Comparative analysis of respiratory motion tracking using Microsoft Kinect v2 sensor.

PURPOSE: To present and evaluate a straightforward implementation of a marker-less, respiratory motion-tracking process utilizing Kinect v2 camera as a gating tool during 4DCT or during radiotherapy treatments. METHODS: Utilizing the depth sensor on the Kinect as well as author written C# code, respiratory motion of a subject was tracked by recording depth values obtained at user selected points on the subject, with each point representing one pixel on the depth image. As a patient breathes, specific anatomical points on the chest/abdomen will move slightly within the depth image across pixels. By tracking how depth values change for a specific pixel, instead of how the anatomical point moves throughout the image, a respiratory trace can be obtained based on changing depth values of the selected pixel. Tracking these values was implemented via marker-less setup. Varian's RPM system and the Anzai belt system were used in tandem with the Kinect to compare respiratory traces obtained by each using two different subjects. RESULTS: Analysis of the depth information from the Kinect for purposes of phase- and amplitude-based binning correlated well with the RPM and Anzai systems. Interquartile Range (IQR) values were obtained comparing times correlated with specific amplitude and phase percentages against each product. The IQR time spans indicated the Kinect would measure specific percentage values within 0.077 s for Subject 1 and 0.164 s for Subject 2 when compared to values obtained with RPM or Anzai. For 4DCT scans, these times correlate to less than 1 mm of couch movement and would create an offset of 1/2 an acquired slice. CONCLUSION: By tracking depth values of user selected pixels within the depth image, rather than tracking specific anatomical locations, respiratory motion can be tracked and visualized utilizing the Kinect with results comparable to that of the Varian RPM and Anzai belt.

Risks and Complications Discussed in Consent for Strabismus Surgery.

This study is a qualitative analysis of the consent process for strabismus surgery, using recordings of physicians doing a mock consent for bilateral medial rectus recession. There is considerable variation in the risks of surgery and odds of complications that are cited by pediatric ophthalmologists during the consent process. We propose a reference table with complication rates for use during the consent process.

Congenital Myasthenic Syndrome associated with acetylcholine receptor deficiency: case report and review of the literature.

INTRODUCTION: Congenital Myasthenic Syndromes are a diverse group of conditions with a broad array of genetic underpinnings and phenotypic presentations. Acetylcholine receptor deficiency is one form that usually involves pathogenic variants in the Cholinergic Receptor Nicotinic Epsilon Subunit (CHRNE) gene encoding the ɛ-subunit of the acetylcholine receptor. METHODS: We report a case of a 4-year-old male with suspected Congenital Myasthenic Syndrome with Acetylcholine Receptor Deficiency who presented with ocular symptoms and generalized muscle weakness. We additionally summarize published findings regarding the genetic, phenotypic, and clinical considerations of Congenital Myasthenic Syndrome with Acetylcholine Receptor Deficiency. RESULTS: Exome sequencing revealed biallelic variants in CHRNE gene with a pathogenic frameshift variant and a variant of uncertain significance. After suboptimal response to pyridostigmine and albuterol, the patient experienced benefit with 3,4-DAP. The most commonly reported clinical characteristics in the literature are ptosis, muscle fatigability or weakness, and ophthalmoplegia. CONCLUSION: We present the case of a patient with biallelic variants in CHRNE gene including a variant of uncertain significance. Evaluation of variants of this gene, including the variant of uncertain significance identified in this case report, through further cases and studies may improve our understanding of Congenital Myasthenic Syndrome with Acetylcholine Receptor deficiency.

Evaluation of a combined school-based vision screening and mobile clinic program.

BACKGROUND: Effective vision screening programs for children require follow-up with eye care providers, but studies demonstrate poor follow-up rates after failed screenings. Programs have attempted to address this issue by providing free examinations and glasses after failed screenings. This study presents data from a mobile clinic program that provides instrument-based vision screening, eye examinations, and free glasses directly to children at school. METHODS: Between 2018 and 2021, a nonprofit organization provided in-school instrument-based screening and noncycloplegic examinations and refractions in elementary, middle, and high schools. Deidentified screening and clinic data were reviewed retrospectively. Information about each school regarding total student enrollment, enrollment based on race, and number of economically disadvantaged students was obtained from the Virginia Department of Education. RESULTS: In the 2019-2020 school year, 14,006 students from 58 schools were screened, and 4,238 (30.3%) were referred. The percentage of economically disadvantaged students was positively correlated to referral rate (R2 = 0.406). Between 2019 and 2020, the mobile clinic examined 3,095 students from the same 58 schools. Of these, 72.9% were prescribed glasses, and 16.3% were referred for a more comprehensive eye examination and treatment. Students were also diagnosed with cataracts, nystagmus, amblyopia, and strabismus. CONCLUSIONS: A combined screening program and mobile clinic traveling directly to schools can provide a pipeline for delivering eye care to vulnerable populations.

Teleophthalmology: Evaluation of Phone-based Visual Acuity in a Pediatric Population.

PURPOSE: With the recent rise of teleophthalmology due to coronavirus disease, health care needs accurate and reliable methods of checking visual acuity remotely. The visual acuity as measured by the GoCheck Kids application was compared with that of the Amblyopia Treatment Study (ATS) and the authors' clinic protocol. DESIGN: This was a prospective, comparison of visual acuity assessment methods. METHODS: Established patients (3-18 years of age) in the practice of a single pediatric ophthalmologist were eligible. Visual acuity was measured 1) by GoCheck Kids mobile application, by the patient's family member; 2) by HOTV-ATS, by study personnel; and 3) by regular clinic protocol, by an ophthalmic technician. To assess agreement between measurement of acuity, intraclass correlations with 95% confidence intervals (CI) were computed. RESULTS: A total of 53 children participated. The mean differences between GoCheck Kids and HOTV-ATS acuities (0.094) were significantly different (P < .001). The intraclass correlation coefficient (ICC) was 0.55 (95% CI: 0.40-0.68). The mean differences between GoCheck Kids and chart acuities (0.010) were not significantly different (P = .319; ICC: 0.59; 95% CI: 0.45-0.71). The mean differences between HOTV-ATS and chart acuities (0.084) were significantly different (P < .001; ICC: 0.66; 95% CI: 0.53-0.76). The percentages of eyes with visual acuity measured by GoCheck Kids within 1 line of the HOTV-ATS and chart acuity were 65.3% and 86.7%, respectively. CONCLUSIONS: GoCheck Kids as checked by a family member provided a modest correlation of visual acuity compared to the chart screen and a fair correlation of visual acuity compared to HOTV-Amblyopia Treatment Study protocol, although most were within 1 line.

The flipped-classroom approach to teaching horizontal strabismus in ophthalmology residency: a multicentered randomized controlled study.

BACKGROUND: The flipped-classroom involves watching prerecorded lectures at home followed by group learning exercises within the classroom. This study compares the flipped classroom approach with the traditional classroom for teaching horizontal strabismus didactics in ophthalmology residency. METHODS: In this multicenter, randomized controlled survey study from October 2017 to July 2018, 110 ophthalmology residents were taught esotropia and exotropia sequentially, randomized by order and classroom style. Flipped classroom participants were assigned a preclass video lecture prior to the in-class case-based activity. The traditional classroom included a preparatory reading assignment and an in-person lecture. Residents completed three identical 5-question assessments (pretest, post-test, and 3-month retention) and surveys for each classroom. The primary outcome measured residents' preferences for classroom styles; the secondary outcome compared knowledge acquisition. RESULTS: In our study cohort, the flipped classroom resulted in greater at-home preparation than the traditional classroom (P = 0.001) and was preferred by 33 of 53 residents (62%); 45 of 53 (85%) wished to see the flipped classroom used at least 25% of the time. The exotropia flipped classroom scored higher than traditional classroom on the pretest (3.71/5 [74%] vs 2.87/5 [57%]; P < 0.001) and post-test (4.53/5 [91%] vs 4.13/5 [83%]; P = 0.01) but not the 3-month retention test (3.53/5 [71%] vs 3.37/5 [67%]; P = 0.48). The esotropia classroom styles did not differ on pre- or post-test but demonstrated higher scores for the traditional classroom at 3-month retention (3.43/5 [69%] vs 2.92/5 [58%]; P = 0.03). Advantages cited for flipped classroom include being interactive and engaging while incentivizing better classroom preparation. CONCLUSIONS: The flipped classroom method was received favorably by trainees and may complement traditional methods of teaching.

Improvements in medical school wellness and career counseling: A comparison of one-on-one advising to an Advisory College Program.

BACKGROUND: Medical students have unmet needs in the areas of career and wellness advising. AIMS: The goal of this study is to describe the development of an Advisory College Program (ACP) and assess its effectiveness compared to a traditional one-on-one faculty advisor system. METHODS: The ACP, consisting of four colleges co-led by Advisory College Directors and supported by key Faculty, was developed to provide structured career and wellness advising. The authors compared the ACP to the former Faculty Advisory Program (FAP) using two parallel questionnaires. RESULTS: Surveys were completed by 74% of first-year students, 60% of second-year students, and 88% of third-year students. Survey data demonstrated a significant increase in the number of students who could identify their advisor, the frequency of student-advisor contacts, and the perceived accessibility of advisors in the ACP compared to the FAP. While an ordinal logistic regression model did not demonstrate a significant effect of the new advising system on overall satisfaction, univariate analysis demonstrated a significant increase in student satisfaction with wellness and career counseling. CONCLUSIONS: The ACP was more effective in promoting student wellness and career counseling than the traditional one-on-one faculty advisor system. Similar college-based programs may be beneficial to students at other medical school programs.

Traditional and instrument-based vision screening in third-grade students.

BACKGROUND: The American Association for Pediatric Ophthalmology and Strabismus recommends optotype-based vision screening for children >5 years of age. Instrument-based screening for 3- to 4-year-old children is more time efficient and has a higher positive predictive value than traditional optotype screening. The purpose of this study was to directly compare instrument-based vision screening and traditional screening of third graders in a school-based setting. METHODS: Third graders from 16 schools in Chesterfield County, Virginia, were screened by traditional methods (optotypes and stereoacuity) and using a photoscreener (Plusoptix S12). Children referred from either method were offered a comprehensive eye examination with cycloplegic refraction. Time to screen was recorded. RESULTS: Screening was performed on 1,593 children, of whom 516 (32.4%) were referred for a complete eye examination by either screening method. Traditional screening and photoscreening referred 287 and 398 children, respectively; 169 were referred by both methods. Cycloplegic examinations were completed on 247 children (47.9%). There was no statistical difference between the two methods for detecting visual acuity of <20/30 or the number of children requiring intervention. The average time to screen a child using the photoscreener and the traditional screening method was 30 seconds and 120 seconds, respectively. CONCLUSIONS: The positive predictive value for detecting a need for glasses in third-graders is not statistically significant between traditional and instrument-based screening. Instrument-based vision screening takes less time than traditional screening.

Longitudinal reproducibility of spectral domain optical coherence tomography in children with physiologic cupping and stable glaucoma.

PURPOSE: To determine whether Spectralis (Heidelberg, Germany) spectral domain optical coherence tomography (SD-OCT) measurements are reproducible over time in children with physiologic cupping and stable glaucoma. METHODS: Subjects were identified from a subset of participants in an earlier retrospective study conducted by our group and included children (<18 years of age) with physiologic cupping and stable primary congenital glaucoma (PCG) having had at least 2 SD-OCTs over a period of more than 1 between April 2010 and September 2015. Thicknesses of average peripapillary retinal nerve fiber layer (pRNFL) and six individual sectors and volumes of three segmented retinal layers and total retina were measured. Spectralis review software was used for segmentation. Intraclass correlation coefficients (ICC) and coefficient of variation (COV) were calculated. RESULTS: A total of 35 eyes of 35 children were included: 15 eyes had physiologic cupping; 20 eyes, PCG. Mean ages at initial SD-OCT were 11.2 ± 3.3 years and 9.7 ± 3.3, respectively; mean intervals between first and last imaging were 2.2 ± 1.1 and 3.0 ± 1.4 years, respectively. ICCs across three visits for both groups for average and sectoral pRNFL thicknesses were 0.887-0.997 and for segmented retinal volumes were 0.806-0.993. ICCs for total retinal volume for physiologic cupping and PCG were 0.993 and 0.954, respectively. COVs for average pRNFL thickness were 0.9% and 1.7%, respectively. For all other measurements, COVs ranged from 0.3% to 5.4%. CONCLUSIONS: Reproducibility of longitudinal SD-OCT measurements for average pRNFL thickness in children with stable glaucoma over about 2 years is comparable to short-term reproducibility (COV) in normal children (1.16%) and normal and glaucoma adults (1.62%-3.4%).

Multi-institutional evaluation of end-to-end protocol for IMRT/VMAT treatment chains utilizing conventional linacs.

We conducted a multi-institutional assessment of a recently developed end-to-end monthly quality assurance (QA) protocol for external beam radiation therapy treatment chains. This protocol validates the entire treatment chain against a baseline to detect the presence of complex errors not easily found in standard component-based QA methods. Participating physicists from 3 institutions ran the end-to-end protocol on treatment chains that include Imaging and Radiation Oncology Core (IROC)-credentialed linacs. Results were analyzed in the form of American Association of Physicists in Medicine (AAPM) Task Group (TG)-119 so that they may be referenced by future test participants. Optically stimulated luminescent dosimeter (OSLD), EBT3 radiochromic film, and A1SL ion chamber readings were accumulated across 10 test runs. Confidence limits were calculated to determine where 95% of measurements should fall. From calculated confidence limits, 95% of measurements should be within 5% error for OSLDs, 4% error for ionization chambers, and 4% error for (96% relative gamma pass rate) radiochromic film at 3% agreement/3 mm distance to agreement. Data were separated by institution, model of linac, and treatment protocol (intensity-modulated radiation therapy [IMRT] vs volumetric modulated arc therapy [VMAT]). A total of 97% of OSLDs, 98% of ion chambers, and 93% of films were within the confidence limits; measurements were found outside these limits by a maximum of 4%, < 1%, and < 1%, respectively. Data were consistent despite institutional differences in OSLD reading equipment and radiochromic film calibration techniques. Results from this test may be used by clinics for data comparison. Areas of improvement were identified in the end-to-end protocol that can be implemented in an updated version. The consistency of our data demonstrates the reproducibility and ease-of-use of such tests and suggests a potential role for their use in broad end-to-end QA initiatives.

Preschool Vision Screening: Where We Have Been and Where We Are Going.

PURPOSE: To discuss the evolution of instrument-based screening to detect amblyopia and its risk factors, and to summarize the importance of preschool vision screening. DESIGN: Expert commentary. METHODS: Author experiences were supplemented by a review and interpretation of pertinent medical literature. RESULTS: Amblyopia remains a public health problem, as it is a common cause of monocular visual impairment. As a disease, amblyopia detection is best obtained by appropriate vision screening rather than by yearly mandated comprehensive eye examinations for all children; the US Preventative Services Task Force (USPSTF) recently reaffirmed their recommendations for vision screening in preschool children. Vision screening devices have evolved over the past 4 decades ranging from photoscreeners that use instantaneously developing film, to autorefractors that detect amblyopia risk factors, to nerve fiber layer scanners that detect the microtropia that nearly always accompanies amblyopia. When it is detected early, effective treatment for amblyopia can be initiated. CONCLUSIONS: Amblyopia is a reversible cause of vision loss in children. Vision screening devices and screening programs have been extensively studied-experts and literature agree: vision screening devices and programs are cost-effective, are efficient, and are effective methods for amblyopia detection. The authors support the regular use of instrument-based vision screening in the medical home for all children until they reach a developmental stage where they can participate reliably in optotype-based vision screening.

Implementation of facial recognition with Microsoft Kinect v2 sensor for patient verification.

PURPOSE: The aim of this study was to present a straightforward implementation of facial recognition using the Microsoft Kinect v2 sensor for patient identification in a radiotherapy setting. MATERIALS AND METHODS: A facial recognition system was created with the Microsoft Kinect v2 using a facial mapping library distributed with the Kinect v2 SDK as a basis for the algorithm. The system extracts 31 fiducial points representing various facial landmarks which are used in both the creation of a reference data set and subsequent evaluations of real-time sensor data in the matching algorithm. To test the algorithm, a database of 39 faces was created, each with 465 vectors derived from the fiducial points, and a one-to-one matching procedure was performed to obtain sensitivity and specificity data of the facial identification system. ROC curves were plotted to display system performance and identify thresholds for match determination. In addition, system performance as a function of ambient light intensity was tested. RESULTS: Using optimized parameters in the matching algorithm, the sensitivity of the system for 5299 trials was 96.5% and the specificity was 96.7%. The results indicate a fairly robust methodology for verifying, in real-time, a specific face through comparison from a precollected reference data set. In its current implementation, the process of data collection for each face and subsequent matching session averaged approximately 30 s, which may be too onerous to provide a realistic supplement to patient identification in a clinical setting. Despite the time commitment, the data collection process was well tolerated by all participants and most robust when consistent ambient light conditions were maintained across both the reference recording session and subsequent real-time identification sessions. CONCLUSION: A facial recognition system can be implemented for patient identification using the Microsoft Kinect v2 sensor and the distributed SDK. In its present form, the system is accurate-if time consuming-and further iterations of the method could provide a robust, easy to implement, and cost-effective supplement to traditional patient identification methods.

Rebound tonometry over an air-filled anterior chamber in the supine child after intraocular surgery.

BACKGROUND: Intracameral air is a critical component of multiple ophthalmic surgical procedures and is frequently used in pediatric intraocular surgery. Among other benefits, it helps to facilitate postoperative examination in uncooperative children by allowing quick confirmation of a formed anterior chamber. The purpose of this study was to evaluate the usefulness and accuracy of a position-independent rebound tonometer (Icare PRO) in measuring intraocular pressure (IOP) intraoperatively in pediatric eyes with intracameral air compared to a commonly used handheld applanation tonometer (Tono-Pen XL). METHODS: In this prospective study of sequential children undergoing intraocular surgery, IOP was measured immediately following general anesthesia induction using both Icare PRO rebound tonometry and Tono-Pen XL tonometry, with instrument order randomized, in the supine child's eye(s). At completion of surgery after standard placement of intracameral air IOP was again measured using both instruments. RESULTS: A total of 42 eyes of 30 children were included. Surgeries included glaucoma (25), cataract-related (16), and both (1). Mean preoperative IOP by Tono-Pen XL was 23.52 ± 9.76 mm Hg; by Icare PRO, 20.94 ± 10.01 mm Hg (P = 0.0012). Mean IOP over intracameral air at surgery conclusion by Tono-Pen XL (n = 41) was 12.66 ± 4.90; by Icare PRO (n = 42), 12.96 ± 5.10 mm Hg (P = 0.46). One eye had postoperative IOP unrecordable by Tono-Pen XL but 7.9 mm Hg by Icare PRO. Bland-Altman analysis, which included only paired measurements, showed a preoperative mean difference in IOP (ΔIOPT-I) of 2.58 mm Hg (95% CI, -6.86 to 12.02); postoperative mean ΔIOPT-I of -0.42 mm Hg [95% CI, -7.57 to 6.73]. CONCLUSIONS: Position-independent rebound tonometry (Icare PRO) accurately measured IOP in supine children's eyes postoperatively in the presence of intracameral air.

The macula in pediatric glaucoma: quantifying the inner and outer layers via optical coherence tomography automatic segmentation.

BACKGROUND: Recent Spectralis (Heidelberg, Germany) spectral domain optical coherence tomography (SD-OCT) research software can automatically quantify the thickness of each individual retinal layer. The macular ganglion cell layer (GCL) and ganglion cell complex may be more sensitive for detecting glaucoma than the peripapillary retinal nerve fiber layer (pRNFL). The aim of this study was to characterize and compare the volume of each macular layer in the eyes of children with glaucoma versus those of normal controls. METHODS: The medical records of children with primary glaucoma and physiologic cupping who had undergone Spectralis SD-OCT imaging of the macula and pRNFL were reviewed retrospectively. Controls were recruited from a separate prospective study. Children with refractive error of <±5 or retinal or neurologic abnormalities were excluded. The average volume of each of the 8 retinal layers in the macula (central 6 mm) and pRNFL were compared among diagnostic groups. RESULTS: A total of 80 eyes of 80 children were included: 37 glaucoma eyes (25 with primary congenital and 12 with juvenile open-angle glaucoma) and 43 nonglaucoma eyes (28 with physiologic cupping). Eyes with glaucoma had significantly thinner mean macular nerve fiber layers, ganglion cell layers, inner plexiform layers, and pRNFLs than nonglaucomatous eyes: 0.82 ± 0.24 µm versus 1.00 ± 0.12 µm; 0.93 ± 0.22 µm versus 1.13 ± 0.10 µm; 0.80 ± 0.14 µm versus 0.91 ± 0.07 µm; 81.6 ± 26.5 µm versus 102.7 ± 10.0 µm, respectively (P < 0.00556 for all). Eyes without cupping and those with physiologic cupping were equivalent for all variables tested. CONCLUSIONS: Children with glaucoma have thinning of the three innermost retinal macular layers.

Field Evaluation of Automated Vision Screening Instruments: Impact of Referral Criteria Choice on Screening Outcome.

PURPOSE: Automated vision screeners can identify children with amblyopia risk factors. Two screening instruments having different referral criteria were evaluated in a community setting: SPOT (Pediavision, Lake Mary, FL) (sensitive manufacturer's referral criteria) and plusoptiX S08 (Plusoptix GmbH, Nuremberg, Germany) (specific modified Arthur referral criteria). METHODS: All children were screened by SPOT, and referred children were then screened using plusoptiX. Referred children received a gold standard examination to determine whether amblyopia risk factors were present. RESULTS: A total of 2,801 treatment-naïve children were screened using SPOT. Of these, 307 (11.0%) were referred by SPOT and subsequently screened by plusoptiX; 100 received a gold standard examination. Amblyopia risk factors were present in 43% (43 of 100) referred by SPOT compared to 72.7% (32 of 44) for plusoptiX. Eleven of 56 referred by SPOT had amblyopia risk factors that would have been missed by plusoptiX, including three with mild amblyopia. CONCLUSIONS: PlusoptiX with modified Arthur referral criteria can be a highly specific screening device detecting amblyopia risk factors without missing children with moderate/severe amblyopia.

Klebsiella pneumonia: An unusual cause of ophthalmia neonatorum in a healthy newborn.

Ophthalmia neonatorum is one of the most common infections during the neonatal period. Chlamydia trachomatis and Neisseria gonorrhoea must be ruled out, given their high virulence and systemic complications. We describe a case of ophthalmia neonatroum from Klebsiella pneumonia. Gram-negative organisms have been reported in hospital-acquired conjunctivitis (HAC), but we are unaware of any published reports of K. pneumonia conjunctivitis in an otherwise healthy full-term infant born in the United States who has received prophylaxis. It is important to promptly identify and treat Klebsiella conjunctivitis because it can lead to severe complications.

Limits on improving the positive predictive value of the Welch Allyn SureSight for preschool vision screening.

PURPOSE: To describe our experience using the Welch Allyn SureSight (Welch Allyn, Inc., Skaneateles Falls, NY) when vision screening a large population of preschool children. Additionally, we explore the usefulness of altering referral criteria to create high specificity for remote field screening in instances in which over-referral is costly. METHODS: Preschool children were screened for amblyogenic factors with the SureSight. Referred children received a gold standard examination with American Association for Pediatric Ophthalmology and Strabismus Vision Screening Committee-established failure criteria. Referral criteria were made increasingly more stringent to lower the rate of referral, and the effect on positive predictive value (PPV) was determined. RESULTS: A total of 15,749 children were screened, with reliable screening obtained in >99%. Rowatt-modified Vision in Preschoolers Study referral criteria produced a referral rate of 7.3% and a PPV of 48.2%. The PPV was >70% for children with unreliable screenings and with estimated refractive errors exceeding the instrument's range. Altering referral criteria improved PPV until referral rate reached 4% (PPV approximately 64%); further refinement past this level did not increase PPV and, hence, inappropriately limited sensitivity. CONCLUSIONS: A good test instrument should have high PPV and a referral rate approaching the population disease. Although altering referral criteria to decrease referral rate also decreases sensitivity, it should improve PPV. The presence of an asymptotic limit to PPV means additional improvement in PPV cannot be obtained with this technology. Thus, SureSight's usefulness for high-specificity screening is limited; however, the current referral criteria are sufficient for large screening programs and provide an acceptable referral rate and PPV.