Continuous Circular Capsulorhexis Research Articles

Preparing porcine lens to mimic human lens capsule.

To develop a chemical method that makes porcine lens anterior capsule resemble human lens anterior capsule in tear force and perforating force. Beijing Tongren Hospital, Beijing, China. Experimental study. Porcine eyes were divided into groups, and reagents (0.9% physiological saline, 0.1% sodium hypochlorite, 0.3% sodium hypochlorite, and 0.5% sodium hypochlorite) were injected into the anterior chamber, respectively, recorded as Groups A, B, C, and D, respectively. A senior physician collected each group of anterior capsules after performing continuous circular capsulorhexis and assessing the anterior capsule's tearing and perforation forces. An additional group, which consisted of human lens anterior capsules taken in the operating room from patients with cataract, recorded as Group E. A tensile system was used to measure each sample's tensile force. A significant difference was found between Group A and any other group in maximum tensile force and average tensile force in both transverse and longitudinal directions. No significant difference was found between any 2 groups from Group B to Group E. According to the surgeon's assessment, the tear force characteristic of the porcine lens anterior capsule treated with 0.1%, 0.3%, and 0.5% sodium hypochlorite solution was similar to that of the human lens anterior capsule. Porcine lens capsule treated using this method can be used for training of new surgeons. The porcine lens anterior capsule treated with 0.5% sodium hypochlorite, which results showed most resembled human lens anterior capsule, can be used for robotic training.

A Tremor Suppression and Noise Removal Algorithm for Microscopic Robot-Assisted Cataract Surgery

Ophthalmic surgery consists of a series of precise manipulations performed using a surgical microscope. A surgical robot with a master–slave paradigm is commonly adopted to improve the precision and guidance intelligence for ophthalmic surgery; however, the surgeon's hand tremor, misoperation, inherent characteristics of the robot, and environmental interference may cause tremors of the end-effector of the surgical manipulator, thus increasing the risk of soft tissue damage and poor prognosis for the patient. A symmetrical threshold noise reduction combiner (STIC) is proposed to suppress hand tremors and reduce environmental noise interference. Additionally, the inverse kinematic model of the eight-degrees-of-freedom surgical robot for cataract surgery is developed, with the constraints of continuous circular capsulorhexis manipulation. Simulation results show that the signal-to-noise ratio of the STIC is increased from 35.3907 to 57.0158 dB, whereas the maximum, average, standard deviation, and root mean square of the output of the STIC are decreased by 64.79%, 77.24%, 74.50%, and 75.86%, respectively. Three sets of in vitro experimental results show that these four indicators of the STIC performance are reduced by 59.73%, 76.57%, 57.23%, and 65.02%, respectively. These results validate the feasibility and effectiveness of the proposed method on hand tremor suppression and inherent high-frequency disturbance elimination, thereby enhancing the accuracy of the microsurgical operation.

BiMNet: A Multimodal Data Fusion Network for continuous circular capsulorhexis Action Segmentation

Completing continuous circular capsulorhexis (CCC) requires the operator to perform fine operations, which is difficult to do accurately when continuous fine actions are out of balance in the classification of CCC procedures. Multimodal deep learning can improve the classifier’s performance, but the recognition accuracy of inferior classes is difficult to improve. To solve these problems, a bidirect-gate recurrent unit (Bi-GRU)-attention-based multimodal, multi-timescale data fusion network (BiMNet) is proposed, which contains a data extraction module called a skip-concatenate gate recurrent unit (SC-GRU), a bimodal data fusion attention computation, and a decoder module. The combination of these modules can fully extract the features of different temporal scales in multimodal action data and fuse them effectively. The model is validated using the ophthalmologist CCC multimodal maneuver dataset, which was collected by the data collection platform constructed in this research, achieving an accuracy of 0.9124 ± 0.0125 in continuous action sequence segmentation and improving the F1-score of minority class recognition to over 80%, making it more effective than baseline algorithms.

Rotating the Intraocular Lens to Prevent Posterior Capsular Opacification in Cataract Surgeries.

Posterior capsule opacification (PCO) is a common postoperative complication of extracapsular cataract surgery, which is caused by the proliferation and migration of lens epithelial cells and can affect long-term visual outcomes significantly. The most effective treatment for PCO is neodymium-doped yttrium aluminum garnet (Nd:YAG) laser capsulotomy; however, this treatment is associated with posterior segment complication and can break the stability of capsular bag, affecting the position and function of trifocal or toric intraocular lenses (IOLs). Advances in surgical procedures, IOL design, and pharmacy have reduced the rate of PCO in recent years, concentrating on the inhibition of proliferative lens epithelial cells (LECs). This protocol aimed to clear LECs more thoroughly during phacoemulsification and IOL implantation. The first several steps, including clear corneal incision, continuous circular capsulorhexis, hydrodissection, hydrodelineation, and phacoemulsification, were completed as conventional procedures. After placing the IOL into the capsular bag, rotation of the IOL by at least 360° was performed using an irrigation/aspiration tip or a hook, with slight stress on the posterior capsule. Some residuals occurred in the originally transparent capsular bag after rotation of the IOLs. Then, these materials and the viscoelastic were cleared completely using an irrigation/aspiration system. A clear posterior capsule was observed after the surgery in patients undergoing this method. This method of rotating IOLs is a simple, effective, and safe way to prevent PCO by clearing residual LECs and can be carried out without extra tools or skills.

Primary Posterior Continuous Circular Capsulorhexis without the Use of Ophthalmic Viscosurgical Device.

Performing primary posterior capsulorhexis (PPCCC) during cataract surgery is an effective prevention of secondary cataracts. It is important not to damage the anterior vitreous membrane to minimize the possible complications and adverse side effects of this step of the surgery. Most authors use a viscoelastic material to protect the anterior vitreous membrane, injected into the space between the posterior lens capsule and the vitreous membrane through a small hole in the posterior capsule. The creation of posterior capsulorhexis using 25G forceps under an implanted intraocular lens while continuously filling the anterior chamber with irrigation fluid from an irrigation cannula, without the use of a viscoelastic material is, in our opinion, a safe, fast and cheap technique of PPCCC. This technique could theoretically lead to a lower incidence of postoperative complications such as higher postoperative intraocular pressure or anterior segment inflammatory response.

Comparison study for the proportion of underdiagnosed zonulopathy in angle closure glaucoma

Objective: To analyze the proportion and clinical characteristics of underdiagnosed zonulopathy in angle closure glaucoma (ACG) patients and to explore the related risk factors. Methods: Case-control study. Continuous cases of ACG patients who underwent phacoemulsification combined with intraocular lens implantation and goniosynechialysis surgery [ACG group, including acute angle closure glaucoma (AACG) and chronic angle closure glaucoma (CACG)] from November 1, 2020 to October 31, 2021 and age-related cataract patients who underwent phacoemulsification combined with intraocular lens implantation surgery in the same period (control group) were included. The diagnosis of zonulopathy was determined according to the intraoperative signs such as wrinkles of the anterior capsule during continuous circular capsulorhexis. The proportion of zonulopathy, preoperative diagnosis rate of zonulopathy, demographic characteristics, anterior chamber depth (ACD), axis length, difference of ACD in both eyes (ACD of the contralateral eye minus ACD of the operated eye) were compared between the two groups. The related risk factors were explored. The paired t-test (comparison between two groups of normally distributed data), non-parametric test (comparison between two groups of non-normally distributed data), Chi-square test (categorical variables), univariate and multivariate logistic regression analysis were used. Results: There were 104 ACG patients (104 eyes), including 63 AACG patients (63 eyes) and 41 CACG patients (41 eyes), and 117 controls (117 eyes). There was no significant difference in age (P=0.29) and gender (P=0.07) between the two groups. The ACG group had shallower anterior chamber (P<0.001), shorter axial length (P<0.001) and more ACD difference in both eyes (P<0.001). In the ACG group, the proportion of zonulopathy was 46.2% (48/104), which was significantly higher than that (6.0%, 7/117) in the control group (P<0.001). In the control group, only zonular laxity was found, while in the ACG group, besides the predominant zonular laxity (68.8%, 33/48), there was zonular dehiscence (31.3%, 15/48). The eyes with AACG (57.1%, 36/63) had a higher proportion of zonulopathy than those with CACG (29.3%, 12/41) (P=0.006). In the ACG group, only 14 cases (29.8%) were diagnosed preoperatively according to slit lamp examination and/or ultrasound biomicroscopy. The proportion of underdiagnosed zonulopathy was 70.8% in the ACG group (34/48). A smaller ACD was found to be related to the zonulopathy in the ACG group. All AACG cases with an ACD ≤2.0 mm and CACG cases with an ACD ≤1.9 mm had zonulopathy. Multivariate logistic regression showed that the ACD difference in both eyes (P=0.025) and the diagnosis of ACG (AACG vs. cataract, P<0.001; CACG vs. cataract, P=0.023) were independent risk factors associated with zonulopathy. Conclusions: The proportion of underdiagnosed zonulopathy among ACG patients is high. Better preoperative diagnostic methods for zonulopathy are needed. Zonulopathy is common in ACG patients, especially in AACG patients, suggesting that zonulopathy may be related to the pathogenesis of ACG. The shallower the ACD, the riskier the zonulopathy. ACD differences between two eyes and ACG types (including AACG and CACG) were related risk factors of zonulopathy.(This article was published ahead of print on the Online-First Publishing Platform for Excellent Scientific Researches of Chinese Medical Association Publishing House on March 11, 2022).

Tunnel-floor entry continuous curvilinear capsulorhexis technique: Rhexis in a controlled and stable anterior chamber always.

Continuous circular capsulorhexis (CCC) was demonstrated independently by Thomas Neuhann, Kimiya Shimizu, and Howard Gimbel in the 1980s and it finds mention in the landmark paper by Gimbel and Neuhann. The authors describe a technique of achieving the rhexis in a stable, viscoelastic-filled anterior chamber using the tunnel floor as the entry. This gets covered by the roof of the tunnel postoperatively and, therefore, does not leak. There is no oar-locking or striae even when cystitome goes beyond the edge of the tunnel. As there is no escape of the viscoelastic substance, there is no change in the pressure or shallowing of the anterior chamber. It is a useful technique for beginners. It is of great help in difficult cases like intumescent cataracts, shallow anterior chambers, hyperopes, nanophthalmos, pseudoexfoliation, small non-dilating pupils, intraoperative floppy iris syndrome (IFIS), and phacomorphic glaucoma.

Особенности строения хрусталика при набухающей катаракте

Purpose. To study the structure of the swelling lens, the dependence of its anatomical parameters on the nucleus sizes and density, patients' age. Material and methods. 64 patients with intumescent mature cataract were examined. All patients underwent phacoemulsification with a two-stage continuous circular capsulorhexis. After the 2–2.5 mm capsulorhexis had been created, the liquid lenticular masses were removed from the anterior and posterior lens compartment with the aspiration/irrigation system. Visually we determined the size of the nucleus, its color and density according to Buratto's classification. Results. When performing this work four types of the swelling lens structure were detected. Type I – a small emerging white nucleus with large amount of liquid lenticular masses in the anterior and posterior lens compartment, II degree of density according to Buratto's classification. The mean age was 49.12 ± 3.11 years old. The related ophthalmic diseases accounted for 36.4 %. Type II – a large white nucleus with the presence of liquefied lenticular masses in the anterior and posterior lens compartment. III degree of density according to Buratto's classification. The mean age was 71.15 ± 5.07 years old. Associated diseases – 65 %. Type III – a large brown nucleus with the presence of liquefied lenticular masses in the anterior and posterior lens compartment. IV degree of density according to Buratto's classification. The mean age was 75.87 ± 1.48 years old. Associated diseases – 79 %. Type IV – a small, very dense, brown nucleus with liquid lenticular masses. V degree of density according to Buratto's classification. The mean age was 77.34 0 ±2.47 years old. Associated diseases – 100 %. Conclusion. Four types of lens structure in intumescent cataract were described depending on the nucleus size, density, the amount of the lenticular masses. By means of UBM it was shown that intumescent cataract was accompanied by the alterations of the ocular anterior segment parameters, which depended on the type of lens structure. It was revealed that the types of swelling lens structure were directly connected to the patients' age: mean age of patients with type I – 49.12 ± 3.11 years old, with type II – 71.15 ± 5.07, with type III – 75.87 ± 1.48, with type IV – 77.34 ± 2.47 years old. Keywords: ophthalmology, intumescent cataract, types of lens structure.

Limbus-centered marking technique-assisted continuous circular capsulorhexis.

To introduce a limbus-centered continuous circular capsulorhexis (CCC) marking technique.Compared with traditional capsulotomy diameter mark technique, a self-designed limbus-centered capsulotomy mark (LCM) was used to perform the routine cataract surgery in this observational study. Ten eyes were included in each group. The area outer/inner 5.5-mm CCC ring, the furthest/nearest distance from the capsule margin to the intraocular lens (IOL) margin, the CCC total coverage IOL area were measured and compared between this 2 groups.No significant differences were found for all the comparison parameters between the 2 groups (all P > .05). However, the capsule total coverage area, area inner 5.5-mm ring was lower in the LCM group, which demonstrated advantage of LCM.The limbus-centered capsulotomy diameter mark, as an inexpensive and convenient method, helps to perform limbus-centered capsulorhexis with not only a 360° overlapping capsular edge but also well-centered IOL optics.

Assessment of age-related changes in lens capsule biomechanics using atomic force microscopy

To assess age-related changes in lens capsule biomechanics based on atomic force microscopy (AFM). The study included 50 central fragments of the anterior capsule of the human lens obtained intraoperatively during ultrasonic phacoemulsification by continuous circular capsulorhexis. The measurements were carried out in the Fast Force Volume (FFV) mode. The force curves were processed in the Nanoscope Analysis software (Bruker, USA) using the Hertz model that allows calculating the Young's modulus of the capsule sample based on the dependence of the force on the puncture depth. There was no statistically significant difference in the «stiffness» of the inner and outer surfaces before and after removal of the subcapsular epithelium (p=0.25). In all cases, the inner surface of the capsule turned out to be «harder» than the outer one. In this case, the ratio of Young's modulus of the inner and outer surfaces has a significant dependence on age (p<0.001). With an increase in age from 50 to 90 years, this ratio decreased from ~7 to ~1.5. This was due to a simultaneous change in Young's modulus of the opposite nature: an increase in the stiffness of the outer surface and its decrease in the inner one. It is possible to assess lens capsule biomechanics using AFM if the subcapsular epithelium is present. In this case, the objects of study are the areas of the capsule free of epithelium, and the epithelial cells themselves can be used to identify the inner surface of the capsule. Regardless of age, the stiffness of the inner surface of the anterior lens capsule significantly exceeds that of the outer surface.

“White-puncture”: A simple technique to prevent tearing of the anterior capsule during capsulorhexis in intumescent white cataracts

In order to avoid radial tearing of the anterior capsule while performing continuous circular capsulorhexis (CCC) in a white intumescent cataract, called the “Argentinian flag sign” when CCC is associated with a previous capsular stain with trypan blue , an initial puncture of the anterior capsule is performed with a 30G needle as the first step of the surgical procedure, that means, prior to any previous aperture of the anterior chamber . This act seems to allow the pressure of the intracrystalline space and the pressure of the anterior chamber to be equalized, as the liquefied content of the intumescent white cataract is released into a presumably hermetic anterior chamber, avoiding the dreaded anterior capsular radial tear. This technique, called “white-puncture”, has been used in 174 cases without any associated complications. Para evitar el desgarro radial de la cápsula anterior al realizar la capsulorrexis circular continua (CCC) que puede ocurrir durante la cirugía en las cataratas blancas intumescentes, el conocido como signo de la bandera argentina cuando se asocia la CCC a una tinción capsular previa con azul de tripano, se hace una punción inicial de la cápsula anterior con una aguja 30 G, como primer paso del procedimiento quirúrgico, es decir, previo a cualquier apertura de la cámara anterior. Este acto parece permitir que la presión del compartimento intracristaliniano y la presión de la cámara anterior se igualen, al liberarse el contenido licuado de la catarata blanca intumescente en una cámara anterior presumiblemente hermética, evitando el temido desgarro radial capsular anterior. Esta técnica, denominada blancopunción, ha sido utilizada en 174 casos sin ninguna complicación asociada.

Blancopunción: una técnica simple para prevenir el desgarro de la cápsula anterior durante la capsulorrexis en cataratas blancas intumescentes

In order to avoid radial tearing of the anterior capsule while performing continuous circular capsulorhexis (CCC) in a white intumescent cataract, called the “Argentinian flag sign” when CCC is associated with a previous capsular stain with trypan blue, an initial puncture of the anterior capsule is performed with a 30G needle as the first step of the surgical procedure, that means, prior to any previous aperture of the anterior chamber. This act seems to allow the pressure of the intracrystalline space and the pressure of the anterior chamber to be equalized, as the liquefied content of the intumescent white cataract is released into a presumably hermetic anterior chamber, avoiding the dreaded anterior capsular radial tear. This technique, called “white-puncture”, has been used in 174 cases without any associated complications.

Notice of Retraction: DIEN Network: Detailed Information Extracting Network for Detecting Continuous Circular Capsulorhexis Boundaries of Cataracts

Notice of Retraction: DIEN Network: Detailed Information Extracting Network for Detecting Continuous Circular Capsulorhexis Boundaries of Cataracts

Clinical observation on retroillumination assisted continuous circular capsulorhexis

Objective To observe the application of illuminator guided retroillumination assisted continuous circular capsulorhexis. Methods A prospective study. Thirty eyes of 30 cases with cataract with vitreous hemorrhage, with poor fundus red reflex, from Sep. 2016 to Aug. 2017 in this hospital, were enrolled. After the ophthalmic endoilluminator was inserted into the vitreous, the endoilluminator was irradiated forward from the posterior lens capsule, then continuous circular capsulorhexis was performed. Phacoemulsification and vitrectomy were carried out routinely. The followed-up time was 8-12 months. Results The continuous circular capsulorhexis and phacoemulsification were performed successfully in all 30 eyes without any posterior capsule rupture. Vitreous hemaorrhage was completely removed, and retinal diseases was properly treated. The visual acuity before operation was HM-0.04 in 27 eyes(90.00%) and 0.05 in 3 eyes(10.00%). Postoperative visual acuity of all patients were 0.05 or better. The difference of visual acuity was statistically significant between before and after operation (χ2=49.091, P=0.000). Conclusion The illuminator guided retroillumination assisted continuous circular capsulorhexis can effectively solve the difficulty of poor red light reflex for cataract patients with vitreous hemorrhage. Key words: Capsulorhexis, circular, continuous, retroillumination; Phacoemulsification, lens; Vitrectomy

Failure iridocapsular fixation of IOL in patients with lens subluxation (preliminary report)

Purpose. To present the preliminary results of iridocapsular fixation of RSP-3 extracapsular IOL in patients with lens subluxation observed within the first year after surgery.Material and methods. 4 patients with cataracts and initial weakness of Zinn ligament fibers were followed up. YAG laser iridectomy was performed one day before facoemulsifcation surgery, which took account of Zinn ligament fiber weakness: it consisted in anterior continuous circular capsulorhexis with a diameter of about 5 mm, fixation of the capsular bag over the edge of capsulorhexis with four iris-capsular retractors (ICRs), phacoemulsification of the nucleus and aspiration of lens masses. The intracapsular ring and the RSP-3 IOL (the latter in the injector through the main incision) was implanted in such a way as to locate the rear support element in the capsular bag, and the front support element, in front of the pupil. After removing the ICRs, iridectomy was monitored.Results. The early postoperative period was uncomplicated. After 10 days, one patient was found to develop a relative pupillary block with the anterior chamber becoming shallower and IOP increased to reach 28 mm Hg. The reason was that iridectomy initially located in the projection area of the rear support element. An additional iridectomy arrested the situation. Visual acuity varied from 0.3 to 1.0 due to the initial state of the optic nerve and retina. The position of the IOL remained stable throughout the year, the capsular bag was unfolded.Conclusion. The possibility to use the capsular bag of the lens under the conditions that Zinn ligament fibers are weak should be considered as an advantage of the technology presented. An additional front support element serves to prevent dislocation of the IOL and the capsular bag as a whole. The obtained positive results of combined iridocapsular fixation of the IOL justify a more extensive clinical testing of the method in cases of weak Zinn ligament fibers.

Torsional and burst mode phacoemulsification for patients with hard nuclear cataract: A randomized control study.

This article aims to evaluate the outcomes of torsional and burst mode phacoemulsification in hard nuclear cataracts.Eighty eyes with grade IV or V nuclear opalescence were treated with phacoemulsification and intraocular lens implantation using conventional mode (Group A, n = 40) or torsional and burst mode phacoemulsification (Group B, n = 40). For good visualization of anterior capsule, trypan blue was injected to the anterior chamber before continuous circular capsulorhexis. The mean cumulative dissipated energy and ultrasound time were recorded. The best-corrected visual acuity, endothelial cell density, and central corneal thickness were measured before and at 1 month after surgery.The cumulative dissipated energy and ultrasound time of Group B were significantly less than that of Group A. The postoperative best-corrected visual acuities of the 2 groups were comparable. At 1 month after surgery, the changes in the endothelial cell density were significantly greater in Group A than in Group B, and the changes in the central corneal thickness were not significantly different between the 2 groups.Torsional and burst mode is a safe and effective surgical method for treating hard cataracts.

Application of self-made iris retractors in surgeries of cataract with small pupil

Objective To evaluate the efficacy of application of self-made iris retractors in surgeries of cataract with small pupil. Methods The data of 35 eyes of 32 cases of cataract with miosis due to glaucoma surgery, uveitis and etc from Jan. 2018 to Aug. 2018 were analyzed retrospectively. All cases underwent phacoemulsification and intraocular lens implantation with self-made iris retractors. The patients were followed up for 3-6 months. Results All the 35 eyes achieved square pupils of 5.0-6.0 mm in side length during operation, and the continuous circular capsulorhexis and phacoemulsification were successfully completed. Only 1 eye had minor iris hemorrhage during operation, but it did not affect the surgery. The pupil was nearly circular with diameter of 3.0-4.0 mm after surgery. The pupillary light reaction was normal or sluggish. Visual acuity was significantly improved after surgery. No complication such as posterior capsule rupture, pupil tear, anterior chamber hemorrhage or elevated intraocular pressure occurred. Conclusion Application of self-made iris retractors for the treatment of cataract with small pupil can enlarge the pupil and obtain favorable results. The self-made iris retractors are easy to make and simple and safe to use. Key words: Iris; Miosis; Phacoemulsification

Types of Lens Structure in Intumescent Cataract

Purpose: to study the structure of the swelling lens, the dependence of its anatomical parameters on the nucleus sizes and density, patients’ age.Patients and methods. 52 patients with intumescent mature cataract were examined. All patients underwent phacoemulsification with a two-stage continuous circular capsulorhexis. After the 2–2.5 mm capsulorhexis had been created, the liquid lenticular masses were removed from the anterior and posterior lens compartment with the aspiration/irrigation system. Visually we determined the size of the nucleus, its color and density according to Buratto’s classification.Results. When performing this work 4 types of the swelling lens structure were revealed. Type I — a small emerging white nucleus with large amount of liquid lenticular masses in the anterior and posterior lens compartment, II degree of density according to Buratto’s classification. The mean age was 49.09 ± 3.19 years old. The related ophthalmic diseases accounted for 36.4%. Type II — a large white nucleus with the presence of liquefied lenticular masses in the anterior and posterior lens compartment. III degree of density according to Buratto’s classification. The mean age was 71.00 ± 1.92 years old. Associated diseases — 84.6%. Type III — a large brown nucleus with the presence of liquefied lenticular masses in the anterior and posterior lens compartment. IV degree of density according to Buratto’s classification. The mean age was 75.84 ± 1.46 years old. Associated diseases — 100%. Type IV — a small, very dense, brown nucleus with liquid lenticular masses. V degree of density according to Buratto’s classification. The mean age was 77.33 ± 2.49 years old. Associated diseases — 100%.Conclusion. 4 types of lens structure in intumescent cataract were described depending on the nucleus size, density, the amount of the lenticular masses. By means of UBM method, it was shown that intumescent cataract is accompanied with the alterations of the ocular anterior segment parameters, which depend on the type of lens structure. It was revealed that the types of swelling lens structure are directly connected to the patients’ age: mean age of patients with type I — 49.09 ± 3.19 years old, with type II — 71.00 ± 1.92, with type III — 75.84 ± 1.46, with type IV — 77.33 ± 2.49 years old.

Virtual-reality Cataract Surgery Simulator Using Haptic Sensory Substitution in Continuous Circular Capsulorhexis.

Cataract is one of the most common geriatric diseases, and surgery is known to be the best treatment. Despite the increasing demand for cataract surgery, the opportunity for novice residents to practice cataract surgery is gradually diminishing as the patient and animal ethics become strict. Therefore, there have been many attempts to overcome the lack of experience by using virtual reality training system. So far, most of the surgical training simulation devices so far focused on visual training, and when they have a haptic sense, they are tethered to a fixed station, which is different from the feeling of moving the actual surgical tool. In this study, we have developed a haptic surgical training tool with sensory substitution and virtual-reality-based cataract surgery simulator. To assess and reproduce the tactile senses during surgery, we prepared viscoelastic lens dummies and measured vibrations in contact and motion required during Continuous Circular Capsulorhexis (CCC). Based on measurement we designed vibration models for haptic sensory substitution and applied them to virtual reality simulator. With complete virtual reality training system, the contact vibration was successfully implemented for virtual contacts to reproduced realistic haptic senses.

Intumescent cataract surgery

Intumescent cataract surgery is one of the topical problems of ophthalmology. The article reviews methods of intumescent cataract diagnostics and structural features of swelling lens. Manual or femtolaser-assisted anterior continuous circular capsulorhexis and intumescent cataract phacoemulsification techniques require further research.