Table 1

Characteristics of the development and testing datasets

CharacteristicsDevelopment set
(SEED)
Internal test set
(SEED)
External test set 1
(SNEC clinic study)
External test set 2
(polyclinic study)
Training setTuning set
Digital camera typesSlit-lamp attachedSlit-lamp attachedSlit-lamp attachedSlit-lamp attachedHand-held
Number of subjects147421142110011904
Number of eyes205728758819473493
Number of images219830562926103701
Age, years64.2 (10.1)64.3 (10.2)63.0 (9.7)64.2 (7.8)62.1 (7.0)
Male gender, n864 (58.6%)114 (54.0%)233 (55.3%)375 (37.6%)713 (37.5%)
Number of pterygium cases (by images):
 Any pterygium, n1085 (49.4%)160 (52.5%)321 (51.0%)73 (2.8%)92 (2.5%)
 Referable pterygium*, n219 (10.0%)27 (8.9%)53 (8.4%)20 (0.7%)34 (0.9%)
  • Data presented as mean (SD) or number (percentage), where appropriate.

  • *Referable pterygium defined as presence of pterygium with >2.50 mm encroachment onto the cornea (measured from the limbus) or base width (at limbus) of >5.00 mm.

  • SEED, Singapore Epidemiology of Eye Diseases study; SNEC, Singapore National Eye Centre.