Which Babies are Screened?

• All babies who are:
  • <1250g birth weight, or 
  • <30 weeks gestation, or
  • selected infants ≥1250g and ≥30 weeks with an unstable clinical course who are believed to be at high risk by their attending neonatologist.
• Note that these values are different to the weight and gestation values recommended in the joint guidelines published by the American Academy of Pediatrics.¹  Annual report data on the incidence of ROP in National Women’s NICU has shown that the frequency of significant ROP in infants ≥1250g and ≥30 weeks is sufficiently low that these infants are not routinely examined.
• Consistently reported risk factors for the development of ROP include:
  • Prematurity
  • Intrauterine growth restriction
  • Male gender
  • Hyperoxia. Note that although the initial epidemic of ROP in the mid 20^th century was due to excessive oxygen administration, this is rarely the sole cause in the modern era of saturation monitoring.
  • Erythropoietin (in high cumulative doses), sepsis, blood transfusions, postnatal dexamethasone use and GM-IVH have been implicated as associations, but may reflect extreme prematurity and severity of illness rather than causation.
• Click here to open the screening form in use (available through the ADHB intranet only).

Classification System

Stage 1	Demarcation line -a flat, thin, whiteish, clear-cut demaraction between vascularised and avascular retina (normal retina has a tenuous, non-linear, feathery border)
Stage 2	Elevated ridge - demarcation line now has "3" dimensions
Stage 3	Neovascularisation - extra-retinal, fibrovascular proliferative tissue
Stage 4	Retinal detachment - may be exudative and/or tractional, and may be partial or total
	4A – macular not involved
	4B – macular detached
Stage 5	Total retinal detachment
Plus Disease	Presence of dilatation and tortuosity of the posterior pole blood vessel involving at least two quadrants of the retina. This is associated with severe disease and worse outcomes. It is more likely to occur with higher stages and lower zones
	Pre-Plus Disease:  more arterial tortuosity and venous dilatation than normal but not severe enough to be classified as "Plus disease".
	"Rush" Disease (Aggressive Posterior ROP, AP-ROP):  A rare and severe form of ROP with increased tortuosity and dilatation of vessels present in all 4 quadrants of zone 1 and sometimes zone 2.  May not sequentially advance through Stage 1 to 3 but often rapidly advances to stage 4 or 5.

When are Babies Screened?

• The initial examination will be 4-6 weeks postnatal, or between 31 and 33 weeks' gestation.
• The NICU database schedules the first appointment on all babies <1250g or <30 weeks at birth.
  • The appointment date is printed on the problem list.
  • The timing is as follows:

PMA=postmenstrual age.  Click here to open the corrected age calculator.

• Follow-up examinations should be recommended by the examining ophthalmologist on the basis of the joint guidelines published by the American Academy of Pediatrics.¹

• It is the responsibility of medical staff and NS-ANPs to ensure that the examinations are scheduled at appropriate ages according to the above guidelines.
• Administer
  • Amethocaine 1% (or Benoxinate 0.4%),
    Cyclopentolate 0.5% (Cyclogyl), and
    Phenylephrine 2.5%
    one drop of each preparation in each eye 30 minutes prior to the ophthalmologist arriving (i.e. 0800hr for 0830 start) and repeat 10 minutes later.
  • The eye drops are effective for up to 2 hours from the last drop.
  • Infants with a darker iris may require a longer time and repeat drops for their pupils to dilate.
• Infants may receive sucrose for analgesia during the procedure.
• The ophthalmologist records the appearance of the retina and comments on its maturity.  Images will usually be taken using the RetCam.  The ophthalmologist documents the vascularity of the retina and the stage of ROP on the ROP screening form, and indicates timing of follow-up.

• Details of eye examinations and recommendations for further examinations MUST be included in transfer letters.
• The transfer letter should specify the stage of ROP (if present) and the zone to which the retina is vascularised as this will influence follow-up arrangements.

• On discharge, NICU should refer all infants screened for ROP for 6-month follow-up examination via the ophthalmology service.
• In general, premature infants are at increased risk of visual impairment from myopia and strabismus, as well as visual impairment as a result of cortical injury.
• Visual impairment can be minimised for some children if early detection and treatment are provided.