More Boys Meet Screening, Treatment Criteria for Retinopathy of Prematurity

More boys than girls meet the screening and treatment criteria in retinopathy of prematurity.

More preterm infant boys meet the criteria to undergo screening and treatment for retinopathy of prematurity (ROP) than girls, according to results of a systematic review and meta-analysis, published in JAMA Ophthalmology. However, the odds of receiving treatment for ROP is similar between sexes, the study shows.

Investigators from Harvard Medical School searched publication databases through February 2022 for studies that reported gender distributions in the setting of ROP treatment. The analysis included 44,095 eyes of 31,026 patients from 316 studies.

The studies, published between 1986 and 2020, were mostly of a retrospective design (79.4%) and conducted in upper-middle- (43.7%) or high- (42.4%) income countries.

The pooled percentage of boys who received ROP treatment was 55% (I2, 34%; P <.001). Stratified by study design, the proportion of boys was 0.46 (I2, 0%; P =.56) for prospective studies, 0.49 for randomized clinical trials (I2, 0%; P =.62), 0.55 (I2, 43%; P =.002) for retrospective studies, and 0.61 for cross-sectional studies (I2, 19%; P =.27).

The suspicion has been confirmed that more male infants are treated for ROP than female infants. 

A total of 170,053 infants were screened for ROP, among whom 2% received ROP treatment. More boys were both screened (53%) and treated (55%) for ROP than girls. The pooled likelihood of receiving treatment tended to be higher among boys than girls (odds ratio [OR], 1.04; 95% CI, 0.91-1.18; I2, 45%; P =.002). Stratified by study design, boys were significantly more likely to receive treatment in prospective studies (OR, 1.23; 95% CI, 1.01-1.49; I2, 0%; P =.45) but not in retrospective studies (OR, 0.96; 95% CI, 0.83-1.12; I2, 47%; P =.005) compared with girls.

National income level was not associated with likelihood of treatment among boys (β, -0.19; P =.05) or girls (β, 0.15; P =.14). Overall, the male-to-female ratios were 59:41 in lower-income countries, 55:45 in upper-middle-income countries, and 54:46 in high-income countries.

This analysis may have been limited by the lack of complete data about infant characteristics, such as the need of resuscitation at birth.

“The suspicion has been confirmed that more male infants are treated for ROP than female infants,” according to the study authors. “This could be due to a known pathophysiological fragility of male neonates in addition to a difference in ROP screening, with more male infants meeting the screening criteria for ROP than female infants. Future clinical studies on ROP screening and treatment will need to account for sex as variable that may impact outcomes.”

Disclosure: Some study authors declared affiliations with the biotech, pharmaceutical, and/or device companies. Please see the original reference for a full list of authors’ disclosures.


Hoyek S, Peacker BL, Acaba-Berrocal LA, et al. The male to female ratio in treatment-warranted retinopathy of prematurity: a systematic review and meta-analysis. JAMA Ophthalmol. 2022;140(11):1110-1120. doi:10.1001/jamaophthalmol.2022.3988