title: Effect of cataract extraction on the results of automated perimetry in glaucoma.
abstract: OBJECTIVE
  To investigate the effect of cataract extraction on the results of automated perimetry in persons with glaucomatous visual field loss.
  
  
  METHODS
  Subjects from a retrospective study of visual field progression who underwent cataract extraction during follow-up were identified. Subjects came from the glaucoma service of a hospital-based tertiary referral center.
  
  
  METHODS
  Subjects had at least 7 Humphrey 24-2 or 30-2 visual fields over 5 years or more, with an abnormal glaucoma hemifield test result on the first 2 examinations. Visual field data were transferred to a microcomputer and comparison of the visual fields immediately before and after cataract extraction was performed.
  
  
  RESULTS
  Sixty-five eyes of 50 subjects (mean age, 71.8 years) were included in the analysis. A mean improvement in mean deviation (MD) of 1.68 dB (P<.001), and a mean worsening in corrected pattern SD (CPSD) of 0.54 dB (P=.09) was observed. The mean unweighted change in threshold in the 52 points of program 24-2 was 1.58 dB, corresponding to a 43.9% increase in sensitivity. A significant correlation between improvement in visual acuity and improvement in MD was also found. A mean increase in CPSD of 1.61 dB (P=.005) occurred in subjects with dense scotomas (minimum threshold value < or = 5 dB) and preoperative CPSD of 8 dB or less.
  
  
  CONCLUSIONS
  In persons with glaucomatous visual field defects, cataract extraction produces only a modest improvement in MD. After cataract surgery, the CPSD index worsened in many subjects with dense scotomas. This suggests that the development of cataract can mask progressive glaucomatous visual field loss in such persons.
authors.affiliation: Dana Center for Preventive Ophthalmology, Wilmer Eye Institute, The Johns Hopkins University School of Medicine, Baltimore, Md 21205-2103, USA.
authors.forename: S D
authors.initials: SD
authors.lastname: Smith
authors.forename: J
authors.initials: J
authors.lastname: Katz
authors.forename: H A
authors.initials: HA
authors.lastname: Quigley
mesh_terms: D000368:Aged; D002387:Cataract Extraction; D005260:Female; D005500:Follow-Up Studies; D005901:Glaucoma / Q000503:physiopathology*; D006801:Humans; D008297:Male; D012189:Retrospective Studies; D014786:Vision Disorders / Q000503:physiopathology; D014792:Visual Acuity; D058609:Visual Field Tests; D014794:Visual Fields / Q000502:physiology*