Acute Monocular Visual Loss

High risk and low prevalence diseases: Open globe injury

INTRODUCTION

Open globe injury (OGI) is a rare but serious condition that carries with it a high rate of morbidity.

OBJECTIVE

This review highlights the pearls and pitfalls of OGI, including presentation, diagnosis, and management in the emergency department (ED) based on current evidence.

DISCUSSION

OGI refers to full-thickness injury to the layers of the eye. OGI can be caused by blunt or sharp trauma, and subtypes include penetration, perforation, intraocular foreign body (IOFB), globe rupture, or mixed types. OGI is more common in males and usually secondary to work-related injury, but in women it is most commonly associated with falls. Emergency clinicians should first assess for and manage other critical, life-threatening injuries. Following this assessment, a thorough eye examination is necessary. Computed tomography (CT) may suggest the disease, but it cannot definitively exclude the diagnosis. While point-of-care ultrasound (POCUS) is highly sensitive and specific for some findings in OGI, its use is controversial due to potential globe content extrusion. Management includes protecting the affected eye from further injury, preventing Valsalva maneuvers that could extrude ocular contents, updating tetanus vaccination status, administering broad-spectrum antibiotics, and ophthalmology consultation for surgical intervention to prevent the sequelae of blindness and endophthalmitis.

CONCLUSION

An understanding of OGI can assist emergency clinicians in diagnosing and managing this sight-threatening traumatic process.

Paediatric patients with sudden vision impairment - An overview of MRI findings

PURPOSE

Sudden visual impairment in children occurs sporadically but, when present, needs urgent attention. Optimal management strategies and timely recognition are required. Often psychogenic disorders are the cause in school-age children; however, this is a diagnosis of exclusion. Therefore, MRI plays an important role in ruling out pathology along the optic pathways or helping with the diagnosis of underlying life threatening diseases, such as hydrocephalus or intracranial mass. The purpose of this study was first to evaluate non-traumatic (tumoural and non-tumoural) causes of acute vision impairment; and, second, to assess whether conventional cerebral and orbital MR imaging is helpful for children with sudden visual impairment.

PATIENTS AND METHODS

We retrospectively analysed the MRI scans and clinical findings of 95 children (47 male, 48 female; median age: 12.5 years, range: from 2 to 17 years) who presented symptoms of monocular or bilateral acute vision impairment.

RESULTS

Patients with acute visual impairment were usually older than 7 years. In 36% of the patients a correlation between the MRI findings and the clinical symptoms was found. The most common causes of visual impairment were: infectious diseases (16%), migraine (12%), autoimmune diseases (11%), optic nerve neuritis with unknown aetiology (8%), neoplasms (8%), idiopathic intracranial hypertension (5%) and orthostatic hypotension (4%). Still, in 23% of the patients the cause remained unclear.

CONCLUSION

Acute vision impairment is frequently caused by infectious diseases, migraine, autoimmune diseases or tumours in children. MRI is highly recommended, especially in the case of children younger than 5 years of whom clinical assessment can be difficult.

Vascular stem cells and ischaemic retinopathies

Retinal ischaemic disorders such as diabetic retinopathy and retinal vein occlusion are common. The hypoxia-related stimuli from oxygen-deprived neural and glial networks can drive expression of growth factors and cytokines which induce leakage from the surviving vasculature and/or pre-retinal and papillary neovascularisation. If left untreated, retinal vascular stasis, hypoxia or ischaemia can lead to macular oedema or fibro-vascular scar formation which are associated with severe visual impairment, and even blindness. Current therapies for ischaemic retinopathies include laser photocoagulation, injection of corticosteroids or VEGF-antibodies and vitreoretinal surgery, however they carry significant side effects. As an alternative approach, we propose that if reparative intra-retinal angiogenesis can be harnessed at the appropriate stage, ischaemia could be contained or reversed. This review provides evidence that reperfusion of ischaemic retina and suppression of sight-threatening sequelae is possible in both experimental and clinical settings. In particular, there is emphasis on the clinical potential for endothelial progenitor cells (EPCs) to promote vascular repair and reversal of ischaemic injury in various tissues including retina. Gathering evidence from an extensive published literature, we outline the molecular and phenotypic nature of EPCs, how they are altered in disease and provide a rationale for harnessing the vascular reparative properties of various cell sub-types. When some of the remaining questions surrounding the clinical use of EPCs are addressed, they may provide an exciting new therapeutic option for treating ischaemic retinopathies.

Temporal arteritis: an approach to suspected vasculitides

Temporal arteritis, also known as giant cell arteritis, is the most common vasculitis in adults. Classic symptoms include polymyalgia rheumatica, new-onset headache, jaw claudication, and visual symptoms such as diplopia and amaurosis fugax. Elevated erythrocyte sedimentation rate is a common laboratory finding in temporal arteritis, and abnormalities on temporal artery biopsy are the gold standard for diagnosis. Rapid treatment with steroids can prevent permanent vision loss, which is the worst ischemic complication of the disease. It is important for primary care physicians to be able to recognize the signs and symptoms of this disease and begin treatment rapidly.

Two presentations of nonarteritic ischemic optic neuropathy

BACKGROUND

Nonarteritic ischemic optic neuropathy (NAION) is the most common acute optic neuropathy in adults over the age of 50. Patients affected notice sudden and painless loss of vision in 1 eye, often upon awaking. Studies have found that the opposite eye may be affected in approximately 15% to 20% of cases within a 5-year period. NAION vision loss results from an ischemic event often affecting the short posterior ciliary arteries. This results in optic nerve pallor, nerve fiber layer defects, and corresponding visual field defects.

CASE REPORTS

Two cases of NAION are discussed here. The first patient, a 57-year-old woman, had a 10-year history of visual symptoms, and the second, a 66-year-old man, presented in less than a week after first noticing symptoms. Both had predisposing systemic risk factors and resultant visual field loss and decreased visual acuity.

CONCLUSIONS

Predisposing factors for NAION include small cup-to-disc ratios of the optic nerve, obstructive sleep apnea, nocturnal hypotension, diabetes, and other vascular diseases. The vision loss is irreversible, and there is no known effective treatment to prevent subsequent disc atrophy or recurring episodes.