Retinopathy of prematurity

NEDROP studies

In 2009 and 2017 a national, prospective inventory on ROP was performed. All neonatologists and ophthalmologists of Dutch hospitals involved in ROP-screening participated. The goal of the NEDROP 1 study was to establish a guideline tot optimize care for infants at risk for ROP.

Data on incidence of ROP, screening logistics and treatment outcome were gathered, a cost-effectiveness analysis was performed and parameters to improve quality of care were formulated. These parameters focused on treatment criteria and loss to follow up after transfer to another hospital. The NEDROP 2 study had the same design with a primary goal to evaluate the measures taken after NEDROP 1. Less infants were lost to follow up, more infants were treated and they were treated in an earlier stage. Again a cost effectiveness study was performed showing that further reduction of the number of infants needing screening is possible. This will be included in a new national guideline (2022-2023).

The NEDROP studies also resulted in many supportive measures for professionals involved in the care for these infants: www.nedrop.nl, NEDROP-app, Siilo for ROP consultation, handouts and an e-learning for ophthalmologists.

In collaboration with Care4Neo, an information folder for parents was developed in several languages.

Oximetry for ROP (ROPOXYMAP)

Retinopathy of prematurity (ROP) consists of 2 phases in which oxygen plays a major role. With the introduction of retinal oximetry for premature infants, in depth insight in oxygen saturation creates opportunities to influence these phases. Retinal oximetry is an imaging technique, which utilizes the difference in light absorption of hemoglobin at different wavelengths of light to determine the relative oxygen saturation of the blood in the retinal vessels. It uses the difference in light absorption of hemoglobin bound and unbound to an oxygen molecule.

To enable oxygen monitoring and vessel diameter measurements in infants, a new, non-contact, infrared camera (Corimap) has been developed by the LUMC and Demcon, Enschede. With this tool, oxygen monitoring makes it possible to optimize tissue rather than blood saturations by adjusting parameters for artificial ventilation or supplemental oxygen administration and can help to optimize saturation levels when artificial ventilation or supplemental oxygen is tapered. Detailed information on changes in vessel diameter can be helpful for the decision when and how to treat ROP.

Placenta as a predictor for ROP (PAPROP)

Major risk factors for developing ROP include low gestational age and low birth weight in relation to age. Also poor prenatal growth has been recognized as a strong independent risk factor. Prenatal growth restriction may be  caused by factors also linked to the development of fetal vessels in the placenta parenchyma and presence and concentration of prenatal placental growth factors. The scope of this project is to gain insight in the effect of the intra-uterine environment on ROP and to assess if the development of ROP is influenced by maternal factors causing abnormal vessel development or inflammation of the placenta, that can be prevented or treated. Clarification of the pathophysiology of ROP can aid to further refine the group of prematurely born neonates with a high-risk profile and provides the opportunity to tailor treatment interventions in a very early stage. Furthermore, early targeting of infants with increased risk for ROP can decrease the number of neonates that need to undergo a distressing eye exam. It may therefore be beneficial to include examination of the placenta post-partum to the screening programme.