Participants had central scotomas
in both, one, or neither eye with the frequency of 35, 39, and 26 percent, respectively.
All patients demonstrated central scotoma
due to macular pathology by means of Amsler chart reading and automated visual field (HVF) testing.
Scanning characters and reading with a central scotoma
For individuals with central scotomas
, using an eccentric retinal area for visual tasks is necessary, because visual tasks such as fixation and reading can no longer be performed effectively with the foveal area .
Low vision practitioners commonly use the Bjerrum tangent screen as a method of mapping the central visual field or the central scotoma
d Central scotoma
, reduced visual acuity and metamorphopsia are some of the symptoms of this condition
In an eye with a central scotoma
affecting the entire fovea, one or more eccentric PRLs naturally and reliably develop [5-7,15-17].
27,28) Observation of an OCT image of a full thickness macular hole makes it easy to understand why patients experience a central scotoma
and distortion due to absence of photoreceptors in the centre of the hole and the presence of a cystic fluid in the cuffs, respectively.
A computer-and-video display-based system for training eccentric viewing in macular degeneration with an absolute central scotoma
18) Visual acuity is typically 6/36-6/60 in these individuals, with an absolute central scotoma
, severe photophobia and nystagmus.
a Bi-temporal superior quadrantanopia b Central scotoma
c Complete bitemporal hemianopia d Arcuate scotoma D [ILLUSTRATION OMITTED] A myopic patient aged 55 presents for a routine eye examination.
Scanning characteristics and reading with a central scotoma
Since the fovea is specialized for fine resolution and excellent visual acuity in a way that the peripheral retina is not, a person with a central scotoma
must use magnification or large-print text.
34) Visual acuity ranges from near-normal to approximately 6/60 and patients may be aware of a central scotoma
The person whose PRL is to the left of the central scotoma
needs different strategies from the person whose PRL is above or to the right of the scotoma.