Document Detail

The development of validated bulbar redness grading scales.
MedLine Citation:
PMID:  18049363     Owner:  NLM     Status:  MEDLINE    
PURPOSE: To develop a perceptually and physically based bulbar redness grading scale. METHODS: Digital conjunctival hyperemia photographs were taken using a photo-slit lamp at controlled exposures. Nine participants arranged 25 images on a tabletop over a range of 1.5 m, using separation to represent changes in redness. The position of each image was recorded and normalized for a 0 to 100 scale, and compared to chromaticity of each image obtained using a spectrophotometer. The performance of two versions of the scale (5 and 10 images) and a continuous grading scale was evaluated based on repeatability data collected from nineteen observers who used each scale twice to grade 30 randomly presented images of bulbar redness. RESULTS: Psychophysical scaling was highly correlated between single observers (Pearson's r >or= 0.92, p < 0.05). The averaged subjective grades significantly correlated with chromaticity (r = 0.95 and r = 0.99, p < 0.001 for CIE u* and log u*, respectively). Across all observers, test and retest ratings were highly correlated with either scale (r >or= 0.98), and showed high levels of repeatability expressed by intraclass correlation coefficients (ICC >or= 0.98), correlation coefficients of concordance (CCC >or= 0.96), and coefficients of repeatability (COR <or= 5.64). Despite single unit increment options, the majority of grade values assigned using the discrete scales were distributed in multiples of 5. CONCLUSIONS: Combining psychophysical and physical attributes is a promising method for the development of novel anterior segment scales; the newly developed scales performed well in a clinical setting.
Marc M Schulze; Deborah A Jones; Trefford L Simpson
Related Documents :
20378393 - The segmentation of colorectal mri images.
20042313 - Image segmentation by em-based adaptive pulse coupled neural networks in brain magnetic...
24665463 - Macroscopic fourier transform infrared scanning in reflection mode (ma-rftir), a new to...
Publication Detail:
Type:  Journal Article; Validation Studies    
Journal Detail:
Title:  Optometry and vision science : official publication of the American Academy of Optometry     Volume:  84     ISSN:  1040-5488     ISO Abbreviation:  Optom Vis Sci     Publication Date:  2007 Oct 
Date Detail:
Created Date:  2007-11-30     Completed Date:  2008-01-16     Revised Date:  -    
Medline Journal Info:
Nlm Unique ID:  8904931     Medline TA:  Optom Vis Sci     Country:  United States    
Other Details:
Languages:  eng     Pagination:  976-83     Citation Subset:  IM    
Centre for Contact Lens Research, School of Optometry, University of Waterloo, Ontario, Canada.
Export Citation:
APA/MLA Format     Download EndNote     Download BibTex
MeSH Terms
Conjunctival Diseases / pathology*
Hyperemia / pathology*
Reproducibility of Results
Severity of Illness Index*

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine

Previous Document:  Visual acuity with spherical and toric soft contact lenses in low- to moderate-astigmatic eyes.
Next Document:  On the longitudinal chromatic aberration of the intraocular lenses.