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 Table of Contents  
INNOVATION
Year : 2022  |  Volume : 60  |  Issue : 1  |  Page : 38-41

Innovative inexpensive wet-lab training model for practicing keratoplasty during COVID-19 pandemic


1 Cataract, Cornea and Refractive Services, Cataract, Pediatric Ophthalmology and Strabismus Services, Puducherry, India
2 Aravind Eye Hospital and Post Graduate Institute of Ophthalmology, Puducherry, India

Date of Submission11-Jul-2021
Date of Decision27-Dec-2021
Date of Acceptance10-Jan-2022
Date of Web Publication22-Mar-2022

Correspondence Address:
Dr. Bharat Gurnani
1, Aravind Eye Hospital and Post Graduate Institute of Ophthalmology, Puducherry - 605 007
India
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Source of Support: None, Conflict of Interest: None


DOI: 10.4103/tjosr.tjosr_99_21

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  Abstract 


Background: With the rapid rise in COVID 19 cases and increasing fatality during the second wave, most of the states have resorted to lockdown. All eye bank activities have come to a halt, and even emergency corneal transplantation is not possible due to the shortage of donor corneas. There is also an urgent need of innovative wet lab keratoplasty training models for continuing the training of the fellows and residents. Aims and Objectives: The authors describe an innovative cost effective wet lab training model for practicing keratoplasty during the COVID 19 pandemic lockdown. Methods: In this innovative wet lab practicing model, we have used Indian gooseberry and thermocol for practicing penetrating keratoplasty in the wet lab. Results: The gooseberry having natural marking over it is marked with an ink pen for suture alignment, and the ink marked trephine is used to punch the gooseberry. The gooseberry button is cut 360 degrees with the help of scissors and then either the same button or donor button cut from thermocol can be used to practice keratoplasty suture in the wet lab. Conclusion: This innovation can be a boon in the COVID 19 era when eye bank practices have come to a halt, and only emergency keratoplasties are being performed requiring skill and expertise..

Keywords: COVID-19, inexpensive, innovative, keratoplasty, wet lab


How to cite this article:
Gurnani B, Kaur K, Kumar MC. Innovative inexpensive wet-lab training model for practicing keratoplasty during COVID-19 pandemic. TNOA J Ophthalmic Sci Res 2022;60:38-41

How to cite this URL:
Gurnani B, Kaur K, Kumar MC. Innovative inexpensive wet-lab training model for practicing keratoplasty during COVID-19 pandemic. TNOA J Ophthalmic Sci Res [serial online] 2022 [cited 2022 Jul 2];60:38-41. Available from: https://www.tnoajosr.com/text.asp?2022/60/1/38/340380




  Introduction Top


The COVID-19 pandemic is one of the greatest challenges ever faced by mankind. There have been major consequences for the poor and vulnerable, in terms of direct impacts of the public health crisis and mortality, and indirect effects on social, mental, and economical health.[1] As COVID-19 has swept worldwide, and India presently struggling with the second wave of the pandemic, forcing millions into a state of near or total lockdown. However, at the same time, we need to make sure to continue the education, surgical training, and research activities amidst the crisis.[2] The pandemic has left a huge impact on corneal transplantation and eye banking services across the globe. The voluntary eye donations (VEDs) and the hospital cornea retrieval program have come to a total halt due to fear of contracting the deadly virus.[3] The challenges faced during the pandemic have resulted in innumerable innovations. There have been many innovations and adaptations to mitigate the shortage of corneal grafts including change of short-term storage media to long-term storage media such as glycerol preservation, freeze-drying, gamma irradiation, and lyophilization allow for corneal preservation when endothelial health is not of particular concern.[4] Several alternatives have been recommended to maintain the anatomical globe integrity when donor cornea is not available. These include cyanoacrylate glue, fibrin, and Gunderson flap.[5] However, these models of long-term preservation involve a setup, and cost factors are involved in following these. This unavailability of corneal grafts on one side is presently costing our patient's vision, and on the other hand, is affecting future young trainee surgeons as they are unable to practice and master this complicated and demanding surgery. Various wet-lab training models have been described for practicing different steps of the surgery. Goat eyes have been used to practice capsulorhexis and trenching in phacoemulsification,[6] pig eyes for capsulorhexis due to viscous, and elastic anterior lens capsule.[7] Kayikcioglu et al.[8] described phacoemulsification in sheep eyes by inserting cataractous lens inside the capsular bag. Miyake‒Apple technique was used by Pandey et al.[9] for wet-lab surgical training by the removal of cornea and iris at the level of the equator, and a glass slide was inserted on the globe using glue. A large number of the simulator and wet-lab training models are available to practice keratoplasty, but none have described an innovative inexpensive model like ours. Thus, we came out with an innovative, cost-effective, easily reproducible keratoplasty model using Indian gooseberry (amla) and thermocol which we believe will help the residents and cornea trainees to gain confidence because of the close similarity of this model to the actual surgical steps.


  Requirements Top


  1. For simulating host tissue (eye) ‒ Indian gooseberry (amla)
  2. For simulating donor tissue ‒ Thermocol (from suture packet)
  3. Instruments ‒ Nanoedge disposable sharp corneal trephine, corneoscleral/Vannas scissors, Colibri forceps, corneal toothed forceps, suturing tying forceps, needle holder, and McPherson forceps
  4. Others ‒ Disposable gloves, 9-0/10-0 nylon suture, Reynolds Liquiflo blue marker ink pen (waterproof ink)/sketch pen [Figure 1].
Figure 1: Material and instruments required for the wet-lab training

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  Preparing the Model Top


First, the wet lab and instruments arrangements were done. The Indian gooseberry (amla) was bought from the market, and few extra pieces were also kept due to their varying sizes. The gooseberry has natural markings over it which are marked with ink and considered reference for applying the sutures (host tissue). We used spring-action apparatus for fixation of eyeball (SAFE)[10] to mount the gooseberry, and we used leftover thermocol of the suture for preparing the donor tissue. The trephined portion of the gooseberry can also act as donor tissue for practice purpose, and in case of cheese wiring of the material, thermocol can also be used [Figure 2] and [Figure 3].
Figure 2: (a) Image depicting Indian gooseberry mounted on spring-action apparatus for fixation of eyeball fixator with ink markings for suture and circular trephine marking of 8 mm. (b) Image depicting host tissue (rim) dissection with cornea scleral scissor and gooseberry being supported with the help of toothed forceps. (c) Image depicting first cardinal suture being taken for securing the graft. (d) Image depicting fourth cardinal suture being taken

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Figure 3: (a) Image depicting donor preparation from thermocol with the help of 8 mm trephine. (b) Image depicting donor tissue (thermocol) being separated from the base with the help of forceps. (c) Image depicting donor tissue (thermocol) secured to the host rim (gooseberry) with two cardinal sutures perfectly aligned to the axis. (d) Image depicting donor tissue (thermocol) in place with four cardinal sutures

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  Surgical Technique Top


After marking and mounting the gooseberry over the SAFE apparatus, the center of the gooseberry considering it to be the host cornea was marked for reference. An 8 mm nanoedge disposable corneal trephine was marked with the help of a Reynolds liquiflo blue marker ink pen (waterproof ink) [Figure 2]a. Further, corneal tooth forceps were used in the left hand to support the host tissue, and the trephine was used in the right hand to partially punch the host tissue keeping the center as the reference. The corneoscleral scissor was used to cut the gooseberry starting at 9 o'clock anticlockwise till 3 o'clock (180°) and then clockwise till 3 o'clock [Figure 2]b. The central adherent portion was cut at the end. The donor button is prepared from the thermocol over which the suture is packed. The same size 8 mm nanoedge disposable trephine was used to fashion the donor button. The thermocol button was then shifted to the gooseberry. The thermocol button was sutured to the gooseberry with interrupted sutures [Figure 2]c. The image shows the four cardinal sutures starting from the thermocol button to the rim of the gooseberry. In the way, 16 interrupted can be placed maintaining radiality with the thermocol button [Figure 2]d. For beginners, we recommend the initial use of thermocol because it is slightly firm in comparison to gooseberry. Once the trainee tissue handling improves, they can switch to practice on gooseberry [Figure 3]a, [Figure 3]b, [Figure 3]c, [Figure 3]d.


  Discussion Top


Innovation is increasingly essential for an effective response to the crisis raised due to the COVID-19 pandemic. Innovations in technology, health care, development, and humanitarian responses to the pandemic led to incremental improvements to repurpose existing aid approaches. The PHACO-I Phaco eyes are artificial eyes made of wax and have been used to practicing basic steps of phacoemulsification.[11] The i-STAND Plus eyeball stand is a portable globe fixator where a slit lamp can also be attached. The basic glaucoma investigations such as applanation tonometry and gonioscopy can be practiced on it by fixing the goat's eye to it.[11] A novel technique for practicing trabeculectomy using half-cut golden apples was described by Porteous et al.[12] They proposed that green apple skin consistency was similar to the sclera and can be used for practicing scleral flaps. Japanese quail eggs inside a silicon cap have also been used to practice vitrectomy, and the inner membrane shell has been used to practice membrane peeling using vitreous forceps using Brilliant Blue G dye.[13] Keratoplasty has been the cornerstone management for the nonresolving ulcers and the nonavailability of donor tissue during the pandemic, and there has been a huge mismatch between the demand and supply. During the first wave of the COVID-19 pandemic, we saw few innovative ideas. Siddharthan et al.[14] described a novel concept in corneal transplantation by utilizing a single donor eye for our recipients, thus putting the available corneal and scleral tissue to maximum use. Bafna et al.[15] described an innovative U-shaped tool for follow-up of corneal ulcer patients during the COVID-19 pandemic. A large number of keratoplasty training models such as three-dimensional (3D) printed trephine for anterior lamellar keratoplasty,[16] artificial chamber, and 3D printed iris for teaching Descemet's membrane endothelial keratoplasty (DMEK),[17] and simulation model for DMEK donor preparation have been described. However, as per the detailed literature review, there is no cost-effective wet-lab practice and teaching model for therapeutic and penetrating keratoplasty (PKP). Hence, we here describe an innovative use of Indian gooseberry as an economical and cloneable model for practicing and training PKP and therapeutic keratoplasty. This model closely simulates the real feel of corneal transplantation, as compared to other simulators and animal eye models available in the market. We believe this innovative idea will help in boosting the confidence of trainee surgeons in these tough times. Moreover, this model can find a permanent place in wet labs for initial training among residents and fellows. Thermocol is a commonly used practicing material in wet-lab training at the junior level, here we also wanted to highlight that gooseberry can be an alternative for wet-lab training, especially for keratoplasty. As per the best of our knowledge, this has not been described previously in the literature


  Advantages Top


  1. This is a very cost-effective model as the Indian gooseberry (amla), and thermocol are easily available at a very cheap cost
  2. This training model can be easily replicated in a wet lab as no special instruments or simulators are required
  3. This practice model can be a boon during the COVID-19 pandemic
  4. There is no requirement for any ophthalmic viscosurgical devices while performing the procedure or while fashioning the donor cornea
  5. The gooseberry is with a thick base, hence giving a real time feel of trephination and suturing
  6. The trephined gooseberry can also be used for suturing practice in case the thermocol is not available
  7. Gooseberry being a natural product is more stretchable and gives a more closer feel of a corneal tissue while suturing the thermocol button to it as compared to thermocol button to thermocol rim
  8. The donor button of thermocol can be prepared after cutting the gooseberry since there is no risk and fear of intraoperative complications like expulsive choroidal hemorrhage
  9. The cadaveric eye or the goat eye obtained during the pandemic for practice in the wet lab can have a low risk of COVID-19 transmission during practice. This model safeguards us against that.


Limitations

  1. The same size graft and donor have to be used due to the inelastic nature of the gooseberry and thermocol
  2. It does not give the feel of an open-sky procedure
  3. Sometimes, the oversized gooseberry may slip while practicing keratoplasty
  4. It misses and does not give a real-time exposure of other steps of keratoplasty like making a peripheral iridotomy, lens removal, and anterior vitrectomy as required in few cases
  5. Excessive manipulation and irregular suture bites can lead to cheese wiring of the material.



  Conclusions Top


Several landmark innovations have been done in the recent past for practicing and mastering the technique of keratoplasty. This article highlights an innovative inexpensive model for training keratoplasty to the residents and fellows before they touch the human eyes. This innovation is a boon in the COVID-19 era when eye bank practices have come to a halt, and only emergency keratoplasties are being performed requiring skill and expertise. With the rapid improvement in global innovation and ease of accessibility of technology, it is expected that this practice model would be accepted and incorporated widespread in clinical practice. This model is cost-effective, can be easily replicated, less time-consuming, safe, and free of any real-time complications. This model we believe will be extremely beneficial for developing countries where there is a scarcity of resources and VED, and hospital corneal retrieval programs have been abandoned forcing lockdown owing to COVID-19 protocols. Thus, all trainees must utilize this opportunity to practice this model to transform their surgical skills at a quicker pace.

Acknowledgments

We would like to thank the Aravind Eye Hospital and Postgraduate Institute of Ophthalmology, Pondicherry.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.



 
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  In this article
Abstract
Introduction
Requirements
Preparing the Model
Surgical Technique
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