PMID- 21760625
OWN - NLM
STAT- MEDLINE
DCOM- 20111222
LR  - 20211020
IS  - 1476-5454 (Electronic)
IS  - 0950-222X (Print)
IS  - 0950-222X (Linking)
VI  - 25
IP  - 10
DP  - 2011 Oct
TI  - Effect of OCT volume scan density on thickness measurements in diabetic macular 
      edema.
PG  - 1347-55
LID - 10.1038/eye.2011.173 [doi]
AB  - PURPOSE: To evaluate the impact of reducing B-scan frame-sampling density on 
      retinal thickness measurements using spectral domain optical coherence tomography 
      (SD-OCT) in eyes with diabetic macular edema (DME). METHODS: We retrospectively 
      collected OCT data for 64 eyes of 43 patients undergoing imaging for DME using 
      the Cirrus HD-OCT 512 x 128 macular cube protocol. For each case, raw OCT data 
      were imported into the 3D-OCTOR software, and retinal thickness maps were 
      generated using all 128 B-scans and for lower densities of B-scans ranging from 
      every other scan to only four scans (every 30-s B-scan). Maps were generated 
      before and after manual correction of retinal boundary segmentation errors. The 
      foveal central subfield (FCS) and total macular volume (TMV) values were used to 
      compare thickness maps of varying densities. RESULTS: The mean difference in FCS 
      retinal thickness and TMV increased as the B-scan density was reduced, 
      particularly when the density was reduced to fewer than 16 B-scans over 6 mm. At 
      a density of 16 B-scans, the mean absolute difference in FCS thickness was 2.43 
      mum (0.79%), with a maximum of 10.1 mum (4.09%). At this density, the mean 
      difference in TMV was 0.012 mm(3) (0.13%), with a maximum difference of 0.04 
      mm(3) (0.47%). Manual correction of OCT segmentation errors resulted in a 
      difference in FCS thickness of >/= 10 mum in only 12.5% of cases, with a maximum 
      difference of 115.7 mum. CONCLUSION: A minimum of 16 equally spaced B-scans appear 
      necessary to generate retinal thickness measurements similar to those produced 
      using all 128 B-scans in eyes with DME. Manual correction of segmentation errors 
      appeared to have a clinically meaningful effect in a small minority of cases. 
      These results may have implications for the design of SD-OCT imaging and grading 
      protocols in clinical trials of DME, particularly when using multiple SD-OCT 
      instruments that acquire varying numbers of B-scans.
FAU - Nittala, M G
AU  - Nittala MG
AD  - The Department of Ophthalmology, Doheny Eye Institute and Keck School of Medicine 
      of University of Southern California, Los Angeles, CA 90033, USA.
FAU - Konduru, R
AU  - Konduru R
FAU - Ruiz-Garcia, H
AU  - Ruiz-Garcia H
FAU - Sadda, S R
AU  - Sadda SR
LA  - eng
GR  - P30 EY003040/EY/NEI NIH HHS/United States
GR  - EY03040/EY/NEI NIH HHS/United States
PT  - Evaluation Study
PT  - Journal Article
PT  - Research Support, N.I.H., Extramural
PT  - Research Support, Non-U.S. Gov't
DEP - 20110715
PL  - England
TA  - Eye (Lond)
JT  - Eye (London, England)
JID - 8703986
SB  - IM
MH  - Diabetic Retinopathy/*pathology/physiopathology
MH  - Female
MH  - Humans
MH  - Macular Edema/*pathology/physiopathology
MH  - Male
MH  - Middle Aged
MH  - Retina/*pathology
MH  - Retrospective Studies
MH  - Tomography, Optical Coherence/*methods
PMC - PMC3194325
EDAT- 2011/07/16 06:00
MHDA- 2011/12/23 06:00
PMCR- 2012/10/01
CRDT- 2011/07/16 06:00
PHST- 2011/07/16 06:00 [entrez]
PHST- 2011/07/16 06:00 [pubmed]
PHST- 2011/12/23 06:00 [medline]
PHST- 2012/10/01 00:00 [pmc-release]
AID - eye2011173 [pii]
AID - 10.1038/eye.2011.173 [doi]
PST - ppublish
SO  - Eye (Lond). 2011 Oct;25(10):1347-55. doi: 10.1038/eye.2011.173. Epub 2011 Jul 15.