Retinopathy of Prematurity Prevalence Variations: Latest SA Research in Nature Highlights Regional Differences

Understanding Retinopathy of Prematurity in Preterm Infants

Retinopathy of Prematurity (ROP), also known as Retinopathy of Prematurity prevalence variations in South Africa, is a serious eye disorder that primarily affects premature babies, particularly those born before 32 weeks of gestational age (GA) or with a birth weight (BW) under 1,250 grams. This condition arises when the retinal blood vessels, responsible for nourishing the retina at the back of the eye, develop abnormally. In full-term infants, these vessels grow steadily before birth, but in preterm babies, the process is interrupted, leading to two phases: first, delayed vessel growth causing hypoxia (oxygen deprivation) in the retina, and second, chaotic overgrowth of vessels that can scar and detach the retina, potentially resulting in permanent blindness if untreated.

The disease progresses through stages classified by the International Classification of Retinopathy of Prematurity: stage 1 (mild demarcation line), stage 2 (ridge formation), stage 3 (extraretinal fibrovascular proliferation), and more severe stages 4 (partial retinal detachment) and 5 (total detachment). Treatment is critical for Type 1 ROP (threshold disease involving zone 1 or plus disease) using laser therapy or anti-vascular endothelial growth factor (anti-VEGF) injections. Early screening via dilated fundus examinations using binocular indirect ophthalmoscopy is the gold standard to detect treatable cases promptly.

In South Africa, where neonatal survival rates have improved due to better neonatal intensive care units (NICUs), ROP has emerged as a leading preventable cause of childhood blindness, accounting for 10.6% to 16.7% of cases in blind schools. This rise underscores the need for robust screening programs, especially as preterm birth rates hover around 12-15% nationally.

🩺 Breakthrough Study from University of Cape Town Researchers

A groundbreaking prospective study published today in Eye, a Nature journal, reveals stark variations in ROP prevalence across five neonatal units in Cape Town, South Africa. Led by Tshilidzi Van der Lecq from the University of Cape Town's (UCT) Division of Ophthalmology at Groote Schuur Hospital, the research draws on data from the Retinopathy of Prematurity South African (ROPSA) register, highlighting how ROP prevalence ranges from 16.1% to 71.2% among screened infants.

The study, spanning February 2023 to April 2024, involved 933 preterm infants meeting national screening criteria (GA <32 weeks or BW <1,250g). Collaborators from UCT's Departments of Paediatrics and Child Health, Stellenbosch University's Division of Ophthalmology at Tygerberg Hospital, University of the Western Cape's Statistics Department, and the South African Medical Research Council exemplify South African higher education's pivotal role in addressing public health challenges. These academic institutions not only conducted the research but also developed the ROPSA register to monitor screening nationwide.

This work builds on prior UCT-led efforts, such as a 2025 BMJ Open Ophthalmology study showing 31.6% ROP prevalence in the same region, emphasizing the continuity of university-driven research in neonatal ophthalmology.

Methodology: A Rigorous Prospective Register-Based Approach

Researchers extracted data from the ROPSA register, a REDCap-based platform launched in 2022 to standardize ROP data collection across South Africa's public sector. Infants were screened starting at 4-6 weeks postnatal age (PNA) or 31-33 weeks postmenstrual age (PMA), with follow-ups until full vascularization or 45 weeks PMA. Examinations used 28-dioptre lens indirect ophthalmoscopy by trained ophthalmologists or supervised trainees at three tertiary (handling 86.7% of cases) and two secondary units in Cape Town Metropole, serving 4.7 million people.

Statistical analysis via SAS compared unit-level differences using Chi-square tests for categorical data and ANOVA for continuous variables like mean GA (28.8 weeks overall) and BW (1,102g). This methodology allowed precise quantification of variations, attributing differences partly to infant acuity (lower GA/BW in tertiary units) and inter-hospital transfers increasing risk in secondary sites.

Such rigorous, register-based studies showcase how research jobs at South African universities drive evidence-based policy, with UCT and Stellenbosch leading in ophthalmology and neonatology training.

Key Findings: Wide ROP Prevalence Variations Across Units

ROP was diagnosed in 33.8% (315/933) of infants overall, with stage 1/2 comprising 83.8% of cases and stage 3 at 16.2% (5.5% overall). Strikingly, prevalence among all screened infants varied from 16.1% in one tertiary unit to 71.2% in a secondary unit. Even among those completing screening (only 50.2%), rates ranged 13.1%-64.3%; incompletely screened infants showed 25.0%-79.2%.

• Unit A (tertiary): 33.4% ROP, 36.8% screening completion
• Unit B (tertiary): Lower ROP, higher completion
• Unit E (secondary): Highest ROP at 71.2%, possibly due to sicker referrals

These disparities within one metropolitan region highlight micro-variations in neonatal care quality, oxygen management, and nutrition protocols, despite uniform national guidelines.

Challenges in Screening Completeness: A Critical Gap

Only 468/933 (50.2%) infants completed screening, varying 36.8%-74.6% by unit. Alarmingly, 56.8% of ROP cases (179/315), including 58.8% of stage 3, had incomplete screening—often due to caregivers failing follow-ups (91.2% of incompletes). Infants with incomplete screens were smaller and less mature, examined later, underscoring socioeconomic barriers like transport costs in Cape Town's sprawling townships.

Prior SA studies report 12.1%-33.4% ROP, but incompleteness likely underestimates true burden. The ROPSA register reveals 46% incompleteness in earlier Cape Town data, higher than many high-income countries (e.g., 75-80% timely screening).

University researchers advocate caregiver education, transport subsidies, and tele-ophthalmology to boost adherence, aligning with global trends in resource-limited settings.

Risk Factors and Demographics in South African Context

Lower GA and BW were key predictors, with ROP infants averaging shorter gestations. Other factors include oxygen therapy fluctuations, sepsis, and transfusions—common in SA's overburdened NICUs. Singleton pregnancies dominated (though multiples screened similarly), and Black African ethnicity prevails in public cohorts, reflecting demographics.

• Mean GA ROP-positive: 28.5 weeks vs. 29.1 weeks ROP-negative
• BW: 1,003g vs. higher
• No significant sex differences

Cultural context: High preterm rates from HIV, hypertension in pregnancy; regional urban-rural divides amplify risks outside Cape Town, where care lags.

Implications for Neonatal Care and Public Health Policy

These findings signal an impending ROP epidemic in sub-Saharan Africa as neonatal survival rises without proportional screening investment. In SA, ~16,000 infants yearly qualify; missed stage 3 cases risk blindness. Policymakers must prioritize ROPSA expansion, guideline revisions (current: GA <32w/BW <1,500g variably applied), and training.

Stakeholder views: Neonatologists like UCT's Lloyd Tooke stress oxygen saturation protocols (target 91-95%); ophthalmologists like Linda Visser (Stellenbosch) call for more specialists. Parents face burdens, but education empowers.

South African Universities Driving ROP Research Innovation

UCT's longstanding ophthalmology program, alongside Stellenbosch and Western Cape universities, positions SA higher education as a hub for pediatric eye research. The ROPSA collaborative, involving multidisciplinary teams, exemplifies inter-university partnerships fostering PhD training and postdocs.

Explore faculty positions or research assistant jobs in South African academia via AcademicJobs South Africa. Careers in neonatology and ophthalmology offer impactful roles amid growing demand.

Comparisons with Other SA Regions and Global Trends

Johannesburg studies (e.g., Chris Hani Baragwanath) report 27% ROP, lower in regional vs. central hospitals; Tygerberg (Cape Town) at 31.1%. Lower rural prevalences (4%) reflect less intensive care, delaying ROP onset. Globally, SSA ROP (6-47%) lags HICs (20-30% mild), but treatment gaps loom.

SA's national guidelines, endorsed by ophthalmology societies, aim uniformity, yet regional resource disparities persist—a focus for university-led advocacy.

Future Outlook: Solutions and Actionable Insights

Optimism lies in ROPSA's monitoring potential, AI screening tools, and wider anti-VEGF access. Universities propose:

• Standardized training modules
• Mobile screening units for townships
• Integration with NSFAS-like funding for follow-ups
• Research into genetic/ethnic risk modifiers

Timelines: Guideline updates by 2027; national coverage targets 80%+. For professionals, higher ed career advice on specializing in pediatric ophthalmology is invaluable. Engage via Rate My Professor for insights into UCT/Stellenbosch programs.

Photo by Annie Spratt on Unsplash

Conclusion: Advancing Through Academic Excellence

This Nature publication underscores South African universities' leadership in tackling ROP prevalence variations, paving the way for zero preventable blindness. Discover opportunities at university jobs, higher ed jobs, or post a job to join the fight. Professionals and students, visit higher ed career advice for next steps.