Computer-simulated phacoemulsification

doi:10.1016/j.ophtha.2003.06.023

Ophthalmology

Volume 111, Issue 4, April 2004, Pages 693-698

Presented, in part, at: American Society of Cataract and Refractive Surgery meeting, May, 2000, Boston; International Biomedical Optics Symposium, January, 2001, San Jose, California; XXth Congress of the European Society of Cataract and Refractive Surgeons, September, 2002, Nice, France.

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Abstract

Objective

To develop a simulator for training in phacoemulsification to be used as a learning device for both beginners and experienced surgeons to shorten the learning curve.

Design

Experimental study.

Methods

The system consists of a personal computer, a 3-dimensional visual interface, a phacoemulsification handpiece, and a nucleus manipulator and foot pedals for control of the phacoemulsification procedure and microscope adjustments. The simulation is based on generalized simulation software that can be also used for the development of other medical simulations.

Main outcome measures

Qualitative statements given in a questionnaire. Medical students and ophthalmic surgeons with varying experience of phacoemulsification were tested.

Results

A simulator for training in phacoemulsification has been developed. The surgical procedures can be practiced any number of times, and there is no risk to patients. The efforts of the surgeon can be evaluated objectively.

Conclusions

Studies have shown that the number of complications for an ophthalmic surgeon learning phacoemulsification decreases exponentially, reaching close to the asymptote only after several hundred procedures. Simulator training might shorten the learning period, reduce expensive supervision by an experienced surgeon, and maintain and improve the skills of experienced surgeons.

Section snippets

Materials and methods

The complexity of phacoemulsification surgery is indicated in Figure 1. The surgeon gets 3-dimensional visual input from the microscope and must provide feedback reactions with the right hand on the phacoemulsification handpiece (3 space dimensions + rotation), with the left hand on the nucleus manipulator (3 space dimensions + rotation), with the right foot on the pedal controlling irrigation, aspiration, and phacoemulsification (movement in 1 dimension with the function related to the

Results

A simulator for training in phacoemulsification has been developed. In the simulator, the most important steps in learning the phacoemulsification procedure might be reproduced. Sculpting and dividing of the lens nucleus can be performed in a realistic manner, followed by aspiration of the nuclear fragments. The movements of the pieces of nucleus are similar to real surgery because of simulated flow and aspiration, attracting the lens pieces to the phacoemulsification tip. The hardness of the

Discussion

The first surgical simulators appeared in the early 1990s.11 Today, the fast development of information technology and computer graphics presents opportunities to create new tools for surgical training. Virtual reality simulators are known to provide a safe training environment for high-risk work environments. The simulators are available at all times and provide a structured curriculum that can be standardized, repeated, and optimized toward the learner's needs. Skills may be assessed

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Cited by (53)

Update on simulation-based surgical training and assessment in ophthalmology: A systematic review
2015, Ophthalmology
Citation Excerpt :
Evidently, this category of trials had a summative evidence-level of 5 based on the OCEBM, with only 4 trials meeting the level 4 criteria (case series). These 4 trials reached level 1 in the Kirkpatrick model as they investigated the reaction of the trainees.76,81,84,85 Most trials investigated only 1 source of validity evidence (n = 48), and no trials investigated more than 2 sources of validity evidence.
This study reviews the evidence behind simulation-based surgical training of ophthalmologists to determine (1) the validity of the reported models and (2) the ability to transfer skills to the operating room.
Simulation-based training is established widely within ophthalmology, although it often lacks a scientific basis for implementation.
We conducted a systematic review of trials involving simulation-based training or assessment of ophthalmic surgical skills among health professionals. The search included 5 databases (PubMed, EMBASE, PsycINFO, Cochrane Library, and Web of Science) and was completed on March 1, 2014. Overall, the included trials were divided into animal, cadaver, inanimate, and virtual-reality models. Risk of bias was assessed using the Cochrane Collaboration's tool. Validity evidence was evaluated using a modern validity framework (Messick's).
We screened 1368 reports for eligibility and included 118 trials. The most common surgery simulated was cataract surgery. Most validity trials investigated only 1 or 2 of 5 sources of validity (87%). Only 2 trials (48 participants) investigated transfer of skills to the operating room; 4 trials (65 participants) evaluated the effect of simulation-based training on patient-related outcomes. Because of heterogeneity of the studies, it was not possible to conduct a quantitative analysis.
The methodologic rigor of trials investigating simulation-based surgical training in ophthalmology is inadequate. To ensure effective implementation of training models, evidence-based knowledge of validity and efficacy is needed. We provide a useful tool for implementation and evaluation of research in simulation-based training.
Time and cost of teaching cataract surgery
2014, Journal of Cataract and Refractive Surgery
To compare the differences in the time of completion of cataract surgery for residents and attending surgeons and to assign a dollar cost.
University of Colorado teaching hospital, Aurora, Colorado, USA.
Comparative case series.
Cataract cases were divided into 3 levels of difficulty for comparison. Main outcome measures were total case time (incision to patch) and degree of difficulty.
Nine residents and 6 attending surgeons participated in the study. Case times were collected for 324 resident cases and 319 attending surgeon cases. The mean attending surgeon case time was 25.75 minutes ± 12.32 (SD) and the mean resident case time, 46.35 ± 16.75 minutes. There was no significant difference in the degree of difficulty between resident cases and attending surgeon cases. Approximately 600 total cases were performed by 4 residents during 3 years of residency training. Taking into account the mean time of case completion for attending surgeons versus residents, the total difference in time if attending surgeons had performed 600 cataracts would be 12 360 minutes. Using a dollar cost of approximately $11.24 per minute at the institution, the cost difference was calculated to be $138 926.40.
There was a significant time and dollar cost incurred in teaching cataract surgery.
No author has a financial or proprietary interest in any material or method mentioned.
Efficacy of surgical simulator training versus traditional wet-lab training on operating room performance of ophthalmology residents during the capsulorhexis in cataract surgery
2013, Journal of Cataract and Refractive Surgery
To compare the operating room performance of ophthalmology residents trained by traditional wet-lab versus surgical simulation on the continuous curvilinear capsulorhexis (CCC) portion of cataract surgery.
Academic tertiary referral center.
Prospective randomized study.
Residents who chose to participate and provided informed consent were randomized to preoperative CCC training in the wet lab or on a simulator. Residents completed pre-practice demographic questionnaires including habits of daily living. After completion of their preoperative training (wet lab versus simulator), residents performed their first CCC of the clinical rotation under the direct supervision of an attending physician as part of their standard training at the facility. Residents then completed satisfaction questionnaires regarding their preoperative training. Two attending surgeons reviewed and graded each video of operating room performance. The mean score between the 2 attending physicians was used as the individual performance score for each of the 12 performance criteria. The overall score was calculated as the sum of these 12 individual performance scores (standardized).
Ten residents trained in the wet lab and 11 on the simulator. There was no significant difference in overall score between the 2 groups (P=.608). There was no significant difference in any individual score except time (wet-lab group faster than simulator group) (P=.038).
Preoperative simulator training prepared residents for the operating room as effectively as the wet lab. The time to pass the simulator curriculum was predictive of the time and overall performance in the operating room.
No author has a financial or proprietary interest in any material or method mentioned.
Design and validation of a simulator for training in continuous circular capsulotomy for phacoemulsification
2013, Archivos de la Sociedad Espanola de Oftalmologia
Diseñar y validar un simulador para el aprendizaje y entrenamiento de la técnica de la capsulorrexis.
El sistema consiste en un soporte de metacrilato con inclinación de 15° para el apoyo de las manos del cirujano y una zona de papel aluminio comercial y otro de similares características donde el alumno realiza la técnica a través de unas hendiduras realizadas previamente en el soporte. Para evaluar la viabilidad de este simulador se toman los datos de 65 oftalmólogos que realizan la técnica durante actividades de formación, dividiéndolos aleatoriamente en un grupo de 30 especialistas que inician directamente su aprendizaje en ojos de cadáver de animal y en otro grupo de 35 especialistas que se inician previamente con este simulador.
Se desarrolla un simulador para entrenamiento de la técnica de capsulorrexis. El grupo de alumnos del grupo simulador consigue una reducción en el uso de ojos de cadáver y una mayor eficiencia en la realización de capsulorrexis correctas, a diferencia del grupo que se inicia directamente en ojos de cadáver.
Este simulador constituye una novedad en el entrenamiento de la técnica de capsulorrexis en cuanto a sencillez, coste y reutilización, frente a otros simuladores virtuales con equipos informáticos más costosos y más complicados de transportar. Es pieza clave como paso previo a la utilización de piezas de cadáver y de animales de experimentación, disminuyendo el número de ambos y, por tanto, el coste de la enseñanza.
To design and validate a simulator for learning and training in the capsulorhexis technique.
The system consists of a methacrylate support inclined 15° for the surgeon's hand, an area of commercially available aluminum foil, and another one of similar characteristics, where the student performs the technique through some slots that are previously made in the support. In order to evaluate the feasibility of this simulator, data were collected from 65 ophthalmologists performing the technique during training activities. The ophthalmologists were randomly divided into one group of 30 specialists who start their learning on the eyes of an animal cadaver, and into another of 35 specialists who previously started with this simulator.
A simulator is developed for training in the capsulorhexis technique. The students from the simulator group achieved a reduction in the use of cadaver eyes, and a higher efficiency in correct capsulorhexis, unlike the group who started directly on the cadaver eyes.
This simulator is an innovation in training of the capsulorhexis technique as regards simplicity, cost, and reuse, as compared to other virtual simulators with more expensive computer equipment (CE) equipment that are more difficult to transport. It is an important step prior to the use of cadaver parts and experimental animals, decreasing the number of both, and therefore the teaching costs.
Rabbit models for continuous curvilinear capsulorhexis instruction
2012, Journal of Cataract and Refractive Surgery
To develop a rabbit model for continuous curvilinear capsulorhexis (CCC) instruction.
University of California San Francisco, San Francisco, California, USA.
Experimental study.
Isolated rabbit lenses were immersed in 2% to 8% paraformaldehyde (PFA) fixative from 15 minutes to 6 hours. Rabbit eyes were treated by substituting aqueous with 2% to 4% PFA for 30 minutes to 6 hours, followed by washes with a balanced salt solution. Treated lenses and eyes were held in purpose-designed holders using vacuum. A panel of 6 cataract surgeons with 5 to 15 years of experience performed CCC on treated lenses and eyes and responded to a questionnaire regarding the utility of these models for resident teaching using a 5-item Likert scale.
The expert panel found that rabbit lenses treated with increasing amounts of fixative simulated CCC on human lens capsules from the third to the seventh decade of life. The panel also found fixative-treated rabbit eyes to simulate some of the experience of CCC within the human anterior chamber but noted a shallower anterior chamber depth, variation in pupil size, and corneal clouding under some treatment conditions.
Experienced cataract surgeons who performed CCC on these rabbit models strongly agreed that isolated rabbit lenses treated with fixative provide a realistic simulation of CCC in human patients and that both models were useful tools for capsulorhexis instruction. Results indicate that rabbit lenses treated with 8% PFA for 15 minutes is a model with good fidelity for CCC training.
No author has a financial or proprietary interest in any material or method mentioned.
Virtual simulation of eyeball and extraocular muscle reaction during cataract surgery
2012, Procedia Engineering
Master-apprentice teaching method is most commonly used in medical education for all the time in transferring the surgical skill from a professional surgeon to a medical practitioner. The current technology has the ability to provide alternative method for different types of surgical practice regardless of ethical issue on human and animal experimentation. Several virtual reality surgery simulators have been developed by the researchers as the purpose to replace web-lab training on human and animal cadavers. Visual realism and haptics realism of the training simulator are the most important parts in imitating the actual surgical atmosphere. This paper presents the implementation of eyeball and extraocular muscles reaction with the response to external force applied from surgical instruments for cataract surgery simulator. An algorithm is created in the system to classify the degrees of rotation relative to the applied force. The application can achieve the visual realism of the reaction of eyeball and extraocular muscle realistically. Finally, the paper concludes with future work to enhance the system.

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^☆

Manuscript no. 230088.

Supported in part by Karolinska Institutet, Stockholm, Sweden, and Melerit AB, Linköping, Sweden.

¹: L. Nordh, E. Skarman, and P. Nordqvist are employed by Melerit AB.

View full text

Original articleComputer-simulated phacoemulsification1 ☆,

Abstract

Objective

Design

Methods

Main outcome measures

Results

Conclusions

Section snippets

Materials and methods

Results

Discussion

J Cataract Refract Surg

J Cataract Refract Surg

J Am Coll Surg

Ophthalmology

Visual results and complications of phacoemulsification with intraocular lens implantation performed by ophthalmology residents

Ophthalmology

Cataract surgery by junior ophthalmologists

Eye

The initial complication rate of phacoemulsification in India

Invest Ophthalmol Vis Sci

Phacoemulsification during the learning curverisk/benefit analysis

Eye

Phacoemulsification—a senior surgeon’s learning curve

Ophthalmic Surg

The phacoemulsification learning curveper-operative complications in the first 3000 cases of an experienced surgeon

Eye

Original article
Computer-simulated phacoemulsification¹ ☆,