Reliability assessment of a rod photoreceptor outer segment grading system

Monica Jablonski, Marshall J. Graney, Stephen B. Kritchevsky, Alessandro Iannaccone

Research output: Contribution to journalArticle

5 Citations (Scopus)

Abstract

The purpose of this study was to assess the reliability of a rod photoreceptor outer segment (PR-OS) grading system based on the analysis of 1 μm thick retinal sections obtained from Xenopus laevis whole-eye organ cultures. Digitally captured images, representative of the entire spectrum of rod PR-OS organization levels, were selected and coded numerically, A total of 102 individual rod PR-OS profiles were graded according to a six-step classification scheme based on the percentage of rod PR-OS membrane organization. Unweighted (exact agreement) and weighted kappa (κ) coefficients (for use with ordered categorical rating scales) were calculated. Differences between κ coefficients were tested for by chi-square analysis. To investigate the intra- and inter-rater variability and the possible presence of an interaction of the measurements with time, a repeated-measures analysis of variance was performed. The overall unweighted and weighted intra-rater κ coefficients were 0.78 and 0.92, respectively. The overall unweighted and weighted inter-rater κ coefficients were 0.73 and 0.90, respectively. There was no significant difference between raters or between first and second reading, nor was interaction between raters and time of rating documented. Individual κ coefficients were equivalent both between raters and between sessions. Intra- and inter-rater agreement was within one step in 100% of cases. The estimated values of the κ coefficients are consistent with a good to excellent degree of reliability and reproducibility of this rod PR-OS grading system. This system will be useful in the assessment of rod PR-OS morphology in studies of photoreceptor physiology and pathology.

Original languageEnglish (US)
Pages (from-to)573-579
Number of pages7
JournalExperimental Eye Research
Volume72
Issue number5
DOIs
StatePublished - Jan 1 2001

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Rod Cell Outer Segment
Retinal Rod Photoreceptor Cells
Organ Culture Techniques
Xenopus laevis
Reading
Analysis of Variance
Pathology
Membranes

All Science Journal Classification (ASJC) codes

  • Ophthalmology
  • Sensory Systems
  • Cellular and Molecular Neuroscience

Cite this

Reliability assessment of a rod photoreceptor outer segment grading system. / Jablonski, Monica; Graney, Marshall J.; Kritchevsky, Stephen B.; Iannaccone, Alessandro.

In: Experimental Eye Research, Vol. 72, No. 5, 01.01.2001, p. 573-579.

Research output: Contribution to journalArticle

Jablonski, Monica ; Graney, Marshall J. ; Kritchevsky, Stephen B. ; Iannaccone, Alessandro. / Reliability assessment of a rod photoreceptor outer segment grading system. In: Experimental Eye Research. 2001 ; Vol. 72, No. 5. pp. 573-579.
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