Retinopathy of prematurity

Clinical Case

History

This infant was born at 25 weeks and 640 g to a 29-year-old primigravida after preterm labour complicated by histological chorioamnionitis. He was intubated in the delivery room and received two doses of surfactant for respiratory distress syndrome. His NICU course was marked by fluctuating oxygen saturations, late-onset staphylococcal sepsis at day 12, two packed red cell transfusions for anaemia of prematurity, and growth that remained below the 10th centile despite fortification [4].

Examination at 33 weeks postmenstrual age

Routine retinal screening showed, in both eyes, Zone I stage 3 disease with prominent plus disease and flat neovascularisation at an ill-defined vascular-avascular junction, extending across five clock-hours temporally [1].

Key Questions

1. What is this infant's classification, and why does it matter? This is Zone I stage 3 ROP with plus disease, which meets Type 1 criteria and is the treatment threshold defined by the ETROP trial [2]. The prominent plus disease and ill-defined junction with flat neovascularisation in Zone I also raise concern for aggressive ROP, which can progress to detachment within days, so this is a sight-threatening emergency [1].

2. How should this infant be treated? Type 1 ROP must be treated within 72 hours [2]. Because the disease is in Zone I, intravitreal anti-VEGF therapy is often preferred over laser, as the BEAT-ROP trial showed bevacizumab was superior to laser for Zone I stage 3 disease with plus [3]. Laser remains an alternative where anti-VEGF is unsuitable or follow-up cannot be guaranteed [2].

3. What follow-up is required after treatment? After anti-VEGF the infant needs close and prolonged surveillance because the drug's effect can wane and late reactivation of disease occurs beyond the usual screening window [3]. Examinations continue until the retina is fully vascularised into Zone III or the ROP has clearly regressed [4].

4. What is the long-term outlook? Most Type 1 ROP treated at the threshold has a good structural outcome, but Zone I disease and aggressive ROP carry higher risk, and even regressed ROP increases lifelong risk of myopia, strabismus, amblyopia, and late retinal detachment [1]. This infant therefore needs lifelong ophthalmology follow-up [4].