Indications for treatment of ROP

Retinopathy of prematurity (ROP) was first described in 1942 but it took more than four decades before an effective treatment, ablative cryotherapy, was identified. Treatment approaches continue to evolve.

Cryotherapy uses a probe through the sclera to deliver freezing temperatures which destroy (ablate) the avascular peripheral retina. Originally used for proliferative diabetic retinopathy, cryotherapy became the treatment of choice for ROP but poor outcomes were a cause for concern. At present, based on clinical studies, the choice of treatment has shifted from cryotherapy to transpupillary laser. New approaches to treatment include anti-VEGF medication although there are doubts about long-term safety and the evidence so far is inconclusive.

Over the years our understanding of ROP has grown in terms of risk factors, natural history, and indications for treatment and their outcomes. A key landmark was the International Classification of ROP which allowed comparison between studies and over time, and agreement on the constellation of signs at which treatment is recommended. The Classification was revised in 1995, and is currently undergoing a further revision.

Evidence timeline for ROP disease and treatment

Adapted from Sternberg & Durrani 2017

• 1942: First observation of retrolental fibroplasia (original name for ROP).
• 1952 – 1953: First description of the role of oxygen in ROP.
• 1984: Publication of the first International Classification of Retinopathy of Prematurity. This was important, as earlier reports on treatment were difficult to interpret because there was no uniform grading system to report changes in the retina.
• 1988: Publication of findings from the Cryotherapy for ROP trial (CRYO-ROP study) for threshold ROP.
• 1994: Meta-analysis by the Laser ROP Study Group concludes that laser is as effective as cryotherapy.
• 2003: The ETROP trial findings led to the recommendation that treatment be given before threshold disease develops, when Type 1, pre-threshold disease is present. This means that more infants now require treatment.
• 2011: The BEAT-ROP trial studied the efficacy of intravitreal Bevacizumab (anti-VEGF injection).
• More recent studies are addressing the optimal dose and anti-VEGF agent to use, to plan trials to explore their effectiveness and long-term ocular and systemic complications.

In the video on this step we show how the evidence on ROP treatment has changed over time, from cryotherapy to laser and anti-VEGF medication. As you watch, consider what this changing evidence means for your setting in terms of resources and infrastructure requirements.