the front or rear surface thereof by ±0.3 mm when rotated at an angle of 360° such that the refractive error of ±0.25D, ±0.50D or ±0.75D is corrected when the optic is rotated at ±90°, ±180° or ±270°.

The optic holder may employ transparent or opaque silicone or acrylic material.

The intraocular lens may further include haptics connected to predetermined areas of the outer circumference of the optic holder.

According to another aspect of the present invention, there is provided a method of correcting a refractive error of an intraocular lens. The method includes preparing the intraocular lens including an optic and an optic holder holding the optic in a ring form, and moving the optic in the optic holder parallel to a central axis of the optic.

Here, the optic holder may include a body forming a body thereof and an optic support extending from the body toward a center thereof, and the body may include a sawtooth part having roots on an inner surface thereof. The optic may be fixedly engaged in one of the roots on an outer circumference thereof, and the optic may be spirally rotated to move parallel to the central axis thereof.

The optic may include at least one first recess or hole in a predetermined area of a front surface thereof, and the optic holder may include at least one second recess or hole in a predetermined area of a front surface thereof. The intraocular lens may be supported on a whole through the second recess or hole, and the optic may be spirally rotated through the first recess or hole.

The first and second recesses or holes may be hooked by hook-shaped instruments so as to support the entire intraocular lens through the second recess or hole and to rotate the optic through the first recess or hole.

The roots may be configured so that the optic moves towards a front surface thereof when the optic is rotated in a clockwise direction and towards a rear surface thereof when the optic is rotated in a counterclockwise direction, or so that the optic moves towards the rear surface thereof when the optic is rotated in the clockwise direction and towards the front surface thereof when the optic is rotated in the counterclockwise direction.

The rotating process of the optic through the first recess or hole while the entire intraocular lens is supported through the second recess or hole may consist of making two side-port incisions in cornea, inserting a hook-shaped instrument into the intraocular space through a side-port incision, hooking the hook-shaped instrument on the second recess or hole to support the entire intraocular lens, inserting another hook-shaped instrument into the intraocular space through the other side-port incision, and hooking the other hook-shaped instrument on the first recess or hole to rotate the optic.

According to the present invention as described above, the intraocular lens can be easily folded and applied to intraocular lens insertion surgery without complicated components, and the method can correct a refractive error of the intraocular lens.

The method can correct a refractive error (hyperopia or myopia) caused after intraocular lens insertion surgery in a simple manner and most of all, with secure safety. And the intraocular lens is suitable for this method.

In addition, the intraocular lens is configured to obviate the need for surgery to remove an intraocular lens that was previously inserted into the eyeball and re-inserting a new intraocular lens whose refractive error is corrected when the refractive error occurs after intraocular lens insertion surgery, and the method can correct the refractive error of the intraocular lens.

Moreover, the method can correct a refractive error (hyperopia or myopia) in a simple and safe manner by rotating the intraocular lens by a simple procedure when the refractive error occurs after intraocular lens insertion surgery, and the intraocular lens is suitable for this method.

FIG. 1 is a top plan view illustrating an example of a conventional soft intraocular lens;

FIG. 2 is a top plan view illustrating an intraocular lens according to the invention;

FIG. 3 is a cross-sectional view illustrating an intraocular lens according to the invention and, particularly, taken along line I-I’ of FIG. 2;

FIG. 4 is a perspective view illustrating the optic holder of an intraocular lens according to the invention;

FIG. 5 is a schematic diagram illustrating the state where an optic moves toward a rear surface thereof in an intraocular lens according to the invention;

FIG. 6 is a schematic diagram illustrating the state where an optic moves toward a front surface thereof in an intraocular lens according to the invention;

FIG 7 is a illustration of a surgical hook which may be used in the manipulation of intraocular lens to correct the refractive error after cataract surgery;

FIG 8 is a top-plan view illustrating the procedure of manipulating the intraocular lens to correct the refractory error; and

FIG 9 is a perspective view illustrating the procedure of manipulating the intraocular lens to correct the refractory error.

The above objects, and other features and advantages of the present invention will become more apparent after reading the following detailed description in conjunction with the accompanying drawings. Further, in the drawings, the lengths, thicknesses, etc. of layers and regions may be exaggerated for clarity. Wherever possible, the same reference numerals will be used throughout the drawings and the description to refer to the same or like parts.

FIG. 2 is a top plan view illustrating an intraocular lens according to the invention, and FIG. 3 is a cross-sectional view illustrating an intraocular lens according to the invention and, particularly, taken along line I-I’ of FIG. 2.

Referring to FIG. 2, the intraocular lens 100 according to the invention includes an optic 110 that refracts incident light to form the image of an external object on the retina and forms a crystalline lens body, an optic holder 120 that holds the optic 110 in the shape of a ring, and fixation members or haptics 130 that are connected to predetermined areas of a circumference of the optic holder 120.

More specifically, the optic 110 has the shape of a biconvex lens, and each haptic 130 is curved in a “C” or “J” shape by backward bending. An entire diameter of the intraocular lens (i.e. indicated by “X” in FIG. 2) may range from about 12.0 mm to about 13.0 mm so as to be suitable for the eyeball of an ordinary person.

At this time, the shape of the optic 110, the shape and type of each haptic 130, and the entire diameter of the intraocular lens 100 are generally known. Thus, it should be noted that the intraocular lens of the invention is not particularly limited to the shape of the optic, the shape and type of each haptic, or to the entire diameter thereof.

However, unlike the ordinary optic, the optic 110 of the intraocular lens 100 of the invention is provided with at least one first recess or hole 111 in a predetermined area of the front surface thereof, and a detailed description thereof will be made below.

Further, in the intraocular lens 100 of the invention, the optic 110 is held in the ring-shaped optic holder 120. Meanwhile, according to the invention, the optic 110 is directly held in the optic holder 120 without using a separate complicated component.

Referring to FIG. 3, the optic holder 120 includes a body 120a and an optic support 120b. The body 120a forms a body of the optic holder 120, and the optic support 120b is formed so as to extend from the body 120a toward the center of the optic holder 120. Further, the body 120a is provided with a sawtooth part 123 having roots 123a in an inner surface thereof. As described below, the sawtooth part 123 and the optic support 120b serve to support the optic 110 such that the optic 110 is not separated from the optic holder 120 in the process in which the optic 110 moves toward the front or rear surface thereof, or in the process in which the intraocular lens 100 is folded so as to be inserted into the eyeball. In other words, the optic 110 is held in the ring-shaped optic holder 120 in such a manner that the outer circumference of the optic 110 is directly engaged and fixed in one root 123a of the sawtooth part 123.

At this time, the sawtooth part 123 is configured so that the optic 110 is spirally rotated along the roots 123a. This spiral rotation of the optic 110 allows the optic 110 to move parallel to the central axis of the optic 110.

In detail, the roots 123a of the sawtooth part 123 may assume the form of a helix such that the optic 110 moves toward the front surface thereof (i.e. the arrow “A” of FIG. 3) when the optic 110 is turned in a clockwise direction, and toward the rear surface thereof (i.e. the arrow “B” of FIG. 3) when the optic 110 is turned in a counterclockwise direction. In contrast, the roots 123a of the sawtooth part 123 may assume the form of a helix such that the optic 110 moves toward the rear surface thereof (i.e. the arrow “B” of FIG. 3) when the optic 110 is turned in a clockwise direction, and toward the front surface thereof (i.e. the arrow “A” of FIG. 3) when the optic 110 is turned in a counterclockwise direction.

At this time, the combination of the roots 123a of the sawtooth part 123 with the optic support 120b supports the optic 110 such that the optic is not separated from the optic holder 120 in the process in which the optic 110 moves toward the front or rear surface thereof, or the process in which the intraocular lens 100 is folded so as to be inserted into the eyeball.

Further, in the intraocular lens 100 of the invention, the optic 110 includes the first recess or hole 111 in a predetermined area of the front surface thereof, and the optic holder 120 is also provided with at least one second recess or hole 122 in a predetermined area of the front surface thereof.

As described above, the first recess or hole 111 and the second recess or hole 122 are provided so as to turn the optic 110 in a clockwise or counterclockwise direction. Thus, a hook-shaped instrument 140 showed in FIG 7 is hooked on the first or second recess or holes 111 or 122, and then turns the optic 110(refer to FIG 8, 9).

For example, one hook-shaped instrument 140a may be hooked on the second recess or hole 122 so as to support the entire intraocular lens, and another hook-shaped instrument 140b may be hooked on the first recess or hole 111 so as to turn the optic 110 in a desired direction(refer to FIG 8, 9).

In this case, as described below, since the optic 110 is rotated when inserted in the small intraocular space of a patient, the first and second recesses or

hole

111 and 122 are preferably formed in a pair so as to be symmetrically located up and down and/or left and right at an angle of 180 °in order to facilitate hooking the hook-shaped instrument on the recess or hole to rotate the optic, as illustrated in FIG. 2.

Further, the second recess or hole 122 is preferably formed in the body 120a in consideration of a thin thickness of the optic support 120b. The first recess or hole 111 is preferably formed near the outer circumference of the optic 110 rather than the central portion of the optic 110 in consideration of easy rotation as well as optical characteristics of the central portion of the optic so as not to have bad influence on a quality of vision due to the existence of the first recess or hole 111. However, in the case where the first recess or hole 111 is located near the outer circumference of the optic 110, the first recess 111 should be designed so as not to overlap with the optic support 120b such that the optic 110 can be rotated.

With this configuration, no separate complex device and component is required to move the intraocular lens in an axial direction, so that a refractive error of the intraocular lens can be corrected by just a simple and safe procedure.

Referring to FIG. 3 again, a length of the sawtooth part 123 (i.e. the zone “b” of FIG. 3) preferably amounts to 0.6 mm or more.

This dimension is based on the following reason. In the intraocular lens of the invention, the optic is initially located in the middle of the sawtooth part 123. In this state, in the case where the optic 110 is rotated along the roots 123a, i.e. moves toward the rear surface thereof (i.e. the arrow “B” of FIG. 3) or toward the front surface thereof (i.e. the arrow “A” of FIG. 3), a distance between the intraocular lens and the retina or an axial length of the eyeball, which determines the position of a focal point of the intraocular lens, can be corrected. As a result, as described above, when the average-sized eyeball has the eyeball axial length of 24 mm, the refractive error of ±1.0D (where D indicates the diopter) can be corrected by movement of the eyeball axial length (or the length between the intraocular lens and the retina) by ±0.3 mm.

In detail, in the case where the optic of the intraocular lens can be displaced by 0.3 mm once toward the front or rear surface thereof, the refractive error of ±1.0D, a total of 2.0D, which actually is that occurring with the highest frequency after intraocular lens insertion surgery, can be corrected. For this reason, the length of the sawtooth 123 preferably is at least 0.6 mm.

Further, in the case of the roots 123a along which the optic 110 is spirally rotated, the roots 123a may have the form of a helix such that the optic 110 is displaced by 0.3 mm toward the front or rear surface thereof when rotated at an angle of 360°. Thereby, when the optic 110 is rotated at ±90°, ±180° or ±270°, the fine refractive error of ±0.25D, ±0.50D or ±0.75D can be corrected.

At this time, when the optic 110 moves toward the front surface thereof, this produces a hyperopia correcting effect. In contrast, when the optic 110 moves toward the rear surface thereof, this produces a myopia correcting effect.

Further, a thickness of the optic support 120b (i.e. the zone “a” of FIG. 3) is preferably of such a minimum thickness that the intraocular lens can be folded to pass through an incision having a length of 3 mm without difficulty at the time of surgery, and simultaneously that the optic can be firmly supported without being separated from the optic support 120b. Thus, a thickness of the optic holder 120 (i.e. the zone “c” of FIG. 3) corresponding to the sum of the thickness of the optic support 120b and the length of the sawtooth part 123 amounts to the thickness made by adding the length of the sawtooth part 123 of 0.6 mm to the thicknesses of the front and rear optic supports (i.e. twice the zone “a” of FIG. 3). Meanwhile, any material will do if a material of the optic support 120b meets the abovementioned conditions. Thus, it should be noted that the material of the optic support 120b is not limited to a specific material.

In addition, in the optic holder 120, a diameter of the body 120a (i.e. the zone “g” of FIG. 3) is preferably of such a minimum diameter that the sawtooth part 123 is formed to be of a minimum length so as to make it possible to firmly support the optic and provide smooth driving of the sawtooth part, and that the optic holder 120 can maintain its shape. A width of the optic support 120b (i.e. the zone “h” of FIG. 3) is preferably of the smallest possible width which makes it possible to provide firm support to the optic and smooth driving of the sawtooth part.

Further, a diameter of the optic 110 that refracts light (i.e. the zone “e” of FIG. 3) is preferably 5 mm or more so as not to interfere with observation of an object although the pupil becomes wide on looking at the object in a dark place (dark adaptation). In this embodiment, the refraction must be caused through a part of the optic 110 (i.e. the zone “f” of FIG. 3) where the part where the optic 110 overlaps with the optic support 120b is precluded from the optic rather than through the entire optic 110, and the optic support 120b must secure the minimum width (i.e. the zone “h” of FIG. 3). Thus, the diameter of the optic 110 that refracts light is reduced by twice the width of the optic support 120b (i.e. the zone “h” of FIG. 3). As such, the diameter of the optic is preferably at least 5 mm including the part (i.e. the zone “h” of FIG. 3) where the optic 110 overlaps with the optic support 120b.

Also, a diameter of the optic holder 120 (i.e. the zone “d” of FIG. 3), which corresponds to the sum of the diameter of the optic and the width of the body 120a, is preferably 6 mm so as not to hinder the intraocular lens from being folded and inserted into the eyeball through a corneal or scleral incision of 3 mm or less, like the typical diameter of a conventional intraocular lens.

Referring to FIG. 2 again, in the intraocular lens 100 of the invention, the optic holder 120 may be provided with notches 121 in predetermined areas. When a soft intraocular lens is folded and inserted into the intraocular space as described above, the notches serve to avoid the problem of the optic holder 120 that is relatively thicker than the other parts of the intraocular lens becoming an obstacle to the folding process of the intraocular lens.

At this time, the notches 121 are preferably formed in a pair so as to be symmetrically located up and down or left and right at an angle of 180° in order to facilitate folding the intraocular lens, as illustrated in FIG. 2. The notches are preferably formed according to the shape and position of each of the haptics 130 that are symmetrically connected to the outer circumference of the optic holder 120.

In detail, when folded in half, the intraocular lens is differently folded according to the shape and position of each haptic. For this reason, the position of each notch is dependent on the shape and position of each haptic.

Further, in the intraocular lens 100 of the invention, the optic 110 may employ polymethylmethacrylate (PMMA) in the case of a rigid intraocular lens, and silicone or acrylic material in the case of a soft intraocular lens. Preferably, the optic 110 is made of soft material such as silicone or acrylic material for the foldablility required for modern cataract surgery.

Further, the optic holder 120 may employ transparent silicone or acrylic material. The intraocular lens may suffer from aberration due to a difference between the thick body and the thin optic support 120b of the optic holder 120 as well as a space of the part where the optic 110 overlaps with the optic support 120b. For this reason, the optic holder 120 may be preferably made of opaque material. Such opaque material may be obtained by mixing a pigment with the silicone or acrylic material.

FIG. 4 is a perspective view illustrating the optic holder of an intraocular lens according to the invention.

As described above, in the intraocular lens 100 of the invention, the optic holder 120 includes the body 120a and the optic support 120b. The body 120a serves as the body of the optic holder 120, and the optic support 120b extends from the body 120a toward the center of the optic holder 120. Further, the inner surface of the body 120a includes the sawtooth part 123 having the roots 123a.

In addition, the optic holder 120 has the second recesses or hole 122 in the predetermined areas of the front surface thereof, and the optic holder 120 may have the notches 121 in the other predetermined areas of the front surface thereof. Meanwhile, the configuration of the optic holder 120 is as described above, and thus detailed description thereof will be omitted.

FIG. 5 is a schematic diagram illustrating the state where an optic moves toward a rear surface thereof in an intraocular lens according to the invention, and FIG. 6 is a schematic diagram illustrating the state where an optic moves toward a front surface thereof in an intraocular lens according to the invention.

In FIG. 5, the optic 110 of the intraocular lens is spirally rotated along the roots of the sawtooth part, thereby moving toward the rear surface thereof. It can be seen from FIG. 2 that the optic is located in the middle of the sawtooth part. However, referring to FIG. 5, it can be seen that the optic 110 is located at the rear of the sawtooth part.

Further, in FIG. 6, the optic 110 of the intraocular lens is spirally rotated along the roots of the sawtooth part, thereby moving toward the front surface thereof. It can be seen from FIG. 2 that the optic is located in the middle of the sawtooth part. However, referring to FIG. 6, it can be seen that the optic 110 is located at the rear of the sawtooth part.

Thus, when the intraocular lens of the invention is inserted into the eyeball at the time of cataract surgery, the surgery is performed in the state where the optic of the intraocular lens is initially located in the middle of the sawtooth part.

However, in the case where the refractive error (hyperopia or myopia) occurs after the intraocular lens insertion surgery due to measurement errors of the corneal curvature and axial length of the eyeball measured before the surgery, factors related to the surgeon, errors of intraocular lens calculation expressions themselves, and so on, the optic 110 of the intraocular lens is displaced toward the rear surface thereof (for myopia correction) or toward the front surface thereof (for hyperopia correction), thereby obtaining an emmetropic condition where the focal point of the intraocular lens accurately falls on the retina. As a result, the refractive error can be corrected.

More specifically, in the case of a conventional intraocular lens, when the postoperative refractive error occurs, the secondary surgery is performed in order to remove the postoperative refractive error by removing an inserted intraocular lens and re-inserting a new intraocular lens whose refractive error is corrected. Otherwise, in most cases, due to the technical difficulty of this secondary surgery, and the risk of causing serious postoperative complications, it is actually difficult to perform the secondary surgery, so that the patient has no alternative but to put up with vision weakening or the inconvenience of wearing eyeglasses due to the refractive error. In contrast, in the intraocular lens of the invention, as illustrated in FIGS. 5 and 6, the optic 110 of the intraocular lens is displaced towards the rear surface thereof or towards the front surface thereof, so that the refractive error occurring after the cataract surgery can be corrected in a simple and safe manner.

As described above, the movement of the optic 110 of the intraocular lens is carried out through the first recesses or hole 111 formed in the optic 110 and the second recesses or hole 122 formed in the optic holder 120. In detail, a hook-shaped instrument 140a is hooked on the second recess or hole 122 so as to support the entire intraocular lens, and another hook-shaped instrument 140b is hooked on the first recess or hole 111 so as to turn the optic 110 in a desired direction(refer to FIG 8,9). Thereby, the postoperative refractive error can be corrected, so that it is not necessary to perform a secondary surgery for removing the intraocular lens that was previously inserted into the eyeball and re-inserting the new intraocular lens whose refractive error is corrected.

Further, the process of rotating the optic through the first recess or hole while the entire intraocular lens is supported through the second recess or hole will be described in detail(refer to FIG 8,9). Two side-

port incisions

150a, 150b having a length of 1 mm or less are made in the cornea. A hook-shaped instrument 140a is inserted into the eyeball through a side-port incision 150a. The hook-shaped instrument 140a is hooked on the second recess or hole 122 so as to support the entire intraocular lens. Another hook-shaped instrument 140b is inserted into the eyeball through the other side-port incision 150b. The other hook-shaped instrument 14-b is hooked on the first recess or hole 111 so as to rotate the optic. This process allows the refractive error to be corrected in a simple and safe manner, compared to surgery wherein the existing intraocular lens is removed and the new intraocular lens is re-inserted.

In the drawings and specification, typical exemplary embodiments of the invention have been disclosed, and although specific terms are employed, they are used in a generic and descriptive sense only and are not for the purposes of limitation, the scope of the invention being set forth in the following claims.

Claims

An intraocular lens comprising:

an optic; and

an optic holder holding the optic in a ring form,

wherein the optic is movable in the optic holder parallel to a central axis of the optic.
The intraocular lens as set forth in claim 1, wherein:

the optic holder includes a body forming a body thereof and an optic support extending from the body towards a center thereof;

the body includes a sawtooth part having roots on an inner surface thereof; and

the optic is fixedly engaged in one of the roots on an outer circumference thereof.
The intraocular lens as set forth in claim 2, wherein:

the optic includes at least one first recess in a predetermined area of a front surface thereof; and

the optic holder includes at least one second recess in a predetermined area of a front surface thereof.
The intraocular lens as set forth in claim 3, wherein:

the optic is spirally rotated along the roots of the sawtooth by hooking hook-shaped instruments on the first and second recesses to support the entire intraocular lens through the second recess and to rotate the optic through the first recess; and

the optic is spirally rotated to be movable parallel to the central axis thereof.
The intraocular lens as set forth in claim 4, wherein the roots are configured so that the optic moves toward a front surface thereof when the optic is rotated in a clockwise direction and toward a rear surface thereof when the optic is rotated in a counterclockwise direction, or so that the optic moves toward the rear surface thereof when the optic is rotated in the clockwise direction and toward the front surface thereof when the optic is rotated in the counterclockwise direction.
The intraocular lens as set forth in claim 4, wherein the optic support supports the optic so as to prevent the optic from being separated from the optic holder when the optic moves towards a front or rear surface thereof or when the intraocular lens is folded for intraocular insertion.
The intraocular lens as set forth in claim 4, wherein the first recesses are symmetrically located in a pair on a front surface of the optic up and down or left and right.
The intraocular lens as set forth in claim 7, wherein the second recesses are symmetrically located in a pair on a front surface of the optic holder up and down or left and right.
The intraocular lens as set forth in claim 8, wherein the optic holder includes notches that are symmetrically located in predetermined areas of the front surface thereof up and down or left and right.
The intraocular lens as set forth in claim 4, wherein the sawtooth part has a length of 0.6 mm or more.
The intraocular lens as set forth in claim 10, wherein the optic is configured to correct a refractive error of ±1.0D (where D indicates the diopter) by movement of ±0.3 mm when moving parallel to the central axis thereof by the spiral rotation thereof.
The intraocular lens as set forth in claim 11, wherein, when moving parallel to the central axis thereof by the spiral rotation thereof, the sawtooth part of the optic includes the roots in a form of a helix such that the optic moves toward the front or rear surface thereof by ±0.3 mm when rotated at an angle of 360° such that the refractive error of ±0.25D, ±0.50D or ±0.75D is corrected when the optic is rotated at ±90°, ±180° or ±270°, or when moving parallel to the central axis thereof by the spiral rotation thereof, the sawtooth part of the optic includes the roots in a form of a helix such that the optic moves toward the front or rear surface thereof by ±0.3 mm when rotated at an angle of 180° such that the refractive error of ±0.25D, ±0.50D or ±0.75D is corrected when the optic is rotated at ±45°, ±90° or ±135°.
The intraocular lens as set forth in one of claims 1 through 12, wherein the optic holder employs transparent or opaque silicone or acrylic material.
The intraocular lens as set forth in one of claims 1 through 12, further comprising haptics connected to predetermined areas of the outer circumference of the optic holder.
A method of correcting a refractive error of an intraocular lens, the method comprising:

preparing the intraocular lens including an optic and an optic holder holding the optic in a ring form; and

moving the optic in the optic holder parallel to a central axis of the optic.
The method as set forth in claim 15, wherein:

the optic holder includes a body forming a body thereof and an optic support extending from the body toward a center thereof;

the body includes a sawtooth part having roots on an inner surface thereof;

the optic is fixedly engaged in one of the roots on an outer circumference thereof; and

the optic is spirally rotated to move parallel to the central axis thereof.
The method as set forth in claim 16, wherein:

the optic includes at least one first recess in a predetermined area of a front surface thereof, and the optic holder includes at least one second recess in a predetermined area of a front surface thereof; and

the intraocular lens is supported on a whole through the second recess, and the optic is spirally rotated through the first recess.
The method as set forth in claim 17, wherein the first and second recesses are hooked by hook-shaped instruments so as to support the entire intraocular lens through the second recess and to rotate the optic through the first recess.
The method as set forth in claim 17, wherein the roots are configured so that the optic moves towards a front surface thereof when the optic is rotated in a clockwise direction and towards a rear surface thereof when the optic is rotated in a counterclockwise direction, or so that the optic moves towards the rear surface thereof when the optic is rotated in the clockwise direction and towards the front surface thereof when the optic is rotated in the counterclockwise direction.
The method as set forth in claim 17, wherein the optic is configured to correct a refractive error of ±1.0D (where D indicates the diopter) by movement of ±0.3 mm when moving parallel to the central axis thereof by the spiral rotation thereof.
The method as set forth in claim 17, wherein, when moving parallel to the central axis thereof by the spiral rotation thereof, the sawtooth part of the optic includes the roots in a form of a helix such that the optic moves toward the front or rear surface thereof by ±0.3 mm when rotated at an angle of 360° such that the refractive error of ±0.25D, ±0.50D or ±0.75D is corrected when the optic is rotated at ±90°, ±180° or ±270°,or when moving parallel to the central axis thereof by the spiral rotation thereof, the sawtooth part of the optic includes the roots in a form of a helix such that the optic moves toward the front or rear surface thereof by ±0.3 mm when rotated at an angle of 180° such that the refractive error of ±0.25D, ±0.50D or ±0.75D is corrected when the optic is rotated at ±45°, ±90° or ±135°.
The method as set forth in claim 18, wherein the rotating of the optic through the first recess while the entire intraocular lens is supported through the second recess includes:

forming two side-port incisions in a cornea;

inserting a hook-shaped instrument into an eyeball through a side-port incision;

hooking a hook-shaped instrument on the second recess or hole to support the entire intraocular lens;

inserting another hook-shaped instrument into the eyeball through the other side port incision; and

hooking the other hook-shaped instrument on the first recess or hole to rotate the optic.