title: Similar Sensitivity to Ladder Contours in Macular Degeneration Patients and Controls.
abstract: OBJECTIVE
  To determine whether people with central field loss (CFL) from macular degeneration have improved ability to recognize a particularly difficult spatial configuration embedded in noise, the peripherally-viewed 'ladder contour'. The visibility of these configuration has been linked to general contour integration ability and crowding limitations in peripheral vision.
  
  
  METHODS
  We used a trial-based yes-no task. CFL patients and normally-sighted controls performed the task, looking for ladder contours embedded in a field of randomly oriented Gabor patches, at a range of stimulus presentation times (varying stimulus difficulty). Viewing eccentricity in CFL patients was set by their preferred retinal loci (PRLs) and matched artificially in the control group. The contours were presented so as to be tangent to the CFL region, given a patient's PRL location.
  
  
  RESULTS
  CFL and normally-sighted groups performed similarly on the task. The only significant determinant of performance was the viewing eccentricity.
  
  
  CONCLUSIONS
  CFL patients do not seem to develop any improved ability to recognize ladder contours with their parafoveal retina, which suggests that there is no underlying improvement in contour integration or reduction in crowding limitations in the region of the PRL despite extended daily use.
authors.affiliation: University of Wisconsin-Madison, Department of Psychology, Madison, Wisconsin, United States of America.
authors.forename: Andrew M
authors.initials: AM
authors.lastname: Haun
authors.affiliation: Schepens Eye Research Institute, Mass Eye and Ear, Department of Ophthalmology, Harvard Medical School, Boston, Massachusetts, United States of America.
authors.forename: Eli
authors.initials: E
authors.lastname: Peli
mesh_terms: D000328:Adult; D000368:Aged; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D008268:Macular Degeneration / Q000473:pathology / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D012160:Retina / Q000473:pathology / Q000503:physiopathology; D014794:Visual Fields