Assessing the phacoemulsification learning curve using duration of each step.

PURPOSE: To assess the phacoemulsification learning curve for ophthalmology residents using duration for each step. SETTING: Single tertiary, training site hospital. DESIGN: Cross-sectional study. METHODS: Emory ophthalmology postgraduate year (PGY) 3 and PGY-4 residents operating at Grady Memorial Hospital between April 2017 and February 2018 were eligible to participate. Duration in seconds for each step of surgery was calculated for incisions, continuous curvilinear capsulorhexis (CCC), hydrodissection, nucleus disassembly, quadrant removal, cortical cleanup, intraocular lens insertion, and closure, and this outcome was analyzed as a function of different experience levels. RESULTS: A total of 528 surgeries were included of 549 total surgeries recorded. 6 categories of experience levels were established as A to F, increasing by increments of 50. There was an overall downward trend across various steps across the 8 case categories, and several adjacent categories demonstrate statistically significant differences. The 3 most time-intensive steps early in training were nucleus disassembly (336.5 ± 16.5 seconds), quadrant removal (275.1 ± 18.0 seconds), and cortical cleanup (244.2 ± 24.6 seconds). There was a sustained drop in mean duration for all steps through at least category D, with most steps showing a drop through category F. CONCLUSIONS: There is a benefit to a higher caseload, well above the Accreditation Council for Graduate Medical Education-mandated 86 cases. Improvements in efficiency were observed after 250 cases, with nuclear disassembly and CCC demonstrating a significant decrease in operative time.

The impact of distance cataract surgical wet laboratory training on cataract surgical competency of ophthalmology residents.

BACKGROUND: This study assessed the impact of distance cataract surgical wet laboratory training on surgical competency of ophthalmology residents at a tertiary-level ophthalmic training center in Trujillo, Peru. METHODS: Three five-week distance wet lab courses were administered through Cybersight, Orbis International's telemedicine platform. Weekly lectures and demonstrations addressed specific steps in phacoemulsification surgery. Each lecture had two accompanying wet lab assignments, which residents completed and recorded in their institution's wet lab and uploaded to Cybersight for grading. Competency was assessed through anonymous grading of pre- and post-training surgical simulation videos, masked as to which occurred before and after training, using a standardized competency rubric adapted from the Ophthalmology Surgical Competency Assessment Rubric (OSCAR, scale of 0-32). Day one best-corrected post-operative visual acuity (BVCA) was assessed in the operative eye on the initial consecutive 4-6 surgeries conducted by the residents as per the norms of their residency training. An anonymous post-training satisfaction survey was administered to trainees'. RESULTS: In total, 21 ophthalmic residents participated in the courses, submitting a total of 210 surgical videos. Trainees' average competency score increased 6.95 points (95%CI [4.28, 9.62], SD = 5.01, p < 0.0001, two sample t-test) from 19.3 (95%CI [17.2, 21.5], SD = 4.04) to 26.3 (95%CI [24.2, 28.3], SD = 3.93). Visual acuity for 92% of post-training resident surgeries (n = 100) was ≥20/60, meeting the World Health Organization's criterion for good quality. CONCLUSIONS: Structured distance wet lab courses in phacoemulsification resulted in significantly improved cataract surgical skills. This model could be applicable to locations where there are obstacles to traditional in-person training, such as the current COVID-19 pandemic.

Combination of lidocaine gel and povidone-iodine to decrease acquired infections in procedures performed using topical anesthesia.

PURPOSE: To test the antiseptic efficacy of povidone-iodine when mixed with topical lidocaine gel. SETTING: Emory School of Medicine, Atlanta, Georgia, USA. DESIGN: Experimental study. METHODS: Staphylococcus epidermidis, Staphylococcus aureus, viridans streptococci (Streptococcus sanguinis), Escherichia coli, and Pseudomonas aeruginosa were grown on blood agar plates with povidone-iodine and/or lidocaine gel. The efficacy of sterilization was quantified by surviving bacterial colony-forming units. RESULTS: Combination of povidone-iodine and lidocaine gel prevented bacterial growth to levels similar to povidone-iodine alone. Application of lidocaine gel to bacteria before povidone-iodine treatment allowed bacterial growth similar to controls not exposed to povidone-iodine. CONCLUSIONS: Povidone-iodine must be applied before lidocaine gel for effective antisepsis, but admixture of povidone-iodine with lidocaine gel was also effective and may reduce the risk of endophthalmitis associated with lidocaine gel use. This strategy offers a practice-changing alternative for preoperative prophylaxis in procedures requiring topical anesthesia.

Ethics in Eye Banking: Understanding Professional Attitudes Toward Industry Changes.

PURPOSE: To describe the ethical attitudes of corneal surgeons and eye bank leadership toward for-profit entities in corneal donation, processing, and distribution. METHODS: Fifty postfellowship corneal surgeons practicing in the United States and 25 eye bank leaders (eg, eye bank directors, CEOs, or presidents) for the Eye Bank Association of America-accredited eye banks completed a 22-question interview, focusing on corneal donation industry changes, including the entry of for-profit institutions. RESULTS: Most participants in both study groups agreed that they have concerns with the entry of for-profit businesses into eye banking (62% corneal surgeons, 68% eye bank leadership), although physicians partnered with a for-profit corneal processor were significantly more likely to have no concerns with the entry of for-profits into eye banking than corneal surgeons partnered with a nonprofit processor (P = 0.04). The most frequently identified concerns with the entry of for-profit businesses into corneal banking were the hypothetical loss of donor trust (56% corneal surgeons, 64% eye bank leadership, P = 0.04) and the potential exploitation of donor generosity (72% corneal surgeons, 60% eye bank leadership). Qualitative theme analysis suggests that both study groups may view increased research/innovation as a potential benefit (64% corneal surgeons, 66% eye bank leadership) of for-profits in eye banking. CONCLUSIONS: Key stakeholders in eye banking do hold relevant ethical beliefs toward recent industry changes, and these attitudes should be considered in the future creation of the ethical corneal donation policy. Further research is needed to assess the attitudes of potential donors and donor families.

Ophthalmology Education in COVID-19: A Remote Elective for Medical Students.

BACKGROUND: The novel coronavirus disease (COVID-19) has created obstacles for medical student education, as clinical rotations were temporarily halted. Recent literature shows online electives may provide an alternative learning platform. We developed a tele-ophthalmology student elective for rising third-year (MS3) and fourth-year (MS4) medical students to continue teaching and exposure to the field. METHODS: A 4-week remote elective was approved by Emory University School of Medicine and offered between April 18, 2020 to May 15, 2020 for rising MS3 and MS4 students. The curriculum consisted of online self-study materials, student presentations, chart review assignments, case-based discussions with faculty, and telehealth experiences. All students were surveyed and tested with questions from USMLE World (UWorld) test bank at the end of the course. RESULTS: A total of 18 students enrolled, with 66.7% MS3 and 33.3% MS4 participance. The mean rating of fulfillment of course learning objectives was 8.1/10 (range, 6.7-8.8), with mean ratings of 8.2 for MS3s and 7.7 for MS4s. There was a significant increase in self-reported knowledge in ophthalmology, with an increase from 4.6 to 8.1 for MS3s (p=0.002) and 6.7 to 8.0 for MS4s (p=0.04). Students also reported higher interest in the field, with an increase from 4.9 to 7.8 for MS3s (p=0.01) and 7.5 to 8.7 for MS4s (p=0.1). The students performed significantly higher on the post-course test (94.8%) than UWorld question bank users (74.1%) (p<0.001). CONCLUSION: Our novel ophthalmology elective significantly enhanced self-reported medical student knowledge and interest in the field during a crisis that required transition to remote learning. Further study of student telehealth experience and objective assessment is needed to improve online learning in ophthalmology.

Design of a Volumetric Imaging Sequence Using a Vantage-256 Ultrasound Research Platform Multiplexed With a 1024-Element Fully Sampled Matrix Array.

Ultrasound imaging using a matrix array allows real-time multi-planar volumetric imaging. To enhance image quality, the matrix array should provide fast volumetric ultrasound imaging with spatially consistent focusing in the lateral and elevational directions. However, because of the significantly increased data size, dealing with massive and continuous data acquisition is a significant challenge. We have designed an imaging acquisition sequence that handles volumetric data efficiently using a single 256-channel Verasonics ultrasound research platform multiplexed with a 1024-element matrix array. The developed sequence has been applied for building an ultrasonic pupilometer. Our results demonstrate the capability of the developed approach for structural visualization of an ex vivo porcine eye and the temporal response of the modeled eye pupil with moving iris at the volume rate of 30 Hz. Our study provides a fundamental ground for researchers to establish their own volumetric ultrasound imaging platform and could stimulate the development of new volumetric ultrasound approaches and applications.

Relative Afferent Pupillary Defect Screening Through Transfer Learning.

Abnormalities in pupillary light reflex can indicate optic nerve disorders that may lead to permanent visual loss if not diagnosed in an early stage. In this study, we focus on relative afferent pupillary defect (RAPD), which is based on the difference between the reactions of the eyes when they are exposed to light stimuli. Incumbent RAPD assessment methods are based on subjective practices that can lead to unreliable measurements. To eliminate subjectivity and obtain reliable measurements, we introduced an automated framework to detect RAPD. For validation, we conducted a clinical study with lab-on-a-headset, which can perform automated light reflex test. In addition to benchmarking handcrafted algorithms, we proposed a transfer learning-based approach that transformed a deep learning-based generic object recognition algorithm into a pupil detector. Based on the conducted experiments, proposed algorithm RAPDNet can achieve a sensitivity and a specificity of 90.6% over 64 test cases in a balanced set, which corresponds to an AUC of 0.929 in ROC analysis. According to our benchmark with three handcrafted algorithms and nine performance metrics, RAPDNet outperforms all other algorithms in every performance category.

Motor Vehicle-Associated Traumatic Ocular Injuries Secondary to External Rear-Facing Sideview Mirrors: A Report of 3 Patients.

IMPORTANCE: Rear-facing sideview mirrors are a potentially reducible source of ocular morbidity following motor vehicle crashes. OBJECTIVE: To report cases highlighting shattered glass from sideview mirrors as a potential cause of ocular trauma in motor vehicle crashes. DESIGN, SETTING, AND PARTICIPANTS: Case series of 3 patients who presented to Grady Memorial Hospital, a level 1 trauma center and tertiary hospital, between May 5, 2017, and July 10, 2017, with ocular trauma as a result of shattered glass from sideview mirrors during motor vehicle crashes. A review of the literature was also conducted. Data were analyzed between July 2017 and August 2017. INTERVENTIONS OR EXPOSURES: Operation for exploration and repair of open globe in all 3 cases. MAIN OUTCOMES AND MEASURES: Visual prognosis and ocular morbidity postoperatively. RESULTS: All patients were white men in the age range of 26 to 43 years. This was a retrospective review of 3 of 208 patients who presented to Grady Memorial Hospital after motor vehicle crashes from May 5, 2017, to July 10, 2017. From the time of presentation of the 3 reported patients from Grady Memorial Hospital, all 3 had 2 surgeries inclusive of the initial open globe repair. Patients with this mechanism of injury experienced ocular morbidity, with all 3 cases resulting in uveal prolapse and 2 of 3 resulting in retinal detachments. Among the 3 patients, visual acuities after the second surgery within the first year were hand motion, 20/100, and 20/150. CONCLUSIONS AND RELEVANCE: Sideview mirrors can be a cause of serious ocular injuries in motor vehicle crashes. These 3 reported cases, combined with cases previously reported, suggest that this mechanism of ocular injury does occur. Further studies seem warranted to investigate the frequency of these findings and whether any design modifications may help reduce the frequency.

A Systematic Review Assessing the Current State of Automated Pupillometry in the NeuroICU.

The aim of this study was to assess the current state of automated pupillometry technology and its application in the neurointensive care unit (neuroICU). We performed a literature search using the PubMed, MEDLINE, and EMBASE databases from database inception through a search end date of October 18, 2018, to identify studies reporting on the use of automated pupillometry in the care of critically ill patients with neurological impairment. Two independent reviewers reviewed all titles and abstracts in two filtering phases. Data were extracted independently. One hundred and forty-one articles/abstracts have been published on the use of automated pupillometry in critical care since inception of the PubMed, MEDLINE, and EMBASE databases. We selected and reviewed 22 full-text articles and 8 abstracts, of which 26 were prospective, 2 were retrospective, and 2 were larger case series. Automated pupillometry increased precision, reliability, and reproducibility compared with the manual pupillary examination; detected subtle and early pupillary changes; detected pupillary changes that indicate a rise, or impending rise, in intracranial pressure detected level of analgesia and depth of sedation; served as a prognostic indicator; estimated the clinical severity of aneurysmal subarachnoid hemorrhage; and served as a noninvasive monitor of response to osmotic therapy. At present, no consensus guidelines exist endorsing routine use of automated pupillometry in the neuroICU. However, an increasing quantity of research supports the usefulness of automated pupillometry in this setting. Further large-scale prospective studies are needed before updated consensus guidelines recommending widespread adoption of automated pupillometry are produced.

Vulnerability of corneal endothelial cells to mechanical trauma from indentation forces assessed using contact mechanics and fluorescence microscopy.

Corneal endothelial cell (CEC) loss occurs from tissue manipulation during anterior segment surgery and corneal transplantation as well as from contact with synthetic materials like intraocular lenses and tube shunts. While several studies have quantified CEC loss for specific surgical steps, the vulnerability of CECs to isolated, controllable and measurable mechanical forces has not been assessed previously. The purpose of this study was to develop an experimental testing platform where the susceptibility of CECs to controlled mechanical trauma could be measured. The corneal endothelial surfaces of freshly dissected porcine corneas were subjected to a range of indentation forces via a spherical stainless steel bead. A cell viability assay in combination with high-resolution fluorescence microscopy was used to visualize and quantify injured/dead CEC densities before and after mechanical loading. In specimens subjected to an indentation force of 9 mN, the mean ±â€¯SD peak contact pressure P0 was 18.64 ±â€¯3.59 kPa (139.81 ±â€¯26.93 mmHg) in the center of indentation and decreased radially outward. Injured/dead CEC densities were significantly greater (p ≤ 0.001) after mechanical indentation of 9 mN (167 ±â€¯97 cells/mm2) compared to before indentation (39 ±â€¯52 cells/mm2) and compared to the sham group (34 ±â€¯31 cells/mm2). In specimens subjected to "contact only" - defined as an applied indentation force of 0.65 mN - the peak contact pressure P0 was 7.31 ±â€¯1.5 kPa (54.83 ±â€¯11.25 mmHg). In regions where the contact pressures was below 78% of P0 (<5.7 kPa or 42.75 mmHg), injured/dead CEC densities were within the range of CEC loss observed in the sham group, suggesting negligible cell death. These findings indicate that CECs are highly susceptible to mechanical trauma via indentation, supporting the established "no-touch" policy for ophthalmological procedures. While CECs can potentially remain viable below contact pressures of 5.7 kPa (42.75 mmHg), this low threshold suggests that prevention of indentation-associated CEC loss may be challenging.

Depth-Dependent Out-of-Plane Young's Modulus of the Human Cornea.

Purpose/Aim: Despite their importance in accurate mechanical modeling of the cornea, the depth-dependent material properties of the cornea have only been partially elucidated. In this work, we characterized the depth-dependent out-of-plane Young's modulus of the central and peripheral human cornea with high spatial resolution. MATERIALS AND METHODS: Central and peripheral corneal buttons from human donors were subjected to unconfined axial compression followed by stress relaxation for 30 min. Sequences of fluorescent micrographs of full-thickness corneal buttons were acquired throughout the experiment to enable tracking of fluorescently labeled stromal keratocyte nuclei and measurements of depth-dependent infinitesimal strains. The nominal (gross) out-of-plane Young's modulus and drained Poisson's ratio for each whole specimen was computed from the equilibrium stress and overall tissue deformation. The depth-dependent (local) out-of-plane Young's modulus was computed from the equilibrium stress and local tissue strain based on an anisotropic model (transverse isotropy). RESULTS: The out-of-plane Young's modulus of the cornea exhibited a strong dependence on in-plane location (peripheral versus central cornea), but not depth. The depth-dependent out-of-plane Young's modulus of central and peripheral specimens ranged between 72.4-102.4 kPa and 38.3-58.9 kPa. The nominal out-of-plane Young's modulus was 87 ± 41.51 kPa and 39.9 ± 15.28 kPa in the central and peripheral cornea, while the drained Poisson's ratio was 0.05 ± 0.02 and 0.07 ± 0.04. CONCLUSIONS: The out-of-plane Young's modulus of the cornea is mostly independent of depth, but not in-plane location (i.e. central vs. peripheral). These results may help inform more accurate finite element computer models of the cornea.

Assessment of the Accuracy and Cut-Failure Rates of Eye Bank-Cut Corneas for Use in Endothelial Keratoplasty: A Comparison of Outcomes Between 2010 and 2013.

PURPOSE: To evaluate the accuracy of eye bank-prepared precut donor corneas over time by comparing cut-failure rates and corneal thickness measurements in 2010 and 2013. METHODS: A total of 2511 human corneas cut by a technician-operated mechanical microkeratome intended for endothelial keratoplasty were evaluated prospectively at one large eye bank facility in 2010 and in 2013. The endothelium was evaluated by slit lamp, and specular microscopy both before and after cutting was performed. Graft thickness as measured by pachymetry and/or optical coherence tomography was collected to assess the accuracy of the cut tissue. Cut-failure rates were compared between normal donor tissue and tissue with significant preexisting scarring. RESULTS: The combined cut-failure rate in 2010 and 2013 was 2.3% (23/1000) and 1.6% (24/1511), respectively (P = 0.23). The cut-failure rate among normal tissue in 2010 and 2013 was 2.0% (19/927) and 1.4% (19/1400), respectively (P = 0.24). The cut-failure rate among previously scarred tissue in 2010 and 2013 was 5.5% (4/73) and 4.5% (5/111), respectively (P = 0.74). The mean surgeon-requested graft thickness was 144.7 µm (range 100-150, SD 13.6) and 127.2 µm (range 75-150, SD 25.2) in 2010 and 2013, respectively (P < 0.0001). The mean deviation from target graft thickness was 21.3 µm (SD 16.3) and 13.6 µm (SD 12.5) in 2010 and 2013, respectively (P < 0.0001). CONCLUSIONS: From 2010 to 2013, the combined cut-failure rates trended toward improvement, while the accuracy of graft thickness improved. This study suggests that the accuracy and success rates of tissue preparation for endothelial keratoplasty improve with experience and volume.

Cost analysis of objective resident cataract surgery assessments.

PURPOSE: To compare 8 ophthalmology resident surgical training tools to determine which is most cost effective. SETTING: University of Rochester Medical Center, Rochester, New York, USA. DESIGN: Retrospective evaluation of technology. METHODS: A cost-analysis model was created to compile all relevant costs in running each tool in a medium-sized ophthalmology program. Quantitative cost estimates were obtained based on cost of tools, cost of time in evaluations, and supply and maintenance costs. RESULTS: For wet laboratory simulation, Eyesi was the least expensive cataract surgery simulation method; however, it is only capable of evaluating simulated cataract surgery rehearsal and requires supplementation with other evaluative methods for operating room performance and for noncataract wet lab training and evaluation. The most expensive training tool was the Eye Surgical Skills Assessment Test (ESSAT). The 2 most affordable methods for resident evaluation in operating room performance were the Objective Assessment of Skills in Intraocular Surgery (OASIS) and Global Rating Assessment of Skills in Intraocular Surgery (GRASIS). CONCLUSIONS: Cost-based analysis of ophthalmology resident surgical training tools are needed so residency programs can implement tools that are valid, reliable, objective, and cost effective. There is no perfect training system at this time.

The location- and depth-dependent mechanical response of the human cornea under shear loading.

PURPOSE: To characterize the depth-dependent shear modulus of the central and peripheral human cornea along the superior-inferior and nasal-temporal directions with a high spatial resolution. METHODS: Cylindrical explants from the central and peripheral corneas of 10 human donors were subjected to a 5% shear strain along the superior-inferior and nasal-temporal directions using a microscope-mounted mechanical testing device. Depth-dependent shear strain and shear modulus were computed through force measurements and displacement tracking. RESULTS: The shear modulus G of the human cornea varied continuously with depth, with a maximum occurring roughly 25% of the way from the anterior surface to the posterior surface. G also varied with direction in the superior region and (at some depths) was significantly higher for superior-inferior shear loading. In the anterior half of the cornea, the shear modulus along the nasal-temporal direction (GNT) did not vary with location; however, the superior region had significantly higher GNT in posterior cornea. In contrast, the shear modulus along the superior-inferior direction (GSI) was independent of location at all depths. CONCLUSIONS: This study demonstrates that the peak shear modulus of the human cornea occurs at a substantial distance within the corneal stroma. Depth-dependent differences between central and peripheral cornea possibly reflect the location-dependent mechanical environment of the cornea. Moreover, the cornea is not a transverse isotropic material, and must be characterized by more than a single shear modulus due to its dependence on loading direction. The material properties measured in this study are critical for developing accurate mechanical models to predict the vision-threatening morphological changes that can occur in the cornea.

In vitro pilot analysis of uniformity, circularity, and concentricity of DSAEK donor endothelial grafts prepared by a microkeratome.

PURPOSE: The aim of this study was to analyze Descemet stripping automated endothelial keratoplasty donor endothelial grafts, prepared by using a microkeratome, in terms of uniformity, circularity, and concentricity. METHODS: In this pilot study, 12 human donor corneas were prepared by means of a microkeratome and imaged using the Visante anterior segment optical coherence tomography along 4 meridians. The microkeratome enters and exits the corneal tissue at an angle, creating a donor graft bed with a uniform stromal (US) thickness in between the angled edges. We termed the angled portion the "nonuniform stromal transitional annulus" (STA), the point of entry and exit of the microkeratome the "epithelium-to-epithelium" (E-E) diameter, and the length of the US bed the "US" diameter. The E-E and US diameters were measured to create a model of each donor graft, from which circularity and concentricity were calculated. The STA length and height were measured, and the slope was calculated. RESULTS: The mean E-E diameter was 10.69 ± 0.32 mm (range, 9.46-11.75 mm) and the mean US diameter was 8.96 ± 0.40 mm (range, 7.62-10.28 mm). The microkeratome generated elliptical rather than circular cuts, with a mean eccentricity of 0.34 ± 0.098 (range, 0.22-0.58). Eccentricity values between 0 and 1 represent ellipses, with zero characterizing a circle. The US ellipses and E-E ellipses were not concentric, with a mean deviation of the centers of the shapes of 177.06 ± 92.06 µm (range, 21.95-322.22 µm). The mean STA length was 0.73 ± 0.31 mm (range, 0.25-1.89 mm), the mean height was 0.43 ± 0.08 mm (range, 0.28-0.64 mm), and the mean slope was 34.11 ± 14.00° (range, 8.43-53.67°). CONCLUSIONS: Microkeratome cuts created nonuniform, noncircular nonconcentric donor grafts. Asymmetry and nonuniformity of donor tissue may help explain suboptimal visual outcomes.