Vision evaluation of eccentric refractive correction.
OBJECTIVE
This study investigates the benefits of eccentric refractive correction to resolution and detection thresholds in different contrasts for seven subjects with central visual field loss (CFL) and for four healthy control subjects with normal vision.


METHODS
Refractive correction in eccentric viewing angles, i.e., the preferred retinal location for the CFL subjects and 20 degrees off-axis for the control subjects, was assessed by photorefraction with the PowerRefractor instrument and by wavefront analysis using the Hartmann-Shack principle. The visual function with both eccentric and central corrections was evaluated using number identification and grating detection.


RESULTS
For the CFL subjects, the resolution and detection thresholds varied between individuals because of different preferred retinal locations and cause of visual field loss. However, all seven CFL subjects showed improved visual function for resolution and detection tasks with eccentric correction compared with central correction. No improvements in high-contrast resolution were found for the control subjects.


CONCLUSIONS
These results imply that optical eccentric correction can improve the resolution acuity for subjects with CFL in situations where healthy eyes do not show any improvements.
Biomedical and X-ray Physics, Department of Physics, Royal Institute of Technology, Stockholm, Sweden. linda@biox.kth.se
Linda
L
Lundström
Jörgen
J
Gustafsson
Peter
P
Unsbo
D000328:Adult; D003941:Diagnostic Techniques, Ophthalmological; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012029:Refraction, Ocular; D012031:Refractometry; D012160:Retina / Q000503:physiopathology*; D012684:Sensory Thresholds; D014786:Vision Disorders / Q000175:diagnosis / Q000503:physiopathology* / Q000534:rehabilitation*; D014785:Vision, Ocular; D014792:Visual Acuity; D014794:Visual Fields