JPH02211119A - Astigmatism degree of toric type eye lens and method for determining degree of eye lens - Google Patents

Abstract

PURPOSE:To obtain the astigmia degree of a toric type eye lens capable of remedying astigmia before operation and a method for determining the degree of the lens by converting the data of corena astigmia degree before operation to the astigmia degree of the eye lens. CONSTITUTION:In a toric type eye lens 10, the eye lens degree of an optical part 12 is determined to enable the remedy of astigmia before operation. The spherical surface degree P1 of the eye lens 10 is obtained from the data R1 of corena radius of curvature in a strong principal meridian direction or the refractive power data K1 of the corena. Also, te peripheral surface degree P2 of the eye lens 10 is obtained from the data R2 of corena radius of curvature in a weak principal meridian direction or the refractive power data K2 of the corena. Then, P1 is deducted from P2, thereby obtaining the degree of circularity P3. In addition, the strong meridian direction is used as a corena axis and P1 is used as the peripheral degree of the eye lens 10. Also, P3 is used as the corena degree of the lens 10. The eye lens 10 set as aforementioned is inserted into an eye, according to the same method as in the conventional operation.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a method for determining the astigmatic power and intraocular lens power of a toric intraocular lens used after delivery of the crystalline lens in cataract surgery. .

[Prior art and problems to be solved by the invention] During cataract surgery, after the nucleus in the crystalline lens is delivered, an intraocular lens, which is an artificial crystalline lens, is inserted to correct visual acuity. There is.

However, in the case of patients who already have corneal astigmatism caused by a disease or the like before surgery (hereinafter referred to as preoperative astigmatism), there is a problem in that the preoperative astigmatism remains even after surgery.

Therefore, in order to correct this astigmatism, astigmatism has conventionally been corrected by using glasses or hard contact lenses (hereinafter referred to as HCL), or by performing surgical procedures such as corneal incision.

However, for glasses and HCL, 3 Dlopter
(Dlopter: hereinafter referred to as (D)). Not only is it difficult to correct astigmatism as described above, but it is also uncomfortable for patients to wear glasses or H'CL.

Furthermore, the following problems exist regarding the corneal incision method.

■ Once a corneal incision or corneal suture is made during cataract surgery, it is difficult to perform surgery on the same area again.

■ Intentionally creating a wound on the cornea, which increases the possibility of corneal infection.

■　Irregular astigmatism may occur.

■ In addition to cataract surgery, it is necessary to perform a new surgery called corneal incision, which is painful for the patient.

■ Damaging healthy corneas is considered an ethical issue.

■ The degree of astigmatism varies from patient to patient, but correction by the surgeon relies on sensory techniques, and it may not be possible to completely correct astigmatism.

For the above reasons, a method of correcting astigmatism by making a corneal incision is not generally performed.

Additionally, several methods have been proposed for correcting corneal astigmatism using intraocular lenses (US Pat. No. 4,277,852).
No. 156915, Utility Model Publication No. 61-156915). These inventions suggest that astigmatism can be corrected with an intraocular lens, but when actually using an intraocular lens on a patient, how to determine the values of spherical power and astigmatic power, etc. No disclosure has been made in important respects.

Therefore, one method for determining the astigmatism power has conventionally been to use corneal astigmatism (hereinafter referred to as intraoperative astigmatism), which occurs when the shape of the cornea changes due to the incision of the cornea and sutures with nylon threads, etc., performed during surgery. ) has been proposed (US Pat. No. 4,512,039) to correct this intraoperative astigmatism. This intraocular lens can correct corneal astigmatism caused by surgery.

However, preoperative astigmatism remains even after surgery and still requires correction with glasses or HCL.

Furthermore, this intraoperative astigmatism is zero within 3 to 6 months after surgery.
．． 5(D) However, in most patients, surgical techniques have improved to the point that intraoperative astigmatism can be resolved approximately one year after surgery. Therefore, the occurrence of intraoperative astigmatism is rarely a problem at present, and the biggest problem that must be solved is the correction of preoperative astigmatism.

[Object of the Invention] The present invention proposes a method for determining the astigmatic power of a toric intraocular lens and an intraocular lens power capable of correcting preoperative astigmatism.

[Means for Solving the Problems] A method for determining the astigmatic power of a toric intraocular lens according to claim 1 is a method in which corneal astigmatic power data before surgery is converted into an astigmatic power of the intraocular lens.

The method for determining the intraocular lens power of a toric type intraocular lens according to claim 2 is to obtain the spherical power PL of the intraocular lens from the corneal curvature radius data R1 or corneal refractive power data Kl in the direction of the ballistic radial line, Determine the spherical power P2 of the intraocular lens from the corneal radius of curvature data R2 or the corneal refractive power data in the direction, and calculate the cylindrical power P3 by subtracting Pl from the P2,
The ballistic radial direction is the astigmatic axis, PL is the spherical power of the intraocular lens, and P3 is the astigmatic power of the intraocular lens.

The method for determining the intraocular lens power of a toric type intraocular lens according to claim 3 is to obtain the spherical power PL of the intraocular lens from the corneal curvature radius data R1 or the corneal refractive power data Kl in the ballistic radial direction, Determine the spherical power P2 of the intraocular lens from the corneal radius of curvature data R2 or the corneal refractive power data in the direction, and calculate the cylindrical power P3 by subtracting P2 from P1,
It is characterized in that the weak principal radial direction is the astigmatic axis, P2 is the spherical power of the intraocular lens, and P3 is the astigmatic power of the intraocular lens.

The method for determining the intraocular lens power of a toric type intraocular lens according to claim 4 is as follows: L-CN-K1 . CN- 2 - CN- 2 . - in 2 (L-C) (1-C・K2 /N),
N is the refractive index of the cornea, aqueous humor, and vitreous body, and L is the axial length data (
), C is the anterior chamber depth data (mm), K1 is the corneal refractive power in the ballistic radial direction, K2 is the corneal refractive power in the weak principal radial direction, and R1 is the corneal radius of curvature data in the ballistic radial direction. (m11
), R2 is the corneal curvature radius data in the direction of the weak principal axis (mm)
, PL and R2 are each a spherical power, the method for determining the power of a toric intraocular lens according to claim 2 or 3.

The method for determining the intraocular lens power of a toric type intraocular lens according to claim 5 includes: PL sea bream NL-Kl (L=C)
(1-C-Kl /N), where N is the refractive index of the cornea, aqueous humor, and vitreous body, L is the axial length data (mu), C is the anterior chamber depth data (am), and Kl is the ballistic radius. Corneal refractive power in the direction, K2 is the corneal refractive power in the weak principal radial direction, R1 is corneal curvature radius data in the ballistic radial direction (+1111), R2 is corneal curvature radius data in the weak principal radial direction (mm), PL and R2
4. The method for determining the intraocular lens power of a toric type intraocular lens according to claim 2 or 3, wherein each of is a spherical power.

The method for determining the intraocular lens power of a toric type intraocular lens according to claim 6 includes: L-CN/Kl-C Corneal curvature radius data (mm) in the principal axis direction, PL and R2
4. The method for determining the intraocular lens power of a toric type intraocular lens according to claim 2 or 3, wherein each of is a spherical power.

The method for determining the intraocular lens power of a toric type intraocular lens according to claim 7 is as follows: , N is the refractive index of the cornea, aqueous humor, and vitreous body, L is the axial length data (am), C is the anterior chamber depth data (++i), and K
l is the corneal refractive power in the ballistic radial direction, K2 is the corneal refractive power in the weak principal radial direction, R1 is corneal curvature radius data (mm) in the ballistic radial direction, R2 is weak, and N is the cornea, tuft. Water, refractive index of vitreous body, L is axial length data (mm), C is anterior chamber depth data (1 ml), K1 is corneal refractive power in the strong principal meridian direction, K
2 is the corneal refractive power in the weak principal meridian direction, R1 is the corneal radius of curvature data in the strong principal meridian direction (w), R2 is the corneal radius of curvature data in the weak principal meridian direction (IIll), and Pl and P2 are the spherical surfaces, respectively. A method for determining the intraocular lens power of a toric type intraocular lens according to claim 2 or 3, wherein the power is determined as the power.

The method for determining the intraocular lens power of a toric type intraocular lens according to claim 8 is a claim in which one ta (am) and R2 are corneal curvature radius data (mm) in the direction of the weak principal axis, and PL and P2 are respectively spherical powers. A method for determining the intraocular lens power of a toric intraocular lens according to claim 2 or 3.

The method for determining the intraocular lens power of a toric type intraocular lens according to claim 9 is as follows: PL-A-2,5L-0,9 to 1 P2-A-2,5L-0,9 to 2 (L-C) ( N Fist Rl 10.3333
- In C), N is the refractive index of the cornea, aqueous humor, and vitreous body, L is the axial length data (+m), and C is the anterior chamber depth data (+
m), where R1 is the corneal curvature radius de in the strong principal radial direction,
A is the intraocular lens constant, N is the refractive index of the cornea, aqueous humor, and vitreous body, L is the axial length data (mm), Kl is the corneal refractive power in the direction of the weak principal axis, and K2 is the refractive power in the direction of the strong principal axis. Corneal refractive power, R1 is corneal curvature radius data (w) in the weak principal axis direction, R2 is corneal curvature radius data (mm) in the weak principal axis direction, and PL and P2 are spherical powers, respectively. This is a method for determining the intraocular lens power of a toric intraocular lens according to item 3.

The toric intraocular lens according to claim 10 is manufactured by the method for determining the astigmatic power of a toric intraocular lens according to claim 1.

The toric intraocular lens according to claim 11 is manufactured by the method for determining the intraocular lens power of a toric intraocular lens according to claim 2 or 3.

[Function] In the method for determining the astigmatic power of a toric intraocular lens according to claim 1, in order to convert the pre-surgery corneal astigmatism power data into the astigmatic power of the intraocular lens, after the surgery, the astigmatic power data of the pre-surgery Corneal astigmatism is corrected with an intraocular lens.

In order to determine the intraocular lens power by the method for determining the intraocular lens power of a toric type intraocular lens according to claim 2, first, 1 is added to the corneal radius of curvature data R1 or the corneal refractive power data in the strong principal axis direction of the cornea. From this, the spherical power Pl of the intraocular lens in this direction is determined, and the corneal curvature radius data R2 in the direction of the weak principal axis is obtained.
Or the spherical power P of the intraocular lens from 2 to the corneal refractive power data.
Find 2. Next, the cylindrical power P3 is obtained by subtracting the spherical power P1 in the strong main radial direction from the spherical power P2 in the weak main radial direction.

Then, the strong principal radial direction is the astigmatic axis, pt is the spherical power of the intraocular lens, and P3 is the astigmatic power of the intraocular lens.

In order to determine the intraocular lens power by the method for determining the intraocular lens power of a toric type intraocular lens according to claim 3, the PL and Find P2, then subtract P2 from PL to find P3. Then, with the direction of the weak principal axis as the astigmatic axis, P2 is the spherical power of the intraocular lens, and P3 is the astigmatic power of the intraocular lens.

[Example code] Hereinafter, one embodiment of the present invention will be described based on the drawings.

Reference numeral 10 is a toric intraocular lens made of PMMA.
This is a shearing type intraocular lens made of a polymer compound such as (polymethyl methacrylate).

Reference numeral 12 denotes an optical part of the intraocular lens, which has a circular planar shape.

Reference numeral 14.14 denotes a fixed portion that protrudes from the opposing position of the optical portion 12.

Reference numeral 16.16 denotes a bojonning hole, which opens at the periphery of the optical section 12. A line connecting these two bojonning holes 1B and 1(i) crosses the center of the circular optical section 12.

A method for determining the intraocular lens power of the optical section 12 in order to correct preoperative astigmatism in the toric intraocular lens with the above configuration will be described below. Note that the intraocular lens power here refers to a combination of a spherical power and an astigmatic power for correcting astigmatism.

There are several methods for determining the intraocular lens power, but the first one is the 5-anders-Retzlaff-Krarf formula (
Hereinafter, it will be referred to as S type. ).

If the spherical power of the intraocular lens 10 is PL and R2, Pi -A-2,5L-0,9Kl...
・(1) 2 to R2-A-2,5L-0,9...
...(2) becomes. However, A is the intraocular lens constant, N is the refractive index of the cornea, aqueous humor, and vitreous body, and L is the axial length data (+1
111) K1 is the corneal refractive power (D) in the ballistic radial direction, K
2 is the corneal refractive power (D) in the weak principal radial direction, R1 is the corneal curvature radius data (Imm) in the ballistic radial direction, and R2 is the corneal curvature radius data (Imm) in the weak principal radial direction.

Next, the astigmatic power P3 is determined as follows.

When the ballistic radial direction is the astigmatic axis, the cylindrical power obtained by subtracting Pl from R2 becomes the astigmatic power P3.

When the weak principal radial direction is set as the astigmatic axis, the cylindrical power obtained by subtracting R2 from PL becomes the astigmatic power P3.

The optical part 12 is manufactured based on the intraocular lens power determined as described above. Then, through surgery, the patient is given an intraocular lens 10.
Just insert .

For example, in the case of a patient whose corneal refractive power measurement showed direct astigmatism of 3 (D) before cataract surgery,
The intraocular lens power S of the retrograde intraocular lens IO inserted to reduce the total astigmatism to 0 (D) after 3 months after surgery is determined as follows.

First, the patient's ocular axial length is measured using an A-mode ultrasonic measuring device or the like.

Then, the corneal curvature radii R1 and R2 are measured using a corneal curvature radius measuring device, a corneal shape Δ-j measuring device, etc., and these 711 determined values R1 and R2 are substituted into equations (3) and (4), respectively, to determine the corneal radius. Calculate 1 and 2 for refractive power. In addition, this corneal refractive power Kl (90@ direction) and 2 (18
0'' direction) may be directly measured using a corneal refractive power meter or the like.

As an example for a patient, L-23,2 (Imm), Kl
-44 (D) and K2-41 (D). Furthermore, since the intraocular lens 10 is a retrograde intraocular lens, the intraocular lens constant is set to A-116.5.

In formula (1), L −23, 2(++++e), K1-44
(D), by substituting A-116,5, P1 bite 18.9
(D). In equation (2), L −23, 2(am), K
2-41(D), Substituting A-116,5 gives R2-
21.6 (D).

Therefore, the intraocular lens power required for this case is 90.
+18.9 (D) in the ° direction, +21. in the 180" direction.
6(D). In other words, spherical power +18.9 (D)
, astigmatic power +2.7 (D), astigmatic axis 90'' or spherical power +21.6 (D), astigmatic power -2.7 (D), astigmatic axis 180°. Note that the power is simplified here. Therefore, the minimum unit is set to 0.5 (D) increments, that is, +1
It is also possible to change 8.9 (D) to +19.0 (D), +2.7 (D) to +2.5 (D), etc.

Next, a method for setting the direction of the astigmatism axis will be explained. The following two conditions are required to determine the astigmatic axis.

■ Physicians must be able to easily determine the direction of the astigmatic axis during surgery.

■ The astigmatism axis crosses the center of the circular optical section 12.

In order to satisfy the above two conditions, in this embodiment, a line connecting the positioning holes te and te is set (see FIG. 1). With this setting method, the direction of the astigmatism axis can be easily determined by the doctor during surgery, and the astigmatism axis crosses the center of the optical section 12. Further, there is also the advantage that there is no need to specially provide a mark for the astigmatic axis in the optical part 12, and the processing of the intraocular lens 10 is easy.

Note that the relationship between the direction of the astigmatic axis and the astigmatic power of the intraocular lens power is determined in advance when determining the intraocular lens power.

The intraocular lens 10 set as described above is inserted using the same surgical method as before. The intraocular lens can be inserted by, for example, a compression method, a dialing method, or a closed procedure. The direction of insertion of the intraocular lens 10 is such that the direction of the weak principal axis of the intraocular lens is aligned with the direction of the strong principal axis of the cornea, and the direction of the strong principal axis of the intraocular lens is aligned with the direction of the weak principal axis of the cornea. match. Figure 4 shows the intraocular lens lO
This shows the state after insertion.

Note that 18 indicates the arcuate cornea, and 20 indicates the anterior capsule.

As a result, in the intraocular lens 10 inserted retrogradely, the fixing portion 14.14 is fixed in the ciliary sulcus or between the anterior capsule of the equatorial region of the crystalline lens and the posterior part.

Therefore, the optical part 12 permanently maintains its position at the insertion site without rotating or moving. Therefore, the astigmatism axis of the intraocular lens 10 is fixed, and astigmatism occurring in the patient can be corrected.

Therefore, there is no need to wear glasses or HCL after surgery as in the past, and there is no pain or discomfort to the patient. Another advantage is that it is possible to correct astigmatism that has already occurred in the patient due to a disease or the like before the surgery. Furthermore, unlike conventional corneal incision methods, this method has the effect of reliably correcting the desired degree of astigmatism.

In the above embodiment, the astigmatic axis of the intraocular lens 10 was set between the positioning holes 16 and 18.
Instead of this, the following setting method can be considered.

■ When the fixing part 14.14 is fixed to the optical part 12, the line connecting the roots 14a and 14a is set as the astigmatism axis x-x (
(See Figure 5).

■ Tabs 22 and 22 are provided on the optical section 12, and this tab 2
2. The line connecting 22 is the mark of the astigmatism axis x-x' (6th
(see figure).

The tabs 22.22 project outwardly at opposite peripheral edges of the optical part 12.

■ Marks 24 and 24 are colored with a dye or the like or are engraved with a laser or the like on the opposing peripheral edges of the optical part 12, and the line connecting these marks 24 and 24 is set as the astigmatic axis x-
Mark x' (see Figure 7).

These three methods can satisfy the above-mentioned conditions that the doctor can easily know the direction of the astigmatic axis during surgery and that the astigmatic axis crosses the center of the optical section 12. Particularly, in the case of method (2), there is no need to provide a special mark for the astigmatic axis, so the intraocular lens can be easily processed.

Furthermore, although the above-mentioned intraocular lens 10 is a sharing type,
Alternatively, other retrograde lenses such as pierced lenses°
Even if the determination method of this embodiment is used in the optical part of the anterior chamber lens, the effects of the present invention can be sufficiently obtained. In this case, the intraocular lens constant A in equations (1) and (2) may be changed. For example, in the case of an anterior chamber lens, A-114,5~
116.0, and in the case of iris supporting lenses, A-11
5.0 to 116.5, and in the case of retrograde lenses, A-
116.0 to 120.0.

In the above example, the intraocular lens power for a patient with corneal astigmatism was calculated from the SRK formula before surgery, but
Next, the intraocular lens power of the toric type intraocular lens is determined using a theoretical calculation formula.

The first method is the Pinkhorst (R, D, Binkho) method.
rst) method, which uses equations (5) and (6).
First, the spherical power Pl and R2 are determined from the equations.

R2-100ON (N -R210,3333-
L) (L-C) (N-R210,3333-C)・
...(6) However, C is the anterior chamber depth (discussed), which is determined by an A-mode ultrasonic measuring device or the like.

The astigmatic power P3 is obtained by subtracting R2 from the spherical power pt. That is, R3■ R2-P
I -100ON (N -R210J333- L
)(L-C) (N-R210,3333-C)(L
-C) (N-R110,3333-C)PI -
100ON (N-R110,3333-L) (L-
C) (N-R110,3333-C)333.3
N -N (1?2-Rl) (N-R2-0,3
333C) (N-R1-0,3333G).

Here, when the ballistic radial direction is the astigmatic axis, PL is the spherical power of the intraocular lens, and R3 is the astigmatic power of the intraocular lens.

Further, when the direction of the weak principal axis is the astigmatic axis, R2 is the spherical power of the intraocular lens, and -R3 is the astigmatic power of the intraocular lens.

For example, the ballistic radial direction of the cornea is the lateral direction, and the pt-
25 (D), the direction of the weak principal axis of the cornea is the longitudinal direction, and when R2-30 (D), R3-R2-P
It becomes L-5(D).

Therefore, the desired intraocular lens power S and the direction of the astigmatism axis can be set to the following two types.

■ If the vertical direction is the astigmatic axis, the spherical power is +30
(D), and the astigmatic power is -5 (D).

■ If the horizontal direction is the astigmatic axis, the spherical power is +25
(D), and the astigmatic power is +5 (D).

Through the above steps, an intraocular lens capable of correcting preoperative astigmatism can be produced.

The second method is a method using the Fyodorov method, in which the spherical power pt and R2 are first determined using equations (8) to (11).

(L-C) (1-C-Kl/N) ... (8)
(L-C) (2/N to 1-C-) ...(
9)...(10) K2-1000 (N-1)...(11) Below, in the same way as the pinkhorst method, the desired eye is the spherical power Pl or P2 plus the astigmatic power P3 or -P3. This is the inner lens power.

The third method is the Colenbrander
(12) and (13).
), the spherical powers P1 and P2 are first determined.

In this method, the spherical power P1 is first determined by equations (14) and (15).
and P2 are found.

-C (1/Kl -C/N)...(14) L-CN/Kl -C...(12) Similarly, astigmatism power P3 or -P3 is set to spherical power pt or P2. The sum of these results in the desired intraocular lens power.

The fourth method is to calculate the sphericity PL or P2 using the Panzol Hage (Va or less), similar to the Pinkhorst method.
The sum of the astigmatic power P3 or -P3 is the desired intraocular lens power.

In addition, since any method using the first to fourth theoretical calculation formulas can be mathematically transformed into the following formulas (16) and (17), the spherical powers P1 and P2 may be determined from these formulas. .

Pl-N -N-Kl L-CN-Kl-C- (1B) In addition to the above embodiments, the ray tracing/error correction method (Ra
y Trapping Error Correction
ng Method, hereinafter referred to as RTEC method. ) can also be used to determine the intraocular lens power of a toric intraocular lens.

This determination method can be determined in the same manner as the Pinkhorst method by determining the spherical power in the ballistic radial direction and the weak principal radial direction of the cornea by the RTEC method.

Note that the power of the intraocular lens can be easily determined by calculating the above equations (1) to (17) using a computer or the like.

By the way, the present invention can simultaneously correct not only preoperative astigmatism but also intraoperative astigmatism.

In this case, the intraocular lens power is determined as follows.

First, predict intraoperative astigmatism for about a year after surgery. The total astigmatism power is calculated by adding the strength of the predicted intraoperative astigmatism and the preoperative astigmatism.

Then, based on this total astigmatic power, the intraocular lens power is determined by the method described above.

Furthermore, humans naturally have milder astigmatism, which causes a physiological phenomenon in which they try to see things better by squinting their eyes.

Therefore, the present invention does not eliminate all astigmatism using an intraocular lens, but can instead create mild astigmatism that can cover the above physiological phenomenon.

The method for determining the intraocular lens power in this case is to calculate the total astigmatism power, which is the sum of the preoperative astigmatism and the intentionally added light astigmatism power.

Then, the intraocular lens power may be determined based on the total astigmatic power.

Note that if the patient is nearsighted or farsighted, the spherical power may be determined to correct this nearsightedness or farsightedness. In addition, if an intraocular lens is inserted in only one eye and myopia or farsightedness remains in the other eye, correction of myopia or farsightedness with an intraocular lens takes into consideration the balance when seeing with both eyes. Therefore, the spherical power should be determined so that some degree of myopia or hyperopia remains.

[Effects of the Invention] As described above, the astigmatic power of a toric intraocular lens and the method for determining the intraocular lens power of the present invention can provide the following effects.

■ It is possible to determine the power of the intraocular lens that can correct the corneal astigmatism that the patient had already developed due to disease etc. before surgery.

■ The desired corneal astigmatism can be reliably corrected.

[Brief explanation of the drawing]

FIG. 1 is a plan view showing an embodiment of the present invention, and FIG. 2 is a plan view showing an embodiment of the present invention.
FIG. 1 is an end view taken along line I-I in FIG. 1, FIG. 3 is an end view taken along line ■-■ in FIG. FIG. 7 is a plan view of an intraocular lens in which an astigmatic axis is set by another method, and FIG. FIG. 6 is a plan view of an intraocular lens in which an astigmatic axis is provided between tabs, and FIG. 7 is a plan view of an intraocular lens in which an astigmatic axis is provided between marks. [Explanation of symbols] 10...Intraocular lens 12...Optical section 14...Fixing section 16...Positioning hole Fig. 5 Fig. 6 Figure 2 Figure 8 Figure 4v! J Figure 7z

Claims (11)

[Claims] 1. A method for determining the astigmatism power of a toric intraocular lens, the method comprising converting preoperative corneal astigmatism power data into the astigmatism power of the intraocular lens. 2. Determine the spherical power P1 of the intraocular lens from the corneal radius of curvature data R1 or the corneal refractive power data K1 in the direction of the strong principal axis, and calculate the spherical power P1 of the intraocular lens from the radius of corneal curvature data R2 or the corneal refractive power data K2 in the direction of the weak principal axis. Calculate the spherical power P2, subtract P1 from P2 to determine the cylindrical power P3, set the direction of the strong principal meridian as the astigmatic axis, set P1 as the spherical power of the intraocular lens, and set P3 as the astigmatic power of the intraocular lens. A method for determining the intraocular lens power of a toric intraocular lens, characterized by: 3. Determine the spherical power P1 of the intraocular lens from the corneal radius of curvature data R1 or the corneal refractive power data K1 in the direction of the strong principal axis, and calculate the spherical power P1 of the intraocular lens from the radius of corneal curvature data R2 or the corneal refractive power data K2 in the direction of the weak principal axis. Find the spherical power P2, subtract P2 from P1 to find the cylindrical power P3, set the direction of the weak principal axis as the astigmatic axis, set P2 as the spherical power of the intraocular lens, and let P3 be the astigmatic power of the intraocular lens. A method for determining the intraocular lens power of a toric intraocular lens, characterized by: 4. P1=N/(L-C)-(N・K1)/(N-K1
・C) P2=N/(L-C)-(N・K2)/(N-K
2.C) K1=1000(N-1)/R1 K2=1000(N-1)/R2 where N is the refractive index of the cornea, aqueous humor, and vitreous body, L is the axial length data (mm), and C is the anterior chamber depth data (mm), K1
is the corneal refractive power in the strong principal meridian direction, K2 is the corneal refractive power in the weak principal meridian direction, and R1 is the corneal radius of curvature data in the strong principal meridian direction (
mm), R2 is the corneal curvature radius data in the direction of the weak principal axis (m
The method for determining the intraocular lens power of a toric type intraocular lens according to claim 2 or 3, characterized in that: m), P1 and P2 are each a spherical power. 5. P1=(N-L・K1)/(L-C)(1-C・K1/
N) P2 = (N-L・K2)/(L-C) (1-C・K
2/N) K1=1000(N-1)/R1 K2=1000(N-1)/R2 where N is the refractive index of the cornea, aqueous humor, and vitreous body, L is the axial length data (mm), and C is the anterior chamber depth data (mm), K1
is the corneal refractive power in the strong principal meridian direction, K2 is the corneal refractive power in the weak principal meridian direction, and R1 is the corneal radius of curvature data in the strong principal meridian direction (
mm), R2 is the corneal curvature radius data in the direction of the weak principal axis (m
The method for determining the intraocular lens power of a toric type intraocular lens according to claim 2 or 3, characterized in that: m), P1 and P2 are each a spherical power. 6. P1=N/(L-C)-N/(N/K1-C)P2=N
/(L-C)-N/(N/K2-C)K1=1000(
N-1)/R1 K2=1000(N-1)/R2 where N is the refractive index of the cornea, aqueous humor, and vitreous body, L is the axial length data (mm), and C is the anterior chamber depth data (mm). , K1
is the corneal refractive power in the strong principal meridian direction, K2 is the corneal refractive power in the weak principal meridian direction, and R1 is the corneal radius of curvature data in the strong principal meridian direction (
mm), R2 is the corneal curvature radius data in the direction of the weak principal axis (m
The method for determining the intraocular lens power of a toric type intraocular lens according to claim 2 or 3, characterized in that m), P and P2 are each a spherical power. 7. P1=N/(L-C)-1/(1/K1-C/N)P2
=N/(L-C)-1/(1/K2-C/N)K1=1
000(N-1)/R1 K2=1000(N-1)/R2 where N is the refractive index of the cornea, aqueous humor, and vitreous body, L is the axial length data (mm), and C is the anterior chamber depth data ( mm), K1
is the corneal refractive power in the strong principal meridian direction, K2 is the corneal refractive power in the weak principal meridian direction, and R1 is the corneal radius of curvature data in the strong principal meridian direction (
mm), R2 is the corneal curvature radius data in the direction of the weak principal axis (m
The method for determining the intraocular lens power of a toric type intraocular lens according to claim 2 or 3, characterized in that: m), P1 and P2 are each a spherical power. 8. P1=1000N(N・R1/0.3333-L)/(
L-C) (N・R1/0.3333-C) P2=100
0N (N・R2/0.3333-L)/(L-C)(N
・In R2/0.3333-C), N is the refractive index of the cornea, aqueous humor, and vitreous body, L is the axial length data (mm), C is the anterior chamber depth data (mm), and R1 is the strong principal meridian. The toric device according to claim 2 or 3, wherein R2 is corneal curvature radius data (mm) in the direction of the weak principal axis, and P1 and P2 are spherical powers, respectively. Method for determining intraocular lens power for type intraocular lenses. 9. P1=A-2.5L-0.9K1 P2=A-2.5L-0.9K2 K1=1000(N-1)/R1 K2=1000(N-1)/R2 where A is the intraocular lens constant , N is the refractive index of the cornea, aqueous humor, and vitreous body, L is the axial length data (mm), K1 is the corneal refractive power in the direction of the strong principal axis, K2 is the corneal refractive power in the direction of the weak principal axis, and R1 is Corneal curvature radius data in strong principal radial direction (mm),
R2 is the corneal curvature radius data (mm) in the direction of the weak principal axis, P
4. The method for determining the intraocular lens power of a toric type intraocular lens according to claim 2 or 3, wherein 1 and P2 are respectively spherical powers. 10. A toric intraocular lens manufactured by the method for determining the astigmatic power of a toric intraocular lens according to claim 1. 11. A toric intraocular lens manufactured by the method for determining the intraocular lens power of a toric intraocular lens according to claim 2 or 3.