[Augmented Reality in Ophthalmology: Technical Innovation Complements Education for Medical Students]. / Augmented Reality in der Augenheilkunde: Technische Innovation ergänzt studentische Lehre.

BACKGROUND: At the Medical Faculty of the University of Ulm, the learning objectives of ophthalmology are taught to students in a one-week block course in the fourth year of study. According to the National Competency-based Learning Objective Catalogue Medicine (NKLM), one of these learning objectives is the clinical examination of the eye, including the eye fundus examination. In order to best train this expertise as defined in the NKLM, a novel, augmented reality-based training simulator (Eyesi Indirect, VRmagic Holding AG, Mannheim, Germany) was integrated into the teaching at the University Eye Hospital Ulm. During the block week, two key questions were examined: Does the one week block lesson increase interest in ophthalmology? How do students assess the use of an innovative e-learning technology compared to three other classical teaching methods for learning ophthalmoscopy? MATERIAL/METHODS: As part of the student teaching (block weeks July and October 2016), 292 students were questioned by questionnaire anonymously and on a voluntary basis regarding their assessment of the block week and the training simulator at the beginning and end of the one week event. The ophthalmoscopies were classically practiced on the ophthalmoscope trainer, head model and on fellow students and then performed on the new training simulator. RESULTS: Overall, there was little interest among the students in ophthalmology. However, the block week helped to increase interest (p < 0.001). The assessments of attractiveness before and after the block week of ophthalmology as a later professional goal and as an optional subject in the practical year were also significantly increased (p < 0.001 or p = 0.031). With regard to the use of e-learning technologies, it was shown that the handling of the simulator for learning ophthalmoscopy was rated more attractive by the students than the classical technology-based teaching methods (all p < 0.01). The joy of learning could only be further increased by practicing on a fellow student (p = 0.051). CONCLUSION: The results of the present study show a positive impact of the block week on the attractiveness assessment of the specialty by the participating students. Innovative e-learning methods can increase the enjoyment of learning. However, the training simulator cannot provide a complete replacement of the training on a real person.

Comparison between Findings in Optical Coherence Tomography Angiography and in Fluorescein Angiography in Patients with Diabetic Retinopathy.

OBJECTIVE: To compare typical findings of diabetic retinopathy in optical coherence tomography angiography (OCTA) and fluorescein angiography (FA). SUBJECTS/METHODS: 42 patients were enrolled in this study. We performed FA and obtained en face 3 × 3 mm OCTA images of the macular region. The count of microaneurysms (MAs) and the size of the foveal avascular zone (FAZ) were compared. The assessability of the imaging modalities was graded in each eye. RESULTS: 53 eyes of 42 patients with a mean age of 61 years were included. 36/53 eyes revealed nonproliferative diabetic retinopathy, 17/53 eyes had proliferative diabetic retinopathy. The mean size of the FAZ was 0.39 mm2 in FA and 0.42 mm2 in OCTA. The mean MA count was 14 in FA and 13 in OCTA. The assessability was favorable to OCTA in 38-41/53 eyes regarding the FAZ and favorable to FA in 45-49/53 eyes regarding MAs. CONCLUSION: We found a good agreement for the size of the FAZ and a weak agreement regarding the count of MAs in both imaging modalities. The readers favored OCTA for the assessment of the FAZ and FA for the assessment of MAs. Complementary use of FA and OCTA ensures the best diagnostic approach in patients with diabetic retinopathy.

Quantity and quality of image artifacts in optical coherence tomography angiography.

OBJECTIVE: To analyze quality and frequency of OCTA artifacts and to evaluate their impact on the interpretability of OCTA images. DESIGN: 75 patients with diabetic retinopathy (DR), retinal artery occlusion (RAO), retinal vein occlusion (RVO), or neovascular age-related macular degeneration (nAMD) and healthy controls were enrolled in this cross-sectional study in the outpatient department of a tertiary eye care center. METHODS: All participants underwent an OCTA examination (spectral domain OCT Cirrus 5000 equipped with the AngioPlex module). OCTA scans were analyzed independently by two experienced ophthalmologists. Frequency of various artifacts for the entire OCTA scan and for different segmentation layers and the grading of OCTA interpretability were investigated. RESULTS: The analysis of 75 eyes of 38 women and 37 men between 24 and 94 years were included. Six eyes had no retinal disease, 19 eyes had nAMD, 16 had DR, 19 eyes had RVO, and 15 eyes showed RAO. A macular edema (ME) was present in 40 of the diseased eyes. Projection artifacts occurred in all eyes in any structure below the superficial retinal vessel layer, segmentation and motion artifacts were found in 55% (41/75) and 49% (37/75) of eyes, respectively. Other artifacts occurred less frequently. Segmentation artifacts were significantly more frequent in diseased than in healthy eyes (p<0.01). Qualitative assessment of OCTA images was graded as excellent in 65% and sufficient in 25% of cases, adding up to 91% images deemed acceptable for examination. Presence of ME was associated with a significantly poorer interpretability (p<0.01). CONCLUSION AND RELEVANCE: Various artifacts appear at different frequencies in OCTA images. Nevertheless, a qualitative assessment of the OCTA images is almost always possible. Good knowledge of possible artifacts and critical analysis of the complete OCTA dataset are essential for correct clinical interpretation and determining a precise clinical diagnosis.

[Innovative Teaching Methods: Wet Lab-based Ophthalmosurgical Education for Medical Students]. / Innovative Lehrmethoden: Einsatz eines ophthalmochirurgischen Wetlabs im Studentenunterricht.

BACKGROUND: An increased demand for young physicians in Germany is causing increased competition to attract the best minds, even during their undergraduate studies. Therefore, it is the task of the university hospitals to offer their students the best possible courses in order to arouse interest in the relevant subject area. We therefore examined the impact of an ophthalmosurgical wet lab on teaching undergraduate medical students. MATERIAL/METHODS: Undergraduate medical students were offered voluntary participation in the ophthalmosurgical wet lab during an ophthalmology block week. At the beginning and at the end of the week, as well as at the end of the wet lab, the students answered questionnaires with questions about the interest in the field of ophthalmology and the specific assessment of the wet lab. RESULTS: The interest of the students in ophthalmology was increased by the block week and additionally by the wet lab. The wet lab enriched the block week and was rated as very good by the participants. The overall rating of the block week was significantly better among participants in the wet lab than in the group without wet lab participation. The wet lab gave the students great pleasure, enabled them to apply the acquired knowledge, gain valuable insights into ophthalmology, and was easily implemented. CONCLUSION: The integration of a wet lab into the block week was evaluated very positively by the students and gives them a valuable insight into the field of ophthalmology.

[Novel Examination Procedures for the Assessment of Retinal Artery Occlusion by OCT Angiography]. / Neue Untersuchungsmöglichkeiten in der Beurteilung retinaler Arterienverschlüsse mittels OCT-Angiografie.

Background Retinal artery occlusion (RAO) is the most common primary angiopathy of the retina. With an incidence of 0.01 - 0.15%, this it is a rather rare disease, but is associated with irreversible damage to the retina and a poor prognosis for visual acuity. Since the 1960s - when fluorescence angiography (FA) was developed -, there has been little change in diagnostic investigations. FA is still the standard procedure for the assessment of retinal artery occlusions. With the development of OCT angiography (OCT-A), new multimodal imaging procedures have become possible. Patients/Methods We used Zeiss AngioPlex®-OCT-A technology in combination with the CIRRUS™ HD-OCT 5000 (Carl Zeiss Meditec, Inc., Dublin, USA) to create 6 × 6 mm and 3 × 3 mm volume scans of the area of non-perfusion in patients with RAO. Qualitative OCT-A analysis was performed on retinal images segmented into the superficial and deep retinal capillary plexus. In addition to this, volumetric scans can be segmented to any specific depth of the retina. On the basis of 4 cases, we demonstrate that OCT-A can be used to evaluate RAO. We present typical OCT-A findings. Results OCT-A images allow the detection of non-perfused areas in patients with acute and chronic RAO. The zones of reduced vascular perfusion are differently distributed in the superficial and deep retinal capillary plexus. In both acute and chronic cases of RAO, OCT-A offers important information on retinal vascular perfusion. Conclusion OCT-A can be used in the diagnosis and monitoring of acute and chronic cases of RAO. The advantages of OCT-A are that this technique is non-invasive and allows three dimensional microvascular visualisation within seconds. Although artefacts and the currently limited field of view can make it difficult to interpret OCT-A images reliably, these findings suggest that OCT-A may in future replace FA in the assessment of RAO in most patients.

[Accurate OCT-angiography Interpretation - Detection and Exclusion of Artifacts]. / Präzise Befundung mit der OCT-Angiografie ­ Artefakte erkennen und ausschließen.

Background Optical coherence tomography angiography (OCTA) provides, non-invasively, a three-dimensional visualization of the microvasculature of the retina and choroid. However, image artifacts may occur in OCTA and have an impact on clinical interpretation. The aim of this article is to describe image artifacts of OCTA and to present a nomenclature. Methods OCTA examinations were performed with the AngioPlex™ OCTA-technology in combination with the CIRRUS HD-OCT 5000 (Carl Zeiss Meditec, Inc., Dublin, USA) as well as with the PlexElite 9000 (Carl Zeiss Meditec, Inc., Dublin, USA). Typical artifacts identified in the OCTA images are described and their causes are explained. Results There are three main groups of artifacts that can be distinguished: (a) artifacts that are inherent in the OCTA technology and occur with all types of devices (projection artifacts, masking, unmasking, loss of signal); (b) artifacts caused by data and image processing algorithms and whose frequency or severity may depend on the device type used (segmentation artifacts, duplications of vessels); (c) motion artifacts that vary in frequency and severity depending on the type of device used, as different methods (e.g., eye tracker) are used to reduce them. The occurrence of artifacts is also dependent on patient cooperation, the clarity of the optical media, and the pathology of the retina. Conclusion As in any other imaging method, artifacts also occur in OCTA images. Nevertheless, qualitative assessment of OCTA images is almost always possible and provides indispensable findings on the morphology and perfusion status of the retina and choroid. A good knowledge of possible artifacts, and a critical analysis of the complete OCTA data set, allows a correct interpretation and is essential for making a precise clinical diagnosis.