We use cookies to distinguish you from other users and to provide you with a better experience on our websites. Close this message to accept cookies or find out how to manage your cookie settings.
To save content items to your account,
please confirm that you agree to abide by our usage policies.
If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your account.
Find out more about saving content to .
To save content items to your Kindle, first ensure no-reply@cambridge.org
is added to your Approved Personal Document E-mail List under your Personal Document Settings
on the Manage Your Content and Devices page of your Amazon account. Then enter the ‘name’ part
of your Kindle email address below.
Find out more about saving to your Kindle.
Note you can select to save to either the @free.kindle.com or @kindle.com variations.
‘@free.kindle.com’ emails are free but can only be saved to your device when it is connected to wi-fi.
‘@kindle.com’ emails can be delivered even when you are not connected to wi-fi, but note that service fees apply.
An adult Indian buffalo (Bubalus bubalis) presented with corneal opacity, irritation, and excessive lacrimation from the left eye in the Referral Veterinary Polyclinic-Teaching Veterinary Clinical Complex (RVC-TVCC), Indian Veterinary Research Institute, Izatnagar. Clinical examination revealed a whitish thread-like worm in the left eye’s anterior chamber. The worm was surgically removed from the eye with supportive nerve blocks. Light microscopy was used for parasite morphological identification, which provided insight into the worm as female Setaria sp. Genomic DNA was isolated, and polymerase chain reaction amplification of 12S rRNA was conducted for molecular confirmation of the parasite. The amplicon was sequenced and analysed by bioinformatics software. Sequence data showed an amplicon size of 243 bp. Phylogenetic analysis with reference data from the NCBI Genbank database revealed the worm was S. digitata, with a similarity of 99.17%. The common predilection site of S. digitata is in the peritoneal cavity of natural hosts like cattle and buffalo and is mostly non-pathogenic. The aberrant migration of the parasite larva to the brain and eye commonly occurs in goats, sheep, and horses, causing clinical conditions like cerebrospinal nematodiasis (lumbar paralysis) and ocular setariasis, respectively. Nevertheless, until now, there have been no reports of ocular setariasis in buffalo. This report is the first unusual occurrence of ocular setariasis in buffalo and its molecular confirmation and phylogenetic analysis using 12S rRNA.
Decreased vision in the aged population poses significant morbidity and decreases quality of life. At least one third of the American population over age 65 has significant vision compromise due to ophthalmic disease. Decreased vision limits independence and poses significant economic and societal burdens. Ophthalmic disease in the elderly poses significant challenges to patients and providers due to the vast and diverse spectrum of ophthalmic conditions, and therefore requires specialized care by optometrists and ophthalmologists.
Ophthalmic diseases are seen at a higher frequency in aged patients and include structural changes, malignancies, and infections of the eyelids and orbit. In addition, diseases such as cataracts, age-related macular degeneration (ARMD), glaucoma, and ischemic optic neuropathy are seen at a significantly higher incidence in elderly patients and can result in severe vision loss. Routine ophthalmic care is required to identify, manage, and treat such diseases in order to prevent sequelae, optimize independence, and preserve vision. Medical therapies, surgical intervention, low-vision aids, and social support systems can be utilized to aid in treatment.
Paediatric otogenic cerebral venous sinus thrombosis is a rare, heterogeneous and life-threatening condition, with possible otological, neurological and ophthalmological sequelae. Its course and outcomes can be widely variable. The publications available often consider individual aspects of paediatric otogenic cerebral venous sinus thrombosis management. The condition itself and the nature of the currently available guidance can lead to uncertainties when holistically managing patients with paediatric otogenic cerebral venous sinus thrombosis.
Objectives
Clear recommendations for the comprehensive assessment and management of paediatric otogenic cerebral venous sinus thrombosis are presented, along with the literature review upon which they are based. Its clinical and radiological assessment are discussed.
Conclusion
A multidisciplinary approach to assessment and management is recommended, inclusive of infectious diseases, ENT surgery, neurology, ophthalmology and haematology. On balance, anticoagulation is recommended for three months. Follow-up imaging is not recommended in the absence of clinical concern. Follow up by ENT surgery, neurology and ophthalmology departments is recommended.
Eye health is an integral part of well-being that may be at increased risk when health service delivery is affected by sudden-onset disasters, complex humanitarian events, or conflict in resource-scarce environments. This study proposes a design plan for a mobile eye hospital to support health systems between the initial emergency response and recovery of health infrastructure in resource-scarce environments of low- and middle-income countries. The facility benefits from high mobility and modularity, it can be assembled and operated by minimal personnel, and easily expanded as necessary. It has capacity to host high-volume ophthalmological services without the logistical complexity of large-scale emergency medical team responses or military operations. The design provides a medium-term service that can either operate from a fixed location or be redeployed in-country with ease. Mobile eye hospitals may provide a useful facility for local governments suffering damaged health systems, or as a way to complement current eye health provision. The design may also be used by charitable nongovernmental organizations during an initial emergency response, with the ability to quickly deploy to a target location and establish eye services.
This study aimed to characterize ophthalmology consultations ordered after Hurricane Harvey compared to consultations ordered during the same time period of the prior year.
Methods:
A retrospective chart review was performed at an urban, level 1 trauma center of a county hospital. All patients were included who received an electronic health record, documented ophthalmology consultation order between September 2017 and October 2017 (the time period immediately following Hurricane Harvey) or September 2016 and October 2016. Patient demographic risk factors were collected. Patient ICD10 clinical diagnoses were categorized as extraocular, intraocular, infectious, physiological, or other, and then subcategorized as trauma or non-trauma-related. A geographical heat map was generated to compare the changes in diagnosis volume by zip code to the magnitude of rainfall in the county.
Results:
Following Hurricane Harvey, ophthalmology consultation volume decreased, number of infectious ophthalmology diagnoses increased (P < 0.001), percentage of patients on immunosuppression increased (P < 0.001), and the number of private insurance payers increased while the number of county-funded insurance payers decreased (P = 0.003).
Conclusions:
The risk of infectious eye diagnosis was double the risk of traumatic eye diagnosis from Hurricane Harvey flooding. During public disaster planning, different ophthalmological medical resources and responses should be considered for flooding versus high-wind events.
The development of photodynamic therapy and anti-vascular endothelial growth factor agents have revolutionized the treatment of retinal diseases, transforming the retina subspecialty by ushering in an age of pharmacological treatments for a wide range of diseases, including age-related macular degeneration (AMD).
The second chapter studies the efforts of the Christian Ḥunayn ibn Isḥāq, whose workshop in ʿAbbāsid Baghdad translated the Galenic sources considered in this book, to enhance the respectability of the specialism of ophthalmology in his Ten Treatises on the Eye. I show that, even more so than medicine, ophthalmology was at a disadvantage in its pursuit for epistemic authority because Galen himself had attacked the sub-field as an exemplar of the worrying tendency among doctors in Rome and other cities towards specialization, which threatened the unity of the discipline and the health of patients. Concerned with his own intellectual status at court, Ḥunayn, I argue, subversively uses Galen's explanation of the Timaeus' description of the eyes' service to the rational soul to give ophthalmologists a stake in medico-philosophical controversies relating to sensation. I also expose how Ḥunayn modifies Galen’s interpretation of Plato’s teleological ocular anatomy and visual theory in order to privilege the eye over all other organs as a window to cosmic knowledge.
TwinsUK is the largest cohort of community-dwelling adult twins in the UK. The registry comprises over 14,000 volunteer twins (14,838 including mixed, single and triplets); it is predominantly female (82%) and middle-aged (mean age 59). In addition, over 1800 parents and siblings of twins are registered volunteers. During the last 27 years, TwinsUK has collected numerous questionnaire responses, physical/cognitive measures and biological measures on over 8500 subjects. Data were collected alongside four comprehensive phenotyping clinical visits to the Department of Twin Research and Genetic Epidemiology, King’s College London. Such collection methods have resulted in very detailed longitudinal clinical, biochemical, behavioral, dietary and socioeconomic cohort characterization; it provides a multidisciplinary platform for the study of complex disease during the adult life course, including the process of healthy aging. The major strength of TwinsUK is the availability of several ‘omic’ technologies for a range of sample types from participants, which includes genomewide scans of single-nucleotide variants, next-generation sequencing, metabolomic profiles, microbiomics, exome sequencing, epigenetic markers, gene expression arrays, RNA sequencing and telomere length measures. TwinsUK facilitates and actively encourages sharing the ‘TwinsUK’ resource with the scientific community — interested researchers may request data via the TwinsUK website (http://twinsuk.ac.uk/resources-for-researchers/access-our-data/) for their own use or future collaboration with the study team. In addition, further cohort data collection is planned via the Wellcome Open Research gateway (https://wellcomeopenresearch.org/gateways). The current article presents an up-to-date report on the application of technological advances, new study procedures in the cohort and future direction of TwinsUK.
Visual alterations, peripheral light loss (PLL) and blackout (BO), are components
of acceleration (+Gz) induced loss of consciousness (LOC) and
recovery of consciousness (ROC). The kinetics of loss of vision (LOV) and
recovery of vision (ROV) were determined utilizing ocular pressure induced
retinal ischemia and compared to the kinetics of LOC and ROC resulting from
+Gz-induced cephalic nervous system (CPNS) ischemia. The time from
self-induced retinal ischemia in completely healthy subjects (N
= 104) to the onset of PLL and complete BO was measured. The time
from release of ocular pressure, with return of normal retinal circulation, to
the time for complete recovery of visual fields was also measured. The kinetics
of pressure induced LOV and ROV was compared with previously developed kinetics
of +Gz-induced LOC and ROC focusing on the rapid onset, vertical arm,
of the +Gz-induced LOC and ROC curves. The time from onset of
increased ocular pressure, immediately inducing retinal ischemia, to PLL was
5.04 s with the time to BO being 8.73 s. Complete recovery of the visual field
from BO following release of ocular pressure, immediately abolishing retinal
ischemia, was 2.74 s. These results confirm experimental findings that visual
loss is frequently not experienced prior to LOC during exposure to rapid onset,
high levels of +Gz-stress above tolerance. Offset of pressure induced
retinal ischemia to ROV was 2.74 s, while the time from offset of
+Gz-induced CPNS ischemia to ROC was 5.29 s. Recovery of retinal
function would be predicted to be complete before consciousness is regained
following +Gz-induced LOC. Ischemia onset time normalization in
neurologic tissues permits comparison between different stress-induced times to
altered function. The +Gz-time tolerance curves for LOV and LOC
provide comparison and integration of neurologic state transition kinetics in
the retina and CPNS.
Ophthalmologic complaints represent approximately 2% of emergency department (ED) visits. Acute vision loss is the most serious of such presentations and requires prompt assessment for a treatable cause. The differential diagnosis for acute vision loss includes retinal detachment, macular disorders, vaso-occlusive disorders, temporal arteritis, neuro-ophthalmologic disorders, and functional disorders. We report the case of a previously healthy 33-year-old man who presented to the ED with acute bilateral vision loss that was ultimately diagnosed as central serous retinopathy (CSR), an idiopathic, self-limited condition that typically affects males age 20 to 50 years. This condition is not mentioned in standard emergency medicine textbooks or the emergency medicine literature, and our hope is that our report will serve to illustrate a typical case of CSR and help prompt emergency physicians to consider this diagnosis in the appropriate circumstances.
The Australian Twin Registry (ATR) is a not-for-profit organization that coordinates research involving Australian twins and researchers. The ATR is one of the largest volunteer registries of its kind and contains over 33,000 twin pairs. The purpose of this review is to provide a broad overview of recent ophthalmic studies that have utilized the ATR for recruitment purposes. Such studies include the Australian Twin Eye Study (ATES) and the Genes in Myopia (GEM) study. The ATES and GEM studies have undertaken studies into the genetic influences on a number of ophthalmic traits through the use of heritability studies, linkage studies, genome-wide association studies, and candidate gene-based studies. An overview of these studies is provided in this review, as well as a description of the recruitment methodologies for both the ATES and GEM studies.
Strabismus represents a complex oculomotor disorder characterized by the deviation of one or both eyes and poor vision. A more sophisticated understanding of the genetic liability of strabismus is required to guide searches for associated molecular variants. In this classical twin study of 1,462 twin pairs, we examined the relative influence of genes and environment in comitant strabismus, and the degree to which these influences can be explained by factors in common with refractive error. Participants were examined for the presence of latent (‘phoria’) and manifest (‘tropia’) strabismus using cover–uncover and alternate cover tests. Two phenotypes were distinguished: eso-deviation (esophoria and esotropia) and exo-deviation (exophoria and exotropia). Structural equation modeling was subsequently employed to partition the observed phenotypic variation in the twin data into specific variance components. The prevalence of eso-deviation and exo-deviation was 8.6% and 20.7%, respectively. For eso-deviation, the polychoric correlation was significantly greater in monozygotic (MZ) (r = 0.65) compared to dizygotic (DZ) twin pairs (r = 0.33), suggesting a genetic role (p = .003). There was no significant difference in polychoric correlation between MZ (r = 0.55) and DZ twin pairs (r = 0.53) for exo-deviation (p = .86), implying that genetic factors do not play a significant role in the etiology of exo-deviation. The heritability of an eso-deviation was 0.64 (95% CI 0.50–0.75). The additive genetic correlation for eso-deviation and refractive error was 0.13 and the bivariate heritability (i.e., shared variance) was less than 1%, suggesting negligible shared genetic effect. This study documents a substantial heritability of 64% for eso-deviation, yet no corresponding heritability for exo-deviation, suggesting that the genetic contribution to strabismus may be specific to eso-deviation. Future studies are now needed to identify the genes associated with eso-deviation and unravel their mechanisms of action.
Visual impairment is a leading cause of morbidity and poor quality of life in our community. Unravelling the mechanisms underpinning important blinding diseases could allow preventative or curative steps to be implemented. Twin siblings provide a unique opportunity in biology to discover genes associated with numerous eye diseases and ocular biometry. Twins are particularly useful for quantitative trait analysis through genome-wide association and linkage studies. Although many studies involving twins rely on twin registries, we present our approach to the Twins Eye Study in Tasmania to provide insight into possible recruitment strategies, expected participation rates and potential examination strategies that can be considered by other researchers for similar studies. Five separate avenues for cohort recruitment were adopted: (1) piggy-backing existing studies where twins had been recruited, (2) utilizing the national twin registry, (3) word-of-mouth and local media publicity, (4) directly approaching schools, and finally (5) collaborating with other research groups studying twins.
Aim: To describe the recruitment, ophthalmic examination methods and distribution of ocular biometry of participants in the Norfolk Island Eye Study, who were individuals descended from the English Bounty mutineers and their Polynesian wives. Methods: All 1,275 permanent residents of Norfolk Island aged over 15 years were invited to participate, including 602 individuals involved in a 2001 cardiovascular disease study. Participants completed a detailed questionnaire and underwent a comprehensive eye assessment including stereo disc and retinal photography, ocular coherence topography and conjunctival autofluorescence assessment. Additionally, blood or saliva was taken for DNA testing. Results: 781 participants aged over 15 years were seen (54% female), comprising 61% of the permanent Island population. 343 people (43.9%) could trace their family history to the Pitcairn Islanders (Norfolk Island Pitcairn Pedigree). Mean anterior chamber depth was 3.32mm, mean axial length (AL) was 23.5mm, and mean central corneal thickness was 546 microns. There were no statistically significant differences in these characteristics between persons with and without Pitcairn Island ancestry. Mean intra-ocular pressure was lower in people with Pitcairn Island ancestry: 15.89mmHg compared to those without Pitcairn Island ancestry 16.49mmHg (P = .007). The mean keratometry value was lower in people with Pitcairn Island ancestry (43.22 vs. 43.52, P = .007). The corneas were flatter in people of Pitcairn ancestry but there was no corresponding difference in AL or refraction. Conclusion: Our study population is highly representative of the permanent population of Norfolk Island. Ocular biometry was similar to that of other white populations. Heritability estimates, linkage analysis and genome-wide studies will further elucidate the genetic determinants of chronic ocular diseases in this genetic isolate.