[Risk factors and prevention of retinopathy of prematurity]

The impact of perinatal brain injury on retinal nerve fiber layer thickness and optic nerve head parameters of premature children

PURPOSE

This study aims to evaluate the impact of birth weight (BW), gestational age (GA), retinopathy of prematurity (ROP), and perinatal brain injury (PBI) on optic nerve head (ONH) parameters and nerve fiber layer thickness (RNFLT) in preterm children.

METHODS

ONH parameters and RNFLT were examined prospectively in 5-15-year-old preterm and full-term children with RTVue-100 OCT (Optovue, USA). The parameters of the two groups were compared and possible influences of BW, GA, ROP, and PBI analyzed in preterm children.

RESULTS

In total, 51 full-term and 55 preterm children were included. The mean age was 9.98 ± 3.4 years in full-term and 10.0 ± 2.5 years in preterm children. The mean GA in preterm children was 29.6 ± 3.8 weeks with a BW of 1523 ± 732 g. RNFLT was significantly lower in preterm than in full-term children in all but temporal quadrants. Cup area, volume, cup/disc area ratio, and horizontal cup/disc ratio (CDR) were significantly larger and rim area significantly thinner in preterm children. GA was positively correlated with superior, nasal, and overall RNFLT and negatively correlated with cup area, volume, and horizontal CDR. ROP stage correlated negatively with superior and nasal RNFLT. PBI was the only significant predicting factor for RNFL thinning in all but temporal quadrant in multiple regression analysis. Preterm children with PBI had a significantly larger optic cup (CDR 0.70 ± 0.33 vs. 0.37 ± 0.27) and thinner optic rim.

CONCLUSION

PBI correlated strongest with RNFL thinning, a thinner optic rim, and a larger optic cup in preterm children and should be evaluated in each patient to prevent incorrect diagnosis like glaucoma.

Screening and Treatment in Retinopathy of Prematurity

BACKGROUND

More than 11 000 children are examined for possible retinopathy of prematurity in Germany each year, and 2-5% of them are treated for it. Even though screening and treatment programs are in place, the affected children can still suffer visual impairment.

METHODS

In this article, we summarize the pathogenesis, screening, and treatment of retinopathy of prematurity on the basis of a selective review of pertinent literature, retrieved by a PubMed search. The article centers on publications from 2011 to 2015 on the new option of treatment with VEGF inhibitors and discusses it in comparison to laser therapy.

RESULTS

All premature neonates with a low gestational age at birth, low birth weight, or prolonged exposure to supplemental oxygen must undergo screening by an ophthalmologist. Laser therapy is effective for stages 1-3 and for aggressive posterior retinopathy of prematurity. Its disadvantages are the induction of scarring and the development of severe myopia in 17-40% of the children so treated. Anti-VEGF treatment (VEGF = vascular endothelial growth factor) does not induce any visible scarring and seems to cause less myopia, but long-term data on safety, dosing, and the choice of anti-VEGF drug are still lacking.

CONCLUSION

The available evidence for anti-VEGF treatment is on a much lower level than the evidence for laser therapy. Anti-VEGF may be a way to avoid the disadvantages of laser therapy (scarring and severe myopia). Unlike laser therapy, however, the intravitreal injection of VEGF inhibitors may suppress systemic VEGF levels and potentially harm the developing brain, lungs, or other organs. The currently open questions about anti-VEGF treatment concern its dosing, choice of drug, and long-term safety.

[Pathogenesis of retinopathy of prematurity]

Retinopathy of prematurity (ROP) is a complex disease with a multifactorial pathogenetic cascade that is still only partially understood. Important pathogenetic factors are gestational age at birth and birth weight. Potent postnatal factors are exposure to supplemental oxygen, slow weight gain and expression of angiogenic growth factors. Some of these crucial aspects of ROP pathogenesis will be discussed in this article and put into clinical context. With the introduction of intravitreal anti-VEGF (vascular endothelial growth factor) treatment into ROP therapy, the pathomechanistic role of VEGF in ROP deserves a special focus. Apart from VEGF, other factors will be discussed that may precede VEGF upregulation and thus may represent targets for an earlier and potentially protective intervention. Among these insulin-like growth factor 1 (IGF-1) appears to be most prominent. Finally, factors such as postnatal weight gain will be discussed in light of their potential role as screening parameters and their ability to predict ROP severity.

[Pharmacological treatment for retinopathy of prematurity]

Mandatory screening performed by an experience ophthalmologist remains the most important pillar in the management of retinopathy of prematurity (ROP). The current gold standard for treatment of proliferative ROP is still panretinal laser photocoagulation, depending on severity, in combination with vitreoretinal surgery if necessary. The first case series of off-label intravitreal anti-VEGF treatment are encouraging. In addition to intravitreal anti-VEGF therapy, other treatment concepts such as supplementation with IGF-1 or omega-3 fatty acids also represent interesting pharmacological approaches to the management of ROP. However, larger controlled trials are required to validate the benefits and safety of these systemic treatment approaches.