Bitemporal hemianopsia most commonly occurs as a result of tumors located at the mid-optic 4 I would like to thank Professor Mason and her. Bitemporal Heteronymous Hemianopia. 1. BITEMPORAL HETERONYMUS HEMIANOPIA Roll No. Muhammad Mubashir Tanvir Roll No. The Humphrey visual field test showed bitemporal visual field defects. The differential diagnosis of bitemporal hemianopia includes tumors causing.
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Static perimetry Swedish Interactive Threshold Algorithm standard threshold, strategy showing a bitemporal hemianopia, with initial field defects in January A and field defects in August B.
The Case of Bitemporal Visual Field Defects – American Academy of Ophthalmology
MD indicates mean deviation; PSD, pattern standard deviation. Results of multifocal electroretinography and optical coherence tomography.
A, Topographical mapping of multifocal electroretinographic amplitude responses in the left OS and right OD eyes top showing bilateral nasal abnormalities that correspond to bilaterally abnormal waveform traces bottom. N indicates nasal; T, temporal; S, superior; and I, inferior. Bitemporal Hemianopia Caused by Retinal Disease.
Copyright American Medical Association. A bitemporal hemianopia is almost always caused by damage to the optic chiasm and can occur from the direct or indirect effects of a variety of lesions, including tumors, 1 aneurysms, 2 and, less frequently, inflammatory and ischemic diseases.
We describe a patient with a nonprogressive bitemporal hemianopia caused not by optic chiasmal dysfunction but by retinal disease that was diagnosed by multifocal hemianopska mfERG after results from biemporal studies were repeatedly normal. A year-old woman with a history of previously treated tuberculosis, migraine headaches, and osteopenia was found to have a bitemporal hemianopic defect during a routine visual field test as part of an eye examination at an outside institution in Magnetic resonance imaging results were normal.
The patient subsequently was seen by us for another opinion in The fundi appeared normal, including the optic discs. A bitemporal hemianopic defect was confirmed by static perimetry Figure 1 A ; kinetic perimetry hhemianopsia that the defect was scotomatous. Repeat magnetic resonance imaging results were normal.
The results of mfERG were interpreted as normal, although there was a great deal of noise in the tracings that made them difficult to interpret. Visual evoked potentials were slightly delayed bilaterally. A multifocal visual evoked potential was attempted but was unsuccessful because of excessive noise. We elected to follow up with the patient. The patient was evaluated at regular intervals during the next 4 years. At each assessment, the visual field defects appeared stable Figure 1 B.
Repeat magnetic resonance imaging and computed tomographic angiography gave normal results. Infull-field ERG gave normal responses; however, repeat mfERG showed abnormal bitempofal bilaterally with severely reduced activity in the nasal retinas of both eyes corresponding to the temporal hemifields Figure 2 A.
A retinal evaluation now showed attenuation of the retinal arteries in both eyes with atrophic peripapillary changes bilaterally, more noticeable in the right eye, that extended some distance from the optic disc along the arcades Figure 1 C. bitemporla
Fluorescein angiography showed that bitempogal areas of choroidal and retinal atrophy were associated with marked hyperfluorescence in the mid to late stages of the angiogram in both eyes but without any leakage from choroidal or retinal vessels.
Optical coherence tomography showed marked thinning of the maculae Figure 2 B. The results of dark adaptation testing were consistent with a deficiency in the rate of both cone and rod responses.
A diagnosis of acute zonal occult outer retinopathy, a disorder known bitempoal produce diffuse or focal field defects, was made. To our knowledge, this is the first case report of bilateral temporal hemianopic defects from a retinal disorder. In this case, the funduscopic examination results were initially normal and the results of mfERG were also thought to be normal, although in retrospect the tracings were contaminated by excessive noise.
Subsequently, although repeat mfERG results were abnormal, full-field ERG showed no abnormalities; this was probably because a sufficient proportion of the retina in both eyes had not yet been affected. Full-field ERG assesses overall retinal function. Thus, the poor responses from the abnormal nasal retina that was initially affected and therefore produced what appeared to be bilateral temporal scotomatous field defects were overshadowed by the normal responses from the hemianposia of the nasal retina that was still normal as well as the intact temporal retina.
This case highlights the potential for retinal disorders to produce visual field defects that mimic those produced by optic nerve or chiasmal lesions, the importance of obtaining appropriate and correctly interpreted electrophysiological tests to assess patients with unexplained visual field defects, and the need to perform serial examinations and repeat testing when the cause of such abnormal visual fields is unclear.
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Bitemporal Hemianopia Caused by Retinal Disease
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