title: Two methods of lens opacity measurements in glaucomas.
abstract: OBJECTIVE
  Determination of lens opacity is important in aging glaucoma patients, because sensory testing may be influenced by increasing lens opacity. Purpose of this study was to measure lens opacity in normals and glaucoma patients using two different techniques, to compare both methods, and to correlate the results with contrast sensitivity testing.
  
  
  METHODS
  94 glaucomatous eyes, 47 ocular hypertensive eyes, and 79 control eyes were studied using the following devices: opacity lens meter (OLM, objective back scatter method), stray light meter (SLM, subjective forward scatter using flicker light), and temporal contrast sensitivity (full-field flicker test). SLM results were separately analyzed at the lower and upper flicker disappearance. All subjects were younger than 66 years and had no significant cataracts.
  
  
  RESULTS
  In patients and in normal subjects OLM readings and SLM findings elicited at the upper disappearance point are significantly correlated with age and with each other (R >0.45, P<0.001), while SLM at the lower disappearance point shows no such correlation. In normals, but not in patients, SLM at the lower disappearance point is significantly correlated with temporal contrast sensitivity.
  
  
  CONCLUSIONS
  Both devices can be used for quantifying lens opacity in glaucoma. SLM readings with increasing light intensity at the lower disappearance point seems to be more influenced by the individual flicker sensitivity than determination of the upper flicker disappearance. Therefore, using the SLM in glaucoma patients, the threshold measurements based on the upper disappearance of the flicker should be used instead of the suggested mean threshold measurements.
authors.affiliation: Department of Ophthalmology and University Eye Hospital, Friedrich-Alexander University Erlangen-Nürnberg at Erlangen, Germany. folkert.horn@augen.imed.uni-erlangen.de
authors.forename: F K
authors.initials: FK
authors.lastname: Horn
authors.forename: A G
authors.initials: AG
authors.lastname: Jünemann
authors.forename: M
authors.initials: M
authors.lastname: Korth
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000375:Aging; D002386:Cataract / Q000150:complications / Q000175:diagnosis*; D015350:Contrast Sensitivity; D003941:Diagnostic Techniques, Ophthalmological; D005902:Glaucoma, Open-Angle / Q000150:complications*; D006801:Humans; D007908:Lens, Crystalline / Q000473:pathology*; D008875:Middle Aged; D009798:Ocular Hypertension / Q000150:complications