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Ophtalmologist, wearing an ophthalmoscope on her head, is bent over the baby and holding a lens close to the baby's eye
ROP screening examination using binocular indirect ophthalmoscopy, Khyber Teaching Hospital, Pakistan

Managing ROP follow up

Adapted from the ‘Guideline for the Screening and Treatment of Retinopathy of Prematurity’ published by the Royal College of Paediatrics and Child Health, United Kingdom, 2008.

At every screening examination for retinopathy of prematurity one of three decisions is made - no further screening, treat or follow up.

Termination of screening

Screening can only be stopped when a baby is no longer at risk of sight-threatening ROP. In some cases where retinal vasculature is mature, the baby may be discharged after the first screening.

In babies who never develop any ROP, the risk of sight-threatening ROP developing is minimal once the retinal vessels have entered Zone III, and cannot occur once the vessels reach the ora serrata. However, it can be difficult to accurately determine Zone III so any decision to stop screening before this must be carefully evaluated. If gestational age is known, and vessels have entered Zone III, it is likely to be safe to terminate screening in low-risk babies after 36 weeks post-menstrual age. If the gestational age is not known, the decision to stop rests on the extent of retinal vascualisation.

Follow up screening in babies with ROP

In babies who develop ROP but do not meet the criteria for treatment, it is important to continue to assess regularly, until the risk of sight threatening ROP is so low that all examination can be stopped. Parents need to be guided closely in this process to maintain follow up reviews.

Below is a list of some of the signs of regression that an ophthalmologist will look out for. Ideally these must be confirmed by at least two examinations:

  • Lack of increase in ROP severity, indicating complete or partial resolution of ROP
  • Reduction of pre-plus disease
  • Retinal vessels seen beyond the demarcation line
  • The ridge may change in colour from salmon pink to white.

Planning appointments for follow up are guided by the signs seen, as shown in the table below.

Table. Follow up examination schedule based on retinal findings

Zone of retinal findings Stage of ROP: Follow up interval
Zone I Immature vasculature: 1 - 2 weeks
Stage 1 or 2: 1 week or less
Regressing ROP: 1 - 2 weeks
Zone II Immature vasculature: 2 - 3 weeks
Stage 1: 2 weeks
Stage 2: 1 - 2 weeks
Stage 3: 1 week or less
Regressing ROP: 1 - 2 weeks
Zone II Stage 1 or 2: 2 - 3 weeks
Regressing ROP: 2 - 3 weeks
Source: (Pejaver et al. 2010)

Follow up after treatment

The post-operative examination after laser treatment has two purposes, to determine whether re-treatment is necessary and to monitor disease regression to determine the frequency of medium to long-term follow up examinations.

One prospective cohort study noted that regression occurred a mean of five days after diode laser therapy (range 2 to 14 days) (Goggin et al. 1993). In another study of 13 patients both plus disease and ROP had resolved in 61.5% (8/13) babies one week after diode laser treatment, this increased to 84.6% (11/13) after two weeks (Ling et al. 1995)

The UK’s ROP screening guidelines therefore suggest that first examination should take place 5 to 7 days after treatment and continued weekly for signs of decreasing activity and regression.

Re-treatment

Where the active ROP fails to regress after the first treatment, re-treatment is required.

Re-treatment should be performed usually 10-14 days after initial treatment when there is failure of the ROP to regress.

Avoiding missed screening or follow up after treatment

Organisation of services to support follow up in the short and long term are central to avoid poor outcomes from screening and treatment for ROP.

There are a number of potential pitfalls in ROP follow up which can lead to cases being missed:

  • Inadequate information in discharge letters and of infants transferred to another unit. In a UK regional audit (2001); before the UK ROP guidelines were implemented, information about ROP screening was included in the transfer letter in only 44% of cases and 80% of those discharged home had no information about arrangements for ROP screening in the discharge summary. It highlights the importance of evaluating local practices (Ziakas et al. 2001).

  • Not clearly agreeing responsibility, ideally under the care of a named consultant, for arranging ROP follow up between the neonatology and ophthalmology teams. This is needed to ensure a seamless transition from what happens in the NICU to the follow up clinic.

  • Instructions for follow up not being clearly stated and explained to parents, for example not including the exact date, location and time of the follow up appointment. Ideally, a follow up reminder is also required.

  • Did not attend or change of appointment - ideally a protocol should be used to follow up and trace those who do not come. Parents should be contacted by telephone and letter to rearrange and reinforce the importance of follow up review.

  • No initial ROP screening before discharge or transfer to another centre. In these cases the consultant neonatologist must ensure that the neonatal team in the receiving unit is aware of the need to start or continue ROP screening and complete screening prior to discharge.

Integrated pathways are essential to manage the complex care journey for a premature baby. Transfers between hospitals and discharge to home and the need for ongoing long-term follow up have the potential for miscommunication between the neonatal and ophthalmic services. Local arrangements agreed with individual clinicians can ensure a better governance for the pathways.

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This article is from the free online course:

Retinopathy of Prematurity: Practical Approaches to Prevent Blindness

London School of Hygiene & Tropical Medicine