title: Quantification of visual field loss in age-related macular degeneration.
abstract: BACKGROUND
  An evaluation of standard automated perimetry (SAP) and short wavelength automated perimetry (SWAP) for the central 10-2 visual field test procedure in patients with age-related macular degeneration (AMD) is presented in order to determine methods of quantifying the central sensitivity loss in patients at various stages of AMD.
  
  
  METHODS
  10-2 SAP and SWAP Humphrey visual fields and stereoscopic fundus photographs were collected in 27 eyes of 27 patients with AMD and 22 eyes of 22 normal subjects.
  
  
  RESULTS
  Mean Deviation and Pattern Standard Deviation (PSD) varied significantly with stage of disease in SAP (both p<0.001) and SWAP (both p<0.001), but post hoc analysis revealed overlap of functional values among stages. In SWAP, indices of focal loss were more sensitive to detecting differences in AMD from normal. SWAP defects were greater in depth and area than those in SAP. Central sensitivity (within 1°) changed by -3.9 and -4.9 dB per stage in SAP and SWAP, respectively. Based on defect maps, an AMD Severity Index was derived.
  
  
  CONCLUSIONS
  Global indices of focal loss were more sensitive to detecting early stage AMD from normal. The SWAP sensitivity decline with advancing stage of AMD was greater than in SAP. A new AMD Severity Index quantifies visual field defects on a continuous scale. Although not all patients are suitable for SWAP examinations, it is of value as a tool in research studies of visual loss in AMD.
authors: Department of Ophthalmology, New York University, New York, New York, United States of America. jenniferhacton@gmail.com
authors: Jennifer H
authors: JH
authors: Acton
authors: Jonathan M
authors: JM
authors: Gibson
authors: Robert P
authors: RP
authors: Cubbidge
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006801:Humans; D008268:Macular Degeneration / Q000473:pathology / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D012720:Severity of Illness Index; D014792:Visual Acuity; D058609:Visual Field Tests / Q000379:methods*; D014794:Visual Fields / Q000502:physiology*