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Toxins in Neuro-Ophthalmology
Published in Vivek Lal, A Clinical Approach to Neuro-Ophthalmic Disorders, 2023
Toxicity includes keratopathy, ciliary body involvement, lens opacities and retinopathy. Retinopathy is the major concern although others are more common but benign. Risk factors of retinopathy include age, daily as well as cumulative dosage, treatment duration and coexisting retinal, renal or liver disease. Visual symptoms include decreased vision, missing central vision, glare, blurred vision, light flashes and metamorphopsia. Characteristic fundus finding is bull's-eye maculopathy. All patients have field defects including paracentral, pericentral, central and peripheral field loss. Color vision is impaired in the advanced stage. Regular screening may be necessary to detect reversible premaculopathy. Cessation of the drug is the only effective management of the toxicity.
Diabetic Retinopathy
Published in Jahangir Moini, Matthew Adams, Anthony LoGalbo, Complications of Diabetes Mellitus, 2022
Jahangir Moini, Matthew Adams, Anthony LoGalbo
Signs of diabetic macular edema include macular thickening with or without hard exudates, as seen during stereobiomicroscopy. Thickening may occur in focal, multifocal, and diffuse areas. The hard exudates may show different patterns, such as circinate rings. Diabetic macular edema can be asymptomatic, but decreased visual acuity usually occurs. It involves moderate vision loss. Some patients have metamorphopsia, a type of distorted vision in which a grid of straight lines appears “wavy.” Parts of the grid may actually appear blank. Some patients first notice this condition while looking at the window blinds in their homes.
Application of Mobile and Wearable Technology in Data Collection for Ophthalmology
Published in Ching-Yu Cheng, Tien Yin Wong, Ophthalmic Epidemiology, 2022
Ashwin Venkatesh, Pradeep Ramulu
Metamorphopsia is a perceived distortion of visual space, commonly seen in disorders of macular function. The ForeseeHome device (Notal Vision, Tel Aviv, Israel) uses preferential hyperacuity perimetry to measure visual distortions in age-related macular degeneration and is designed for unsupervised use by patients in their homes. The test involves 500 retinal data points over 14° of the patient’s central visual field, collected in approximately 3 minutes, and allows quantitative monitoring of changes in macular function in metamorphopsia with greater sensitivity than the Amsler grid.14 Results are automatically transmitted to Notal Vision’s Monitoring Center, where they are logged with all previous tests from that patient. Patients who generate an alert on the ForeseeHome test trigger an immediate recall to their ophthalmologist’s office for additional diagnostic testing and examination. The utility of this device is highlighted by the AREDS2-HOME clinical trial, which concluded that the ForeseeHome device enabled earlier detection of choroidal neovascularization in high-risk patients with age-related macular degeneration.15
Stellate nonhereditary idiopathic foveomacular retinoschisis in an asymptomatic patient
Published in Clinical and Experimental Optometry, 2022
Thomas A Keith, Megan C Mills, Eric Tidmore
Stellate nonhereditary idiopathic foveomacular retinoschisis (SNIFR) is a relatively new classification of macular retinoschisis that occurs in patients without any known predisposing ocular conditions or genetic factors. The condition tends to be unilateral but may be bilateral and tends to occur in women more than men. Patients present with symptoms of metamorphopsia and blurred vision or may be asymptomatic. The visual acuity of the patient typically remains better than or equal to 6/12,1 and they are often asymptomatic to peripheral scotomata.2 In this case report, eye care providers are alerted to the detection of stellate nonhereditary idiopathic foveomacular retinoschisis as an incidental finding in otherwise asymptomatic patients or as a differential diagnosis to mild non-specific visual symptoms.
Posterior segment conditions associated with myopia and high myopia
Published in Clinical and Experimental Optometry, 2020
Divya Jagadeesh, Krupa Philip, Cathleen Fedtke, Monica Jong, Angelica Ly, Padmaja Sankaridurg
In approximately 10-per cent of eyes with posterior staphyloma, a dome‐shaped macula (Figure 5B), that is, a convex (dome‐shaped contour) macula is observed within the concavity of the posterior staphyloma.2007 Possible aetiological factors for dome‐shaped macula include scleral in‐folding similar to hypotony, tangential vitreomacular traction, choroidal thickening and scleral thickening.2008 The condition results in vision loss and metamorphopsia. Foveal serous retinal detachment, choroidal neovascularisation, and retinal pigment epithelial detachments were also reported in association with the dome‐shaped macula. No reports on the progression of the dome‐shaped macula are currently available. The dome‐shaped macula is reportedly observed in both children and adults who are highly myopic; however, the prevalence is low.2017
Transient vision loss: a neuro-ophthalmic approach to localizing the diagnosis
Published in Expert Review of Ophthalmology, 2018
Helen Chung, Jodie M. Burton, Fiona E. Costello
The quality of the visual disturbance also needs to be characterized. Often patients with TVL will describe their vision as ‘blurry,’ which lacks precision. Further questioning is often required, during which time patients may reveal that they cannot see the beginning of words (left homonymous visual field loss), the ends of words (right homonymous vision loss), the center of objects (central scotomas), or the top or bottom of images (superior or inferior altitudinal defects, respectively). Alternatively, patients may report distorted images such that lines appear bent (metamorphopsia) or images appear slightly misshapen or disfigured (metamorphopsia or migraine). Some patients with cortical causes of vision loss report seeing persistent images, referred to as palinopsia. During this part of the history taking, it should be ascertained whether the quality of the vision loss includes positive and/or negative phenomena. Simple, short-lived positive visual disturbances in one hemi-field of vision can indicate occipital lobe seizures, whereas more complicated visual phenomena are commonly reported in migraine. Occasionally, elderly patients with vision loss describe seeing recurrent patterns or figures with Charles Bonnet Syndrome [4].