The impact of a multidisciplinary intervention to reduce severe retinopathy of prematurity in Kampala, Uganda

doi:10.21203/rs.3.rs-4404555/v1

Download PDF

Article

The impact of a multidisciplinary intervention to reduce severe retinopathy of prematurity in Kampala, Uganda

https://doi.org/10.21203/rs.3.rs-4404555/v1

This work is licensed under a CC BY 4.0 License

Journal Publication

published 30 Jul, 2024

Read the published version in Journal of Perinatology →

You are reading this latest preprint version

Background: To address the threat of retinopathy of prematurity (ROP) in Sub-Saharan Africa (SSA), the Stop Infant Blindness in Africa (SIBA) project introduced a comprehensive program, including subspecialty training and oxygen management equipment.

Methods: A before-and-after retrospective cohort study compared preterm infants <1750g or <34 weeks’ gestation before (2022) and after (2023) program implementation. Outcomes included: the proportion with severe ROP, the proportion with Zone III vascularization on first examination, and factors associated with severe ROP.

Results: Overall, 140 infants were screened before and 122 after program implementation. The proportion with Zone III vascularization increased from 16.1% (N=11) pre-intervention to 44.9% (N=32) post-intervention (p=0.001). The proportion with severe ROP decreased from 27.8% (N=19) to 12.8% (N=9, p=0.03). Factors predicting severe ROP on adjusted analyses were gestational age and blood transfusion.

Conclusion: In SSA, introduction of a comprehensive program to prevent and treat ROP can decrease the risk of severe ROP.

Health sciences/Risk factors

Health sciences/Medical research/Outcomes research

The incidence of Retinopathy of Prematurity (ROP) has grown rapidly in middle and low income countries over the past two decades. This condition can cause vision loss and blindness in children, if not prevented. In middle-income countries, it is known as the “third epidemic” of ROP. [1] In 2008, an estimated 39,000 children blinded from ROP lived in Latin America, the Caribbean, and Eastern Europe, indicating that ROP was a significant cause of childhood blindness in these countries [2] One reason for this high incidence of blinding ROP was the expansion of neonatal care to save newborn lives [3]. The expansion of neonatal care in a developing countries follows the same path as high and middle income countries. Although, basic equipment is now available to save more infant lives, additional resources are needed to ensure that more infants survive without disabilities. Specifically, premature infants now receive life-saving oxygen to save their lives; however, the necessary equipment to blend oxygen with room air and monitor oxygen saturation in order to maintain optimal, physiologic blood oxygen saturation levels is often unavailable. A recent survey of oxygen management in Africa reported that only 64% of the responding neonatal units had any blended oxygen; only one unit had access to continuous monitoring for all the newborns receiving oxygen [1]

Premature infants’ exposure to unregulated oxygen, while lifesaving, is a known risk factor for developing severe ROP [4]. Ten years ago, an estimated 900 premature infants in sub-Saharan Africa (SSA) were blind, and 400 infants had minor visual impairment due to ROP. This number amounts to 4.2% of at-risk preterm infants who received care in a neonatal intensive care unit (NICU) that year [5]. It has now been suggested that SSA is the “new frontier” of ROP [6], and since 2022, blindness from ROP has been reported in 23 countries across SSA. At least 6 out of 48 countries in SSA have documented blindness due to ROP in the past ten years. [7]–[9].

These reports may underestimate the magnitude of the current problem due to incomplete medical records, [7] lack of screening occurring within the facilities, [10] high rates of patients lost to follow-up, [8] the unrepresentative nature of studies in schools for the blind,¹ and the likely continual decrease of neonatal mortality since previous studies were conducted [11]. Thus far, only two countries in SSA have established national screening guidelines for ROP, an essential measure for preventing blinding ROP [12]. Without a centralized protocol for ROP screening before and after discharge, it is likely that many infants develop severe ROP without physicians’ knowledge m[13].

Stop Infant Blindness in Africa (SIBA), a joint project of Children’s Eye Foundation (CEF), the American Association for Pediatric Ophthalmology and Strabismus (AAPOS), and the International Pediatric Ophthalmology and Strabismus Council (IPOSC), introduced a comprehensive prevention, screening and treatment program to reduce ROP in preterm infants. This study describes the impact of the SIBA program on the proportion of at risk before to those screened after the introduction of ROP subspecialty training and oxygen management equipment.

Study design

This observational, retrospective, cohort study examined the clinical outcome of preterm newborns at risk for ROP before and after the introduction of a comprehensive, multidisciplinary program to prevent, identify and treat ROP.

Study site

The study was performed at the Level III Neonatal Intensive Care Unit (NICU) at St. Francis Hospital, Nsambya Hospital, a 361 bed, private, not-for profit, teaching hospital in Kampala, Uganda.

Study population

All inborn preterm newborns with birth weight < 1750 grams or gestational age < 34 weeks by Ballard score or by obstetrical dates who received oxygen therapy for at least 48 hours after birth and survived to discharge were included in the study. Infants with a birth weight between 1750 and 2000g or born at 34–36 weeks’ gestation were also included if they received oxygen therapy for at least 48 hours after birth and had one or more of the risk factors for ROP (e.g., prolonged oxygen use, blood transfusions, respiratory distress syndrome, asphyxia, necrotizing enterocolitis, anemia, and persistent ductus arteriosus). Infants with chromosomal abnormalities, congenital ophthalmologic, cranial or other significant abnormalities were excluded from this study.

Consent

Both verbal and written informed consent was obtained from parents/guardians using their preferred English or local Luganda languages for the study. IRB approval was obtained from the St Francis Hospital Nsambya Institutional research board and the National Research Board.

Intervention

The SIBA program was started at Nsambya Hospital in May 2022. The goal was to develop a model teaching and training center for the prevention, identification, and treatment of ROP. The hospital administration was fully supportive of the SIBA program, and did not yet have the equipment needed for ROP prevention and treatment. The program provided in-line oxygen blenders and pulse oximeters for preterm babies receiving oxygen therapy, an in-service curriculum for all NICU nursing and physician staff focusing on the etiology, prevention, identification, and treatment of ROP, and a nursing protocol to maintain the oxygen saturation between 90–95% for all infants receiving supplemental oxygen and to monitor and record the oxygen saturation in the patient chart every 2 hours. In addition to oxygen sensors and blenders, the SIBA program also provided ROP examination equipment (scleral depressors, lid specula, and an indirect ophthalmoscope), an ICON III Phoenix Camera (NeoLight, Scottsdale AZ), and an indirect laser (Alcon Purepoint Laser). Oxygen blenders were fully operational by January 2023. There were also two one-week training visits from the joint visiting neonatology and ophthalmology SIBA team in 2022 and 2023.

Screening for ROP by indirect ophthalmoscopy was routinely performed at 2–4 weeks after birth or just prior to discharge, with earlier examination recommended for larger, more mature infants treated with oxygen. Prior to discharge, all parents were counseled concerning the risk of ROP, the need for an eye examination and the importance of ongoing follow-up. At discharge, all families were given an outpatient ophthalmology appointment.

Data Collection

Study data were collected for all newborns meeting eligibility criteria for the 9 months before the intervention was introduced (January-September 2022) and 9 months after protocol introduction (January-September 2023) when all oxygen blenders were fully functional and oxygen saturation was being routinely monitored to maintain saturations within the target range. Babies were excluded from Sept 2022 – Jan 2023 to allow for a washout period, until blenders gradually became fully functional in Jan 2023. Variables recorded included year of birth (2022 vs 2023), birth weight, gestational age by Ballard score, sex, small for gestational age status (SGA), duration of oxygen therapy (days), presence of symptomatic patent ductus arteriosus documented by cardiac ultrasound, suspected necrotizing enterocolitis, blood transfusion, and severe ROP defined as ROP requiring treatment in either eye for Type 1 ROP as defined by the Early Treatment of ROP study.¹⁴ All infants with severe ROP received intravitreal bevacizumab (IVB). Intraventricular hemorrhage, sepsis and breastmilk feeding were not included as variables since portable ultrasound equipment and blood cultures were infrequently available, and more than 95% of all babies received exclusive breast milk feeding. All infants < 1500g received caffeine as standard of care.

Outcome measures: The primary outcome measures were the proportion of infants treated for severe ROP and the proportion of infants with zone 3 vascularization on first examamination, comparing infants evaluated before and after all oxygen blenders were functional and oxygen saturation was being routinely monitored to maintain saturations within the target range. Secondary outcomes included clinical factors associated with severe ROP requiring treatment in the entire study cohort: birth weight, gestational age, symptomatic patent ductus arteriosis, necrotizing enterocolitis, blood transfusion, and days on oxygen.

Statistical analyses were performed using Stata version 17.0 (StataCorp LP, College Station, TX). For baseline data, Pearson chi square test or Fisher’s exact test was used to evaluate categorical data and the Wilcoxon Rank-sum test was used to compare continuous variables. Univariate and multivariate logistic regression models were used to evaluate predictors of severe ROP requiring treatment. Due to the small number of treated infants, only BW and GA were included in the multivariable regression. P-values < 0.05 were considered statistically significant. Unadjusted and adjusted odds ratios (OR) and 95% confidence intervals (CI) were reported.

A total of 262 infants were eligible for study inclusion during the study period, 140 from January to September 2022 and 122 from January to September 2023. There were no differences in baseline data comparing the infants included before and after the intervention (Table 1). Among smaller, more immature infants (< 1500g and < 31 weeks GA), the median duration of oxygen therapy was 13 days (IQR 7–28) in 2022 before intervention vs. 8 days (IQR 3.5–17) in 2023, p = 0.10 after intervention.

Table 1

**Baseline data comparing infants examined before and after the SIBA intervention**.
	Overall	Pre-Intervention (n = 140)	Post-Intervention (n = 122)	P-value
Median BW, Grams (IQR)	1500 (1150–2000)	1500 (1100–2000)	1500 (1200–2000)	0.46
Median GA, Weeks (IQR)	33 (30–35)	33 (30–34.5)	32 (30–35)	0.74
Male Sex (%)	114 (44.02)	62 (44.60)	52 (43.33)	0.84
PDA (%)	47 (18.08)	25 (18.12)	22 (18.03)	0.99
Suspected NEC (%)	26 (10.00)	14 (10.14)	12 (9.84)	0.93
Blood Transfusion (%)	116 (44.62)	58 (41.73)	58 (47.93)	0.32
Median Days on Oxygen (IQR)	6 (3–12)	5 (3–12)	5 (3–12)	0.91
IQR = interquartile range, BW = birth weight, GA = gestational age, PDA = Patent ductus arteriosus, NEC = necrotizing enterocolitis

Screening

The overall proportion of infants screened was 54%. (Table 2). Infants who were screened had significantly lower BW (median 1450, IQR 1200–1800) than infants who were not screened (median 1900g, IQR 1000–2200), p = 0.048. Infants not screened had significantly fewer days on oxygen [median 4 days (IQR 2–7 days) vs. median 8 days (IQR 4–15 days), p < 0.001]. The median GA for those not screened was 34 weeks (IQR 29–35) vs. 32 weeks (IQR 31–34) for those screened, p = 0.750.

Table 2

Characteristics of infants screened and treated for severe ROP before and after the SIBA intervention.
	Overall	Pre-Intervention (n = 140)	Post-Intervention (n = 122)	P-value
Screened (%)	141 (53.8)	70 (50.0)	71 (58.2)	0.18
Median PMA at First Exam, Weeks (IQR)	36.3 (35.0–37.6)	36.0 (35.0–37.4)	36.4 (35.1–38.0)	0.39
Zone III Vascularization at First Exam (%)	42 (30.4)	11 (16.1)	31 (44.3)	0.001
Treated ROP (%)	28 (20.1)	19 (27.5)	9 (12.9)	0.03
Median PMA at Treatment, Weeks (IQR)	36.3 (34.5–38.8)	36.4 (36.3–39.1)	34.0 (34.0–37.0)	0.10
Median BW of Treated Infants, Grams (IQR)	1140 (1000–1325)	1090 (900–1300)	1280 (1150–1350)	0.18
Median GA of Treated Infants, Weeks (IQR)	30 (29–32)	29 (29–32)	30 (30–30)	1.00
Median Days on Oxygen in Treated Infants (IQR)	15 (8–32)	19 (8–33)	13 (8–20)	0.32
IQR = interquartile range; PMA = postmenstrual age; BW = birth weight; GA = gestational age

Treatment:

The median BW of all treated infants was 1140 grams (IQR 1000–1325 grams). There were no BW differences among treated babies in pre-intervention vs. post-intervention periods [1090g (IQR 900–1300g) vs.1280g (IQR 1150- 1350g) p = 0.18 respectively]. The median GA of all treated infants was 30 weeks (IQR 29–32 weeks) and was likewise similar for pre-intervention vs. post-intervention periods [29 weeks (IQR 29–32) vs. 30 weeks (IQR 30–30), p = 1.00 respectively]. Median duration of oxygen therapy of all treated infants was 15 days (IQR 8–32 days), being 19 days (IQR 8–33) in pre-intervention and 13 days (8–20), p = 0.32 in post-intervention periods (p = 0.32). All treated infants received oxygen for at least 4 days.

As shown in Table 2, the overall proportion of infants with severe ROP requiring treatment decreased from 28% before to 13% after the intervention (p = 0.03). In addition, the proportion of infants with more anterior vascularization (zone III) increased significantly from 16–44%, p = 0.001. There were no significant differences in either median BW or GA at the time of treatment, comparing infants before and after the intervention (p = 0.74 and p = 0.46, respectively).

In the overall study cohort, factors associated with severe ROP included BW, GA, PDA, NEC, Blood transfusion, and days on oxygen (Table 3). The odds of treatment increased 6% per day on oxygen in both pre-intervention (CI 2% − 11%, p = 0.005) and post-intervention (CI 0–13%, p = 0.035) periods. When controlled for GA and BW, only GA and blood transfusion remained significant predictors of severe ROP requiring treatment (Table 3).

Table 3

Factors associated with severe ROP requiring treatment
	Univariate Analysis			Adjusted analysis*
	OR	95% CI	p-value	OR	95% CI	p-value
Birth Weight, grams	0.997	0.995–0.998	< 0.001	0.999	0.997–1.001	0.23
Gestational Age, weeks	0.57	0.44–0.72	< 0.001	0.65	0.47–0.88	0.006
Gender	0.58	0.25–1.34	0.2	0.45	0.17–1.24	0.12
Small for gestational age	0.34	0.095–1.21	0.095	1.18	0.389–8.31	0.45
Patent ductus arteriosus¹	7.54	2.94–19.30	< 0.001	2.78	0.88–8.76	0.08
Presumed Sepsis	0.73	0.22–2.45	0.61	0.39	0.09–1.60	0.20
Necrotizing Enterocolitis²	6.23	2.22–17.48	0.001	2.6	0.79–8.57	0.11
Blood Transfusion	6.64	2.35–18.78	< 0.001	3.51	1.12–11.0	0.03
Days on Oxygen	1.07	1.03–1.11	< 0.001	1.02	0.97–1.06	0.48
*Adjusted for BW and GA
1. Clinically significant patent ductus arteriosus
2. Suspected necrotizing enterocolitis

In this retrospective before and after cohort study, we showed that after the introduction of oxygen blenders and oxygen saturation targeting, the proportion of infants screened needing treatment for ROP decreased from 27–13%. While we might also expect to see the BW and GA among treated infants to have trended down as a result of this information, the number of treated infants in the post-intervention period was small (n = 9), and more data is likely necessary.

In addition to a decrease in the proportion of infants with severe ROP, the proportion of infants attaining vascular maturation in zone III at the time of first examination increased from 16–44%. This likely indicates more physiologic vascularization that was not inhibited by excessive oxygen exposure. While on first glance, 44% of infants with mature vascularization on first examination may seem high, the median PMA on first examimation was 36.4 weeks, which is consistent with expected vascularization under conditions of oxygen management in high income countries. For example, the median PMA at which zone III vascularization was obtained in patients without a history of ROP was 35.6 weeks in the CRYO-ROP study.¹⁵

Perhaps related to the improved physiologic vascularization, there was a trend towards fewer days on oxygen after the SIBA intervention among the smaller infants < 1500g and 31 weeks GA. In addition to providing oxygen blenders, the SIBA intervention included a multifaceted training program for nurses, neonatologists, and ophthalmologists. As a result, this may reflect more judicious use of oxygen after the intervention, especially among the highest risk infants.

Many of the factors associated with an increased risk of ROP have been identified in various other studies.¹⁶ In this study, blood transfusion remained a significant risk factor after controlling for GA and BW. Needing a blood transfusion may reflect the degree of prematurity and general severity of illness that places a baby at increased risk for ROP. Of note, previous studies evaluating the Third Epidemic of ROP have suggested that BW may be more important than GA in predicting risk of ROP.^16,17 The increased significance of GA in this study likely reflects the use of Ballard scores at our center to more accurately ascertain GA, which best predicts the time course of retinal development and ROP. This may not be the case at other neonatal care sites where only BW is available. Given the substantial range of BW at each week of gestation, it is not surprising that GA is a better predictor of ROP in our cohort.

Despite the decrease in the proportion of infants with severe ROP, the BW and GA among treated infants remains higher than that found in high income countries^14,18 and consistent with other data from the expanding Third Epidemic of ROP.³ Overall, the median BW of treated infants was 1140 g (IQR 1000–1325) and the median GA overall was 30 weeks (IQR 29–32). However, the decreased proportion of infants treated, combined with the increased proportion of infants with more physiologic vascularization, are likely the results of improved oxygen management.

An important limitation of this study is the high number of infants who were not screened for ROP. These infants tended to have more advanced GA, higher BW, fewer days on oxygen than those who were screened, and were likely discharged prior to the first ROP examination scheduled at 2 weeks after birth. While we would anticipate that a smaller proportion of these infants would have required treatment, the number is also not likely zero given that the IQR of the BW and GW overlap with the IQR of the GA and BW of treated infants. In general, the transition between inpatient to outpatient ROP care remains a high-risk time-point in ROP care worldwide, and this intervention did not specifically address outpatient follow-up in ROP. These data demonstrate an ongoing challenge in ROP care that will need to be addressed with a multifactorial approach including parent education, care coordination, advocacy, and national guidelines for ROP. Limitations of time, financial constraints, access to treatment and lack of awareness, are all barriers that will need addressed as this ROP program expands.

These data may not be generalizable to the rest of Uganda. Limitations are inherent in this retrospective study lead by an experienced neonatologist at a single Level III NICU in an otherwise well-equipped, private, non-profit hospital. For instance, GA as determined by routine Ballard score was more predictive of the need for treatment than BW. However, as a universally available, objective indicator, BW may be more practical when considering screening guidelines across Uganda.^15,16

Overall, implementation of the SIBA program demonstrates the short-term impact that a comprehensive program addressing neonatology and ophthalmology can have on the incidence of ROP as this small, single center, retrospective study shows that reducing the risk of ROP is possible. The earliest markers of improvement may be a decrease in the proportion with severe ROP accompanied by an increased in the proportion with zone III vascularization on first examination. While long-term data collection is ongoing, this program could potentially prevent dozens of infants each year at a single hospital from a lifetime of blindness or visual impairment. Even in the absence of ROP treatment, decreasing the rate of severe ROP by 50% in a single year demonstrates the potential impact of an effective oxygen management program. Advocating for similar comprehensive ROP prevention and management programs across Uganda and SSA including neonatology, ophthalmology, and the nursing staff will be important in addressing the “New Frontier” of ROP.

Overall, this single-center, before-and-after study shows that a multifaceted intervention including the introduction of blended oxygen can significant decrease the rate of severe ROP and improve the rate of normal physiologic vascularization among a cohort of high-risk infants at a private hospital in SSA. A comprehensive approach including not only ROP screening and treatment, but also primary prevention with improved oxygen management is needed to address the evolving Third Wave of ROP in SSA. [15] There is an urgent need for increased efforts across Uganda to increase knowledge about the risk of ROP, to provide resources for appropriate oxygen management and to improve access to ROP screening and treatment.

Acknowledgements:

This study was made possible in part by a generous grant from the Knights Templar Eye Foundation to the Stop Infant Blindness in Africa Initiative (SIBA) of the Children’s Eye Foundation of the American Association for Pediatric Ophthalmology and Strabismus and the International Strabismus and Pediatric Ophthalmology Council.

Disclosures: None of the authors has any relevant financial conflicts of interest to disclose.

Herrod SK, Stevenson A, Vaucher, YE, et al. Oxygen management among infants in neonatal units in sub-Saharan Africa: a cross-sectional survey. J. Perinat 2021; 41:2631–2618.
Sabril Kourosh, Ells L A, Lee Y E, et al. Retinopathy of Prematurity: A Global Perspective and Recent Developments Pediatr 2022;150(3):e2021053924.
Gilbert C, Fielder Alistair, Gordillo L, et al. Characteristics of infants with severe retinopathy of prematurity in countries with low, moderate, and high levels of development: implications for screening programs. Pediatr 2005;115(5):e 518–25.
Cunningham S, Mclntosh N, Fleck BW, et al. doi: 10.1016/S0140-6736(95)92475-2[published Online First: Epub Date]|.
Blencowe H, Lawn E Joy, Vazquez T, et al. Preterm-associated visual impairment and estimates of retinopathy of prematurity at regional and global levels for 2010. Pediatr Res 2013;74(Suppl 1);35–49.
Gilbert C, Malik N J A, Nahar N, et al. Epidemiology of ROP update - Africa is the new frontier. Semin Perinatol 2019;43(6):317–322.
Gyawali R, Bhayal K B, Adhikary R, et al. Retrospective data on causes of childhood vision impairment in Eritrea. BMC Opthalmo 2017; 17:209.
du Bruyn A, Visser L. Eight years of treatable retinopathy of prematurity in KwaZulu-Natal: are we winning the battle? South Afr Ophthalmol J 2017;12(2):8–10.
Herrod K, Scott,, Adio A, Isenberg J, sherwin,, et al. Blindness Secondary to Retinopathy of Prematurity in Sub-Saharan Africa. Opthalmic Epidemiology 2022;29(2):156–163.
Dadoo Z, Ballot E D. An evaluation of the screening for retinopathy of prematurity in very-low-birth-weight babies at a tertiary hospital in Johannesburg, South Africa. South African Journal of Child Health 2016;10(1):79–82.
Hug L, Alexander M, You D, et al. National, regional, and global levels, and trends in neonatal mortality between 1990 and 2017,with scenario-based projections to 2030: a systematic analysis. 2019; Lancet Glob Health;7(6):e710-e720.
Kulkarni S, Gilbert C, Zuurmond M, et al. Blinding Retinopathy of Prematurity in Western India: Characteristics of Children, Reasons for Late Presentation, and Impact on Families. Indian Pediatr 2018;55(8):665–670.
Wang Danieel, Duke Roseline, Chan RV Paul, et al. Retinopathy of Prematurity in Africa: A Systematic Review. Opthalmic Epidemiology 2019;26(4):223–230
Early Treatment For Retinopathy Of Prematurity Cooperative Group. Revised indications for the treatment of retinopathy of prematurity: results of the early treatment for retinopathy of prematurity randomized trial. Arch Ophthalmol. 2003;121(12):1684-94. doi: 10.1001/archopht.121.12.1684. PMID: 14662586.
Reynolds JD, Dobson V, Quinn GE, et al. Evidence-Based Screening Criteria for Retinopathy of Prematurity: Natural History Data From the CRYO-ROP and LIGHT-ROP Studies. Arch Ophthalmol. 2002;120(11):1470–1476. doi:10.1001/archopht.120.11.1470
Kim SJ, Port AD, Swan R, Campbell JP, Chan RVP, Chiang MF. Retinopathy of Prematurity: A Review of Risk Factors and their Clinical Significance. Surv Ophthalmol 2018; 63: 618–637
Wang D, Duke R, Chan RP, Campbell JP. Retinopathy of prematurity in Africa: a systematic review. Ophthalmic Epidemiol. 2019;26(4):223–230. doi: 10.1080/09286586.2019.1585885. Epub 2019 Mar 1. PMID: 30821627; PMCID: PMC6759209.
Palmer EA. Results of U.S. randomized clinical trial of cryotherapy for ROP (CRYO-ROP). Doc Ophthalmol. 1990;74(3):245 – 51. doi: 10.1007/BF02482615. PMID: 2209383.

There is NO conflict of interest to disclose.

Download PDF

Journal Publication

published 30 Jul, 2024

Read the published version in Journal of Perinatology →

Editorial decision: revise
31 May, 2024
Review #2 received at journal
28 May, 2024
Review #1 received at journal
22 May, 2024
Reviewer #2 agreed at journal
15 May, 2024
Reviewer #1 agreed at journal
14 May, 2024
Reviewers invited by journal
14 May, 2024
Submission checks completed at journal
14 May, 2024
First submitted to journal
13 May, 2024
Unknown event
13 May, 2024
Editor assigned by journal
11 May, 2024

You are reading this latest preprint version

The impact of a multidisciplinary intervention to reduce severe retinopathy of prematurity in Kampala, Uganda

Status:

Journal Publication

Version 1

Abstract

Background

Methods

Results

Treatment:

Discussion

Conclusion

Declarations

References

Additional Declarations

Status:

Journal Publication

Version 1