June 2013
Volume 54, Issue 15
Free
ARVO Annual Meeting Abstract  |   June 2013
Association between Iris Surface Features and Iris Thickness in Asian Eyes
Author Affiliations & Notes
  • Elizabeth Sidhartha
    Singapore Eye Research Institute, Singapore, Singapore
    Department of Ophthalmology, National University of Singapore, Singapore, Singapore
  • PREETI GUPTA
    Singapore Eye Research Institute, Singapore, Singapore
    Department of Ophthalmology, National University of Singapore, Singapore, Singapore
  • Jiemin Liao
    Singapore Eye Research Institute, Singapore, Singapore
  • Yih Chung Tham
    Singapore Eye Research Institute, Singapore, Singapore
    Department of Ophthalmology, National University of Singapore, Singapore, Singapore
  • Carol Cheung
    Singapore Eye Research Institute, Singapore, Singapore
    Department of Ophthalmology, National University of Singapore, Singapore, Singapore
  • Tien Wong
    Singapore Eye Research Institute, Singapore, Singapore
    Department of Ophthalmology, National University of Singapore, Singapore, Singapore
  • Tin Aung
    Singapore Eye Research Institute, Singapore, Singapore
    Department of Ophthalmology, National University of Singapore, Singapore, Singapore
  • Ching-Yu Cheng
    Singapore Eye Research Institute, Singapore, Singapore
    Department of Ophthalmology, National University of Singapore, Singapore, Singapore
  • Footnotes
    Commercial Relationships Elizabeth Sidhartha, None; PREETI GUPTA, None; Jiemin Liao, None; Yih Chung Tham, None; Carol Cheung, None; Tien Wong, Allergan (C), Bayer (C), Novartis (C), Pfizer (C), GSK (F), Roche (F); Tin Aung, Alcon (R), Alcon (C), Alcon (F), Allergan (R), Allergan (C), Carl Zeiss Meditec (F), Carl Zeiss Meditec (R), Ellex (F), Ellex (R), Santen (R); Ching-Yu Cheng, None
  • Footnotes
    Support None
Investigative Ophthalmology & Visual Science June 2013, Vol.54, 2151. doi:
  • Views
  • Share
  • Tools
    • Alerts
      ×
      This feature is available to Subscribers Only
      Sign In or Create an Account ×
    • Get Citation

      Elizabeth Sidhartha, PREETI GUPTA, Jiemin Liao, Yih Chung Tham, Carol Cheung, Tien Wong, Tin Aung, Ching-Yu Cheng; Association between Iris Surface Features and Iris Thickness in Asian Eyes. Invest. Ophthalmol. Vis. Sci. 2013;54(15):2151.

      Download citation file:


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

      ×
  • Supplements
Abstract

Purpose: To describe a grading system to assess iris surface features in Asian eyes and to examine the association between iris surface features and iris thickness measured by anterior segment optical coherence tomography (AS-OCT).

Methods: We recruited 50 subjects from the Singapore Malay Eye Study (SiMES), a population-based survey of Singaporean Malays aged 40-80 years. Iris surface features including iris crypts, contraction furrows, and iris color were graded from photographs taken using slit lamp digital camera with standard protocol. We proposed a grading system to assess iris surface features including iris crypts (grade 1-5, by their number and size), furrows (grade 1-3, by their number and circumferential extent), and iris color (grade 1-5, comparing with standard photos, with higher grade denoting darker iris). Intra- and inter-grader agreements between two graders were assessed by weighted kappa (Κw). Vertical and horizontal cross-sections of anterior chamber were imaged using AS-OCT. Iris thickness at 750µm (IT750) and 2000µm (IT2000) from the scleral spur and maximum central iris thickness (ITCM) were measured using Zhongshan Angle Assessment Program. Associations between iris features and average thickness from the four quadrants were assessed by Spearman’s rank correlation (ρ) and generalized estimating equations to control for inter-eye correlation.

Results: Of the 50 subjects, 75 eyes had complete AS-OCT data and were gradable for iris crypts and color; 64 eyes were graded for furrows. The grading scheme for iris surface features showed good to optimal inter-grader (Crypt Κw=0.775, Furrow Κw=0.836, Color Κw=0.718) and intra-grader (Crypt Κw=0.919, Furrow Κw=0.901, Color Κw=0.925) agreements. Higher crypt grade was significantly correlated with thinner IT2000 (ρ=-0.342, p=0.022). More extensive furrows were correlated with thicker IT750 (ρ=0.453, p=0.008) and ITCM (ρ=0.250, p=0.031). We did not observe any significant correlations between iris color and iris thickness (all p>0.05).

Conclusions: Iris surface features are clinically observable. Our results show that several iris surface features can be graded from slit lamp photographs and are associated with iris thickness. Irises with larger and more crypts are thinner centrally, and irises with more extensive furrows are thicker peripherally. These findings may have important implications in assessing the risk of angle closure based on iris surface features.

Keywords: 571 iris • 550 imaging/image analysis: clinical • 731 texture  
×
×

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.

×