December 2002
Volume 43, Issue 13
Free
ARVO Annual Meeting Abstract  |   December 2002
Mechanisms of UV B Cataractogenesis: The Importance of the Lens Epithelium
Author Affiliations & Notes
  • AM Noury
    Rayne Institute St Thomas' Hospital London United Kingdom
    GKT Dept of Opthalmology
  • G Heacock
    GKT Dept of Ophthalmology
    Rayne Institute St Thomas' Hospital London United Kingdom
  • W Watters
    GKT Dept of Ophthalmology
    Rayne Institute St Thomas' Hospital London United Kingdom
  • J Mellerio
    Dept of Visual Science University of Westminster London United Kingdom
  • J Marshall
    GKT Dept of Ophthalmology
    Rayne Institute St Thomas' Hospital London United Kingdom
  • Footnotes
    Commercial Relationships   A.M. Noury, None; G. Heacock, None; W. Watters, None; J. Mellerio, None; J. Marshall, None. Grant Identification: TFC Frost Charitable Trust
Investigative Ophthalmology & Visual Science December 2002, Vol.43, 3572. doi:
  • Views
  • Share
  • Tools
    • Alerts
      ×
      This feature is available to authenticated users only.
      Sign In or Create an Account ×
    • Get Citation

      AM Noury, G Heacock, W Watters, J Mellerio, J Marshall; Mechanisms of UV B Cataractogenesis: The Importance of the Lens Epithelium . Invest. Ophthalmol. Vis. Sci. 2002;43(13):3572.

      Download citation file:


      © ARVO (1962-2015); The Authors (2016-present)

      ×
  • Supplements
Abstract

Abstract: : Purpose: To determine the primary target and subsequent damage patterns involved in acute UV B cataractogenesis, using an in vitro whole lens model. Methods: Sixty four, aseptically dissected, porcine lenses were randomly assigned to a control group or immediately irradiated with 302nm UV B. 50% of the lenses recieved exposure to the anterior surface and 50% to the posterior surface. Three different exposure doses were used: 0.08J/cm2 (threshold), 0.64J/cm2 (supra-threshold)or 2.56J/cm2 (supra-threshold) for each orientation. All lenses were subsequently cultured in MEM for 10 days. Lens damage was measured daily using a novel scatter meter, consisting of a rotating 650nm diode laser illumination source, light sink and photoresistor. Epithelial/sub-capsular morphological changes were also independently assessed by daily in vivo photomicroscopy and by subsequent histological analysis at day 10(LM and EM). Results: The direction of exposure was independent of the scatter and photomicroscopy changes that developed. Control lenses showed mild transient equatorial opacification on day 1, not manifest in irradiated groups. Lenses exposed to 0.64J/cm2 and 2.56J/cm2 subsequently developed dose-dependent progressive lenticular opacification. The threshold group, in contrast, showed no significant difference from controls. Early in vivo photomicroscopy revealed dose-dependent morphological changes to the anterior aspect of the irradiated lenses but none posteriorly. Posterior damage did occur at later stages in the opacifying suprathreshold groups but this but this was always following marked anterior damage. Histology revealed gross anterior epithelial and adjacent lens fibre cell damage but only in the supra-threshold doses. Conclusion: This data collectively suggests that the anterior epithelium is the primary target in acute UVB cataractogenesis. Threshold doses transiently affect the epithelial pump but do not progress to permanent opacification. Higher supra-thresold doses cause progressive cataractogenesis, with evidence of cell death and progressive secondary lens fibre damage. This has relevance for managing UV cataract risk.

Keywords: 537 radiation damage: light/UV • 338 cataract • 341 cell death/apoptosis 
×
×

This PDF is available to Subscribers Only

Sign in or purchase a subscription to access this content. ×

You must be signed into an individual account to use this feature.

×