title: Intra- and inter-rater agreement between an ophthalmologist and mid-level ophthalmic personnel to diagnose retinal diseases based on fundus photographs at a primary eye center in Nepal: the Bhaktapur Retina Study.
abstract: BACKGROUND
  Early detection can reduce irreversible blindness from retinal diseases. This study aims to assess the intra- and inter-rater agreement of retinal pathologies observed on fundus photographs between an ophthalmologist and two-mid level ophthalmic personnel (MLOPs).
  
  
  METHODS
  A population-based, cross-sectional study was conducted among subjects 60 years and above in the Bhaktapur district of Nepal. Fundus photographs of 500 eyes of 500 subjects were assessed. The macula-centered 45-degree photographs were graded twice by one ophthalmologist and two MLOPs. Intra-rater and inter-rater agreements were assessed for the ophthalmologist and the MLOPs.
  
  
  RESULTS
  Mean age was 70.22 years ± 6.94 (SD). Retinal pathologies were observed in 55.6 % of photographs (age-related macular degeneration: 34.2 %; diabetic retinopathy: 4.2 %; retinal vein occlusion: 3.8 %). Twelve (2.4 %) fundus pictures were non-gradable. The intra-rater agreement for overall retinal pathologies, retinal hemorrhage, and maculopathy were substantial both for the ophthalmologist as well as for the MLOPs. There was moderate inter-rater agreement between the ophthalmologist and the first MLOP on second rating for overall retinal pathologies, [kappa (k); 95 % CI = 0.59 (0.51-0.66)], retinal hemorrhage [k; 95 % CI = 0.60 (0.41-0.78)], and maculopathy [k; 95 % CI = 0.52 (0.43-0.60)]. Inter-rater agreement between the ophthalmologist and the second MLOP for second rating was moderate for overall retinal pathologies [k; 95 % CI = 0.52 (0.44-0.60)], substantial agreement for retinal hemorrhage [k; 95 % CI = 0. 68 (0.52-0.84)], moderate agreement for maculopathy [k; 95 % CI = 0.59 (0.50-0.67)].
  
  
  CONCLUSIONS
  There is moderate agreement between the MLOPs and the ophthalmologist in grading fundus photographs for retinal hemorrhages and maculopathy.
authors.affiliation: Vitreo-retina Service, Tilganga Institute of Ophthalmology, P O Box: 561, Kathmandu, Nepal. rabathapa@live.com.
authors.forename: Raba
authors.initials: R
authors.lastname: Thapa
authors.affiliation: Vitreo-retina Service, Tilganga Institute of Ophthalmology, P O Box: 561, Kathmandu, Nepal.
authors.forename: Sanyam
authors.initials: S
authors.lastname: Bajimaya
authors.affiliation: Vrije University Medical Center, Amsterdam, The Netherlands.
authors.forename: Renske
authors.initials: R
authors.lastname: Bouman
authors.affiliation: Vitreo-retina Service, Tilganga Institute of Ophthalmology, P O Box: 561, Kathmandu, Nepal.
authors.forename: Govinda
authors.initials: G
authors.lastname: Paudyal
authors.affiliation: Central Department of Statistics, Tribhuvan University, Kirtipur, Nepal.
authors.forename: Shankar
authors.initials: S
authors.lastname: Khanal
authors.affiliation: Vrije University Medical Center, Amsterdam, The Netherlands.
authors.forename: Stevie
authors.initials: S
authors.lastname: Tan
authors.affiliation: Tilganga Institute of Ophthalmology, Kathmandu, Nepal.
authors.forename: Suman S
authors.initials: SS
authors.lastname: Thapa
authors.affiliation: Vrije University Medical Center, Amsterdam, The Netherlands.
authors.forename: Ger
authors.initials: G
authors.lastname: van Rens
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D002983:Clinical Competence / Q000706:statistics & numerical data*; D003430:Cross-Sectional Studies; D003941:Diagnostic Techniques, Ophthalmological; D005260:Female; D006801:Humans; D008297:Male; D008403:Mass Screening / Q000379:methods / Q000592:standards; D008875:Middle Aged; D009390:Nepal; D015588:Observer Variation; D009885:Ophthalmology; D010781:Photography; D012164:Retinal Diseases / Q000000981:diagnostic imaging*
keywords: Fundus photograph grading; Mid-level ophthalmic personnel; Ophthalmologist; Retinal pathology