ResearchPad - Ophthalmology https://www.researchpad.co Default RSS Feed en-us © 2020 Newgen KnowledgeWorks <![CDATA[Improved Tear Film Stability in Patients with Dry Eye After Hyaluronic Acid and Galactoxyloglucan Use]]> https://www.researchpad.co/product?articleinfo=N2f0fdddb-b251-4767-a83e-56201cce36a4

Purpose

Artificial tears only provide transient relief for dry eye. To the best of our knowledge, this is the first study to objectively compare treatment with artificial tears with Keratograph 5M, which allows accurate and objective investigation of dry eye and artificial tear treatment. We aimed to evaluate whether a preservative-free combination of 0.4% hyaluronic acid and 0.2% galactoxyloglucan can improve dry eye using the new topographer, Keratograph 5M.

Patients and Methods

This prospective longitudinal, single-arm interventional cohort study was performed at a tertiary referral center and involved 20 patients with dry eye (40 eyes). Preservative-free artificial tears were administered every 3 h. The participants underwent clinical and instrumental evaluations at baseline, 15, 30, 60, 90 and 120 min after instillation and 1 week and 1 month after treatment. Baseline values were considered as the controls. All patients were assessed with Keratograph 5M for non-invasive Keratograph first break-up time and non-invasive Keratograph average break-up time, conjunctival hyperemia, and tear meniscus height. Ocular surface staining with fluorescein was evaluated using the slit-lamp and fluorescein break-up time examinations, and the Ocular Surface Disease Index score was recorded for each patient.

Results

The signs and symptoms improved after 1 month of preservative-free 0.4% hyaluronic acid and 0.2% galactoxyloglucan treatment. There was a significant increase in the non-invasive Keratograph first break-up time and non-invasive Keratograph average break-up time at 15, 30, 60, and 90 min, and 1 week and 1 month (P < 0.05) and a decrease in hyperemia, corneal staining, and Ocular Surface Disease Index scores after 1 week and 1 month (P < 0.05). No treatment-related adverse event was observed.

Conclusion

A combination of 0.4% hyaluronic acid and 0.2% galactoxyloglucan artificial tears seems effective for treating dry eye. Keratograph 5M can objectively detect these changes during the follow-up period.

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<![CDATA[Global eye health and the sustainable development goals: protocol for a scoping review]]> https://www.researchpad.co/product?articleinfo=Nc7396649-faf1-45c6-9afa-640a59848d9a

Introduction

In 2015, most governments of the world committed to achieving 17 sustainable development goals (SDGs) by the year 2030. Efforts to improve eye health contribute to the advancement of several SDGs, including those not exclusively health-related. This scoping review will summarise the nature and extent of the published literature that demonstrates a link between improved eye health and advancement of the SDGs.

Methods and analysis

Searches will be conducted in MEDLINE, Embase and Global Health for published, peer-reviewed manuscripts, with no time period, language or geographic limits. All intervention and observational studies will be included if they report a link between a change in eye health and (1) an outcome related to one of the SDGs or (2) an element on a pathway between eye health and an SDG (eg, productivity). Two investigators will independently screen titles and abstracts, followed by full-text screening of potentially relevant articles. Reference lists of all included articles will be examined to identify further potentially relevant studies. Conflicts between the two independent investigators will be discussed and resolved with a third investigator. For included articles, data regarding publication characteristics, study details and SDG-related outcomes will be extracted. Results will be synthesised by mapping the extracted data to a logic model, which will be refined through an iterative process during data synthesis.

Ethics and dissemination

As this scoping review will only include published data, ethics approval will not be sought. The findings of the review will be published in an open-access, peer-reviewed journal. A summary of the results will be developed for website posting, stakeholder meetings and inclusion in the ongoing Lancet Global Health Commission on Global Eye Health.

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<![CDATA[Testicular Seminoma Presenting with Bilateral Blindness: Looking Beyond the Eye]]> https://www.researchpad.co/product?articleinfo=Necf45000-b079-4867-aa96-af09094097db

Cancer-associated retinopathy (CAR) is a rare cause of vision loss that was first reported in 1976. It is reported that the retinopathy associated with cancer occurs due to antibodies against the tumor antigens that cross-react with retinal cell layers. We present the case of a young male who came to the emergency department with sudden onset of bilateral vision loss. He had a large-sized testicular seminoma with metastatic retroperitoneal lymphadenopathy. Several primary ophthalmological and systemic conditions were considered. He had multiple, positive anti-retinal antibodies. The cancer was felt to be the cause of the vision loss based on the clinical presentation and the presence of anti-retinal antibodies. He was treated with intravenous steroids, plasmapheresis, and curative chemotherapy, but there was no improvement in vision. Unfortunately, he died due to multiorgan failure. Our case is the second on seminoma-associated retinopathy in the literature.

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<![CDATA[Validity and feasibility of a self-administered home vision examination in Yueqing, China: a cross-sectional study]]> https://www.researchpad.co/product?articleinfo=N4fc4c4ee-3b31-463e-9978-203d18c8fe36

Objective

To investigate the validity and feasibility of a self-administered home vision examination programme in China.

Design

Cross-sectional study.

Setting

Yueqing, China.

Participants

A two-stage convenience sampling procedure was used to randomly select 600 households from 30 communities participating in the Yueqing Eye Study (YES). The aim of YES is to encourage home-based vision screening, reporting of visual acuity (VA) annually through social media and encouraging people to attend follow-up clinic appointments as a way to improve eye care access for adults with VA ≤+0.5 log of the minimum angle of resolution (logMAR).

Interventions

Household screeners (one per household) who tested other family members’ VA completed a questionnaire on family structure, demographic information and knowledge about screening procedures. Other family members then underwent confirmatory VA testing by researchers.

Outcome measures

The completion rate of home-based VA screening, its sensitivity and specificity were used to evaluate validity. Factors that determined whether families participated in the self-VA screening were used to evaluate feasibility.

Results

345 (66%) of the 523 (87.2%) households with valid data form their home-based vision examinations also were retested by researchers. There was no statistically significant difference in scores on the family-administerd or researcher-administerd VA test (VA≤+0.5 logMAR, p=0.607; VA >+0.5 logMAR, p=0.612). The sensitivity and specificity of home-based vision screening were 80.5% (95% CI 70.2% to 86.9%) and 95.1% (95% CI 92.6% to 96.8%), respectively. 14.7% (77/523) of tested respondents had VA ≤+0.5 logMAR. Predictors of performing home screening for VA remaining in regression models included higher economic status (‘fair and above’ vs ‘poor’: OR 1.74; 95% CI 1.08 to 2.76; p=0.022), age (<45 years vs ≥45 years: OR 0.46; 95% CI 0.25 to 0.85; p=0.014) and living in a nuclear (OR 5.17; 95% CI 2.86 to 9.36; p<0.001) or extended family (OR 8.37; 95% CI 4.93 to 14.20; p<0.001).

Conclusion

Self-administered home vision screening is reliable and highly accepted by Chinese adults.

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<![CDATA[Lightness induction enhancements and limitations at low frequency modulations across a variety of stimulus contexts]]> https://www.researchpad.co/product?articleinfo=N6d87ae3f-503f-46d8-a447-fc9bd638a450

Lightness illusions are often studied under static viewing conditions with figures varying in geometric design, containing different types of perceptual grouping and figure-ground cues. A few studies have explored the perception of lightness induction while modulating lightness illusions continuously in time, where changes in perceived lightness are often linked to the temporal modulation frequency, up to around 2–4 Hz. These findings support the concept of a cut-off frequency for lightness induction. However, another critical change (enhancement) in the magnitude of perceived lightness during slower temporal modulation conditions has not been addressed in previous temporal modulation studies. Moreover, it remains unclear whether this critical change applies to a variety of lightness illusion stimuli, and the degree to which different stimulus configurations can demonstrate enhanced lightness induction in low modulation frequencies. Therefore, we measured lightness induction strength by having participants cancel out any perceived modulation in lightness detected over time within a central target region, while the surrounding context, which ultimately drives the lightness illusion, was viewed in a static state or modulated continuously in time over a low frequency range (0.25–2 Hz). In general, lightness induction decreased as temporal modulation frequency was increased, with the strongest perceived lightness induction occurring at lower modulation frequencies for visual illusions with strong grouping and figure-ground cues. When compared to static viewing conditions, we found that slow continuous surround modulation induces a strong and significant increase in perceived lightness for multiple types of lightness induction stimuli. Stimuli with perceptually ambiguous grouping and figure-ground cues showed weaker effects of slow modulation lightness enhancement. Our results demonstrate that, in addition to the existence of a cut-off frequency, an additional critical temporal modulation frequency of lightness induction exists (0.25–0.5 Hz), which instead maximally enhances lightness induction and seems to be contingent upon the prevalence of figure-ground and grouping organization.

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<![CDATA[Uveitis as a Predictor of Predisposition to Autoimmunity]]> https://www.researchpad.co/product?articleinfo=N93546187-5229-43ab-a386-272535aea743

The right environmental trigger can lead to immune system activation, which, in turn, can create an autoimmune reaction. Although each autoimmune disease is characterized by specific symptoms, many nonspecific symptoms can make these conditions difficult to diagnose. In this literature review, we seek an association between immunization-induced uveitis and an autoimmune diagnosis and/or autoimmune flare-up in patients. Our goal is to consider adverse reactions to vaccines as a possible warning sign of current or future autoimmune disease. If an immunization-induced adverse reaction is known to be a predictor of an autoimmune disease, the clinician could raise suspicion for autoimmune disease when a patient presents with vaccine-associated uveitis. While no direct correlations can be made yet, our review supports closer scrutiny of the association of immunizations and autoimmune disorders. The occurrence of uveitis across several autoimmune diseases could mean a possible link between vaccine-induced uveitis and undiagnosed autoimmune disease. Researchers can, therefore, perform retrospective studies on vaccinated patients and investigate the occurrence of uveitis, along with the timeframe of resolution and presenting symptoms at the time of the diagnosis of autoimmune disease.

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<![CDATA[Association Between Visual Impairment and Decline in Cognitive Function in a Multiethnic Asian Population]]> https://www.researchpad.co/product?articleinfo=N750f7dce-b463-4490-946d-401c2ef951c8

This cohort study examines the association between visual impairment and decline in cognitive function in a multiethnic Asian population in Singapore over a 6-year period.

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<![CDATA[Can the dexamethasone intravitreal implant Ozurdex be safely administered in an out-of-operating room setting?]]> https://www.researchpad.co/product?articleinfo=Nb53d6be5-7838-4028-b496-3480118e1a7b

Abstract

Purpose: To describe a standardized protocol of the dexamethasone intravitreal (DEX) implant Ozurdex (Allergan, Dublin, Ireland) performed in a controlled environment surgical cabin (CESC).

Methods: Retrospective and observational study conducted on patients who underwent a DEX implant between May 2011 and June 2019, in a third level University Hospital. The controlled environment surgical cabin (ArcSterile, Imex, Valencia, Spain) used in this study was the MB 20 (2 m width, 1.60 m depth, and 2 m height) with an uninterrupted power system (ARSSAI1) to keep the cabin working for 20 min. The cabin was used in the open mode. A standardized protocol of intravitreal injections in controlled environment surgical cabin was designed.

Results: From May 2011 to February 2015, a total of 454 DEX implants were performed in the operating room, whereas from March 2015 to June 2019, 1054 DEX devices were implanted using the CESC. The mean number of DEX implants/per week was significantly lower in the operating room than in the CESC [2.3 (2.1 to 2.5) versus 3.8 (3.6 to 4.1), mean difference 1.5 (1.2 to 1.8), p < 0.0001]. The incidence of endophthalmitis was similar in the two populations, 0/454 (0.0%; 95% CI 0.0 to 0.81%) and 0/1054 (0.0%; 95% CI 0.0 to 0.35%) in the operating room and in the CESC, respectively.

Conclusions: The CESC may be a good alternative to the conventional operating room for the administration of the intravitreal DEX implant.

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<![CDATA[Neuroprotective effects of exogenous erythropoietin in Wistar rats by downregulating apoptotic factors to attenuate N-methyl-D-aspartate-mediated retinal ganglion cells death]]> https://www.researchpad.co/product?articleinfo=N85685bba-c047-422b-abfc-358a98ed1fe7

The aim of this study was to investigate whether exogenous erythropoietin (EPO) administration attenuates N-methyl-D-aspartate (NMDA)-mediated excitotoxic retinal damage in Wistar rats. The survival rate of retinal ganglion cells (RGCs) were investigated by flat mount analysis and flow cytometry. A total of 125 male Wistar rats were randomly assigned to five groups: negative control, NMDA80 (i.e., 80 nmoles NMDA intravitreally injected), NMDA80 + 10ng EPO, NMDA80 + 50ng EPO, and NMDA80 + 250ng EPO. The NMDA80 + 50ng EPO treatment group was used to evaluate various administrated points (pre-/co-/post- administration of NMDA80). Meanwhile, the transferase dUTP Nick-End Labeling (TUNEL) assay of RGCs, the inner plexiform layer (IPL) thickness and the apoptotic signal transduction pathways of μ-calpain, Bax, and caspase 9 were assessed simultaneously using an immunohistochemical method (IHC). When EPO was co-administered with NMDA80, attenuated cell death occurred through the downregulation of the apoptotic indicators: μ-calpain was activated first (peak at ~18hrs), followed by Bax and caspase 9 (peak at ~40hrs). Furthermore, the images of retinal cross sections have clearly demonstrated that thickness of the inner plexiform layer (IPL) was significantly recovered at 40 hours after receiving intravitreal injection with NMDA80 and 50ng EPO. Exogenous EPO may protect RGCs and bipolar cell axon terminals in IPL by downregulating apoptotic factors to attenuate NMDA-mediated excitotoxic retinal damage.

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<![CDATA[Ocular Thermal Burn Injury in the Emergency Department]]> https://www.researchpad.co/product?articleinfo=N6bb3b975-10c1-4850-814b-745165b24456

We present a case of an ocular thermal burn from a cooking accident where vegetable oil splashed into the patient's face. The emergency department evaluation and management of ocular thermal burns is discussed. Prompt evaluation, copious irrigation, and consultation with ophthalmology are recommended. Teaching points are highlighted.

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<![CDATA[Computer Vision Syndrome Among Health Sciences Students in Saudi Arabia: Prevalence and Risk Factors]]> https://www.researchpad.co/product?articleinfo=Nbd610bc0-2dc7-432e-a6a0-3c3a59298019

Introduction

Computer vision syndrome (CVS) is defined as a group of vision-related symptoms that result from the continuous use of devices with digital displays, such as computers, tablets, and smartphones. Students nowadays can find resources and books online on their smartphones easily, hence, reducing the use of paper-based reading materials. This might lead to a number of ocular symptoms. In this study, we aim to assess the prevalence and determine the risk factors of CVS among students at King Saud Bin Abdulaziz University for Health Sciences (KSAUHS) in Jeddah.

Materials and methods

This is an observational descriptive cross-sectional study design. Students of Colleges of Medicine, Applied Medical Sciences, and Science and Health Professions at KSAUHS were asked to fill an electronic self-administered survey. The survey instrument included questions on demographic information, digital devices using habits, frequency of eye symptoms, and ergonomic practices. 

Results

The sample size was 334 students, 55% of whom were males. The most used device was the mobile phone (78%), and the most common reason for using an electronic device was for entertainment (80%). The frequency of reported eye symptoms was as follows: headache (68%), feeling of an affected eyesight (short- or long-sightedness (65%)), eye itchiness (63%), burning sensation (62%), excessive tearing (58%), unclear vision (52%), redness (51%), dryness (48.3%), photophobia (47%), painful eye (44%), foreign body sensation (40%), excessive blinking (40%), difficulty in focusing on near objects (31%), halos around objects (28%), double vision (21%), and difficulty moving eyelids (9%). The most commonly applied ergonomic practice was adjusting display brightness based on the surrounding light brightness (82%). The rest of the ergonomic practices were less applied as follows: taking breaks while using the device (66%), sitting with the screen on face level (59%), sitting while the top of the screen on eye level (43%), sitting with the screen more than 50 cm away (32%), using antiglare filter (16%). The number of eye symptoms reported was significantly greater in female students (using Mann-Whitney U test) (U= 11056.500, p= 0.002), students who wear glasses (U= 11026, 0.002), and students who observe glare on their screens (U= 8363, p= 0.043).

Conclusion

CVS symptoms are commonly reported among health sciences students who use different electronic devices. The occurrence of CVS symptoms was significantly higher among female students, those who observe glare on screens, and those who wear eyeglasses. However, long duration of device use was not significantly associated with increased CVS symptoms. Ergonomic practices are not usually applied by most of the students, which necessitates more efforts to increase their awareness of the correct way of using devices.

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<![CDATA[Icariin affects cell cycle progression and proliferation of human retinal pigment epithelial cells via enhancing expression of H19]]> https://www.researchpad.co/product?articleinfo=N004f532e-a2fb-4932-a002-cbe76b780185

Background

Aberrant proliferation of retinal pigment epithelial (RPE) cells under pathologic condition results in the occurrence of proliferative vitreoretinopathy (PVR). Icariin (ICA)-a flavonol glucoside-has been shown to inhibit proliferation of many cell types, but the effect on RPE cells is unknown. This study aimed to clarify the inhibitory effects of ICA on RPE cells against platelet-derived growth factor (PDGF)-BB-induced cell proliferation, and discuss the regulatory function of H19 in RPE cells.

Methods

MTS assay was conducted to determine the effects of ICA on cell proliferation. Flow cytometry analysis was performed to detect cell cycle progression. Quantitative real-time PCR and western blot assay were used to measure the expression patterns of genes in RPE cells.

Results

ICA significantly suppressed PDGF-BB-stimulated RPE cell proliferation in a concentration-dependent manner. Moreover, since administration of ICA induced cell cycle G0/G1 phase arrest, the anti-proliferative activity of ICA may be due to G0/G1 phase arrest in RPE cells. At molecular levels, cell cycle regulators cyclin D1, CDK4, CDK6, p21 and p53 were modulated in response to treatment with ICA. Most importantly, H19 was positively regulated by ICA and H19 depletion could reverse the inhibitory effects of ICA on cell cycle progression and proliferation in PDGF-BB-stimulated RPE cells. Further mechanical explorations showed that H19 knockdown resulted in alternative expressions levels of cyclin D1, CDK4, CDK6, p21 and p53 under ICA treatment.

Conclusions

Our findings revealed that ICA was an effective inhibitor of PDGF-BB-induced RPE cell proliferation through affecting the expression levels of cell cycle-associated factors, and highlighted the potential application of ICA in PVR therapy. H19 was described as a target regulatory gene of ICA whose disruption may contribute to excessive proliferation of RPE cells, suggesting that modulation of H19 expression may be a novel therapeutic approach to treat PVR.

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<![CDATA[Inverted Papilloma of the Lacrimal Sac and Nasolacrimal Duct: A Case Report and Review of the Literature]]> https://www.researchpad.co/product?articleinfo=Nc56fa161-3231-428d-a86d-7e659033b480

Inverted papillomas of the lacrimal sac and nasolacrimal duct are exceedingly rare. Though histologically benign, these tumors are locally aggressive, have propensity for recurrence and are associated with a chance of malignant transformation. These tumors can present in an innocuous manner, masquerading as more common conditions such as primary acquired nasolacrimal duct obstruction. We present our experience with one such case and a review of the literature to emphasize the importance of pre-operative assessment and intra-operative vigilance, so as to aid in accurate diagnosis and early treatment.

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<![CDATA[What hinders congenital ectopia lentis patients’ follow-up visits? A qualitative study]]> https://www.researchpad.co/product?articleinfo=N47b32eb9-1666-4515-86ed-4a05b68c606e

Objectives

The aim of our study is to give insight into congenital ectopia lentis (CEL) patients’ care-seeking behaviour and explore the factors affecting their follow-up visits.

Design

Cross-sectional study; in-depth and face-to-face semistructured interview.

Setting

A large-scale ophthalmology hospital in China.

Participants

35 patients with CEL and their parents from May 2017 to August 2017.

Main outcome measures

Themes and categories. The interviews were audio-recorded, transcribed verbatim, coded and analysed using grounded theory. Data collection was closed when new themes did not emerge in subsequent dialogues.

Results

The factors affecting the timely visits included insufficient awareness of CEL, shame on hereditary disease, lack of effective doctor–patient communication, lack of reliable information online and daily stressors.

Conclusion

Continuing medical education of severe and rare disease, reforming the pattern of medical education, constructing an interactive platform of the disease on the internet and improving healthcare policy are effective ways to improve the diagnosis and treatment status of CEL in China.

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<![CDATA[Pattern of corneal astigmatism induced by primary pterygium in patients with cataract in a secondary hospital in Southern China: a cross-sectional study]]> https://www.researchpad.co/product?articleinfo=Nad1a70ee-b646-4dfa-85fc-f675d3fef821

Objectives

To review the pattern of primary pterygium-induced corneal astigmatism in patients with cataract in a southern Chinese population.

Design

Clinic-based cross-sectional retrospective study.

Setting

A secondary hospital at southern China.

Participants

A group of 1689 eyes with primary pterygium (PT group) and the other group of 4062 eyes without pterygium (NPT group) were included.

Main outcome measures

Corneal power was measured by an autokeratorefractometer. Corneal astigmatism was calculated as the difference in corneal power between the steepest and flattest meridians. Distribution of corneal astigmatism was compared between eyes with pterygium and eyes without pterygium.

Results

Distribution of corneal astigmatism was different between PT group (skewness=2.548, kurtosis=8.237) and NPT group (skewness=2.778, kurtosis=15.52). Mean corneal astigmatism was significantly higher in the PT group (1.62±1.49D) compared with the NPT group (1.17±0.89D, p<0.0001). The prevalence of corneal astigmatism >1D (PT 52.3%, NPT 40.9%, p<0.0001), >2D (PT 22.4%, NPT 10.6%, p<0.0001) or >3D (PT 10.5%, NPT 3.2%, p<0.0001) was significantly higher in the PT group compared with the NPT group. Eyes in the PT group had significantly higher corneal astigmatism than the NPT group in almost every age group (all p<0.05), with the exception of patients ≥90 years. Moreover, eyes in the PT group had significantly higher with-the-rule (PT 1.72±1.59D, NPT 1.19±0.88D, p<0.0001) and against-the-rule (PT 1.63±1.46D, NPT 1.18±0.88D, p<0.0001) but similar oblique astigmatism (PT 1.11±1.00D, NPT 0.99±0.89D, p=0.065) corneal astigmatism compared with the NPT group. Power vector analysis indicated that the axis of corneal astigmatism was not significantly different between the two groups (J0, PT −0.01±0.74D, NPT 0.01±0.52D, p=0.48; J45, PT −0.03±0.82D, NPT 0.00±0.52D, p=0.54).

Conclusions

Pattern of corneal astigmatism in eyes with cataract and coexisting primary pterygium was different from eyes without pterygium. Pterygium is associated with higher magnitude but not different axis of corneal astigmatism.

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<![CDATA[Utilization of Ocular Ultrasound in the Evaluation of Posterior Reversible Encephalopathy Syndrome: A Case Report]]> https://www.researchpad.co/product?articleinfo=N61cac398-99b8-4a43-b0cb-131114d26e86

Posterior reversible encephalopathy syndrome (PRES) is an infrequently encountered cause of altered mental status and seizure activity in the emergency setting. Diagnosis is often delayed by extensive testing and failure to consider PRES in the differential. Though MRI remains the gold standard for diagnosis, ultrasound-guided measurement of intra-ocular pressure is a safe, effective alternative that can expedite the diagnosis. The treatment of PRES involves the rapid reversal of offending agents and aggressive blood pressure management. The prognosis of PRES is favorable and neurologic sequelae are uncommon. This clinical case highlights the importance of the emergency physicians’ consideration of this pathology and the utilization of ultrasound as a non-invasive means of assessing intra-ocular pressure.

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<![CDATA[Non-infective Unilateral Panuveitis: Topical Steroids and Posterior Vitrectomy as a Cheap and Safe Alternative to Modern Treatment Modalities]]> https://www.researchpad.co/product?articleinfo=N877c4a76-2738-4f16-84ca-ab3beffef313

Uvea of the eye is a term that includes the iris, choroid, and ciliary body. Inflammation of all layers of the uvea is called panuveitis. Panuveitis can even spread to involve the optic nerve, retina, vitreous humor, or lens. This process can lead to redness and pain in the eye, blurring of vision, and even blindness. The condition is usually treated with topical steroids, but it becomes difficult in steroid-responders. Here, we present the case of a rare non-infective unilateral case of panuveitis that was successfully treated in an unorthodox manner.

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<![CDATA[Rare Presentation of Bilateral Central Retinal Vein Occlusion and Leukemic Retinopathy in a Young Adult Diagnosed with T-cell Acute Lymphoblastic Leukemia]]> https://www.researchpad.co/product?articleinfo=N3d4d3a64-d974-4a9c-a0b7-c5eb8b87e244

Simultaneous bilateral central retinal vein occlusion (CRVO) is a rare presentation that warrants consideration of an underlying hyperviscosity state. Increased serum viscosity can lead to the hematologic emergency of leukostasis with resultant vascular obstruction and hypoxic tissue damage. The following case demonstrates the first case of bilateral CRVO in a young adult secondary to acute lymphoblastic leukemia (ALL). A 23-year-old female presented to the emergency department (ED) with two days of worsening bilateral blurry vision and bitemporal headache. Her ocular exam was significant for bilateral intraretinal hemorrhages consistent with CRVO with chest radiograph demonstrating widened mediastinum with perihilar lymphadenopathy and serologic testing revealing ALL with blast crisis. The patient was subsequently admitted to the oncology service for induction chemotherapy. Patients with new headache and bilateral vision changes should prompt a thorough neurological and ophthalmologic exam to assess for underlying systemic pathologies. Concurrent bilateral CRVO is a rare but specific finding for systemic hyperviscosity syndrome, blood dyscrasia, polycythemia, or other serious illness. Early recognition and treatment of the underlying condition can prevent further vision loss and overall morbidity and mortality.

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<![CDATA[Response Properties of Cells Within the Rostral Superior Colliculus of Strabismic Monkeys]]> https://www.researchpad.co/product?articleinfo=Nfa99306f-c586-48b3-bb55-0d5592118425

Purpose

The superior colliculus (SC) is an important oculomotor structure which, in addition to saccades and smooth-pursuit, has been implicated in vergence. Previously we showed that electrical stimulation of the SC changes strabismus angle in monkey models. The purpose of this study was to record from neurons in the rostral SC (rSC) of two exotropic (XT; divergent strabismus) monkeys (M1, M2) and characterize their response properties, including possible correlation with strabismus angle.

Methods

Binocular eye movements and neural data were acquired as the monkeys performed fixation and saccade tasks with either eye viewing.

Results

Forty-two cells with responses likely related to eye misalignment were recorded from the rSC of the strabismic monkeys of which 29 increased firing for smaller angles of exotropia and 13 increased firing for larger exotropia. Twenty-six of thirty-five cells showed a pause (decrease in firing rate) during large amplitude saccades. Blanking the target briefly during fixation did not reduce firing responses indicating a lack of visual sensitivity. A bursting response for nystagmus quick phases was identified in cells whose topographic location matched the direction and amplitude of quick phases.

Conclusions

Certain cells in the rSC show responses related to eye misalignment suggesting that the SC is part of a vergence circuit that plays a role in setting strabismus angle. An alternative interpretation is that these cells display ocular preference, also a novel finding, and could potentially act as a driver of downstream oculomotor structures that maintain the state of strabismus.

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<![CDATA[Focal Thickness Reduction of the Ganglion Cell-Inner Plexiform Layer Best Discriminates Prior Optic Neuritis in Patients With Multiple Sclerosis]]> https://www.researchpad.co/product?articleinfo=N8c150c98-f63f-46e5-824c-c9428f2046a9

Purpose

The goal was to visualize topographic thickness maps of the intraretinal layers and evaluate their discrimination abilities and relationships with clinical manifestations in patients with multiple sclerosis (MS) and a history of optic neuritis (ON).

Methods

Thirty patients with relapsing-remitting MS (34 eyes with a history of ON [MSON] and 26 non-ON fellow eyes [MSFE]) were recruited together with 63 age- and sex-matched controls (HC). Ultrahigh resolution optical coherence tomography was used to image the macula and the volumetric data set was segmented to yield six intraretinal layers. Topographic thickness maps were aligned and averaged for the visualization. The thickness maps were partitioned using the Early Treatment Diabetic Retinopathy Study (ETDRS) and related to Sloan low-contrast letter acuity (LCLA), Expanded Disability Status Scale (EDSS), and disease duration.

Results

Focal thickness reduction occurred in the macular retinal nerve fiber layer (mRNFL) and ganglion cell-inner plexiform layer (GCIPL), with the most profound reduction occurring in MSON eyes (P < 0.05). A horseshoe-like thickness reduction pattern (U Zone) in the GCIPL appeared in MSON. The thickness of the U Zone had better discrimination power than the ETDRS partitions (area under the curve = 0.97) and differentiated 96% of MSON from HC. The thickness of the U Zone was positively correlated to 2.5% LCLA (r = 0.38, P < 0.05) and 1.25% LCLA (r = 0.57, P < 0.05).

Conclusions

The horseshoe-like thickness reduction of the GCIPL appeared to be an ON-specific focal thickness alteration with the highest discrimination power of prior ON.

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