A Novel Virtual Wet Lab-Using a Smartphone Camera Adapter and a Video Conference Platform to Provide Real-Time Surgical Instruction.

PURPOSE: Proctored surgical instruction has traditionally been taught through in-person interactions in either the operating room or an improvised wet lab. Because of the COVID-19 pandemic, live in-person instruction was not feasible owing to social distancing protocols, so a virtual wet lab (VWL) was proposed and implemented. The purpose of this article is to describe our experience with a VWL as a Descemet membrane endothelial keratoplasty (DMEK) skills-transfer course. This is the first time that a VWL environment has been described for the instruction of ophthalmic surgery. METHODS: Thirteen participant surgeons took part in VWLs designed for DMEK skills transfer in September and October 2020. A smartphone camera adapter and a video conference software platform were the unique media for the VWL. After a didactic session, participants were divided into breakout rooms where their surgical scope view was broadcast live, allowing instructors to virtually proctor their participants in real time. Participants were surveyed to assess their satisfaction with the course. RESULTS: All (100%) participants successfully injected and unfolded their DMEK grafts. Ten of the 13 participants completed the survey. Respondents rated the experience highly favorably. CONCLUSIONS: With the use of readily available technology, VWLs can be successfully implemented in lieu of in-person skills-transfer courses. Further development catering to the needs of the participant might allow VWLs to serve as a viable option of surgical education, currently limited by geographical and social distancing boundaries.

The learning curve for Descemet membrane endothelial keratoplasty performed by two experienced corneal surgeons: a consecutive series of 40 cases.

PURPOSE: To describe the learning curve for Descemet's membrane endothelial keratoplasty (DMEK) in the Rotterdam Eye Hospital and to evaluate safety and visual outcome. METHODS: This was a single-centre prospective study of 40 consecutive patients with Fuchs' endothelial dystrophy who underwent a DMEK procedure in the Rotterdam Eye Hospital. The performance of two corneal surgeons, each conducting their first series of 20 procedures, was examined with the cumulative summation test for the learning curve (LC-CUSUM). The surgical procedure was considered unsuccessful when >30% of the graft was not attached at any time during the first 12 postoperative weeks and a mixture of SF6 (20%) and air (80%) had to be injected in the anterior chamber (rebubbling) to reattach the graft. Also assessed were visual outcome, intraocular pressure and peri- and postoperative complications. RESULTS: In total, nine rebubbling procedures were performed in seven eyes. Following repeated rebubbling, two eyes did not achieve a satisfactory result and secondary surgery was required to restore visual function. Complications were usually manageable. The last 13 DMEK procedures (33%) of this series did not require rebubbling. After 3 months, 86% of the eyes had reached a Snellen visual acuity of 0.5 or more. CONCLUSION: Together with the two surgeons' personal experience, the aggregate learning curve was considered to justify incorporation of Descemet membrane endothelial keratoplasty as a regular option of the standard of care for endothelial dysfunction in the Rotterdam Eye Hospital.

Learning Descemet Membrane Endothelial Keratoplasty: A Survey of U.S. Corneal Surgeons.

PURPOSE: The transition to Descemet membrane endothelial keratoplasty (DMEK) is frequently challenging, requiring the adoption of new techniques, skills, and methods. We sought to draw on surgeons' initial experiences with DMEK to characterize the learning curve associated with this procedure and identify factors that could be linked to the frequency of primary graft failure (PGF) in the first 10 cases. METHODS: We invited corneal surgeons based in the United States who started performing the DMEK procedure within the past 2 years to answer a 12-question survey using an online survey platform. We analyzed quantitative and qualitative data. A Fisher exact test was used to determine whether preoperative approaches to preparation were associated with decreased PGF rates. RESULTS: A total of 100 US-based corneal surgeons replied from 34 of 50 states. Of these, 68% reported that DMEK comprised a majority of their endothelial keratoplasty cases. Approximately half of surgeons (52%) had performed more than 20 DMEK cases by the time of the survey, and 51% felt equally comfortable performing DMEK relative to Descemet stripping endothelial keratoplasty. Among the respondents, 37% answered that they had experienced PGF in the first 10 cases. Scrubbing in with an experienced colleague before surgery was associated with a decreased likelihood of at least one case of PGF (31%, P = 0.049), but not participation in a wet lab with an experienced instructor or mentor (38%, P = 0.50), nor having an eye bank representative present in the operating room (43%, P = 0.886). CONCLUSIONS: The collective experience of 100 surgeons beginning DMEK confirms the importance of mentorship and that the accompaniment of an experienced colleague during the learning curve is associated with lower rates of PGF.

Learning curve of two common Descemet membrane endothelial keratoplasty graft preparation techniques.

OBJECTIVE: To compare the learning curve of two Descemet membrane endothelial keratoplast (DMEK) graft preparation techniques. DESIGN: Experimental study. PARTICIPANTS: Twenty paired donor corneoscleral rims. METHODS: The corneas were randomized to DMEK peeling using the peripheral blunt dissection technique (n = 10) or the modified submerged cornea using backgrounds away (mSCUBA) technique (n = 10). Outcome measures included graft peeling time, surgeon's peeling difficulty grading (on a scale of 1 to 10, 1 being the easiest and 10 the hardest), number of tears, and percentage tissue loss. RESULTS: Average graft peeling time using the peripheral blunt dissection technique and the mSCUBA technique was 15.75 ± 4.01 minutes and 8.43 ± 3.26 minutes, respectively (p < 0.0005). The first 3 grafts' average peeling time was longer than the last 7 grafts: 19.14 ± 2.40 versus 14.21 ± 3.50 minutes in the peripheral blunt dissection technique (p = 0.06) and 12.36 ± 3.76 versus 6.67 ± 0.49 minutes in the mSCUBA technique (p = 0.016). In the latter, there were significantly fewer radial tears compared to the former: 1.5 ± 1.0 and 3.1 ± 1.9, respectively (p = 0.049). No tissue loss was noted in the mSCUBA group compared to one (10%) in the peripheral blunt dissection group. The average difficulty grading for the mSCUBA was significantly lower than the peripheral blunt dissection technique: 3.3 ± 1.9 and 5.8 ± 1.6, respectively (p = 0.024). CONCLUSIONS: Our study suggests a shorter learning curve with the mSCUBA technique for DMEK graft preparation, with shorter peeling time and fewer complications in comparison to the peripheral blunt dissection technique.

Descemet Membrane Endothelial Keratoplasty Outcomes During the Initial Learning Curve of Cornea Fellows.

PURPOSE: To describe the outcomes of Descemet membrane endothelial keratoplasty (DMEK) performed by cornea fellows during their initial learning curve. METHODS: This prospective study included the first consecutive series of 53 DMEK surgeries performed by 14 corneal fellows at Sorocaba's Ophthalmological Hospital. Best spectacle-corrected visual acuity, endothelial cell density (ECD), and complications were evaluated. RESULTS: Of the eyes without ocular comorbidities and with complete visual acuity measurements, 97% of 33 eyes achieved a best spectacle-corrected visual acuity of ≥20/40 in 6 months. The mean (SD) preoperative donor ECD was 2453 (361) cells/mm, and at 6 months postoperatively, the in vivo mean ECD (SD) was found to be 1300 (587) cells/mm, an average loss of 47%. Preparation of the DMEK graft by the cornea fellows was successful in all cases. There were 9 eyes (17%) that experienced partial graft detachment requiring rebubbling. A total of 3 eyes (5.7%) failed to clear the cornea, all of which were managed with successful secondary endothelial keratoplasty. None of the eyes experienced pupillary block. CONCLUSIONS: Establishing DMEK in a fellowship program was successful with the supervision of an experienced DMEK surgeon. Even without the facility of a prestripped DMEK graft by an eye bank and with no backup tissue, no surgery was canceled because of graft preparation failure. Good visual outcomes were achieved with satisfactory ECD at 6-month follow-up, with an acceptable complication rate. Even the 3 eyes that failed to clear the cornea evolved well after secondary endothelial keratoplasty by the cornea fellows.

Descemet stripping automated endothelial keratoplasty performed by trainees.

PURPOSE: To assess the surgical outcomes of Descemet stripping automated endothelial keratoplasty (DSAEK) performed by trainees. STUDY DESIGN: Retrospective, case control comparative study. METHODS: This study compared cases performed by trainees with those performed by an experienced surgeon. First 10 cases of DSAEK performed by trainees with more than 6 months follow-up periods were recruited. The surgical outcomes of DSAEK performed by the trainees (Trainee group) were compared with disease-matched pairs of cases performed by an experienced surgeon (Experienced group). Graft clarity, best spectacle-corrected visual acuity, corneal endothelial cell density, and incidence of intra- or post-operative complications were studied. RESULTS: Forty-one pairs were recruited. The graft clarity rate was not different between the Trainee and Experienced groups, with 95.1% and 97.6%, respectively, maintaining clear grafts at 12 months postoperatively. Trainee best spectacle corrected visual acuity was significantly worse at 6 and 12 months postoperatively compared with the Experienced group, and percent decreases in corneal endothelial density was more in the Trainee group at 3 months following surgery (P = 0.0029). While intra- or late post-operative complication rates were similar in both groups, incidences of early post-operative complications such as double chamber formation or pupillary block were observed more frequently in the Trainee group than in the Experienced group (P = 0.049). CONCLUSION: DSAEK can be performed relatively safely by training physicians with careful preparation and supervision by attending physicians. However, careful case selection and education on management of air injected in the anterior chamber seemed to be a key to long-term success.

Artificial chamber and 3D printed iris: a new wet lab model for teaching Descemet's membrane endothelial keratoplasty.

PURPOSE: To describe a new wet lab model of Descemet membrane endothelial keratoplasty (DMEK) using human corneas mounted on an artificial anterior chamber with an artificial iris and to compare the performance time and scores between beginners and experienced anterior segment surgeons. METHODS: Corneas were mounted on an artificial chamber. To simulate an anterior chamber and to avoid loosing the graft into the tubing, a 3D printed iris was added. Each DMEK procedure required only one cornea for graft preparation, insertion, orientation, unfolding and centration. Ten human research corneas were used for training purposes. Intraoperative OCT was only used to validate the different steps of the procedure. Operators were divided into two groups, two beginners and three experienced DMEK surgeons. RESULTS: All DMEK procedures were successfully performed. Descemet's tears were frequent but harvesting was successful in all procedures. All combinations of graft unfolding techniques were possible. Experienced surgeons performed statistically better then beginners with faster harvesting (12.8 versus 28.2 min; p = 0.02) and insertion (13.5 versus 20.8 min; p = 0.05) times and better performance score (94 versus 52; p = 0.03). CONCLUSION: This DMEK wet lab model offers a close to reality, feasible, resource-sparing and valid teaching technique that permits to perform all DMEK surgical steps. It also offers the possibility of varying the surgical difficulty by changing the anterior chamber depth.

Outcomes of complex Descemet Stripping Endothelial Keratoplasty performed by cornea fellows.

BACKGROUND: A major obstacle that academic institutions face is the steep learning curve for cornea fellows initially learning to perform Descemet Stripping Endothelial Keratoplasty (DSEK). The purpose of this study is to evaluate the outcomes of complex DSEK performed by cornea fellow supervised by an attending surgeon at an academic institution. METHODS: Patients who underwent a complex DSEK procedure performed by a cornea fellow during the years 2009-2013 were included. All the surgeries were supervised by the same cornea attending. All patients had a minimum follow-up of 6 months. Charts were reviewed for demographic data, intraoperative and postoperative complications and clinical outcomes. Corneal graft survival was calculated using the Kaplan-Meier analysis. RESULTS: Fifty-seven eyes of 55 patients (mean age 77.5 ± 8.5 years) were included in the study with a mean follow-up time of 16.4 ± 15.6 months. Previous graft failure, presence of a tube and history of trabeculectomy were the leading diagnoses to define the surgery as complex. No intraoperative complications occurred. In 21.1% of cases a corneal graft detachment was documented in the first postoperative day. Mean visual acuity improved from 1.06 LogMAR (20/230) preoperatively to 0.39 LogMAR (20/50, p < 0.001) by the sixth postoperative month and to 0.52 LogMAR (20/65, p < 0.001) at the last follow-up visit. Graft failure rate was 29.8%. Kaplan-Meier analysis found a 67.2% graft survival rate at 20 months. CONCLUSIONS: Complex DSEK can be performed successfully with an acceptable postoperative complication rate by cornea fellows during their training period when supervised by an experienced attending.

Partitioning an Artificial Anterior Chamber With a Latex Diaphragm to Simulate Anterior and Posterior Segment Pressure Dynamics: The "DMEK Practice Stage," Where Surgeons Can Rehearse the "DMEK Dance".

PURPOSE: To present a novel apparatus for simulating the anterior and posterior segment pressure dynamics involved in executing Descemet membrane endothelial keratoplasty (DMEK) surgery when using a chamber-shallowing technique. METHODS: An artificial anterior chamber (AAC), 18-mm trephine, latex glove, two 3-mL syringes, and one donor cornea comprising an intact corneoscleral cap from which a DMEK tissue was peeled and punched are required for the model. After making the corneal incisions with the corneoscleral cap mounted on the AAC in the usual fashion, the corneoscleral cap is remounted onto the dried AAC over an 18-mm latex diaphragm. The space between the latex diaphragm and the cornea is filled with saline to pressurize the anterior chamber, and the posterior segment is pressurized with air from a syringe. The resulting apparatus comprises a posterior segment and anterior chamber that exert pressure on each other by way of a distensible latex diaphragm. RESULTS: A novice and experienced DMEK surgeon and 2 eye bank technicians were able to assemble the apparatus and perform the routine steps of a DMEK procedure, including maneuvers that require shallowing the anterior chamber and lowering its pressure. Only one cornea was required per apparatus. CONCLUSIONS: We present a novel in vitro model of the human eye that more closely mimics the anterior and posterior segment pressure dynamics of in vivo DMEK surgery than average human and animal cadaveric globes. The model is easy to assemble, inexpensive, and applicable to a range of teaching environments.

Anatomy-based DMEK Wetlab in Homburg/Saar: Novel aspects of donor preparation and host maneuvers to teach descemet membrane endothelial keratoplasty.

Use of Descemet Membrane Endothelial Keratoplasty (DMEK) has been limited because of problems with donor preparation, i.e. tearing of the Descemet membrane and difficulties in unfolding the Endothelium-Descemet-Membrane-Layer (EDML) in the anterior chamber (AC). The purpose of this work was to describe a novel approach to teaching anatomy-based donor and recipient preparation in a DMEK-Wetlab. We teach successful mono-manual donor preparation of human corneas in organ culture not suitable for transplantation, including peripheral markers for orientation. We also teach safe recipient preparation in a freshly-enucleated pig eye in organ culture preservation medium for atraumatic introduction of the EDML roll into the AC, reliable orientation of the EDML during surgery, and stepwise unfolding within the AC. Twenty-two candidates in the 1. Homburg Cornea Curriculum HCC 2015 who practiced both preparations using three human donor corneas and three pig eyes assessed the procedure as follows: (1) overall grade of the Wetlab 1.4 (median 1, range 1 to 2 - on a scale from 1 (excellent) to 6 (terrible); (2) most participants and tutors stated that the Wetlab is most effective for colleagues who have some previous experience with corneal microsurgery. Our novel anatomy-based approach to simulating donor preparation and graft implantation for DMEK seems to meet the expectations and requirements of colleagues with previous experience in corneal microsurgery and will help to reduce the rate of complications for incipient DMEK surgeons in the future. Clin. Anat. 31:16-27, 2018. © 2017 Wiley Periodicals, Inc.

Learning DMEK From YouTube.

PURPOSE: To evaluate the outcomes of the first cases of Descemet membrane endothelial keratoplasty (DMEK) performed by an anterior segment surgeon, learning the procedure, including graft preparation, primarily from watching YouTube videos. DMEK surgery was not learned during fellowship training; there was no attendance at DMEK courses, no witnessing of live surgery, and no supervision by an experienced DMEK surgeon. All graft tissue was prepared by the surgeon on the day of surgery. METHODS: This is a retrospective review of the 3-month postoperative results of the first 40 consecutive cases. The success rate of graft preparation, intraoperative and postoperative complications, spectacle-corrected visual acuity, endothelial cell density, and central corneal thickness were evaluated. RESULTS: Grafts were successfully prepared in all cases with no loss of donor tissue. DMEK surgery was successful in 39 of 40 eyes with the one failure occurring in a vitrectomized eye without an intact iris-lens diaphragm. Spectacle-corrected visual acuity was ≥6/6 in 23 of the 25 eyes without comorbidity. Mean endothelial cell density was 1515 (±474) cells/mm. Mean central corneal thickness decreased from 624 (±40) µm preoperatively to 513 (±34) µm postoperatively. CONCLUSIONS: Although formal training is desirable, good results can be obtained by an anterior segment surgeon learning DMEK, including graft preparation, without it. DMEK should no longer be considered a procedure with a long learning curve in routine cases.

Is there evidence for a surgeon learning curve for endothelial keratoplasty in Australia?

IMPORTANCE: Expected outcomes from endokeratoplasty may vary with surgeon experience. BACKGROUND: It was explored whether a surgeon learning curve exists for Descemet stripping endothelial keratoplasties (manual or automated) performed in Australia. DESIGN: This is a prospective cohort study, with various clinical settings. PARTICIPANTS: There were 2139 recipients of 2615 endothelial grafts, registered by 85 surgeons between January 2006 and December 2013. METHODS: Kaplan-Meier survival analyses and Cox proportional hazards regression were used to examine longitudinal graft survival. Manual and automated Descemet stripping endothelial keratoplasties were analysed together. Pearson chi-squared analyses were performed to examine differences amongst groups. Continuity correction was used for 2 × 2 tests, and statistical significance was set at P < 0.05 (two-sided). MAIN OUTCOME MEASURE: The main parameter measured was endothelial graft survival. RESULTS: Survival of the first 56 registered grafts was significantly poorer than survival of subsequent grafts (χ2  = 8.83, df = 1, P = 0.003), when data were combined for all surgeons. Surgeon workload influenced graft survival significantly (P < 0.001). This variable was retained in multivariate analysis designed to investigate independent factors influencing graft survival. Primary non-functioning grafts were significantly less likely to be reported for endokeratoplasties performed by surgeons with more than 56 registered grafts, compared with those registering 56 or fewer grafts (4.3% vs. 8.5%; χ2  = 18.38, df = 1, P < 0.001). CONCLUSIONS AND RELEVANCE: Our findings suggest that for less experienced or low-volume surgeons, longitudinal graft survival improved once 56 or more endokeratoplasties had been performed, indicative of a learning curve. The learning curve was less apparent for surgeons with 57 or more Descemet stripping endothelial keratoplasties and/or Descemet stripping automated endothelial keratoplasties registered during the 8-year study period. Different learning curves may be anticipated for these two groups of surgeons.

Human Ex Vivo Artificial Anterior Chamber Model for Practice DMEK Surgery.

PURPOSE: To describe a wet lab model using human corneas for practicing all steps of Descemet membrane endothelial keratoplasty (DMEK). METHODS: Twelve human research corneas were used for training purposes. Each DMEK surgery required 2 corneas; one for donor graft preparation and one to practice graft insertion and unfolding in a novel artificial anterior chamber model. RESULTS: Six complete DMEK procedures were successfully performed. Apart from donor graft preparation and graft insertion into the anterior chamber, it was feasible to practice different and combinations of graft unfolding techniques in conditions similar to real human procedures. CONCLUSIONS: This wet lab model allows practicing steps of DMEK and learning significant surgical skills. Reusable instruments can be used in regular operating facilities resulting in reasonable costs.

Techniques for Learning Descemet Membrane Endothelial Keratoplasty for Eyes of Asian Patients With Shallow Anterior Chamber.

PURPOSE: To describe several essential surgical techniques that overcome difficulties in performing Descemet membrane endothelial keratoplasty (DMEK) for inexperienced surgeons, especially those who perform DMEK on eyes of Asian patients. METHODS: Nine eyes of 9 Asian patients with bullous keratopathy who underwent DMEK were analyzed retrospectively. All patients were given a diuretic such as D-mannitol or acetazolamide shortly before surgery, with retrobulbar anesthesia and a Nadbath facial nerve block. Core vitrectomy before DMEK was performed in several cases in which a high vitreous pressure during surgery was predicted. The donor graft was stained with trypan blue, and a 25-G anterior chamber maintenance cannula was used to maintain the anterior chamber depth during graft insertion in all eyes. RESULTS: The cornea became clear in all eyes. The best spectacle-corrected visual acuity had improved significantly 6 months after the surgery compared with preoperative values (P = 0.026). The corneal endothelial cell density was 1371 cells per square millimeter at postoperative 6 months. CONCLUSIONS: Although DMEK is technically difficult, especially for inexperienced surgeons who operate on eyes of Asian patients, controlling anterior chamber pressure using various manipulations may help to prevent iatrogenic primary graft failure and lead to successful DMEK.

A simple ex vivo model for teaching Descemet membrane endothelial keratoplasty.

PURPOSE: To describe a simple ex vivo porcine model for teaching Descemet Membrane Endothelial Keratoplasty (DMEK). METHODS: Twenty freshly enucleated porcine eyes were used to create a pseudo-graft from the porcine lens capsule and implant it into an intact porcine globe using the standardized 'no-touch' technique of the Netherlands Institute for Innovative Ocular Surgery (NIIOS). RESULTS: The DMEK pseudo-graft could be inserted, centred, unfolded and appositioned in all cases. CONCLUSIONS: Practicing DMEK surgery under wetlab conditions was feasible by the described simple and low-cost model. This new tool may facilitate the adaptation of DMEK by cornea surgeons.

Descemet membrane endothelial keratoplasty: learning curve of a single surgeon.

PURPOSE: To evaluate the learning curve of standardized "no-touch" Descemet membrane endothelial keratoplasty (DMEK) of a single surgeon in a clinic without an in-house eye bank facility. METHODS: For 25 eyes of 22 patients, Descemet graft preparation and DMEK surgery were performed according to the protocols of the Netherlands Institute for Innovative Ocular Surgery with minor modifications. Best spectacle-corrected visual acuity, subjective refraction, Scheimpflug tomography, and endothelial cell density of the donor tissue were documented before and at 1, 3, and 6 months after the surgery; intraoperative and postoperative complications were recorded. RESULTS: No donor tissue was lost owing to preparation failure of the Descemet graft allowing all surgeries to be completed as planned. At 6 months after the surgery, 83% of eyes reached ≥ 20/40 (≥ 0.5), 48% ≥ 20/28 (≥ 0.8), and 30% (7/23) ≥ 20/20 (≥ 1.0) (n = 23). The mean change in both spherical equivalent and refractive cylinder in the same interval was minimal (0.03 diopter). Mean donor endothelial cell density decreased from 2444 cells per square millimeter (± 198 cells/mm2) before the surgery to 1331 cells per square millimeter (± 491 cells/mm2) at 6 months after the surgery. Partial graft detachment requiring rebubbling occurred in 9 cases (36%). One eye developed primary graft failure. CONCLUSIONS: This case series shows that DMEK by a beginning surgeon can achieve good results without preparing the graft in an eye bank. Use of backup tissue can be avoided by strictly adhering to the Netherlands Institute for Innovative Ocular Surgery techniques and by harvesting the graft the day before surgery to avoid last-minute cancellation.

Making the transition from PK to DSEK: experiences during the learning curve.

PURPOSE: To report our experiences during the transition from penetrating keratoplasty to Descemet's stripping with endothelial keratoplasty (DSEK). METHODS: All patients undergoing DSEK during the period of April 2008 to April 2009 were included in this study. RESULTS: All grafts were attached and clear at both the 6- and 12 -month follow-up examinations. Mean best-corrected visual acuity was 0.6 at 6 months and 0.7 at 12 months for patients without other ocular comorbidity. CONCLUSION: With adequate attention to detail, DSEK seems to be a safe and successful treatment for corneal endothelial disease, also during the surgeon's learning curve.