Retinopathy of Prematurity

The VEHSS team conducted a review of published literature on examination-based population studies reporting the prevalence of retinopathy of prematurity.

Retinopathy of prematurity (ROP) is a proliferative condition of the retinal vasculature that primarily affects premature infants and is a leading cause of visual impairment and blindness among infants.(Lad, 2008; NEI, 2015) Infants with a birth weight (BW) of less than 1,250 grams and/or those with a gestational age of 31 weeks or less are particularly at risk. The development of ROP is due to abnormal retinal development likely tied to varying levels of oxygenation experienced by infants after birth. There are five categorizations of ROP, ranging from mild to severe. Stage I and II involve mild and moderate abnormal vascular growth in the retina that can resolve without treatment and without subsequent vision impairment in most cases. Stage III is distinguished by severely abnormal vascular growth in the retina, in which vessels grow toward the center of the eye rather than along the surface of the retina. Some infants in stage II are considered to have “plus disease,” characterized by enlarged or contorted vessels. In Stages IV, abnormal vessels cause the retina to become partially detached, and in Stage V, abnormal vessels cause complete retinal detachment. An assessment of which zone of the eye is affected in conjunction with time spent at each stage is used to gauge the severity of the disease.(Quinn, 2016)

Retinopathy of Prematurity Literature Review Results

There were four studies that published prevalence estimates for ROP from 1991 to 2016.

Table 1. Retinopathy of Prematurity Prevalence Sources.

Retinopathy of Prematurity Prevalence Sources
Author Date of Publication Title Date of Data Collection Data Source Sample Size
Quinn GE, Barr C, et al. 2016 Changes in Course of Retinopathy of Prematurity from 1986 to 2013: Comparison of Three Studies in the United States 1986–2013 CRYO-ROP, ETROP, e-ROP 4,099; 6,998; 1,284
Quinn, GE, et al. 2014 Telemedicine Approaches to Evaluating Acute-Phase Retinopathy of Prematurity: Study Design 2011–2013 e-ROP 1,284
Lad EM, Nguyen TC, et al. 2008 Retinopathy of Prematurity in the United States 1997–2002 NIS 22,939,000
Good WV, Hardy RJ, et al. 2005 The Incidence and Course of Retinopathy of Prematurity: Findings from the Early Treatment for Retinopathy of Prematurity Study 2000–2002 ETROP 6,998
Palmer EA, Flynn JT, et al. 1991 Incidence and Early Course of Retinopathy of Prematurity. The Cryotherapy for Retinopathy of Prematurity Cooperative Group 1986–1987 CRYO-ROP 4,099

Overall Retinopathy of Prematurity (ROP) Prevalence Rates

Figure 1 below shows prevalence estimates from the four selected studies. Estimates varied from 0.12% reported by Lad et al. (2008) to 68% reported by Good et al. (2005). The estimate reported by Lad et al. (2008) is based on the entire sample of newborns, whereas the estimates reported by Quinn et al. (2004), Good et al. (2005), and Palmer et al. (1991) are based on a high-risk population. The CRYO-ROP, ETROP and e-ROP studies determined the incidence of ROP by using ophthalmologists to diagnose infants enrolled in the respective study. These literature review results demonstrate the lack of data available on the burden of ROP among the general population and among different socioeconomic and demographic groups.

Figure 1  Overall ROP Prevalence Rates in Selected Studies.

Table shows the following information. Per infant at risk: e-ROP (Quinn et al., 2014) displays 63.7 percent. Per infant at risk: ETROP (Good et al., 2005) displays 68 percent. Per infant at risk: CRYO-ROP (Palmer et al., 1991) displays 65.8 percent. Per all infants: NIS (Lad et al., 2008) displays 0.12 percent.