However, despite resolution of ocular signs, all reported residual mild central scotoma
that was reflected on HVF as an area of subtle decrease in sensitivity in the central vision (Figure 1).
A computer and video display-based system for training eccentric viewing in macular degeneration with an absolute central scotoma
Limited portability and the lack of access to a microperimeter or a tangent screen have led to the development of more simplified methods of testing the boundaries of a central scotoma
for training in eccentric viewing.
Nilsson reported that, since the 1970s, a low-vision service in Sweden has been instructing patients in the use of a trained retinal locus (TRL) in a retinal area that is "more advantageous to reading," defined as above or below an absolute central scotoma
as opposed to the left or right of the scotoma .
Patients with AMD and large absolute central scotoma
can be trained successfully to use eccentric viewing, as demonstrated in scanning laser ophthalmoscope.
Visual acuity is often about 6/18 with a relative central scotoma
, moderate photophobia and low-grade nystagmus; the foveal mosaic is irregular and reduced in density.
Some persons with central scotomas
are able to adopt a regular and reliable fixation pattern; they look to the side or above the object of interest in a consistent way and thereby move the central scotoma
out of the way.
In advanced cases, patients can report an absolute central scotoma
, which can be corroborated by performing the Amsler grid test.
The most frequent of these diseases is age-related macular degeneration (AMD), in which foveal vision is often impaired by a central scotoma
that impairs vision of fine detail and causes problems with reading and recognizing faces.
A central visual field analysis using SLO demonstrated a large central scotoma
in the right eye with no established preferred retinal locus.
The natural development of the use of nonfoveal loci to improve potential sight in the presence of a central scotoma
has been well described in the literature, with the anomalous fixation point described as a preferred retinal locus (Crossland, Sims, Galbraith, & Rubin, 2004; Fletcher & Schuchard, 1997; Macedo, Nascimento, Gomes, & Puga, 2007; Reinhard et al.
For instance, Wolffe (1995) reported that a group of youngsters were capable of painting landscapes or still lifes as accurately as sighted people, despite a severe central field loss that was due to a dense central scotoma