A method for 3D printing scleral lenses for keratoconus based on digital medical technology

Abstract

This invention belongs to the technical field of scleral lens molding devices, specifically relating to a method for 3D printing scleral lenses for keratoconus based on digital medical technology. The method includes the following steps: creating a three-dimensional model using computer-aided design and manufacturing software; interdisciplinary collaboration between clinical departments and 3D technology; and combining digital medical technology to achieve personalized scleral contact lens design for keratoconus patients using 3D printing technology. Drawing on cutting-edge domestic research based on SD-OCT, a wide-range AS-OCT is developed: imaging width > 18mm, depth > 7mm, covering the entire corneal and scleral area, capturing complete 3D images with high speed and repeatability. After obtaining the images, a deep learning network, combined with artificial intelligence, identifies the boundaries of the anterior and posterior surfaces, lens, tear film layer, cornea, and sclera. The network outputs intuitive data and graphics, improving accuracy and reducing subjective measurement errors by doctors, thereby improving safety and efficacy, and shortening the manufacturing process.

Description

Technical Field

[0001] This invention relates to the field of scleral lens molding device technology, specifically a method for digital medical 3D printing of scleral lenses for keratoconus. Background Technology

[0002] Currently, personalized medical treatment is one of the development directions of medicine in the 21st century. 3D printing technology, a new technology combining digital and intelligent manufacturing with materials science, also known as "rapid prototyping" or "additive manufacturing," is a cumulative manufacturing technology that uses digital models to print materials layer by layer to create objects. 3D printing can achieve low-cost design and production of tools, help in the early detection of common eye diseases, build diagnostic and treatment devices specifically for individual patients, 3D print contact lenses and intraocular implants, and models to assist in surgical planning and improve patient and medical staff education. Its various applications in ophthalmology are likely to become part of mainstream medicine. Scleral lenses are specially designed large-diameter rigid gas-permeable contact lenses. Broadly speaking, scleral lenses include corneal-scleral lenses (also known as limbal lenses or hemiscleral lenses) and total scleral lenses (also known as true scleral lenses). The former refers to lenses where the landing area is partly on the cornea and partly on the sclera, while the latter refers to lenses where the landing area is entirely located on the anterior surface of the sclera. Scleral lenses have broad application prospects, providing mechanical protection for the cornea and showing great potential in improving the visual quality and quality of life of patients with various eye diseases.

[0003] Common indications for scleral lenses include: 1. Diseases causing irregular astigmatism: irregular astigmatism caused by corneal scarring due to keratoconus, corneal ectasia, corneal transplantation, herpes simplex virus infection, etc.; corneal degeneration or malnutrition; corneal trauma with obvious scarring and severe irregular astigmatism. 2. Severe dry eye syndrome: Scleral lenses cross the limbus and do not move on the cornea, improving tear osmotic pressure, promoting corneal epithelial healing, forming tears behind the lens, and continuously hydrating the ocular surface, thereby protecting the ocular surface.

[0004] The parameters required for clinical scleral lens fitting in existing technologies are as follows: 1. Corneal and scleral morphology; 2. Corneal sagittal height in different meridian directions; 3. Corneal inflection angles in different meridian directions; 4. Tear lens thickness and its distribution; 5. Tear lens sinking pattern, etc. The clinical challenges are: 1. Trial and error; 2. Time-consuming; 3. In terms of physician experience, the growth cycle for contact lens physicians is significantly longer compared to other specialties, and experienced physicians are extremely rare; 4. Relatively high cost; 5. Methods for obtaining fitting parameters: limited to obtaining the sag (OCT) at a chord length of less than 15mm. Most techniques cannot obtain the complete tear film thickness under the lens, and small-area OCT requires multiple images. There is a lack of information on the full scleral morphology assessment. There are ESP ocular surface profilometers abroad, which have a slightly larger imaging range, but they cannot show the effect of wearing the lens and have limitations. Corneal morphology detection uses corneal topography. Based on current clinical practice, fitting irregular corneas and severe ocular surface diseases such as keratoconus is more difficult. Optometrists or doctors often need to try multiple times to determine relatively satisfactory lens customization parameters. This repeated trial process and the need for patients to wear the lenses for about 2 hours to observe changes in tear film thickness not only increase patient discomfort but also increase the risk of corneal epithelial detachment or corneal infection. Summary of the Invention

[0005] The purpose of this invention is to provide a method for fitting scleral lenses for keratoconus based on digital medical 3D printing, which solves the problem of the difficulty in fitting scleral lenses for irregular corneas and severe ocular surface diseases such as keratoconus with SCL in current clinical practice.

[0006] To achieve the above objectives, the present invention provides the following technical solution: a method for 3D printing scleral lenses for keratoconus based on digital medical technology, comprising the following steps: using computer-aided design and manufacturing software to create a three-dimensional model, establishing a patient-specific finite element model, and using finite element analysis software to simulate the dynamic pressure on the eyeball during scleral lens wearing and measurement, namely eyelid pressure, tear tension under the lens, and measured intraocular pressure.

[0007] Step S2: Combining 3D printing technology, we can directly or indirectly manufacture scleral lenses using existing materials with micro-nano 3D printing technology: using surface projection micro-stereolithography technology.

[0008] Step S3: Design the digital medical data into an indirect mold to fully present the optical curvature conditions to be corrected, and eliminate the traditional processing of curvature conditions with multi-order equations, so as to make its corrective effect better;

[0009] Step S4: Explore how to design indirect molds based on the complex conditions of digital medical data using 3D printing technology to achieve quadrant-based optimization design;

[0010] Step S5: Achieve personalized scleral lens customization. Combining optical data, accurately design a 3D model of the scleral lens that conforms to the patient's condition in terms of optical curvature and corneal and scleral morphology. Intelligently predict the pattern data of lens sinking and realize the customization of scleral lenses using 3D printing technology.

[0011] Step S6: Precautions for personalized custom scleral lenses. The current scleral lens printing technology is not yet mature and needs to be researched, observed and continuously improved. Although it is not common, if some abnormalities occur and are not dealt with in time, it will harm the health of the eye.

[0012] Step S7: Clean and disinfect the customized scleral lenses to ensure a cleaner environment for patients and promote eye health. After cleaning with all-purpose contact lens solution, soak the lenses in the solution for at least 4 hours before wearing. Before wearing, fill the concave surface of the lens with 0.9% saline solution. It is recommended to perform protein removal treatment once a week, with a soaking time of no more than half an hour. After soaking, rinse with 0.9% saline solution and then soak in the contact lens solution for at least 4 hours.

[0013] Preferably, in step S1, the specific steps for creating the 3D model using computer-aided design and manufacturing software are as follows:

[0014] (1) A three-dimensional finite element model of the whole eyeball and sclera was established by using dynamic ocular surface topography data based on wide-angle anterior segment OCT images. The mechanical contact finite element model of the whole eyeball and sclera consisted of two parts: the whole eyeball model and the sclera model. Drawing on the most cutting-edge research in China, a large-scale tomography scanner was developed based on the spectral domain optical coherence tomography imaging system. The imaging width was >18mm and the depth was >7mm, covering the entire corneal and scleral regions. The complete 3D image was captured in just 0.3 seconds, which was fast and highly repeatable. After image reconstruction error deformation correction algorithm, the deformation correction problem of OCT images under any circumstances was solved, and individual characteristic images of irregular ocular surface morphology of patients were obtained.

[0015] (2) By simulating the distribution of tear film thickness and the deformation and stress distribution of ocular surface under pressure, after obtaining the image, the combination of deep learning network and artificial intelligence identifies the boundaries of the anterior and posterior surfaces, the lens, the tear film layer, the cornea and the sclera, and the asymmetry of the sclera and the corneal limbus. The network outputs intuitive data and graphics to improve accuracy and realize personalized design, thereby reducing the subjective measurement error of doctors, improving safety and efficacy.

[0016] (3) The above model is optimized by reverse analysis (starting with the problem and working backward step by step to deduce the necessary conditions and related basic problems for solving the problem or obtaining the necessary conditions).

[0017] Preferably, the specific steps in step S2, which combine 3D printing technology to achieve micro-nano 3D printing technology, are as follows:

[0018] (1) Set the dynamic eye surface topography map output by the model as simulated data;

[0019] (2) The reverse analysis method is used to make the fitted data of each region fit the target data as closely as possible;

[0020] (3) Combine the optical data provided by the physician to accurately design a three-dimensional model of the sclera with optical curvature and corneal morphology that matches the patient's condition, and combine OCT data to intelligently predict the pattern of lens sinking.

[0021] Preferably, in step S3, the specific steps for designing the digital medical data as indirect are as follows:

[0022] (1) Using a high-precision positional photolithography projection system, the pattern to be printed is projected onto the surface of the resin tank, the resin is cured on the surface of the liquid and quickly formed into a three-dimensional shape;

[0023] (2) Directly process complex 3D models and prototypes from digital models to complete product manufacturing;

[0024] (3) Polish the 3D printed scleral lens products directly manufactured or the scleral lens indirect manufacturing molds by chemical vapor polishing to make the surface roughness reach below 5nm.

[0025] Preferably, in step S4, the complex conditions of the digital medical data are designed as an indirect mold based on 3D printing technology. Using the current clinical scleral lens fitting technology theory, a three-dimensional finite element model of the whole eyeball and scleral lens is established based on the dynamic ocular surface topography data of the wide-angle anterior segment OCT image.

[0026] Preferably, in step S5, personalized scleral lens customization is achieved, and the scleral lens design mainly considers four aspects:

[0027] (1) Main structure of scleral lens: including central tear film area, limbal area and scleral landing area. The central tear film area is arched in the center of the cornea, providing a stable and appropriate thickness of the lens-like tear film and customized clear vision. The limbal area provides an independently designed lens-like corneal fluid. The scleral landing area presents an angle that fits the sclera or the contact area of ​​the lens.

[0028] (2) Regarding the shape of the lens, it includes flat round and flat elongated shapes. The flat round shape is suitable for normal eyes, eyes and refractive surgery, mild corneal ectasia, etc., while the flat elongated shape is suitable for severe corneal ectasia and various types of keratoconus.

[0029] (3) There are three design types for personalized customization of the full arc area, including spherical, toroidal and multifocal, which better fit the shape of the cornea and sclera of the eye surface;

[0030] (4) Quadrant-specific adjustment scheme: It is proposed to adjust the horizontal and vertical diameters and the height of the hemispherical or ellipsoidal body in different quadrants so that the lens fits the shape of the anterior surface of the cornea better.

[0031] Preferably, in step S6, the precautions for personalized scleral lenses specifically include: Scleral lenses are external tissues attached to the ocular surface, which can alter the physiological environment and metabolism of the ocular surface, interfering with its structure and potentially inducing complications. Issues with lens material and thickness can lead to corneal hypoxia, resulting in corneal edema, thinning of the epithelium, decreased sensitivity, neovascularization, and endothelial cell reduction, as well as immune responses and inflammation. This is more common in atopic diseases, ocular surface diseases, and postoperative eyes. While lens adhesion is uncommon after long-term wear, it can harm eye health if not addressed promptly. Therefore, designing and customizing scientifically sound full-curvature scleral lenses is crucial.

[0032] Preferably, in step S7, the customized scleral lenses should be cleaned with a multi-functional contact lens solution and then soaked in the solution for at least 4 hours before wearing. Before wearing, the concave surface of the lens should be filled with 0.9% saline solution. It is recommended to perform protein removal care once a week, with a soaking time of no more than half an hour. After soaking, rinse with 0.9% saline solution and then soak in the contact lens solution for at least 4 hours. Strict care is required to ensure safe wearing.

[0033] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0034] 1. The beneficial effects of this invention are: interdisciplinary collaboration between clinical departments and 3D technology, combined with digital healthcare, enables the manufacture of personalized scleral contact lenses for keratoconus patients using 3D printing technology. Drawing on cutting-edge domestic research based on SD-OCT, a wide-area AS-OCT system has been developed: imaging width > 18mm, depth > 7mm, covering the entire corneal and scleral region, capturing complete 3D images in just 0.3 seconds, offering high speed and repeatability. After obtaining the images, an image reconstruction error correction algorithm is used to solve the distortion correction problem of OCT images under any circumstances, obtaining individual characteristic images of irregular morphology of the patient's ocular surface. The combination of deep learning networks and artificial intelligence identifies the boundaries of the anterior and posterior surfaces, lens, tear film layer, cornea, and sclera, as well as the asymmetry between the sclera and the limbus. The network outputs intuitive data and graphics, improving accuracy to achieve personalized design, thereby reducing subjective measurement errors by doctors and improving safety and efficacy.

[0035] 2. The beneficial effects of this invention are that it applies the theory of scleral lens fitting for keratoconus and fully utilizes the advantages of OCT3D data. Specifically, it utilizes the principle of low coherence light interference, is non-contact, non-invasive, radiation-free, and provides high-resolution tomographic imaging. The key advantage is that it is based on the boundary segmentation of OCT3D images, which can automatically calculate the limbus morphology and quantified angles, sagittal curves, and the regularity and symmetry of the scleral topography in different meridional directions. Combined with corneal topography, this allows for personalized scleral lenses designed for each quadrant of the ocular surface.

[0036] 3. The beneficial effects of this invention are that it demonstrates the feasibility of using digital reconstruction and 3D printing technology to customize scleral lenses for patients with keratoconus. By combining optical data and optimizing design and manufacturing software, a three-dimensional model of the scleral lens that conforms to the patient's eye shape is created. By combining 3D printing technology to customize scleral lens samples, highly personalized 3D printed scleral lenses can be achieved, thereby shortening the manufacturing process and reducing economic costs. Attached Figure Description

[0037] Figure 1 This is an optical curvature diagram of the ocular condition in patients with keratoconus according to the present invention;

[0038] Figure 2 This is a three-dimensional model diagram of a personalized scleral lens for the scleral morphology of the present invention.

[0039] Figure 3 This is a 3D printing effect diagram of the scleral lens of the present invention;

[0040] Figure 4 This is a pre-polishing effect diagram of the scleral lens indirect manufacturing mold of the present invention;

[0041] Figure 5 This is a polished image of the indirect manufacturing mold for the scleral lens of the present invention.

[0042] Figure 6 The scleral elevation curves for different meridian directions and the integrated reconstructed scleral topographic map are shown in the present invention.

[0043] Figure 7 This is a rendering of the finished product of the present invention. Detailed Implementation

[0044] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0045] Example 1:

[0046] Please see Figure 1-7 A method for 3D printing scleral lenses for keratoconus based on digital medical technology includes the following steps;

[0047] Step S1: Use computer-aided design and manufacturing software to create a three-dimensional model, establish a patient-specific finite element model, and use finite element analysis software to simulate the dynamic pressure on the eyeball during scleral lens wearing measurement, namely eyelid pressure, tear tension under the lens, and measured intraocular pressure. The specific steps of creating a three-dimensional model using computer-aided design and manufacturing software in step S1 are as follows: (1) Establish a three-dimensional finite element model of the whole eyeball and scleral lens by using dynamic ocular surface topography data based on wide-angle anterior segment OCT images. The finite element model of the mechanical contact between the whole eyeball and scleral lens includes two parts: the whole eyeball model and the scleral lens model. Based on the most cutting-edge research in China, a large-scale tomography scanner is developed based on the spectral domain optical coherence tomography imaging system. The imaging width is 16mm and the depth is 5mm, covering the entire corneal and scleral area. A complete 3D image is captured, requiring only 0. 3 seconds, fast, highly repeatable; after image reconstruction error deformation correction algorithm, solve the deformation correction problem of OCT image under any circumstances, and obtain individual characteristic image of irregular shape of patient's ocular surface; (2) by simulating the distribution of tear film thickness and the pressure deformation and stress distribution of ocular surface, after obtaining the image, the combination of deep learning network and artificial intelligence identifies the boundaries of anterior and posterior surfaces, lens, tear film layer, cornea and sclera, the asymmetry of sclera and corneal limbus area, the network outputs intuitive data and graphics, improves accuracy, so as to realize personalized design, thereby reducing the subjective measurement sag error of doctors, and improving safety and efficacy; (3) optimize the above model by reverse analysis method (starting from the problem, step by step deduce the required conditions for solving the problem or obtaining the required conditions and related basic problems).

[0048] Step S2: Combining 3D printing technology to realize the direct or indirect manufacture of scleral lenses using existing materials with micro-nano 3D printing technology: Using surface projection micro-stereolithography technology, the specific steps of combining 3D printing technology to realize the manufacture of scleral lenses with micro-nano 3D printing technology in step S2 are as follows: (1) Set the dynamic ocular surface topography map output by the model as simulated data; (2) Use the reverse analysis method to make the fitting data of each region fit the target data as closely as possible; (3) Combine the optical data provided by the physician to accurately design a 3D model of scleral lenses with optical curvature and scleral morphology that conforms to the patient's condition, and combine OCT data to intelligently predict the regular data of lens sinking.

[0049] Step S3: Design the digital medical data into an indirect mold to fully present the optical curvature conditions to be corrected, and eliminate the traditional processing of curvature conditions with multi-order equations, so that the correction effect is better. The specific steps of designing the digital medical data into an indirect mold in step S3 are as follows: (1) Use a high-precision positional lithography projection system to project the pattern to be printed onto the surface of the resin tank, solidify the resin on the surface of the liquid and quickly form a three-dimensional shape; (2) Process the three-dimensional complex model and sample directly from the digital model to complete the product production; (3) Polish the 3D printed scleral lens product or the scleral lens indirect manufacturing mold by chemical vapor polishing so that the surface roughness reaches below 5nm.

[0050] Step S4: Explore the design of indirect molds based on the complex conditions of digital medical data using 3D printing technology to achieve quadrant-based optimization design. In step S4, explore the design of indirect molds based on the complex conditions of digital medical data using 3D printing technology. Using the current clinical scleral lens fitting technology theory, and based on the dynamic ocular surface topography data of wide-angle anterior segment OCT images, establish a three-dimensional finite element model of the whole eyeball and the sclera.

[0051] Step S5: Achieve personalized scleral lens customization. Combining optical data, accurately design a 3D model of the scleral lens that conforms to the patient's condition in terms of optical curvature and corneal and scleral morphology. Intelligently predict the regular data of lens sinking. Achieve scleral lens customization using 3D printing technology. In step S5, personalized scleral lens customization is achieved. The scleral lens design mainly considers four aspects: (1) Main structure of the scleral lens: including the central tear film area, the limbal area and the scleral landing area. The central tear film area is arched in the center of the cornea, providing a stable and appropriate tear film thickness under the lens for customized clear vision. The limbal area provides independently designed corneal microscopic fluid. The scleral landing area presents an angle that fits the sclera or the contact area of ​​the lens; (2) In terms of lens shape, it includes flat round and flat elongated shapes. The flat round shape is suitable for normal eyes, eyes and refractive surgery, mild corneal ectasia, etc., while the flat elongated shape is suitable for severe corneal ectasia and various types of keratoconus, etc.; (3) There are three design types for full-arc area customization, including spherical, toroidal and multifocal, which fit the shape of the cornea and sclera of the ocular surface better; (4) Quadrant-specific adjustment scheme is: to adjust the horizontal and vertical diameters and the hemispherical or ellipsoidal height in different quadrants so that the lens fits the shape of the anterior surface of the cornea better.

[0052] Step S6: Precautions for Personalized Customized Scleral Lenses. Current scleral lens printing technology is not yet mature and requires continuous research and improvement. Although uncommon, if some abnormalities occur and are not addressed promptly, they can harm eye health. Specifically, the precautions for personalized customized scleral lenses mentioned in Step S6 are as follows: Scleral lenses are external tissues attached to the ocular surface, altering the physiological environment and metabolism of the ocular surface, interfering with its structure, and thus inducing complications. Hypoxia reactions can occur due to lens material and thickness issues, leading to corneal hypoxia, resulting in corneal edema, thinning of the epithelium, decreased sensitivity, neovascularization, and endothelial cell reduction, as well as immune responses and inflammation. This is more common in atopic diseases, ocular surface diseases, and post-operative eyes. Lens adhesion can occur after long-term lens wear, which is uncommon, but if not addressed promptly, it can harm eye health. Therefore, designing and customizing scientifically sound full-curvature scleral lenses is crucial.

[0053] Step S7: Clean and disinfect the customized scleral lenses to ensure a cleaner fit for the patient and promote eye health. After cleaning with all-purpose contact lens solution, soak the lenses in the solution for at least 4 hours before wearing. Before wearing, fill the concave side of the lens with 0.9% saline solution. It is recommended to perform protein removal treatment once a week, with a soaking time not exceeding half an hour. After soaking, rinse with 0.9% saline solution and then soak in the contact lens solution again. Strict care is essential for safe wear.

[0054] Example 2:

[0055] Step S1: Use computer-aided design and manufacturing software to create a three-dimensional model, establish a patient-specific finite element model, and use finite element analysis software to simulate the dynamic pressure on the eyeball during scleral lens wearing measurement, namely eyelid pressure, tear tension under the lens, and measured intraocular pressure. The specific steps of creating a three-dimensional model using computer-aided design and manufacturing software in step S1 are as follows: (1) Establish a three-dimensional finite element model of the whole eyeball and scleral lens by using dynamic ocular surface topography data based on wide-angle anterior segment OCT images. The finite element model of the mechanical contact between the whole eyeball and scleral lens includes two parts: the whole eyeball model and the scleral lens model. Based on the most cutting-edge research in China, a large-scale tomography scanner is developed based on the spectral domain optical coherence tomography imaging system. The imaging width is 19mm and the depth is 8mm, covering the entire corneal and scleral area. A complete 3D image is captured, requiring only 0. 3 seconds, fast, highly repeatable; after image reconstruction error deformation correction algorithm, solve the deformation correction problem of OCT image under any circumstances, and obtain individual characteristic image of irregular shape of patient's ocular surface; (2) by simulating the distribution of tear film thickness and the pressure deformation and stress distribution of ocular surface, after obtaining the image, the combination of deep learning network and artificial intelligence identifies the boundaries of anterior and posterior surfaces, lens, tear film layer, cornea and sclera, the asymmetry of sclera and corneal limbus area, the network outputs intuitive data and graphics, improves accuracy, so as to realize personalized design, thereby reducing the subjective measurement sag error of doctors, and improving safety and efficacy; (3) optimize the above model by reverse analysis method (starting from the problem, step by step deduce the required conditions for solving the problem or obtaining the required conditions and related basic problems).

[0056] Step S2: Combining 3D printing technology to realize the direct or indirect manufacture of scleral lenses using existing materials with micro-nano 3D printing technology: Using surface projection micro-stereolithography technology, the specific steps of combining 3D printing technology to realize the manufacture of scleral lenses with micro-nano 3D printing technology in step S2 are as follows: (1) Set the dynamic ocular surface topography map output by the model as simulated data; (2) Use the reverse analysis method to make the fitting data of each region fit the target data as closely as possible; (3) Combine the optical data provided by the physician to accurately design a 3D model of scleral lenses with optical curvature and scleral morphology that conforms to the patient's condition, and combine OCT data to intelligently predict the regular data of lens sinking.

[0057] Step S3: Design the digital medical data into an indirect mold to fully present the optical curvature conditions to be corrected, and eliminate the traditional processing of curvature conditions with multi-order equations, so that the correction effect is better. The specific steps of designing the digital medical data into an indirect mold in step S3 are as follows: (1) Use a high-precision positional lithography projection system to project the pattern to be printed onto the surface of the resin tank, solidify the resin on the surface of the liquid and quickly form a three-dimensional shape; (2) Process the three-dimensional complex model and sample directly from the digital model to complete the product production; (3) Polish the 3D printed scleral lens product or the scleral lens indirect manufacturing mold by chemical vapor polishing so that the surface roughness reaches below 5nm.

[0058] Step S4: Explore the design of indirect molds based on the complex conditions of digital medical data using 3D printing technology to achieve quadrant-based optimization design. In step S4, explore the design of indirect molds based on the complex conditions of digital medical data using 3D printing technology. Using the current clinical scleral lens fitting technology theory, and based on the dynamic ocular surface topography data of wide-angle anterior segment OCT images, establish a three-dimensional finite element model of the whole eyeball and the sclera.

[0059] Step S5: Achieve personalized scleral lens customization. Combining optical data, accurately design a 3D model of the scleral lens that conforms to the patient's condition in terms of optical curvature and corneal and scleral morphology. Intelligently predict the regular data of lens sinking. Achieve scleral lens customization using 3D printing technology. In step S5, personalized scleral lens customization is achieved. The scleral lens design mainly considers four aspects: (1) Main structure of the scleral lens: including the central tear film area, the limbal area and the scleral landing area. The central tear film area is arched in the center of the cornea, providing a stable and appropriate tear film thickness under the lens for customized clear vision. The limbal area provides independently designed corneal microscopic fluid. The scleral landing area presents an angle that fits the sclera or the contact area of ​​the lens; (2) In terms of lens shape, it includes flat round and flat elongated shapes. The flat round shape is suitable for normal eyes, eyes and refractive surgery, mild corneal ectasia, etc., while the flat elongated shape is suitable for severe corneal ectasia and various types of keratoconus, etc.; (3) There are three design types for full-arc area customization, including spherical, toroidal and multifocal, which fit the shape of the cornea and sclera of the ocular surface better; (4) Quadrant-specific adjustment scheme is: to adjust the horizontal and vertical diameters and the hemispherical or ellipsoidal height in different quadrants so that the lens fits the shape of the anterior surface of the cornea better.

[0060] Step S6: Precautions for Personalized Customized Scleral Lenses. Current scleral lens printing technology is not yet mature and requires continuous research and improvement. Although uncommon, if some abnormalities occur and are not addressed promptly, they can harm eye health. Specifically, the precautions for personalized customized scleral lenses mentioned in Step S6 are as follows: Scleral lenses are external tissues attached to the ocular surface, altering the physiological environment and metabolism of the ocular surface, interfering with its structure, and thus inducing complications. Hypoxia reactions can occur due to lens material and thickness issues, leading to corneal hypoxia, resulting in corneal edema, thinning of the epithelium, decreased sensitivity, neovascularization, and endothelial cell reduction, as well as immune responses and inflammation. This is more common in atopic diseases, ocular surface diseases, and post-operative eyes. Lens adhesion can occur after long-term lens wear, which is uncommon, but if not addressed promptly, it can harm eye health. Therefore, designing and customizing scientifically sound full-curvature scleral lenses is crucial.

[0061] Step S7: Clean and disinfect the customized scleral lenses to ensure a cleaner fit for the patient and promote eye health. After cleaning with all-purpose contact lens solution, soak the lenses in the solution for at least 4 hours before wearing. Before wearing, fill the concave side of the lens with 0.9% saline solution. It is recommended to perform protein removal treatment once a week, with a soaking time not exceeding half an hour. After soaking, rinse with 0.9% saline solution and then soak in the contact lens solution again. Strict care is essential for safe wear.

[0062] Using imaging width and imaging depth as indicators, n sets of experiments were designed (Table 1), and compared with the actual scanning results to determine the optimal combination as the scanning position.

[0063] Table 1 Experimental Design

[0064]

[0065] Based on the above four sets of experimental data and compared with Comparative Example 1, it can be concluded that the optimal combination is achieved when the imaging width is 20mm and the imaging depth is 9mm. Thus, the optimal scanning position is determined when the imaging width is 20mm and the imaging depth is 9mm.

[0066] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A method for 3D printing scleral lenses for keratoconus based on digital medical technology, characterized in that, Includes the following steps: Step S1: Use computer-aided design and manufacturing software to create a three-dimensional model, establish a personalized finite element model for the patient, and use finite element analysis software to simulate the dynamic pressure on the eyeball during scleral lens wearing and measurement, namely eyelid pressure, tear tension under the lens, and measured intraocular pressure. Step S2: Combining 3D printing technology, we can directly or indirectly manufacture scleral lenses using existing materials with micro-nano 3D printing technology: using surface projection micro-stereolithography technology. Step S3: Design the digital medical data into an indirect mold to fully present the optical curvature conditions to be corrected; Step S4: Explore how to design indirect molds based on the complex conditions of digital medical data using 3D printing technology to achieve quadrant-based optimization design; Step S5: Achieve personalized scleral lens customization. Combining optical data, accurately design a 3D model of the scleral lens that conforms to the patient's condition in terms of optical curvature and corneal and scleral morphology. Intelligently predict the pattern data of lens sinking and realize the customization of scleral lenses using 3D printing technology. Step S6: Personalized scleral lenses require timely handling of abnormal situations and continuous research and observation for improvement. Although uncommon, failure to address any abnormal situations promptly can harm eye health. Step S7: Clean and care for the customized scleral lenses to ensure they are clean for the patient. After cleaning with the all-purpose cleaning solution, soak them for at least 4 hours before wearing. Before wearing, fill the concave surface of the lens with saline solution. Perform protein removal care once a week, soaking for no more than half an hour. After soaking, rinse with 0.9% saline solution and then soak in the cleaning solution for at least 4 hours. In step S1, the specific steps for creating a 3D model using computer-aided design and manufacturing software are as follows: (1) A three-dimensional finite element model of the whole eyeball and sclera was established based on dynamic ocular surface topography data of wide-angle anterior segment OCT images. The three-dimensional finite element model of the whole eyeball and sclera consists of two parts: the whole eyeball model and the sclera model. Based on the spectral domain optical coherence tomography imaging system, a large-area tomography scanner was developed with an imaging width > 18 mm and a depth > 7 mm, covering the entire corneal and scleral regions, capturing complete 3D images in 0.3 seconds. After image reconstruction error deformation correction algorithm, the deformation correction problem of OCT images under any circumstances was solved, and individual characteristic images of irregular ocular surface morphology of patients were obtained. (2) By simulating the distribution of tear film thickness and the deformation and stress distribution of ocular surface under pressure, after obtaining the image, the combination of deep learning network and artificial intelligence identifies the boundaries of the anterior and posterior surfaces, lens, tear film layer, cornea and sclera, determines the asymmetry between the sclera and the corneal limbus, and outputs intuitive data and graphics to improve accuracy, realize personalized design, and reduce the subjective measurement error of doctors. (3) The three-dimensional finite element model is optimized by using the reverse analysis method, that is, starting with the problem and working backward step by step to deduce the necessary conditions for solving the problem or obtaining the necessary conditions and related basic problems.

2. The method for using a scleral lens for keratoconus based on digital medical 3D printing according to claim 1, characterized in that: In step S2, the specific steps for implementing micro-nano 3D printing technology, combined with 3D printing technology, are as follows: (1) Set the dynamic eye surface topography map output by the model as simulated data; (2) The reverse analysis method is used to make the fitted data of each region fit the target data as closely as possible; (3) Combine the optical data provided by the physician to accurately design a three-dimensional model of the sclera with the optical curvature and scleral morphology that conforms to the patient's corneal condition, and combine OCT data to intelligently predict the pattern of lens sinking.

3. The method for using a scleral lens for keratoconus based on digital medical 3D printing as described in claim 1, characterized in that... The characteristic is that, in step S3, the specific steps for designing the digital medical data as indirect are as follows: (1) Using a high-precision photolithography projection system, the pattern to be printed is projected onto the surface of the resin tank, and the resin is cured on the surface of the liquid and quickly formed in three dimensions. (2) Directly process complex 3D models and prototypes from digital models to complete product manufacturing; (3) Polish the 3D printed scleral lens products directly manufactured or the scleral lens indirect manufacturing molds by chemical vapor polishing to make the surface roughness reach below 5nm.

4. The method for using a scleral lens for keratoconus based on digital medical 3D printing according to claim 1, characterized in that: In step S4, we explore using 3D printing technology to design an indirect mold based on the complex conditions of digital medical data. Using current clinical scleral lens fitting technology theory, we establish a three-dimensional finite element model of the whole eyeball and scleral lens based on dynamic ocular surface topography data from wide-angle anterior segment OCT images.

5. The method for digital medical 3D printing of scleral lenses for keratoconus according to claim 1, characterized in that: In step S5, personalized scleral lens customization is achieved. The design of the scleral lens mainly considers four aspects: (1) Main structure of scleral lens: including central tear film area, limbal area and scleral landing area. The central tear film area is arched in the center of the cornea, providing a stable and appropriate thickness of the lens-like tear film and customized clear vision. The limbal area provides an independently designed lens-like corneal fluid. The scleral landing area presents an angle that fits the sclera or the contact area of ​​the lens. (2) Regarding the shape of the lens, it includes oval and elongated shapes. The oval shape is suitable for normal eyes, eyes, and after refractive surgery, and for mild corneal ectasia. The elongated shape is suitable for severe corneal ectasia and various keratoconus conditions. (3) There are three design types for personalized customization of the full arc area, including spherical, toroidal and multifocal, which better fit the shape of the cornea and sclera of the eye surface; (4) Quadrant-specific adjustment scheme: It is proposed to adjust the horizontal and vertical diameters and the height of the hemispherical or ellipsoidal body in different quadrants so that the lens fits the shape of the anterior surface of the cornea better.

6. The method for digital medical 3D printing of scleral lenses for keratoconus according to claim 1, characterized in that: In step S6, abnormal situations include: scleral lenses can induce some complications, such as hypoxia reaction, that is, problems with lens material and lens thickness can cause corneal hypoxia, leading to corneal edema, thinning of epithelium, decreased sensitivity, neovascularization and reduction of endothelial cells, immune response and inflammation, and lens adhesion after long-term lens wear.

7. The method for digital medical 3D printing of scleral lenses for keratoconus according to claim 1, characterized in that: In step S7, the customized scleral lenses should be cleaned and soaked in a full-function cleaning solution for at least 4 hours before wearing. Before wearing, the concave surface of the lens should be filled with saline solution. Protein removal should be performed once a week, with the soaking time not exceeding half an hour. After soaking, rinse with 0.9% saline solution and then soak in the cleaning solution again. Strict care is required to ensure safe wearing.

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