• propranolol
• newborn
• preterm
• retinopathy of prematurity
• ROP

ABSTRACT

Background
Despite remarkable progress achieved in many areas of neonatal medicine, Retinopathy Of Prematurity (ROP) still remains a very common and disabling complication of premature birth; it represents a major cause of childhood blindness worldwide.
ROP is a multifactorial disease characterized by perturbation of normal vascular development in the retina.
Current therapeutic strategies that reduce ROP progression are applied only at the most advanced stages; however, laser photocoagulation treatment causes a loss of visual field and intravitreal treatment is not completely safe.
Propranolol may represent the turning point for the previous problems. It has been tested on animal models and in numerous clinical trials in order to reduce the progression of ROP through earlier administration than the various surgical treatments. It has been shown that: oral propranolol reduces ROP progression, although not safely; propranolol 0.1% eye micro – drops administered to newborns with stage 2 ROP are well tolerated, but not sufficiently effective; propranolol 0.2% eye micro – drops are well tolerated and appeared to reduce the ROP progression. Further randomized placebo – controlled trials that will using propranolol 0.4% micro – drops are required to confirm the current results.
Following the numerous works using propranolol, our retrospective observational study had as its final objective the evaluation of the efficacy of treatment with propranolol in premature births in the Neonatal Intensive Care Unit of Pisa University Hospital.

Methods
Neonatal, obstetric and premature retinopathy data of all infants who had ROP from January 2010 to August 2022 were collected by means of a specific software and through the medical record in order to carry out the descriptive analysis and the retrospective study. The infants included in the study were divided into two groups: newborns who received no treatment for ROP (historical – control group) and those who received propranolol (treated group).
The collected data were stored in an Excel spreadsheet in order to obtain a better analysis.

Results
114 newborns were enrolled.
In the first analysis of the study, by comparing the historical – control group with treated group, it emerged that in the first group 15/84 (17.86%) infants needed surgical treatment while in the second one only 1/30 (3.3%).
In the second analysis, newborns treated with propranolol showed a reduced trend towards progression of ROP as only 4 (13.3%) passed to stage 3, approximately 3 times less than observed in the control group, p = 0.002; moreover, in the treated group only 1 newborn (3.3%) advanced to stage 2 or 3 with plus (precisely to stage 3 with plus), an event that occurred about 6 times more in the control group, p = 0.04988.
Furthermore, the birth weight of newborns in the treated group is significantly lower than in the historical group (808.4 ± 207.9 vs 938.2 ± 321.8, p = 0.042).

Conclusion
On the basis of the present study, there is further confirmation that propranolol could represent an ideal strategy in counteracting ROP in a sufficiently effective way. Propranolol treatment is well tolerated even in preterm newborns with a high prevalence of co-morbidities. Propranolol eye micro – drops treatment is definitely safer than an oral administration, inexpensive and an easily affordable.
Further studies are required to identify the optimal dosage and administration schedule and it is to date a crucial issue.