Assessment of Orbital Compartment Pressure: A Comprehensive Review.

The orbit is a closed compartment defined by the orbital bones and the orbital septum. Some diseases of the orbit and the optic nerve are associated with an increased orbital compartment pressure (OCP), e.g., retrobulbar hemorrhage or thyroid eye disease. Our aim was to review the literature on the different approaches to assess OCP. Historically, an assessment of the tissue resistance provoked by the retropulsion of the eye bulb was the method of choice for estimating OCP, either by digital palpation or with specifically designed devices. We found a total of 20 articles reporting direct OCP measurement in animals, cadavers and humans. In nine studies, OCP was directly measured in humans, of which five used a minimally invasive approach. Two groups used experimental/custom devices, whilst the others applied commercially available devices commonly used for monitoring the compartment syndromes of the limbs. None of the nine articles on direct OCP measurements in humans reported complications. Today, OCP is mainly estimated using clinical findings considered surrogates, e.g., elevated intraocular pressure or proptosis. These diagnostic markers appear to reliably indicate elevated OCP. However, particularly minimally invasive approaches show promises for direct OCP measurements. In the future, more sophisticated, specifically designed equipment might allow for even better and safer measurements and hence facilitate the diagnosis and monitoring of orbital diseases

Evaluation of Bicanalicular Nasolacrimal Duct Intubation as an Adjunct in Surgical Ectropion Correction.

Background and Objectives: We aimed to analyze and compare the outcomes of conventional ectropion surgery procedures with and without concurrent bicanalicular nasolacrimal duct intubation to identify if the combination of procedures could serve as a novel surgical approach to treat lower eyelid ectropion. Materials and Methods: A retrospective review of all patients who underwent surgical correction for lower eyelid ectropion at the Cantonal Hospital of Aarau between January 2019 and December 2020 was performed. Patient medical records were examined for etiology, surgical correction technique and intra- and postoperative complications. The postoperative punctal position, the pre- and postoperative epiphora and reoperation rate were also documented. Two study groups consisting of cases with isolated and combined procedures were compared, with respect to postoperative punctual and lower lid position. Results: A total of 53 lower eyelids (35 patients) were included in this study. Six months postoperatively, the correct punctum position (p = 0.1188) and improvement of epiphora (p = 0.7739) did not significantly differ between the two groups. More complications were seen in the nasolacrimal duct intubation group (p = 0.0041), which consisted of cheese wiring and one tube dislocation. Conclusion: In our study, bicanalicular nasolacrimal intubation during ectropion surgery does not seem to improve the outcome of ectropion surgery and is, therefore, not recommended on a routine basis

Volume-rendered optical coherence tomography angiography during ocular interventions: Advocating for noninvasive intraoperative retinal perfusion monitoring.

We aimed to test for feasibility of volume-rendered optical coherence tomography angiography (OCTA) as a novel method for assessing/quantifying retinal vasculature during ocular procedures and to explore the potential for intraoperative use. Thirty patients undergoing periocular anaesthesia were enrolled, since published evidence suggests a reduction in ocular blood flow. Retinal perfusion was monitored based on planar OCTA image-derived data provided by a standard quantification algorithm and postprocessed/volume-rendered OCTA data using a custom software script. Overall, imaging procedures were successful, yet imaging artifacts occurred frequently. In interventional eyes, perfusion parameters decreased during anaesthesia. Planar image-derived and volume rendering-derived parameters were correlated. No correlation was found between perfusion parameters and a motion artifact score developed for this study, yet all perfusion parameters correlated with signal strength as displayed by the device. Concluding, volume-rendered OCTA allows for noninvasive three-dimensional retinal vasculature assessment/quantification in challenging surgical settings and appears generally feasible for intraoperative use

Assessment of Orbital Compartment Pressure: A Comprehensive Review

The orbit is a closed compartment defined by the orbital bones and the orbital septum. Some diseases of the orbit and the optic nerve are associated with an increased orbital compartment pressure (OCP), e.g., retrobulbar hemorrhage or thyroid eye disease. Our aim was to review the literature on the different approaches to assess OCP. Historically, an assessment of the tissue resistance provoked by the retropulsion of the eye bulb was the method of choice for estimating OCP, either by digital palpation or with specifically designed devices. We found a total of 20 articles reporting direct OCP measurement in animals, cadavers and humans. In nine studies, OCP was directly measured in humans, of which five used a minimally invasive approach. Two groups used experimental/custom devices, whilst the others applied commercially available devices commonly used for monitoring the compartment syndromes of the limbs. None of the nine articles on direct OCP measurements in humans reported complications. Today, OCP is mainly estimated using clinical findings considered surrogates, e.g., elevated intraocular pressure or proptosis. These diagnostic markers appear to reliably indicate elevated OCP. However, particularly minimally invasive approaches show promises for direct OCP measurements. In the future, more sophisticated, specifically designed equipment might allow for even better and safer measurements and hence facilitate the diagnosis and monitoring of orbital diseases

Comparison of Glaucoma-Relevant Transcriptomic Datasets Identifies Novel Drug Targets for Retinal Ganglion Cell Neuroprotection

Glaucoma is a leading cause of blindness and is characterized by the progressive dysfunction and irreversible death of retinal ganglion cells. We aimed to identify shared differentially expressed genes (DE genes) between different glaucoma relevant models of retinal ganglion cell injury using existing RNA-sequencing data, thereby discovering targets for neuroprotective therapies. A comparison of DE genes from publicly available transcriptomic datasets identified 12 shared DE genes. The Comparative Toxicogenomics Database (CTD) was screened for compounds targeting a significant proportion of the identified DE genes. Forty compounds were identified in the CTD that interact with >50% of these shared DE genes. We next validated this approach by testing select compounds for an effect on retinal ganglion cell survival using a mouse retinal explant model. Folic acid, genistein, SB-431542, valproic acid, and WY-14643 (pirinixic acid) were tested. Folic acid, valproic acid, and WY-14643 demonstrated significant protection against retinal ganglion cell death in this model. The increasing prevalence of open access-omics data presents a resource to discover targets for future therapeutic investigation

Minimally invasive measurement of orbital compartment pressure and implications for orbital compartment syndrome: a pilot study.

BACKGROUND Diagnosis of orbital compartment syndrome is mainly based on clinical findings, such as intraocular pressure and proptosis, which try to estimate the orbital compartment pressure. However, the reliability of these surrogates is unclear. Current techniques for the direct measurement of orbital compartment pressure are widely experimental and impractical in the clinical setting. Our aim was to explore the feasibility of minimally invasive needle manometry for direct measurement of orbital compartment pressure under reproducible conditions in an in vivo model of orbital congestion. We further sought to evaluate intraocular pressure and proptosis as indicators for elevated orbital compartment pressure. METHODS A total of 7 ml of mepivacaine 2% solution was injected into the orbital compartment in 20 patients undergoing cataract surgery under local anesthesia. A commercially available single-use manometer device was inserted between the syringe and the injection needle to measure the orbital compartment pressure for each milliliter of intraorbital volume increment. Additionally, intraocular pressure (subgroup A; n = 10) or axial globe position (subgroup B; n = 10) were measured. RESULTS Needle manometry allowed for rapid and continuous measurement of orbital compartment pressure. Overall mean orbital compartment pressure increased from 2.5 mmHg pre- to 12.8 mmHg post-interventionally. Both, intraocular pressure (Spearman's correlation coefficient rs = 0.637, p < 0.0001) and proptosis (rs = 0.675, p < 0.0001) correlated strongly with the orbital compartment pressure. CONCLUSIONS Needle manometry appears to be a feasible minimally invasive instrument to directly measure orbital compartment pressure, showing promises for a more routine application in managing orbital compartment syndrome. The results further suggest that both elevated intraocular pressure and proptosis are valuable indicators for orbital compartment syndrome

Ophthalmic Screening in Patients with Coronavirus Disease 2019: A Prospective Cohort Study

Postmortem pathological examinations, animal studies, and anecdotal reports suggest that coronavirus disease 2019 (COVID-19) could potentially affect intraocular tissue. However, published evidence is scarce and conflicting. In our study, we screened 100 eyes of 50 patients hospitalized for COVID-19. Relevant medical and ophthalmological history was assessed as well as symptoms, laboratory results, specific treatments, clinical course, and outcome. Ophthalmic exams including assessment of best corrected visual acuity (BCVA), intraocular pressure (IOP), color perception, ocular motility, ophthalmoscopy as well as optical coherence tomography (OCT) of the macula and the optic disc was performed at hospital admission and 29 to 192 days later. Of the 50 patients included, 14 (28%) were female. Median age was 64.5 (range 29–90) years. COVID-19 severity was mild in 15 (30%), severe in 30 (60%), and critical in five cases (10%). At baseline, median BCVA was 0.1 (0–1.8) Logarithm of the Minimum Angle of Resolution (LogMAR) and median IOP was 16 (8–22) mmHg. At follow-up, no relevant changes in BCVA and IOP were documented. No signs of active intraocular inflammation or optic nerve affection were found and OCT findings were widely stable during the observation period. Our findings suggest that COVID-19 does not regularly affect intraocular tissue

Human selection bias drives the linear nature of the more ground truth effect in explainable deep learning optical coherence tomography image segmentation

Supervised Deep Learning (DL) algorithms are highly dependent on training data for which human graders are assigned, e.g. for optical coherence tomography (OCT) image annotation. Despite the tremendous success of DL, due to human judgement, these ground truth labels can be inaccurate and/or ambiguous and cause a human selection bias. We therefore investigated the impact of the size of the ground truth and variable numbers of graders on the predictive performance of the same DL architecture and repeated each experiment 3 times. The largest training dataset delivered a prediction performance close to that of human experts. All DL systems utilized were highly consistent. Nevertheless, the DL under‐performers could not achieve any further autonomous improvement even after repeated training. Furthermore, a quantifiable linear relationship between ground truth ambiguity and the beneficial effect of having a larger amount of ground truth data was detected and marked as the more‐ground‐truth effect.This article is protected by copyright. All rights reserved

Human selection bias drives the linear nature of the more ground truth effect in explainable deep learning optical coherence tomography image segmentation

Supervised deep learning (DL) algorithms are highly dependent on training data for which human graders are assigned, for example, for optical coherence tomography (OCT) image annotation. Despite the tremendous success of DL, due to human judgment, these ground truth labels can be inaccurate and/or ambiguous and cause a human selection bias. We therefore investigated the impact of the size of the ground truth and variable numbers of graders on the predictive performance of the same DL architecture and repeated each experiment three times. The largest training dataset delivered a prediction performance close to that of human experts. All DL systems utilized were highly consistent. Nevertheless, the DL under-performers could not achieve any further autonomous improvement even after repeated training. Furthermore, a quantifiable linear relationship between ground truth ambiguity and the beneficial effect of having a larger amount of ground truth data was detected and marked as the more-ground-truth effect