title: Variations in the morphology of retinopathy of prematurity in extremely low birthweight infants.
abstract: OBJECTIVE
  To investigate the clinical observations that arteriovenous shunts typical of threshold retinopathy of prematurity (ROP) are morphologically different in extremely low birthweight infants weighing less than 1000 g.
  
  
  METHODS
  An observational case series of six extremely low birthweight infants displaying specific features of threshold retinopathy of prematurity enrolled between 1998 and 2001 at one centre. The variant morphology was documented with colour photography and fundus fluorescein angiography before laser therapy.
  
  
  RESULTS
  Stage 3 threshold ROP in extremely premature infants may be characterised by a different morphology not demonstrating classic shunt formation. A poorly developed capillary bed is present in already vascularised retina in these cases.
  
  
  CONCLUSIONS
  This case series of extremely low birthweight infants display variations in the typical morphological appearance of threshold ROP. In these cases, established plus disease may be present in the absence of arteriovenous shunting. Delaying treatment until a classic stage 3 ridge with extraretinal neovascularisation develops may be detrimental to controlling the disease process. The authors propose that the criteria for threshold disease requiring treatment do not accurately apply in this extremely low birthweight group as defined by the CRYO-ROP study and that treatment should be instituted before the typical threshold features arise. Plus disease remains the most reliable sign indicating the need for treatment.
authors.affiliation: Western Eye Hospital, 171 Marylebone Road, London NW1 5YE, UK. edschulenburg@blueyonder.co.uk
authors.forename: W E
authors.initials: WE
authors.lastname: Schulenburg
authors.forename: G
authors.initials: G
authors.lastname: Tsanaktsidis
mesh_terms: D000208:Acute Disease; D005451:Fluorescein Angiography / Q000379:methods; D005865:Gestational Age; D006801:Humans; D007231:Infant, Newborn; D019102:Infant, Very Low Birth Weight; D012160:Retina / Q000473:pathology; D012171:Retinal Vessels / Q000473:pathology; D012178:Retinopathy of Prematurity / Q000473:pathology*