Incidence of retinopathy of prematurity type 1 and type 2 in a regional Hospital of Social Security in the state of Queretaro, Mexico (2017-2018).

backgroundRetinopathy of prematurity (ROP), the primary cause of blindness in children, is a potential complication for 7.7% of live births in Mexico. Given that less than one-third of all neonatal intensive care units follow Mexican National ROP guidelines, there have been few reports regarding the incidences of types 1 and 2 ROP.

methodsThis was a retrospective study that investigated the incidence and onset of ROP in a representative sample of children in Mexico. We analyzed the results obtained by the ROP Detection and Treatment Program, compliant with the Mexican National ROP guidelines, over a 1-year period. This study included 132 children who were born prematurely, were initially screened between October 2, 2017 and October 1, 2018, and underwent follow-up based on their risk group (in accordance with the Mexican National ROP guidelines).

resultsThe mean gestational age (GA) at birth was 32 weeks and 3 days (32w3d) (95% CI, ± 3 days), and the mean birth weight (BW) was 1594 g (95% CI, ± 96 g). The clinical features were as follows: 36.4% had immature retina without ROP, 22.0% had mild ROP, 5.3% had type 2 ROP, 27.3% had type 1 ROP, and 1.5% had advanced disease. Premature children with ROP requiring treatment (i.e., type 1 ROP + advanced ROP) were born at an MGA of 30w4d (95% CI, ± 5d; range, 26-35 weeks); their MBW was 1316 g (95% CI, ± 110 g; range, 830-2220 g). Diagnosis of ROP requiring treatment was made at a mean postmenstrual age (PMA) of 37w3d (95% CI, ± 5d; range, 31w1d to 42w1d).

conclusionIn Mexico, screening and close ophthalmological follow-up of children who present with risk factors of birth weight < 1750 g and gestational age ≤ 34 weeks, both of which are observed more frequently in children with type 1 ROP, appears essential for implementing timely treatments (within 72 h). This is particularly important for children with PMA between 36 and 38 weeks, which is considered to be the peak age for disease stages that require timely intervention.