Increasing sampling density improves reproducibility of optical coherence tomography measurements

R. Gurses-Ozden, H. Ishikawa, S. T. Hoh, J. M. Liebmann, A. Mistlberger, D. S. Greenfield, H. L. Dou, R. Ritch

Research output: Contribution to journalArticle

47 Scopus citations

Abstract

Purpose: Published series of peripapillary retinal nerve fiber layer (RNFL) measurements using optical coherence tomography (OCT) have sampled 100 evenly distributed points on a 360° peripapillary circular scan. The goal of this study was to determine whether a four-fold increase in sampling density improves the reproducibility of OCT measurements. Methods: Complete ophthalmic examinations, achromatic automated perimetry, and OCT imaging were performed in all patients. The OCT scanning consisted of three superior and inferior quadrantic scans (100 sampling points/quadrant) and three circular scans (25 points/quadrant). The RNFL thickness measurements and coefficient of variation (CV) were calculated for the superior and inferior quadrants for each sampling density technique. Results: The study included 22 eyes of 22 patients (3 control subjects; 2 patients with ocular hypertension; and 17 patients with glaucoma). Quadrants with associated glaucomatous visual field loss on automated achromatic perimetry had thinner RNFLs than quadrants without functional defects for both the 25- and 100-points/quadrant scans. For quadrants associated with normal visual hemifields (n = 22), there was no difference between the 25- and 100-points/quadrant scans in mean RNFL thickness and CV. Among quadrants with visual field defects (n = 22), RNFL thickness measurements were thinner in the 25-points/quadrant scans than in the 100-points/quadrant scans. The CV for the 25-points/quadrant scans (25.9%) was significantly higher than that for the 100-points/quadrant scans (11.9%). Conclusion: Increasing the sampling density of OCT scans provides less variable representation of RNFL thickness. The optimal sampling density to achieve maximal reliability of OCT scans remains to be determined.

Original languageEnglish (US)
Pages (from-to)238-241
Number of pages4
JournalJournal of glaucoma
Volume8
Issue number4
StatePublished - Dec 1 1999
Externally publishedYes

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Keywords

  • Glaucoma
  • Optical coherence tomography
  • Reliability
  • Reproducibility
  • Retinal nerve fiber layer
  • Sampling density

ASJC Scopus subject areas

  • Ophthalmology

Cite this

Gurses-Ozden, R., Ishikawa, H., Hoh, S. T., Liebmann, J. M., Mistlberger, A., Greenfield, D. S., Dou, H. L., & Ritch, R. (1999). Increasing sampling density improves reproducibility of optical coherence tomography measurements. Journal of glaucoma, 8(4), 238-241.