CN114613240B - A processing method of isolated porcine eye anterior capsule and a capsulorhexis training model for cataract surgery - Google Patents

Abstract

The invention provides a method for treating an isolated pig eyeball anterior capsule, which is characterized in that the isolated pig eyeball anterior capsule is treated by sodium hypochlorite solution with proper concentration, and the obtained pig eyeball anterior capsule has similar mechanical characteristics with the human eye anterior capsule, and can better simulate the experience of cataract operation during continuous annular capsulorhexis. The invention also provides a cataract operation capsulorhexis training model prepared by the processing method, and cataract operation beginners can use the model to carry out cataract operation continuous annular capsulorhexis training and can also be used for evaluating ophthalmic operation robot capsulorhexis operation.

Description

A method for processing the anterior capsule of isolated porcine eyes and capsulorhexis training in cataract surgery Model

technical field

The invention belongs to the technical field of medicine, and relates to a method for processing an isolated pig eye anterior capsule and a capsulorhexis training model for cataract surgery.

Background technique

Surgical extirpation is currently the only effective treatment for cataracts. The most mainstream surgical procedure for cataracts today is phacoemulsification, in which continuous circular capsulorhexis is recognized by experts as the most critical step, and the learning curve is long. Mohanna Al-Jindan et al. A prospective study concluded that capsulorhexis is one of the most difficult steps to learn in cataract surgery and has the highest complication rate of all surgical steps at 40%. Huang Aiping analyzed 300 cases of continuous circular capsulorhexis of cataract and found that the success rate was only 86.7%. And even when performed by the same skilled surgeon, the size and shape of the capsulorhexis can vary widely.

Many researchers at home and abroad have established simple and effective cataract animal models, providing cataract surgeons with a model for training surgical techniques. Such cataract models are usually based on freshly isolated porcine eyeballs that are readily available and inexpensive. Takeshi Sugiura et al. found that the use of 0.2ml of a mixed reagent (formalin, ethanol and isopropanol in a ratio of 4:3:3) injected into the lens through the corneoscleral limbus could induce cataracts in pig eyes. Using an 800W microwave oven to heat fresh isolated pig eyeballs for 20 seconds can create a cataract model with cloudy lens and capsulorhexis success rate close to the clinical success rate of practitioners, but 23.3% of them have decreased corneal transparency, resulting in blurred surgical field of view and increasing the difficulty of practice, 3.3 % of pig eyes could not be used for practice due to severe corneal clouding. Xingchao et al. mixed 38% formaldehyde and 100% methanol at a ratio of 2:1, injected it on the surface of the anterior capsule through the main corneal incision on the isolated porcine eyeball, and then injected 0.2mL of the mixed reagent into the lower part of the anterior capsule, combined with a microwave oven With heating, it is possible to obtain a clear cornea, reduced tension and elasticity of the anterior capsule, and a model of lens sclerosis cataract. Robert William randomly divided isolated pig eyeballs into two groups, which were treated with microwaves and chemical reagents to make cataract models. In the microwave treatment group, the lens became cloudy but the anterior chamber became shallow and the anterior capsule remained highly elastic, which was not conducive to capsulorhexis training. The chemical treatment group can fuse the cortex with the capsule, which is not conducive to water separation. In conclusion, none of the models can well simulate the experience of continuous circular capsulorhexis in cataract surgery.

For the evaluation of this type of cataract animal model, focus on evaluating the degree of opacity of the lens. This type of model is very helpful for the surgeon to practice the chopping technique, and for the doctor to grasp and experience the shape and size of the lens. However, such models neglect the evaluation of the hand feel during capsulorhexis. Compared with the anterior capsule of human cataract, the anterior capsule of the pig eyeball is tougher, and the capsulorhexis feel is completely different. Sueiras et al. observed under the atomic force microscope that the surface of the anterior capsule of the human lens is obviously rougher than that of the pig and the anterior capsule of the human lens is significantly rougher. The roughness of the capsule increases significantly with age. At present, beginners in cataract surgery usually use the easy-to-obtain young pig eyeballs from the meat factory when performing continuous circular capsulorhexis. It is obviously inappropriate to use pig eyeballs to practice cataract capsulorhexis.

Therefore, there is an urgent need to develop a method that can convert the mechanical properties of the anterior capsule of the isolated porcine lens into similar mechanical properties of the anterior capsule of the human eye, so as to facilitate continuous circular capsulorhexis practice for beginners in cataract surgery.

Contents of the invention

In order to solve the above problems, the main purpose of the present invention is to provide a method for processing the anterior capsule of the isolated porcine eye, which can change the mechanical characteristics of the anterior capsule of the isolated porcine lens to make it similar to the anterior capsule of the human eye lens The mechanical characteristics can better simulate the experience of cataract surgery.

Another object of the present invention is to provide a capsulorhexis training model for cataract surgery.

In order to achieve the above object, the invention provides a kind of processing method of isolated porcine eye anterior capsule, comprising the steps:

1) 1% sodium hypochlorite solution is diluted with water to be 0.3% sodium hypochlorite solution in mass percent concentration;

2) Place the isolated porcine eyeball in the porcine eye fixation device with the cornea facing upward;

3) Use a 3.0mm puncture knife to puncture an opening with a diameter of 3.0mm at the corneoscleral limbus;

4) Use corneal scissors to cut off the cornea along the corneal limbus to expose the anterior lens capsule;

5) Drop 0.3% sodium hypochlorite solution onto the surface of the anterior capsule with a syringe and infiltrate for 5 minutes;

6) Immediately rinse the surface of the anterior capsule 3 times with 0.9% normal saline.

The present invention also provides a cataract surgery capsulorhexis training model prepared by adopting the above-mentioned processing method of isolated porcine eye anterior capsule.

The processing method of the isolated porcine anterior capsule provided by the invention can reach the mechanical characteristics similar to the anterior capsule of the human eye lens by processing the porcine lens anterior capsule with an appropriate concentration of sodium hypochlorite solution.

The beneficial effects of the present invention are:

The invention provides a method for processing the anterior capsule of the isolated porcine eye. The processing method can change the toughness of the anterior capsule of the isolated porcine eye lens to achieve mechanical characteristics similar to those of the human eye lens. This model can well simulate the experience of cataract surgery, which is beneficial for beginners in cataract surgery to carry out continuous circular capsulorhexis training, and can also be used to evaluate the capsulorhexis operation of ophthalmic surgery robots.

Description of drawings

Fig. 1 is a photo diagram of fixing a pig's eye using a pig's eye fixing device according to the present invention.

Fig. 2 is a photographic view of a stretching machine used in the present invention.

Detailed ways

The embodiments of the present invention will be described in detail below, so that the advantages and features of the present invention can be more easily understood by those skilled in the art, so as to define the protection scope of the present invention more clearly.

Material:

1. Fresh isolated pig eyeballs were purchased from Pengcheng Food Company, collected from 6-month-old Duroc and Landrace dual hybrid pigs, and passed the quarantine inspection.

2. The anterior capsule of the human lens: the anterior capsule specimens from the director of equine department of Beijing Tongren Hospital, which passed the review of the Ethics Committee of Beijing Tongren Hospital Affiliated to Capital Medical University.

3.1% sodium hypochlorite solution was purchased from Langli Biomedicine (Wuhan) Co., Ltd.

4. Laboratory tertiary water was purchased from Shanghai Suitian Environmental Protection Technology Co., Ltd.

5. The ophthalmic operating microscope (topcon) is used for capsulorhexis operation, and the capsulorhexis operation is performed under the operating microscope.

6. The pig's eye fixation device is the eyeball simulation bracket MR-D300 purchased from Suzhou Mingren Medical Instrument Co., Ltd., which is used to fix the pig's eyeball.

7. The stretching machine is composed of Nano17 six-dimensional force sensor (ATI Industrial Automation, NC, USA) and linear displacement stage MTS 203 (Beijing Beiguang Century Instrument Co., Ltd., China).

The rest of the instruments and equipment whose sources are not indicated are common instruments and equipment for ophthalmic surgery.

Example 1: Treatment of isolated porcine eye anterior capsule and evaluation of capsulorhexis

Take 20 fresh pig eyeballs in vitro, and check through slit lamp to get rid of diseases such as iritis, lens lesion and corneal lesion. The isolated porcine eyeballs were stored in a 4°C refrigerator, and the experiment was carried out within 24 hours after the eyeballs were removed.

1. Dilute 1% sodium hypochlorite solution with laboratory tertiary water to 0.1%, 0.3%, 0.5%, 0.7%, 0.9% sodium hypochlorite solution with different concentrations.

2. Place the isolated porcine eye in the porcine eye fixture with the cornea facing upwards, as shown in Figure 1.

3. Use a 3.0mm puncture knife to puncture an opening with a diameter of 3.0mm at the corneoscleral limbus.

4. Use corneal scissors to cut off the cornea along the corneal limbus.

5. The sodium hypochlorite solutions of 0.1%, 0.3%, 0.5%, 0.7%, and 0.9% concentrations are divided into groups, corresponding to 1-5 groups, and each group is randomly assigned two freshly isolated pig eyeballs with cornea removed.

6. Use a syringe to drop the sodium hypochlorite solution of the corresponding concentration onto the surface of the anterior capsule in each group from 1 to 5, so that the anterior capsule is fully infiltrated, and time it for 5 minutes.

7. Immediately use a large amount of normal saline to wash the surface of the anterior capsule 3 times to obtain the isolated porcine anterior capsule of the treated humanoid anterior capsule.

Physicians skilled in cataract capsulorhexis operation use capsulorhexis forceps to perform capsulorhexis under ophthalmic operating microscope, measure the thickness of the anterior capsule obtained by capsulorhexis with a micrometer, and compare and evaluate it with the hand feel of human cataract surgery capsulorhexis, the results As shown in Table 1.

The evaluation criteria for capsulorhexis are as follows:

Grade Ⅰ: The texture is tough, and the capsulorhexis is obviously laborious, and it is difficult to control the shape of the capsulorhexis, and it can form a round shape when pulled hard.

Grade II: The texture is relatively tough, and it can be pulled into a round shape with a relatively strong pull.

Grade III: Moderate texture, easy to handle during capsulorhexis, and easy to handle until round.

Grade IV: The texture is relatively brittle, and it is easy to split outward during capsulorhexis, the force is difficult to control, and it is difficult to form a round shape.

Table 1: Anterior Capsule Thickness and Tear Evaluation

serial number Thickness (μm) lens opacity Capsular Toughness Rating prickly feel Capsulorhexis feel 1 42 I III III III 2 47 I III III III 3 50 I III III III 4 60 I Ⅲ+ Ⅲ+ Ⅲ+ 5 48 I IV IV IV

Capsule toughness ratings of 1-5, nematode feel, and capsulorhexis feel are grade Ⅲ, which is closest to the human eye, with only slight differences. Therefore, the capsulorhexis evaluation experiment believes that the porcine anterior capsule is treated with 0.1%-0.5% concentration Sodium hypochlorite treatment is most similar to capsulorhexis in human cataract surgery.

Example 2: Processing and Mechanical Testing of the Anterior Capsule of the Isolated Porcine Eye

Take 60 isolated fresh pig eyeballs, and check through slit lamp to get rid of diseases such as iritis, lens lesions and corneal lesions. The isolated porcine eyeballs were stored in a refrigerator at 4°C before use. Experiments were performed within 24 hours of eyeball removal.

15 groups of human lens anterior capsule specimens were stored in normal saline before use, stored in a refrigerator at 4°C, and experiments were performed within 24 hours.

1. Dilute 1% sodium hypochlorite solution with laboratory tertiary water to 0.1%, 0.3%, 0.5% sodium hypochlorite solution.

2. Place the isolated porcine eye in the porcine eye fixation device prepared in Example 1, with the cornea facing upward.

3. Use a 3.0mm puncture knife to puncture an opening with a diameter of 3.0mm at the corneoscleral limbus.

4. Use corneal scissors to cut off the cornea along the limbus of the pig's eyeball.

5. Randomly divide 60 fresh isolated pig eyeballs with corneas removed into four groups A, B, C and D, with 15 pig eyeballs in each group, numbered 1-15 respectively. Group A is the control group without any treatment; Group B is the experimental group treated with 0.1% sodium hypochlorite solution; Group C is the experimental group treated with 0.3% sodium hypochlorite solution; Group D is the experimental group treated with 0.5% sodium hypochlorite solution; Group E is the anterior capsule of human lens Membrane specimen set.

6. After removing the cornea from pig eyeballs in group B, use a syringe to drop 0.1% sodium hypochlorite solution on the surface of the anterior capsule and infiltrate for 5 minutes, and rinse the surface with a large amount of normal saline immediately after the time is up. Continuous circular capsulorhexis was then performed, and the anterior lens capsule specimen obtained by capsulorhexis was preserved.

After the cornea was removed from pig eyeballs in group C, 0.3% sodium hypochlorite solution was dropped on the anterior capsule surface with a syringe to infiltrate for 5 minutes, and the surface was rinsed with a large amount of normal saline immediately after the time was up. Continuous circular capsulorhexis was then performed, and the anterior lens capsule specimen obtained by capsulorhexis was retained.

After the cornea was removed from pig eyeballs in group D, 0.5% sodium hypochlorite solution was dropped on the anterior capsule surface with a syringe to infiltrate for 5 minutes, and the surface was rinsed with a large amount of normal saline immediately after the time was up. Continuous circular capsulorhexis was then performed, and the anterior lens capsule specimen obtained by capsulorhexis was retained.

Use the stretching machine shown in Figure 2 to stretch five groups of anterior capsule specimens, and detect the size of the force required for longitudinal stretching. The experimental results are shown in Table 2 below, and the experimental data retains two decimal places.

Table 2 Statistical results of longitudinally stretched lens anterior capsule specimens

The result can be concluded by the rank sum test that there are significant differences between groups C, D, E and group A, and there is no significant difference between groups C, D and group E. That is, there is a significant difference in the force required for stretching between the anterior capsule of the pig eye treated with 0.3% (group C) and 0.5% (group D) sodium hypochlorite solution and the anterior capsule of the pig eye without treatment. The mechanical characteristics of pig eye anterior capsule treated with 0.3% (group C) and 0.5% (group D) sodium hypochlorite solution were similar to those of human lens anterior capsule (group E), and the capsule of group D was easy to tear during the actual capsulorhexis. The capsulorhexis of group C is closer to that of human beings when it is split outward. There was no significant difference between group B and group A, but there was significant difference between group B and group E. That is, there is no significant difference in the force required for stretching between the anterior capsule of the pig eye treated with 0.1% (group B) sodium hypochlorite solution and the anterior capsule of the pig eye without treatment, and the mechanical characteristics are relatively similar. There were significant differences in the mechanical characteristics of the porcine anterior capsule treated with 0.1% (group B) sodium hypochlorite solution and the anterior capsule of human lens (group E).

This illustrates that the porcine anterior capsule after processing obtained by the isolated pig eye anterior capsule processing method provided by the present invention can be used as a practice model for cataract surgery practitioners.

The above-mentioned embodiments only express several implementation modes of the present invention, and the description thereof is relatively specific and detailed, but should not be construed as limiting the patent scope of the present invention. It should be noted that for those skilled in the art, without departing from the concept of the present invention, several modifications and improvements can be made, and these all belong to the protection scope of the present invention. Therefore, the scope of protection of the patent for the present invention should be based on the appended claims.

Claims (2)

1. The method for treating the anterior capsule of the in-vitro pig eyeball is characterized by comprising the following steps of:

1) Diluting 1% sodium hypochlorite solution with water to obtain sodium hypochlorite solution with mass percent concentration of 0.3% or sodium hypochlorite solution with mass percent concentration of 0.5%;

2) Placing the isolated pig eyeball in a pig eye fixing device with the cornea level upward;

3) Puncturing an opening with a caliber of 3.0mm at the corneoscleral edge with a 3.0mm puncture knife;

4) Cutting the cornea along the cornel limbus using a corneal scissors to expose the anterior capsule of the lens;

5) Dripping a sodium hypochlorite solution with the concentration of 0.3% or a sodium hypochlorite solution with the concentration of 0.5% on the surface of the anterior capsule membrane by a syringe for 5 minutes;

6) The anterior capsule surface was then immediately rinsed 3 times with 0.9% physiological saline.

2. A training model of capsulorhexis for cataract surgery prepared by the method for treating the anterior capsule of an isolated pig eyeball according to claim 1.

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