title: Retinal video recordings at different compression levels: a novel video-based imaging technology for diabetic retinopathy screening.
abstract: BACKGROUND
  To evaluate the optimal compression level of retinal color digital video recordings, a novel video-based imaging technology, in screening for diabetic retinopathy (DR).
  
  
  METHODS
  Evaluation of a diagnostic technique.
  
  
  METHODS
  A total of 36 retinal videos, captured using EyeScan (Ophthalmic Imaging System), were compressed from original uncompressed file size of 1 GB (gigabyte) to four different compression levels-100 MB (megabyte) (Group 1); 30 MB (Group 2); 20 MB (Group 3); and 5 MB (Group 4). The videos were subsequently interpreted by an ophthalmologist and a resident using the International Clinical Diabetic Retinopathy Severity Scales.
  
  
  METHODS
  The sensitivity, specificity and κ coefficient for DR grading detected by were calculated for each compression level (Groups 1-4), with reference to the original uncompressed retinal videos.
  
  
  RESULTS
  Groups 1, 2, and 3 graded by both readers had sensitivity and specificity >90% in detecting DR, whereas for group 4, the sensitivity and specificity were 70.6% and 94.7% for ophthalmologist and 80.0% and 72.2% medical officer, respectively. The κ correlation in detecting DR for groups 1, 2, and 3 were >0.95, whereas for Group 4, the κ was 0.76 and 0.66 for ophthalmologist and medical officer, respectively.
  
  
  CONCLUSIONS
  Retinal video recording is a novel and effective DR screening technique with high sensitivity, specificity and κ correlation. With its compressibility, this is a potential effective technique that can be widely implemented in a routine, mobile, and tele-ophthalmology setting for DR screening services.
authors: Center for Ophthalmology and Visual Sciences, Lions Eye Institute, University of Western Australia, Nedlands, Western Australia, Australia. daniel_ting45@hotmail.com
authors: D S W
authors: DS
authors: Ting
authors: M L
authors: ML
authors: Tay-Kearney
authors: I
authors: I
authors: Constable
authors: J
authors: J
authors: Vignarajan
authors: Y
authors: Y
authors: Kanagasingam
mesh_terms: D003930:Diabetic Retinopathy / Q000175:diagnosis*; D003941:Diagnostic Techniques, Ophthalmological / Q000592:standards*; D001330:Electronic Data Processing / Q000379:methods; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008403:Mass Screening / Q000379:methods; D012680:Sensitivity and Specificity; D014741:Video Recording / Q000379:methods* / Q000592:standards
references: Ophthalmology. 2003 Sep;110(9):1677-82
references: 13129861
references: Ophthalmology. 2011 Aug;118(8):1588-93
references: 21684608
references: Eye (Lond). 2007 Apr;21(4):487-93
references: 16456597
references: Br J Ophthalmol. 2001 Jul;85(7):799-802
references: 11423452
references: Eye (Lond). 2004 Oct;18(10):963-83
references: 15232600
references: JAMA. 2007 Aug 22;298(8):902-16
references: 17712074
references: Invest Ophthalmol Vis Sci. 2000 Jun;41(7):1916-24
references: 10845617
references: JAMA. 1993 Mar 10;269(10):1290-1
references: 8437309