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Infiltrative Optic Neuropathies
Published in Vivek Lal, A Clinical Approach to Neuro-Ophthalmic Disorders, 2023
Aniruddha Agarwal, Sabia Handa, Vishali Gupta
The most common manifestation in the leukemic infiltration of optic nerve head is blurring of vision. The loss of vision may be acute, though rarely patients may remain asymptomatic despite optic nerve infiltration.51 Profound vision loss including no light perception is common. Other symptoms and signs include ocular pain, conjunctival congestion and photophobia. Signs of increased ICP such as sixth cranial nerve palsy may indicate a diffuse meningeal involvement. Ophthalmoscopic examination may reveal optic disc edema with or without hemorrhages. Occasionally, the optic disc may appear normal.52 Presence of leukemic infiltrates results in the disc to appear creamy white with infiltrates, elevated, with peripapillary dot and blot or flame-shaped hemorrhages, along with serous macular detachment (Figure 10.3). Occlusion of the central retinal artery and vein is common association. Retinal hemorrhages may also be associated with anemia or pancytopenia (Figure 10.4).52–56
Neuroanatomy
Published in Ibrahim Natalwala, Ammar Natalwala, E Glucksman, MCQs in Neurology and Neurosurgery for Medical Students, 2022
Ibrahim Natalwala, Ammar Natalwala, E Glucksman
FALSE – Amaurosis fugax is a transient curtain-like loss of vision and precedes central retinal artery occlusion (CRAO). The central retinal artery is a branch of the ophthalmic artery which arises from the internal carotid. Once CRAO occurs, it usually results in permanent monocular blindness. CRAO may be caused by an embolus (e.g. thrombotic), inflammatory diseases such as GCA and infection – for instance, toxoplasmosis. Certain drugs like cocaine can also cause vasoconstriction and lead to CRAO.3
Non-DR Retinal Vascular Diseases
Published in Ching-Yu Cheng, Tien Yin Wong, Ophthalmic Epidemiology, 2022
Sobha Sivaprasad, Luke Nicholson, Shruti Chandra
Central retinal artery occlusion is known to occur perioperatively following ophthalmic, orbital, or head and neck surgical procedures. Reports of central retinal artery occlusion associated with peribulbar or retrobulbar injection and intraocular gas injection are present in the literature. One of the most frequently practiced procedures in medical retina is intravitreal injections of anti-vascular growth factor injections for various macular diseases. Gao et al. observed a cohort of 16,686 patients who received a cumulative number of 125,108 injections over a 2-year period (113). Twelve patients in total (8 with CRAO, 4 with BRAO) developed retinal artery occlusion within 90 days of injection. They reported an incidence of one retinal artery occlusion per 1,389 patients, i.e., 0.072%.
Giant cell arteritis
Published in Postgraduate Medicine, 2023
The most serious complication of GCA remains permanent visual loss which can occur in up to 20% of patients before glucocorticoid therapy initiation [66]. In a study of patients with biopsy-proven GCA, patients with ocular involvement were older, with a lower ESR and were less likely to have a headache or other systemic symptoms of giant cell arteritis than those without ocular involvement [67]. Two proposed reason for this variability in ocular involvement are the lack of classic symptoms of GCA making patients less likely to be referred for temporal artery biopsy and treatment in a prompt fashion and that those with a highly inflammatory response (elevated inflammatory indices) had more circulating IL-6 which has angiogenic properties and could counteract the arteritic ischemia of GCA [66]. GCA has a predilection for the ophthalmic artery and its branches most importantly the posterior ciliary arteries and the central retinal artery. The posterior ciliary arteries perfuse the choroid which nourishes the photoreceptors in the outer third of the retina and the optic nerve head. The central retinal artery provides blood to the inner two third of the retina including the retinal ganglion cells – the axons forming the optic nerve. The ophthalmic artery in addition to these two branches, also provides blood to the extraocular muscles and the vasa nervorum of the ocular motor nerves [68]. Vision changes in GCA have been described as a result of each of these vessels, in addition, vessels in the vertebrobasilar circulation can become involved which supplies circulation to the occipital lobe.
Impact of visual impairment following stroke (IVIS study): a prospective clinical profile of central and peripheral visual deficits, eye movement abnormalities and visual perceptual deficits
Published in Disability and Rehabilitation, 2022
Fiona J. Rowe, Lauren R. Hepworth, Claire Howard, Kerry L. Hanna, Jim Currie
Visual acuity is a primary measure of central visual function. The majority (81.4%) of stroke survivors needed glasses and wore their current glasses for visual acuity assessments. The mean near and distance visual acuities were below cut-off levels of low vision defined by the World Health Authority [20] and, by default, below levels acceptable for driving according to international driving regulations [21,28]. Our findings are similar to other studies reporting reduced central vision with reports of 15–25% at logMAR levels worse than 0.5 [29,30]. New onset reduced central vision may be due to stroke-related impact to the visual pathway. Arterial blood supply to the retina is from the central retinal artery – a branch from the anterior cerebral artery. Healthy vascular perfusion of the retina, and particularly the foveal and macular areas, is essential to high level central vision [2]. It is feasible that reduced central vision following stroke may reflect reduced perfusion and relative ischaemia within the anterior visual pathway. Visual field loss was predominantly homonymous hemianopia and quadrantanopia as is frequently reported [31–34].
Ocular ischaemia: signs, symptoms, and clinical considerations for primary eye care practitioners
Published in Clinical and Experimental Optometry, 2022
Michael Kalloniatis, Henrietta Wang, Paula Katalinic, Angelica Ly, Warren Apel, Lisa Nivison-Smith, Katherine F Kalloniatis
In patients with acute central retinal artery occlusions, referral for urgent intervention is critical. A study by Hayreh et al.139 using rhesus monkeys showed that if retinal blood flow can be restored within 97 minutes of ischaemia, there will be no detectable retinal damage. However, in the episode of ischaemia which persists for longer than 105 minutes, the retina undergoes irreversible damage. While there is a plethora of treatments proposed to improve visual outcomes in acute central retinal artery occlusions via either reducing intraocular pressure, removing clot or increasing vasodilation to increase the oxygen content of the blood, there is a lack of consistent evidence to support their application.140 These treatments are outside the scope of practice for optometrists however immediate referral to the nearest hospital with a specialised stroke unit (or ophthalmologist if hospital referral is not possible) is essential to ensure minimal retinal damage and the best possible outcome for the patient.