Rare occult macular dystrophy with a pathogenic variant in the RP1L1 gene in a patient of Swiss descent

Purpose: We report a first case of bilateral occult macular dystrophy (OMD) with a c.133C>T (p.Arg45Trp) pathogenic variant in the retinitis pigmentosa 1-like 1 (RP1L1) gene in a patient of Caucasian Swiss decent. Observations: A 34-year-old man presented with decreased visual acuity known since childhood. Fundus examination of both eyes revealed no pathology other than mildly increased granularity of the foveal retinal pigment epithelium. The full-field electroretinogram (ffERG) presented with normal findings while the multifocal electroretinogram (mfERG) showed severely reduced amplitudes of the foveal response. Optical coherence tomography (OCT) showed foveal outer retinal atrophy. Fundus autofluorescence (FAF) imaging demonstrated near-normal findings with minimal mottling at the posterior pole. The genetic analysis revealed a heterozygous pathogenic variant (c.133C>T, p.Arg45Trp) in the RP1L1 gene. Conclusion and importance: Our present case suggests that OMD shows a wide range of clinical presentations with a variety of ophthalmological findings, age of disease onset, visual acuity, and genetic diversity

Neuregulin 1 Type III/ErbB Signaling Is Crucial for Schwann Cell Colonization of Sympathetic Axons

Analysis of Schwann cell (SC) development has been hampered by the lack of growing axons in many commonly used in vitro assays. As a consequence, the molecular signals and cellular dynamics of SC development along peripheral axons are still only poorly understood. Here we use a superior cervical ganglion (SCG) explant assay, in which axons elongate after treatment with nerve growth factor (NGF). Migration as well as proliferation and apoptosis of endogenous SCG-derived SCs along sympathetic axons were studied in these cultures using pharmacological interference and time-lapse imaging. Inhibition of ErbB receptor tyrosine kinases leads to reduced SC proliferation, increased apoptosis and thereby severely interfered with SC migration to distal axonal sections and colonization of axons. Furthermore we demonstrate that SC colonization of axons is also strongly impaired in a specific null mutant of an ErbB receptor ligand, Neuregulin 1 (NRG1) type III. Taken together, using a novel SC development assay, we demonstrate that NRG1 type III serves as a critical axonal signal for glial ErbB receptors that drives SC development along sympathetic axons

Reproducibility and normal values of static pupil diameters

Purpose - To provide additional information on normal values of static pupil diameter measurements for binocular infrared pupillometry with PupilX, a commercial pupillometer, and assess the reproducibility of this device's measurements. Methods - The pupil diameters from 91 study participants with normal eyes with an average age of 39.7 years (SD 16.4 years) were measured with PupilX under scotopic (0 lx), mesopic (1 lx), and photopic (16 lx) illumination. To assess the repeatability of the device, each measurement was repeated 5 times. Results - The mean pupil diameters were 6.5 mm (SD 1.3 mm), 5.5 mm (SD 1.2 mm), and 4.03 mm (SD 0.9 mm) under scotopic, mesopic, and photopic illumination. Left and right eyes showed no difference in mean pupil diameters. The mean unsigned anisocoria was 0.26 mm (SD 0.32 mm) under scotopic, 0.26 mm (SD 0.27 mm) under mesopic, and 0.19 mm (SD 0.19 mm) under photopic illumination. The decrease in pupil diameter with age was largest for scotopic (≈0.057 mm/y) and smallest for photopic illumination (≈0.025 mm/y). The repeatability of the pupillometer was better than 0.2 mm. Conclusion - This study provides reference values for age- and light-related pupil diameters measured with the PupilX digital pupillometer in normal subjects

Safety analysis and results of a borosilicate glass cartridge for no-touch graft loading and injection in Descemet membrane endothelial keratoplasty

PurposeThe aim of this study was to investigate the clinical outcome after standardized DMEK using a glass injector.MethodsA total of 254 patients undergoing DMEK surgery using a disposable DMEK borosilicate glass cartridge system were included in this retrospective study. The mean follow-up time was 13.2 months (SD8.1, range 6-36 months). The used glass cartridge system has an aperture diameter of 1.6 mm and a posterior loading orifice of 4.29 mm. Scanning electron microscopy (SEM) was used for estimation of the surface relief of the glass cartridge and comparison with a standard plastic injector cartridge.ResultsMean endothelial cell count of donor grafts was 2465 cells/mm(2) (SD +/- 199). After 6 weeks of DMEK endothelial cell count decreased by -28.6% to 1759 cells/mm(2) (SD +/- 435) (Wilcoxon p=0.001) and remained stable at the final follow-up at 1735 cells/mm(2) (SD +/- 442) (Wilcoxon p=0.89). SEM showed smoother surface of the glass cartridge in comparison with a plastic cartridge.Conclusionp id=ParThis study showed that this simple and effective DMEK cartridge seems to be a safe and viable device for minimized graft manipulation during DMEK surgery

Relation of Pupil Size and retinal diseases

Purpose: The aim of this study was to evaluate differences in pupil size of subjects with diabetes mellitus, age-related macular degeneration and retinal vein occlusion at different illumination levels with a novel pupilometer. Methods: The pupil size of study participants was measured with an infrared-video pupillometer (PupilX, Albomed) at 5 different illumination levels (0, 0.5, 4, 32 and 250 lux). Measurements were performed by the same investigator. 90 images were executed during a measurement period of 3 seconds. Results: This cross-sectional study analysed 484 eyes of 242 patients with diabetes mellitus (DM), age-related macular degeneration (AMD) and retinal vein occlusion (RVO); mean age 73.8 ± 12 years, range 45-92 years. A healthy control group had 342 eyes, mean age 61.4 ± 12.5 years, range 40-87 years. There was a statistically significant smaller pupil size at the DM-group in comparison to AMD, RVO and control group at all illumination levels, except 250 lux (p=0.041, Kruskal Wallis test). There was no statistically significant difference in pupil size of RVO and AMD in comparison to the control group. Conclusion: This study provides comparative data for pupil size at different retinal diseases at different illumination conditions measured with PupilX. Pupil size in diabetic patients was significantly smaller at scotopic and mesopic illuminance conditions. Therefore we confirm using pupillometry as a noninvasive and simple tool for additive detection of autonomic dysfunction in diabetes mellitus

AbdomenNet: Deep neural network for abdominal organ segmentation in epidemiologic imaging studies.

Background: Whole-body imaging has recently been added to large-scale epidemiological studies providing novel opportunities for investigating abdominal organs. However, the segmentation of these organs is required beforehand, which is time consuming, particularly on such a large scale. Methods: We introduce AbdomentNet, a deep neural network for the automated segmentation of abdominal organs on two-point Dixon MRI scans. A pre-processing pipeline enables to process MRI scans from different imaging studies, namely the German National Cohort, UK Biobank, and Kohorte im Raum Augsburg. We chose a total of 61 MRI scans across the three studies for training an ensemble of segmentation networks, which segment eight abdominal organs. Our network presents a novel combination of octave convolutions and squeeze and excitation layers, as well as training with stochastic weight averaging. Results: Our experiments demonstrate that it is beneficial to combine data from different imaging studies to train deep neural networks in contrast to training separate networks. Combining the water and opposed-phase contrasts of the Dixon sequence as input channels, yields the highest segmentation accuracy, compared to single contrast inputs. The mean Dice similarity coefficient is above 0.9 for larger organs liver, spleen, and kidneys, and 0.71 and 0.74 for gallbladder and pancreas, respectively. Conclusions: Our fully automated pipeline provides high-quality segmentations of abdominal organs across population studies. In contrast, a network that is only trained on a single dataset does not generalize well to other datasets