Variable supplemental oxygen during recovery does not reduce retinal neovascular severity in experimental ROP

Area of Science:

• Ophthalmology
• Neonatal Medicine
• Physiology

Background:

• Retinopathy of prematurity (ROP) is a leading cause of blindness in premature infants.
• Oxygen therapy is crucial for neonatal care but can contribute to ROP.
• Variable supplemental oxygen (VSO) strategies are being explored to mitigate ROP risks.

Purpose of the Study:

• To evaluate the efficacy of two variable supplemental oxygen (VSO) protocols during recovery in a newborn rat model of ROP.
• To compare VSO effectiveness against constant supplemental oxygen in reducing retinal neovascular severity.

Main Methods:

• Newborn rats were exposed to a variable oxygen model for 14 days, followed by 6 days of recovery.
• Two VSO recovery protocols were tested: 24-hour cycled and interrupted oxygen exposure.
• Retinal neovascularization (NV) incidence, severity, and avascularity were analyzed on day 20.

Main Results:

• No significant difference in NV incidence or severity was observed between the 24-hour cycled and interrupted VSO groups.
• Both VSO groups exhibited significantly greater retinal NV severity compared to constant supplemental oxygen treatment.
• Peripheral avascularity percentages did not differ significantly between the two VSO groups.

Conclusions:

• The study hypothesis was supported: VSO during recovery is less effective than constant oxygen in reducing retinal NV severity.
• These findings suggest that constant supplemental oxygen may be more beneficial for ROP recovery in this model.
• The results have potential implications for clinical trials like STOP-ROP, guiding oxygen management strategies.