Article Text

Download PDFPDF

Comparison of two reference standards in validating two field mydriatic digital photography as a method of screening for diabetic retinopathy
  1. P H Scanlon1,
  2. R Malhotra2,
  3. R H Greenwood3,
  4. S J Aldington4,
  5. C Foy5,
  6. M Flatman6,
  7. S Downes7
  1. 1Gloucestershire Eye Unit, Cheltenham General Hospital, Sandford Road, Cheltenham GL53 7AN, UK
  2. 2Oxford Eye Hospital, Oxford, UK
  3. 3Norfolk and Norwich University Hospital, Norwich, UK
  4. 4Retinopathy Grading Centre, Imperial College, London, UK
  5. 5Gloucestershire R & D Support Unit, UK
  6. 6Norwich Diabetes Eye Screening Service, UK
  7. 7Oxford Eye Hospital, Oxford, UK
  1. Correspondence to: Dr P H Scanlon, Gloucestershire Eye Unit, Cheltenham General Hospital, Sandford Road, Cheltenham GL53 7AN, UK; peter.scanlon{at}egnhst.org.uk

Abstract

Aim: To compare two reference standards when evaluating a method of screening for referable diabetic retinopathy.

Method: Clinics at Oxford and Norwich Hospitals were used in a two centre prospective study of 239 people with diabetes receiving an ophthalmologist’s examination using slit lamp biomicroscopy, seven field 35 mm stereophotography and two field mydriatic digital photography. Patients were selected from those attending clinics when the ophthalmologist and ophthalmic photographer were able to attend. The main outcome measures were the detection of referable diabetic retinopathy as defined by the Gloucestershire adaptation of the European Working Party guidelines.

Results: In comparison with seven field stereophotography, the ophthalmologist’s examination gave a sensitivity of 87.4% (confidence interval 83.5 to 91.5), a specificity of 94.9% (91.5 to 98.3), and a kappa statistic of 0.80. Two field mydriatic digital photography gave a sensitivity of 80.2% (75.2 to 85.2), specificity of 96.2% (93.2 to 99.2), and a kappa statistic of 0.73. In comparison with the ophthalmologist’s examination, two field mydriatic digital photography gave a sensitivity of 82.8% (78.0 to 87.6), specificity of 92.9% (89.6 to 96.2), and a kappa statistic of 0.76. Seven field stereo gave a sensitivity of 96.4% (94.0 to 98.8), a specificity of 82.9% (77.4 to 88.4), and a kappa statistic of 0.80. 15.3% of seven field sets, 1.5% of the two field digital photographs, and none of the ophthalmologist’s examinations were ungradeable.

Conclusion: An ophthalmologist’s examination compares favourably with seven field stereophotography, and two field digital photography performs well against both reference standards.

  • screening
  • diabetic retinopathy
  • ophthalmoscopy
  • digital photography
View Full Text

Statistics from Altmetric.com

Footnotes

  • Competing interests: None declared.

  • Funding: R & D Project Grant: R/21/01.98/Scanlon/ R from the South West R&D Directorate.

  • MD Thesis: PHS is submitting this work for an MD thesis to UCL.

Request Permissions

If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.