Eccentric correction for off-axis vision in central visual field loss.
BACKGROUND
Subjects with absolute central visual field loss use eccentric fixation and magnifying devices to utilize their residual vision. This preliminary study investigated the importance of an accurate eccentric correction of off-axis refractive errors to optimize the residual visual function for these subjects.


METHODS
Photorefraction using the PowerRefractor instrument was used to evaluate the ametropia in eccentric fixation angles. Methods were adapted for measuring visual acuity outside the macula using filtered optotypes from high-pass resolution perimetry. Optical corrections were implemented, and the visual function of subjects with central visual field loss was measured with and without eccentric correction.


RESULTS
Of the seven cases reported, five experienced an improvement in visual function in their preferred retinal locus with eccentric refraction.


CONCLUSIONS
The main result was that optical correction for better image quality on the peripheral retina is important for the vision of subjects with central visual field loss, objectively as well as subjectively.
Gustafsson
Jörgen
J
Department of Design Sciences, Lund University, Sweden. jorgen.gustafsson@certec.lth.se
Unsbo
Peter
P
D000293:Adolescent; D000328:Adult; D000368:Aged; D015350:Contrast Sensitivity; D005139:Eyeglasses; D005403:Fixation, Ocular; D006801:Humans; D008875:Middle Aged; D012030:Refractive Errors / Q000150:complications* / Q000175:diagnosis / Q000628:therapy*; D016896:Treatment Outcome; D014786:Vision Disorders / Q000150:complications* / Q000503:physiopathology*; D014785:Vision, Ocular; D014792:Visual Acuity; D058609:Visual Field Tests; D014794:Visual Fields