Safety of Retinopathy of Prematurity Examination and Imaging in Premature Infants

Retinopathy of prematurity screening: can the examination time be reduced?

CLINICAL RELEVANCE

Retinopathy of prematurity (ROP) is a significant cause of childhood blindness. Screening examinations that maintain accuracy, while improving the experience for families, could increase adherence to follow-up and decrease workload.

BACKGROUND

Traditional ROP screening examinations are known to be uncomfortable for babies and stressful for parents. A new strategy is proposed and tested for the accuracy of the outcome and the time taken.

METHODS

In this new screening strategy, the examiner performs a complete retinal examination on the first visit. If the area and stage of the nasal and temporal retinal regions are similar or the stage of the temporal half is worse, only the posterior pole and temporal half of the retina are evaluated at subsequent visits. A retrospective patient file review was conducted to compare the new proposal with accepted methods. ROP examination time was compared prospectively.

RESULTS

The data of 57 consecutive patients treated for ROP were evaluated. The ROP zone was the same in the nasal and temporal retina in all eyes at the first and last visit before treatment. Only two eyes had worse ROP stage in the nasal half at presentation but both halves developed the same degree of stage during follow-up. None of the treatment decisions were based only on the nasal region of the retina. Examination time was evaluated in 40 eyes of 20 infants. The average total time required for an examination with the accepted method was 241.3 ± 112.5 seconds. However, with the proposed strategy, the examination time was significantly reduced to 172.3 ± 69.2 seconds (p < 0.001).

CONCLUSIONS

This screening strategy shortens examination time, which may help reduce pain and related adverse events.

Cost-Effectiveness of Addressing Retinopathy of Prematurity in Rwanda

PURPOSE

With the expansion of neonatal care in sub-Saharan Africa (SSA), an increasing number of premature babies are at risk to develop retinopathy of prematurity (ROP). Previous studies have quantified the cost-effectiveness of addressing ROP in middle-income countries, but few have focused on SSA. This study estimates the cost of a national program for ROP screening and anti-VEGF injection treatment in Rwanda compared to the status quo.

METHODS

Medical cost data were collected from King Faisal Hospital in Rwanda (July 2022). Societal burden of vision loss included lost productivity and quality-adjusted life years (QALYs). Published data on epidemiology and natural history of ROP were used to estimate burden and sequelae of ROP in Rwanda. Cost of a national program for screening and treating a one-year birth cohort was compared to the status quo using a decision analysis model.

RESULTS

Cost of ROP screening and treatment was $738 per infant. The estimated equipment cost necessary for the startup of a national program was $58,667. We projected that a national program could avert 257 cases of blindness in the cohort and increase QALYs compared to the status quo. Screening and treatment for ROP would save an estimated $270,000 for the birth cohort from reductions in lost productivity.

CONCLUSION

The cost of screening and anti-VEGF treatment for ROP is substantially less than the indirect cost of vision loss due to ROP. Allocating additional funding towards expansion of ROP screening and treatment is cost-saving from a societal perspective compared to current practice.

Vasoactive peptides as biomarkers for the prediction of retinopathy of prematurity

BACKGROUND

Retinopathy of prematurity (ROP) is a major complication in preterm infants. We assessed if plasma levels of midregional pro-atrial natriuretic peptide (MR-proANP) and C-terminal pro-endothelin-1 (CT-proET1) serve as early markers for subsequent ROP development in preterm infants <32 weeks gestation.

METHODS

Prospective, two-centre, observational cohort study. MR-proANP and CT-proET1 were measured on day seven of life. Associations with ROP ≥ stage II were investigated by univariable and multivariable logistic regression models.

RESULTS

We included 224 infants born at median (IQR) 29.6 (27.1-30.8) weeks gestation and birth weight of 1160 (860-1435) g. Nineteen patients developed ROP ≥ stage II. MR-proANP and CT-proET1 levels were higher in these infants (median (IQR) 864 (659-1564) pmol/L and 348 (300-382) pmol/L, respectively) compared to infants without ROP (median (IQR) 299 (210-502) pmol/L and 196 (156-268) pmol/L, respectively; both P < 0.001). MR-proANP and CT-proET1 levels were significantly associated with ROP ≥ stage II in univariable logistic regression models and after adjusting for co-factors, including gestational age and birth weight z-score.

CONCLUSIONS

MR-proANP and CT-proET1 measured on day seven of life are strongly associated with ROP ≥ stage II in very preterm infants and might improve early prediction of ROP in the future.

IMPACT

Plasma levels of midregional pro-atrial natriuretic peptide and C-terminal pro-endothelin-1 measured on day seven of life in very preterm infants show a strong association with development of retinopathy of prematurity ≥ stage II. Both biomarkers have the potential to improve early prediction of retinopathy of prematurity. Vasoactive peptides might allow to reduce the proportion of screened infants substantially.

Validation and Feasibility of the Postnatal Growth and Retinopathy of Prematurity Retinal Screening Criteria at a Level IV Tertiary Care Neonatal Intensive Care Unit

OBJECTIVE

Retinopathy of prematurity (ROP) is detected in preterm infants by standardized screening programs, but in general, they have poor sensitivity. The Postnatal Growth and Retinopathy of Prematurity (G-ROP) algorithm uses weight gain to predict ROP superior reported sensitivity. Our objectives are to (1) independently validate the sensitivity of G-ROP criteria for the detection of ROP in infants born at >28 weeks' gestation in a tertiary care unit in the United States and (2) to calculate the cost savings associated with a potential reduction in examinations.

STUDY DESIGN

This is a retrospective analysis of retinal screening examination data, with post-hoc application of G-ROP criteria to determine whether G-ROP criteria had acceptable sensitivity and specificity in diagnosing Type 1 and Type 2 ROP. All infants born at >28 weeks who were screened by current American Academy of Pediatric Ophthalmologists/American Academy of Pediatrics guidelines at Oklahoma Children's Hospital at the University of Oklahoma Health Sciences Center, between 2014 and 2019, were included. Subset analysis of infants screened by second tier criteria was also performed. Potential cost savings were estimated by analyzing frequency of billing codes. And by calculating the number of infants who could have potentially been spared examination.

RESULTS

The G-ROP criteria had 100% sensitivity in detecting type 1 and 87.6% sensitivity in detecting type 2 ROP, which would have reduced infants screened by 50%. All infants in the second tier who would require treatment were detected. A cost saving of 49% was projected.

CONCLUSION

The G-ROP criteria are easy to apply in real-world setting, thus establishing feasibility. The algorithm identified all cases of type 1 ROP; however, some cases of type 2 ROP were not detected. The annual savings in hospital examination cost by using these criteria would be 50%. Therefore, G-ROP criteria can safely be used to screen for ROP and may reduce the number of unnecessary examinations.

KEY POINTS

· The G-ROP screening criteria are safe and predict 100% of treatment warranted ROP.. · Adoption of G-ROP criteria is feasible for level IV NICUs.. · Adoption of G-ROP screening guidelines will result in significant cost savings..

Early Single-Examination Optical Coherence Tomography Biomarkers for Treatment-Requiring Retinopathy of Prematurity

Purpose

Optical coherence tomography (OCT) is an emerging adjunct imaging modality to evaluate retinopathy of prematurity (ROP). From an 11-year research database, we identify early OCT biomarkers that predict treatment-requiring ROP (TR-ROP).

Methods

For preterm infants with acceptable OCT images at 32 ± 1 weeks postmenstrual age (PMA), we extracted the following measures: total retina, inner retinal layer (IRL), and outer retinal layer (ORL) thicknesses at the fovea and the parafovea, inner nuclear layer (INL) and choroidal thickness, parafovea/fovea (P/F) ratio, and presence of macular edema. Using univariable and multivariable logistic regression models, we evaluated the association between retinal and choroidal OCT measurements at 32 ± 1 weeks PMA and development of TR-ROP.

Results

Of 277 eyes (145 infants) with usable OCT images, 67 eyes had TR-ROP. Lower P/F ratio (P < 0.0001), thicker foveal IRL (P = 0.0001), and thinner choroid (P = 0.03) were associated with TR-ROP in univariable analysis, but lost significance of association when adjusted for gestational age and race. Absence of macular edema was associated with TR-ROP when adjusted for gestational age and race (P = 0.01). In 185 eyes without macular edema, P/F ratio was associated with TR-ROP in both univariable analysis (P < 0.0001) and multivariable analysis (P = 0.02) with adjustment for gestational age and race.

Conclusions

Presence of macular edema at 32 ± 1 weeks PMA in infants with lower gestational age may be protective against TR-ROP. In infants without macular edema, P/F ratio may be an early OCT biomarker for development of TR-ROP. Incorporation of early OCT biomarkers may be useful in prediction of TR-ROP.

Mechanical Ventilation, Retinal Avascularity and Rate of Vascularisation: A Triad of Predictors for Retinopathy of Prematurity Treatment

AIM

The temporal avascular area of the retina and the duration of mechanical ventilation (DMV) may predict the need to treat retinopathy of prematurity (ROP). This study considers whether the rate of retinal vascularisation and related risk factors should be included in a predictive model of the need for ROP treatment.

METHODS

This single-centre, observational retrospective case-control study was conducted on 276 preterm infants included in an ROP screening programme. All had undergone at least three examinations of the fundus. The main outcome measures considered were DMV (in days of treatment), the temporal avascular area (in disc diameters, DD) and the rate of temporal retinal vascularisation (DD/week).

RESULTS

The multivariate logistic model that best explains ROP treatment (R2 = 63.1%) has three significant risk factors: each additional day of mechanical ventilation (OR, 1.05 [95% CI, 1.02-1.09]; p = 0.001); each additional DD of temporal avascular area (OR, 2.2 [95% CI, 1.7-2.9]; p < 0.001) and a vascularisation rate <0.5 DD/week (OR, 19.0 [95% CI, 6.5-55.5]; p < 0.001). Two tables are presented for calculating the expected need for ROP treatment according to these three risk factors.

CONCLUSIONS

A greater DMV, a broad avascular area of the temporal retina at the first binocular screening and slow retinal vascularisation strongly predict the need for ROP treatment. The predictive model we describe must be validated externally in other centres.

Accuracy of the postnatal growth and retinopathy of prematurity screening criteria in predicting prethreshold retinopathy of prematurity in the tertiary hospital, Bangkok, Thailand

PURPOSE

The postnatal growth and retinopathy of prematurity (G-ROP), retinopathy of prematurity (ROP) predictive model, was developed in North America with high sensitivity and fewer infants examined. This study aimed to validate this model in Thai infants by assessing sensitivity and comparing it to the current American Academy of Ophthalmology (AAO) screening guideline.

MATERIALS AND METHODS

The records of infants screened for ROP were retrospectively reviewed from 2015 to 2020. G-ROP model was applied to calculate sensitivity for prethreshold type 1 and 2 ROP and the reduction of the number of infants examined.

RESULTS

Of 129 infants screened, there were 102 infants who met G-ROP criteria. The mean gestational age at birth was 29.7 ± 2.7 weeks. The mean birth weight was 1177.8 ± 401.3 g. Both G-ROP and AAO detected prethreshold type 1 ROP in 24 of 24 infants (sensitivity, 100%; 95% confidence interval [CI], 85.8%-100%). Furthermore, they detected all four infants prethreshold type 2 ROP with 100% of sensitivity (95% CI, 39.8-100.0). The reduction in infants receiving examinations using G-ROP was 20.9%.

CONCLUSIONS

G-ROP model provided high sensitivity and lessen unnecessary examinations for ROP screening in Thai infants.

Variations in medical practice of retinopathy of prematurity among 8 Asian countries from an international survey

Advances in perinatal care have led to the increased survival of preterm infants with subsequent neonatal morbidities, such as retinopathy of prematurity (ROP). This study aims to compare the differences of neonatal healthcare systems, resources, and clinical practice concerning ROP in Asia with review of current literature. An on-line survey at the institutional level was sent to the directors of 336 neonatal intensive care units (NICU) in 8 collaborating national neonatal networks through the Asian Neonatal Network Collaboration (AsianNeo). ROP screening was performed in infants born at < 34 weeks in Indonesia and Japan. In South Korea, Malaysia, and Taiwan, most screened for ROP in infants born at < 32 weeks. In all networks, majority of NICUs conducted ROP screening to infants with birth weight < 1500 g. In most NICU's in-hospital ophthalmologists performed indirect ophthalmoscopy and some were supplemented with digital imaging. Both laser photocoagulation and anti-vascular endothelial growth factor injection are performed for treatment and, vitreous surgeries are conducted less frequently in all countries. Despite limited information collected by the survey, this first study to compare ROP practices implemented in eight Asian countries through AsianNeo will enable an understanding of the differences and facilitate quality improvement by sharing better practices.

Ocular Pigmentation Impact on Retinal Versus Choroidal Optical Coherence Tomography Imaging in Preterm Infants

Purpose

To evaluate the association of fundus pigmentation with the visibility of retinal versus choroidal layers on optical coherence tomography (OCT) in preterm infants.

Methods

For infants enrolled in BabySTEPS, ophthalmologists recorded fundus pigmentation (blond, medium, or dark) at the first retinopathy of prematurity (ROP) examination. Bedside OCT imaging was performed at each examination, and a masked grader evaluated all OCT scans from both eyes of each infant for visibility (yes/no) of all retinal layers and of the chorio-scleral junction (CSJ). Multivariable logistic regression was used to assess associations between fundus pigmentation and visibility of all retinal layers and CSJ, controlling for potential confounders (i.e., birth weight, gestational age, sex, OCT system, pupil size, and postmenstrual age at imaging).

Results

Among 114 infants (mean birth weight, 943 grams; mean gestational age, 27.6 weeks), 43 infants (38%) had blond, 56 infants (49%) had medium, and 15 infants (13%) had dark fundus pigmentation. Of 1042 scans, all retinal layers were visible in 977 (94%) and CSJ in 895 (86%). Pigmentation was not associated with retinal layer visibility (P = 0.49), but medium and dark pigmentation were associated with decreased CSJ visibility (medium: odds ratio [OR] = 0.34, P = 0.001; dark: OR = 0.24, P = 0.009). For infants with dark pigmentation, retinal layer visibility increased (OR = 1.87 per week; P ≤ 0.001) and CSJ visibility decreased (OR = 0.78 per week; P = 0.01) with increasing age.

Conclusions

Although fundus pigmentation was not associated with the visibility of all retinal layers on OCT, darker pigmentation decreased CSJ visibility, and this effect increased with age.

Translational Relevance

The ability of bedside OCT to capture retinal layer microanatomy in preterm infants, regardless of fundus pigmentation, may represent an advantage over fundus photography for ROP telemedicine.

Vitreoretinal biomarkers of retinopathy of prematurity using handheld optical coherence tomography: a review

Retinopathy of prematurity (ROP) is caused by abnormal retinal vascularization in premature infants that has the potential for severe long-term vision impairment. Recent advancements in handheld optical coherence tomography (OCT) have enabled noninvasive, high-resolution, cross-sectional imaging of the infant eye at the bedside. The use of handheld OCT devices in the diagnosis of ROP in premature infants has furthered our understanding of disease state and progression. This review discusses the known and novel biomarkers of ROP severity in premature infants identified through handheld OCT and potential for future directions.

ASSESSMENT OF NEONATAL CARE STANDARD BY THE PREDICTIVE MODEL FOR RETINOPATHY OF PREMATURITY BASED ON WEIGHT GAIN

Care of extremely premature infants is in constant need for evaluation and progress. WINROP, a predictive model based on weight gain, has been developed to reduce the number of stressful examinations for retinopathy for prematurity. Validation studies of WINROP emphasize the difference of applicability in neonatal units of various practice. The aim of the study was to assess the standard of neonatal care by WINROP. Data on extremely premature infants were collected from medical records and entered in WINROP. High- and low-risk WINROP distribution and retinopathy of prematurity outcomes were analyzed. Fifty-four infants, gestational age ≤28 weeks, were included in the study after exclusion of weight related comorbidities. High risk was noted in 74% (n=40) of infants with 24% (n=13) developing retinopathy of prematurity requiring treatment. In low alarm group, there were 3 cases with severe disease. In conclusion, WINROP is not just a provider of predictive information on the severity of retinopathy of prematurity. High-risk alarm indicates the need of adjustment of nutritional strategies. Infants without pathological growth morbidities who develop severe retinopathy of prematurity in low-risk group point to other risk factors for retinopathy of prematurity to be evaluated and changed in future practice.

Retinopathy of Prematurity: A Global Perspective and Recent Developments

Retinopathy of prematurity (ROP) is a significant cause of potentially preventable blindness in preterm infants worldwide. It is a disease caused by abnormal retinal vascularization that, if not detected and treated in a timely manner, can lead to retinal detachment and severe long term vision impairment. Neonatologists and pediatricians have an important role in the prevention, detection, and management of ROP. Geographic differences in the epidemiology of ROP have been seen globally over the last several decades because of regional differences in neonatal care. Our understanding of the pathophysiology, risk factors, prevention, screening, diagnosis, and treatment of ROP have also evolved over the years. New technological advances are now allowing for the incorporation of telemedicine and artificial intelligence in the management of ROP. In this comprehensive update, we provide a comprehensive review of pathophysiology, classification, diagnosis, global screening, and treatment of ROP. Key historical milestones as well as touching upon the very recent updates to the ROP classification system and technological advances in the field of artificial intelligence and ROP will also be discussed.

Comparison of RetCam and Smartphone-Based Photography for Retinopathy of Prematurity Screening

This study aimed to compare the clinical performance between a smartphone-based fundus photography device and a contact imaging device for retinopathy of prematurity (ROP) screening. All patients were first examined with binocular indirect ophthalmoscopy (BIO), which served as the reference standard. The patients were then assessed by two devices. Imaging quality, ability to judge the zone and stage of ROP, agreement with the BIO results, vital signs, and pain scores were compared between these two devices. In total, 142 eyes of 71 infants were included. For the smartphone-based fundus photography, image quality was graded excellent or acceptable in 91.4% of examinations, although it was still significantly inferior to that of the contact imaging device (p < 0.001). The smartphone-based fundus photography images had moderate agreement with the BIO results regarding the presence or absence of plus disease (Cohen’s κ = 0.619), but evaluating the zone (p < 0.001) and stage (p < 0.001) of ROP was difficult. Systemic parameters, except for heart rate, were similar between the two imaging devices (all p > 0.05). In conclusion, although the smartphone-based fundus photography showed moderate agreement for determining the presence or absence of plus disease, it failed to identify the zone and stage of ROP.

The clinical use of ultra - Wide field imaging and intravenous fluorescein angiography in infants with retinopathy of prematurity

PURPOSE

To investigate the potential benefits and practicality of ultra - wide field (UWF) imaging and intravenous UWF fluorescein angiography (IV UWF - FA) in infants with retinopathy of prematurity (ROP) using an Optos® California device.

METHODS

This retrospective study involved 46 infants with a history of ROP who underwent UWF imaging with or without IV UWF - FA. ROP characteristics were identified using UWF color imaging. Retinal vascular findings following treatment were also assessed at IV UWF - FA analysis. All imaging sessions were performed under topical anesthesia without sedation. Main outcomes were the appearance of ROP at UWF color imaging and IV UWF-FA analysis, including status of ROP, neovascularizations, presence of plus disease, retinal vascular details, and resolution after treatment.

RESULTS

Seven (three girls) of the 46 infants (22 girls) underwent IV UWF-FA. Twelve IV UWF-FA sessions were performed in total. The oldest infant during IV UWF-FA analysis was at 55 postmenstrual weeks. Clinical characteristics of disease were easily identified at UWF color imaging. IV UWF-FA images also clearly revealed non-perfused retinal areas, fluorescein leakage, macular edema, retinal vascular abnormalities, and the status of the peripheral vascular termini. Complications of IV UWF-FA occurred in one infant in the form of patchy yellow skin discoloration around the injection site which completely disappeared on the first day following the procedure.

CONCLUSIONS

Providing a high resolution panoramic view of the retina in a single image capture with no need for contact with the cornea appear to represent potential advantages of UWF imaging in infants with ROP. IV UWF-FA also seems to be a safe procedure which can be performed under topical anesthesia and that shows detailed retinal vascular alterations in patients with ROP.

Retinopathy of Prematurity Screening Examination and Changes in Vital Signs

BACKGROUND AND OBJECTIVE

Dilation and examination during retinopathy of prematurity (ROP) screening can cause systemic complications and even life-threatening adverse events (AEs). The main objective of this study is to assess the prevalence and significance of AEs and changes in vital signs during ROP screenings, and to correlate birth weight, gestational age, and length of exam as possible predictors of these changes.

PATIENTS AND METHODS

This is a prospective, observational study that includes 1,360 screening exams from 680 premature infants in two neonatal intensive care units. Systolic blood pressure, diastolic blood pressure, heart rate, respiratory rate, and oxygen saturation were monitored from the time that dilating drops were administered until 4 hours after the examination was completed. Any clinical deterioration or complication was documented.

RESULTS

Of 1,360 infant screening exams, 153 (11%) screening exams resulted in at least one change in vital sign that alerted the monitor. There was one serious AE requiring bag valve mask resuscitation 30 minutes after dilating drops were placed. Gestational age, birth weight, and length of ROP exam were not significant predictors of AEs. There were statistically significant changes when comparing pre- and post-vital signs following dilation and funduscopy exam.

CONCLUSIONS

Although ROP screening exams are essential for at-risk neonates, mydriatic drops and retinal exams can result in changes to vital signs and AEs. It is important to closely monitor neonates during these examinations. [Ophthalmic Surg Lasers Imaging Retina. 2021;52:458-463.].

Preterm Infant Stress During Handheld Optical Coherence Tomography vs Binocular Indirect Ophthalmoscopy Examination for Retinopathy of Prematurity

Importance

Binocular indirect ophthalmoscopy (BIO) examination for retinopathy of prematurity (ROP) is a well-known cause of repeated preterm infant stress.

Objective

To compare stress during investigational optical coherence tomography (OCT) imaging to that during BIO for ROP.

Design, Setting, and Participants

This cross-sectional study examined infants at the bedside in the intensive care nursery. Consecutive preterm infants enrolled in Study of Eye Imaging in Preterm Infants (BabySTEPS) who had any research OCT imaging as part of the study. Patients were recruited from June to November 2019, and analysis began April 2020.

Main Outcomes and Measures

Infant stress was measured using modified components of a neonatal pain assessment tool before (baseline) and during OCT imaging and BIO examination of each eye.

Results

For 71 eye examinations of 16 infants (mean [SD] gestational age, 27 [3] weeks; birth weight, 869 [277] g), change from baseline to each eye examination was lower during OCT imaging than during BIO and the difference between OCT imaging and BIO at each eye examination was significant for the following: infant cry score (first eye examination: mean [SD], 0.03 [0.3] vs 1.68 [1.2]; -1.65 [95% CI, -1.91 to -1.39]; second eye examination: mean [SD], 0.1 [0.3] vs 1.97 [1.2]; -1.87 [95% CI, -2.19 to -1.54]), facial expression (first eye: 3 [4%] vs 59 [83%]; -79% [95% CI, -87% to -72%]; second eye: 4 [6%] vs 61 [88%]; -83% [95% CI, -89% to -76%]), and heart rate (first eye: mean [SD], -7 [16] vs 13 [18]; -20 [95% CI, -26 to -14]); second eye: mean [SD], -3 [18] vs 20 [20] beats per minute; -23 [95% CI, -29 to -18]) (P < .001 for all). Change in respiratory rate and oxygen saturation did not differ between OCT imaging and BIO.

Conclusions and Relevance

While the role of OCT alone or in combination with BIO is currently unknown for ROP, these findings suggest that investigational OCT imaging of ROP is less stressful than BIO examination by a trained ophthalmologist.

Incidence of retinopathy of prematurity in Germany: evaluation of current screening criteria

OBJECTIVE

To evaluate current screening criteria for retinopathy of prematurity (ROP) by investigating the incidence of ROP requiring treatment in infants with gestational age (GA) ≥30 weeks or postmenstrual age (PMA) <32 weeks in Germany.

METHODS

Three patient databases were analysed, that is, the German Quality Assurance Procedure in Neonatology (years 2011-2017; n=52 461 infants screened for ROP, 1505 infants treated for ROP), the German Retina.net ROP Registry (years 2011-2018; n=281 treated infants) and the ROP screening programme of two German university hospitals (years 2012-2016; n=837 screened infants).

RESULTS

In the analysed cohorts, infants with GA ≥30 weeks represented 33.1%-38.5% of the screening populations but only 1.40%-1.42% of the cases requiring ROP treatment. In a cohort of 281 infants treated for ROP, all 4 infants with GA ≥30 weeks had additional risk factors for ROP including prolonged oxygen supplementation and/or significant comorbidities. Five infants (1.8%) were treated at 32 weeks PMA and none at PMA <32 weeks.

CONCLUSIONS

In the investigated cohorts, preterm infants with GA ≥30 weeks carried a very low or no risk for developing treatment-requiring ROP unless additional risk factors were present, and no treatment was performed earlier than 32 weeks PMA. These findings are of relevance for the ongoing re-evaluation of ROP screening criteria.

Auto-Processed Retinal Vessel Shadow View Images From Bedside Optical Coherence Tomography to Evaluate Plus Disease in Retinopathy of Prematurity

Purpose

To describe the creation of en face retinal vessel shadow view (RVSV) optical coherence tomography (OCT) images and assess the feasibility of using these for evaluating vascular disease in preterm infants at risk for retinopathy of prematurity (ROP).

Methods

In this exploratory study, we selected images from eyes with a range of ROP vascular disease, prospectively acquired from preterm infants using an investigational, noncontact, handheld, bedside swept-source OCT. We autosegmented OCT volumes using custom infant-specific software, extracted RVSV-OCT images from volumetric data bracketed around the retinal pigment epithelium, and automontaged the resulting RVSV-OCT images. Three masked ophthalmologists graded the RVSV-OCT montages as plus, pre-plus, or neither and ranked them by relative vascular disease severity.

Results

We selected images from 17 imaging sessions (7 plus, 4 pre-plus, 6 neither on clinical examination). On review, 15/17 (88%) RVSV-OCT montages were gradable for plus, pre-plus, or neither and all 17 montages were rankable for relative severity. Intergrader agreement for plus, pre-plus, or neither grading was good (κ, 0.67; 95% confidence interval, 0.42–0.86) and for relative severity ranking was excellent (intraclass correlation coefficient, 0.98; 95% confidence interval, 0.96–0.99).

Conclusions

Our novel automatic processing method can create RVSV-OCT montages optimized for retinal vessel visualization for ROP screening. Although our data support the feasibility of using RVSV-OCT montages for ranking relative vascular disease severity, there is room for improved OCT image capture and processing methods in preterm infants screened for ROP.

Translational Relevance

Creation and grading of RVSV-OCT images could eventually be integrated into an alternative method for ROP screening.

Optimised retinopathy of prematurity screening guideline in China based on a 5-year cohort study

PURPOSES

To develop an optimised retinopathy of prematurity (ROP) screening guideline by adjusting the screening schedule and thresholds of gestational age (GA) and birth weight (BW).

METHODS

A multicentre retrospective cohort study was conducted based on data from four tertiary neonatal intensive care units in Shanghai, China. The medical records of enrolled infants, born from 2012 to 2016 who underwent ROP examinations, were collected and analysed. The incidence and risk factors for ROP were analysed in all infants. Postnatal age (PNA) and postmenstrual age (PMA) of infants, detected to diagnose ROP for the first time, were compared with the present examination schedule. The predictive performance of screening models was evaluated by internally validating sensitivity and specificity.

RESULTS

Of the 5606 eligible infants, ROP was diagnosed in 892 (15.9%) infants; 63 (1.1%) of them received treatment. The mean GA of ROP patients was 29.4±2.4 weeks, and the mean BW was 1260±330 g. Greater prematurity was associated with an older PNA at which ROP developed. The minimum PMA and PNA at which diagnosis of treatable ROP occurred were 32.43 and 3 weeks, respectively. The optimised criteria (GA <32 weeks or BW <1600 g) correctly predicted 98.4% type 1 ROP infants, reducing the infants requiring examinations by 43.2% when internally validated.

CONCLUSIONS

The incidence of type 1 ROP and the mean GA and BW of ROP infants have decreased in China. The suggested screening threshold and schedule may be reliably used to guide the modification of ROP screening guideline and decrease medical costs.

Practice Guidelines for Ocular Telehealth-Diabetic Retinopathy, Third Edition

Contributors The following document and appendices represent the third edition of the Practice Guidelines for Ocular Telehealth-Diabetic Retinopathy. These guidelines were developed by the Diabetic Retinopathy Telehealth Practice Guidelines Working Group. This working group consisted of a large number of subject matter experts in clinical applications for telehealth in ophthalmology. The editorial committee consisted of Mark B. Horton, OD, MD, who served as working group chair and Christopher J. Brady, MD, MHS, and Jerry Cavallerano, OD, PhD, who served as cochairs. The writing committees were separated into seven different categories. They are as follows: 1.Clinical/operational: Jerry Cavallerano, OD, PhD (Chair), Gail Barker, PhD, MBA, Christopher J. Brady, MD, MHS, Yao Liu, MD, MS, Siddarth Rathi, MD, MBA, Veeral Sheth, MD, MBA, Paolo Silva, MD, and Ingrid Zimmer-Galler, MD. 2.Equipment: Veeral Sheth, MD (Chair), Mark B. Horton, OD, MD, Siddarth Rathi, MD, MBA, Paolo Silva, MD, and Kristen Stebbins, MSPH. 3.Quality assurance: Mark B. Horton, OD, MD (Chair), Seema Garg, MD, PhD, Yao Liu, MD, MS, and Ingrid Zimmer-Galler, MD. 4.Glaucoma: Yao Liu, MD, MS (Chair) and Siddarth Rathi, MD, MBA. 5.Retinopathy of prematurity: Christopher J. Brady, MD, MHS (Chair) and Ingrid Zimmer-Galler, MD. 6.Age-related macular degeneration: Christopher J. Brady, MD, MHS (Chair) and Ingrid Zimmer-Galler, MD. 7.Autonomous and computer assisted detection, classification and diagnosis of diabetic retinopathy: Michael Abramoff, MD, PhD (Chair), Michael F. Chiang, MD, and Paolo Silva, MD.

Telemedicine for Retinopathy of Prematurity

Background: Retinopathy of prematurity (ROP) is a disease of the retinal vasculature that remains a leading cause of childhood blindness worldwide despite improvements in the systemic care of premature newborns. Screening for ROP is effective and cost-effective, but in many areas, access to skilled examiners to conduct dilated examinations is poor. Remote screening with retinal photography is an alternative strategy that may allow for improved ROP care. Methods: The current literature was reviewed to find clinical trials and expert consensus documents on the state-of-the-art of telemedicine for ROP. Results: Several studies have confirmed the utility of telemedicine for ROP. In addition, several clinical studies have reported favorable long-term results. Many investigators have reinforced the need for detailed protocols on image acquisition and image interpretation. Conclusions: Telemedicine for ROP appears to be a viable alternative to live ophthalmoscopic examinations in many circumstances. Standardization and documentation afforded by telemedicine may provide additional benefits to providers and their patients. With continued improvements in image quality and affordability of imaging systems as well as improved automated image interpretation tools anticipated in the near future, telemedicine for ROP is expected to play an expanding role for a uniquely vulnerable patient population.

Factors in Premature Infants Associated With Low Risk of Developing Retinopathy of Prematurity

Importance

Most premature infants will not develop retinopathy of prematurity (ROP) of clinical relevance, yet screening evaluations often continue beyond hospital discharge, even for those infants without ROP.

Objectives

To identify the characteristics of infants at low risk for ROP, for whom further postdischarge screening may be of limited value.

Design, Setting, and Participants

This study took place in North American neonatal intensive care units where clinicians had expertise in ROP. Infants with birth weight less than 1251 g who were born at or transferred into an Telemedicine Approaches to Evaluating Acute-Phase ROP (e-ROP) study center were enrolled. The study included post hoc analysis of prospectively collected in-hospital ROP examination results among infants enrolled in the e-ROP study. We characterized infants without ROP and performed logistic regression on the subset of infants who were 27 to 33 weeks' gestational age to determine characteristics associated with the absence of ROP during all in-hospital examinations.

Main Outcomes and Measures

The main measure was the absence of ROP prior to hospital discharge; the main outcome was treatment for ROP.

Results

A total of 1257 infants born at 22 to 35 weeks' gestation (median [interquartile range (IQR)], 26 [25-28] weeks) with birth weights less than 1251 g (median [IQR], 860 [690-1040] g) underwent 4113 ROP examinations between 31 and 47 weeks' postmenstrual age. Overall, 1153 examinations (38%) showed no ROP, and 456 infants (36%) did not have ROP prior to study center discharge or study end point. Among infants without ROP during examinations at 32 and 33 weeks' postmenstrual age, 16 (9.4%) and 14 (5.3%) subsequently underwent ROP treatment, respectively. At hospital discharge, there was no ROP in 59% of infants of 27 to 33 weeks' gestational age, compared with 15% of those who were less than 27 weeks' gestational age (difference, 44% [95% CI, 38.5%-48.1%]; P ≤ .001). With more than 85% follow-up among infants without ROP by 37 weeks' postmenstrual age, none (95% CI, 0%-0.98%) were treated for ROP. In multivariate analysis of infants born at 27 to 33 weeks' gestation, larger birth weight (OR, 4.1 [95% CI, 1.6-10.3]) and higher gestational age (OR, 4.0 [95% CI, 1.5-10.8]) were significantly associated with absence of ROP.

Conclusions and Relevance

These findings suggest that, for infants of 27 weeks' gestational age or greater and birth weights larger than 750 g, if no ROP has been detected by discharge at near-term postmenstrual age, then further ROP surveillance has limited value. Studies of all infants at risk are needed to develop more specific, objective criteria for termination of ROP surveillance and focus resources on infants at higher risk of ROP.

Trial Registration

ClinicalTrials.gov Identifier: NCT01264276.

The role of retinal photography and telemedicine in ROP screening

Until advances in retinal imaging over recent decades, detection of retinopathy of prematurity requiring treatment depended largely on indirect ophthalmoscopy by ophthalmologists with experience in examination of low birth weight, often fragile infants. Recent studies have added to our understanding of the pros and cons of using this technology to provide timely care for the increasing number of infants at risk for ROP blindness worldwide.

Diagnostic Accuracy of Ophthalmoscopy vs Telemedicine in Examinations for Retinopathy of Prematurity

Importance

Examinations for retinopathy of prematurity (ROP) are typically performed using binocular indirect ophthalmoscopy. Telemedicine studies have traditionally assessed the accuracy of telemedicine compared with ophthalmoscopy as a criterion standard. However, it is not known whether ophthalmoscopy is truly more accurate than telemedicine.

Objective

To directly compare the accuracy and sensitivity of ophthalmoscopy vs telemedicine in diagnosing ROP using a consensus reference standard.

Design, Setting, and Participants

This multicenter prospective study conducted between July 1, 2011, and November 30, 2014, at 7 neonatal intensive care units and academic ophthalmology departments in the United States and Mexico included 281 premature infants who met the screening criteria for ROP.

Exposures

Each examination consisted of 1 eye undergoing binocular indirect ophthalmoscopy by an experienced clinician followed by remote image review of wide-angle fundus photographs by 3 independent telemedicine graders.

Main Outcomes and Measures

Results of both examination methods were combined into a consensus reference standard diagnosis. The agreement of both ophthalmoscopy and telemedicine was compared with this standard, using percentage agreement and weighted κ statistics.

Results

Among the 281 infants in the study (127 girls and 154 boys; mean [SD] gestational age, 27.1 [2.4] weeks), a total of 1553 eye examinations were classified using both ophthalmoscopy and telemedicine. Ophthalmoscopy and telemedicine each had similar sensitivity for zone I disease (78% [95% CI, 71%-84%] vs 78% [95% CI, 73%-83%]; P > .99 [n = 165]), plus disease (74% [95% CI, 61%-87%] vs 79% [95% CI, 72%-86%]; P = .41 [n = 50]), and type 2 ROP (stage 3, zone I, or plus disease: 86% [95% CI, 80%-92%] vs 79% [95% CI, 75%-83%]; P = .10 [n = 251]), but ophthalmoscopy was slightly more sensitive in identifying stage 3 disease (85% [95% CI, 79%-91%] vs 73% [95% CI, 67%-78%]; P = .004 [n = 136]).

Conclusions and Relevance

No difference was found in overall accuracy between ophthalmoscopy and telemedicine for the detection of clinically significant ROP, although, on average, ophthalmoscopy had slightly higher accuracy for the diagnosis of zone III and stage 3 ROP. With the caveat that there was variable accuracy between examiners using both modalities, these results support the use of telemedicine for the diagnosis of clinically significant ROP.

A Novel, Low-Cost, Wide-Field, Infant Retinal Camera, "Neo": Technical and Safety Report for the Use on Premature Infants

Purpose

To report the technical aspects, systemic, and ocular safety of a novel, low-cost, wide-field, infant retinal camera for use on premature infants.

Methods

The device, the “3nethra Neo” (Neo) is a 120° portable, contact, wide-field, unibody camera, with a CMOS sensor (2040 × 2040 resolution) and a warm light-emitting diode (LED) illumination source. The Neo was used to image 140 awake, preterm infants between postmenstrual age (PMA) of 28 to 37 weeks, undergoing retinopathy of prematurity (ROP) screening. Baseline, ‘during procedure', at 5 minutes, and for 60 minutes postprocedure, readings of oxygen saturation and heart rate were recorded. The device design, optics, illumination, and software specifications were compared with the RetCam 3.

Results

Study defined bradycardia (9 infants, 6.4%), tachycardia (3 infants, 2.1%), and hypoxia (2 infants, 1.4%) were observed but there were no clinically significant systemic changes that required intervention during or following any of the study time intervals. There was a transient increase in heart rate by 9.68 (7.53–11.83; P < 0.0001) and marginal decrease in oxygen saturation (−1.94 [−1.60 to −2.28], P < 0.0001), which started to return to baseline 5 minutes after the procedure. Transient redness was seen in two eyes (0.7%) of two infants. No other ocular adverse effects were observed.

Conclusions

The Neo is easy to use in preterm infants and being compact was readily portable. There were no significant ocular or systemic adverse effects, potentially allowing it to be a viable low-cost device for ROP screening in low resource settings.

Translational Relevance

The camera provides a safe and affordable alternative to image the retina of infants by using novel illumination and lens mechanics and has the potential of worldwide acceptance.

N-terminal B-type natriuretic peptide urinary concentrations and retinopathy of prematurity

BackgroundTo validate the findings of a single-center pilot study showing elevated urinary N-terminal B-type natriuretic peptide (NTproBNP) concentrations in preterm infants subsequently developing severe retinopathy of prematurity (ROP) in a multicenter setting across eight European and Middle East countries.MethodsProspective observational study in 967 preterm infants <30 weeks' gestational age assessing the capacity of urinary NTproBNP on days of life (DOLs) 14 and 28 to predict ROP requiring treatment.ResultsUrinary NTproBNP concentrations were markedly elevated in infants who developed ROP requiring treatment (n=94) compared with survivors without ROP treatment (n=837), at both time points (median (interquartile range) DOL14: 8,950 (1,925-23,783) vs. 3,083 (1,193-17,393) vs. 816 (290-3,078) pg/ml, P<0.001) and DOL28 (2,203 (611-4,063) vs. 1,671 (254-11,340) vs. 408 (162-1,126) pg/ml, P<0.001). C-statistic of NTproBNP for treated ROP or death was 0.731 (95% confidence interval 0.654-0.774) for DOL14 and 0.683 (0.622-0.745) for DOL28 (P<0.001). Threshold scores were calculated, potentially enabling around 20% of infants with low NTproBNP scores never to be screened with ophthalmoscopy.ConclusionThere is a strong association between early urinary NTproBNP and subsequent ROP development, which can be used to further refine subgroups of patients with high or low risk of severe ROP.

Analysis of Discrepancy Between Diagnostic Clinical Examination Findings and Corresponding Evaluation of Digital Images in the Telemedicine Approaches to Evaluating Acute-Phase Retinopathy of Prematurity Study

Importance

As effective treatments for potentially blinding retinopathy of prematurity (ROP) have been introduced, the importance of consistency in findings has increased, especially with the shift toward retinal imaging in infants at risk of ROP.

Objective

To characterize discrepancies in findings of ROP between digital retinal image grading and examination results from the Telemedicine Approaches to Evaluating Acute-Phase Retinopathy of Prematurity study, conducted from May 2011 to October 2013.

Design, Setting, and Participants

A poststudy consensus review of images was conducted by 4 experts, who examined discrepancies in findings between image grades by trained nonphysician readers and physician examination results in infants with referral-warranted ROP (RW-ROP). Images were obtained from 13 North American neonatal intensive care units from eyes of infants with birth weights less than 1251 g. For discrepancy categories with more than 100 cases, 40 were randomly selected; in total, 188 image sets were reviewed.

Main Outcomes and Measures

Consensus evaluation of discrepant image and examination findings for RW-ROP components.

Results

Among 5350 image set pairs, there were 161 instances in which image grading did not detect RW-ROP noted on clinical examination (G-/E+) and 854 instances in which grading noted RW-ROP when the examination did not (G+/E-). Among the sample of G-/E+ cases, 18 of 32 reviews (56.3%) agreed with clinical examination findings that ROP was present in zone I and 18 of 40 (45.0%) agreed stage 3 ROP was present, but only 1 of 20 (5.0%) agreed plus disease was present. Among the sample of G+/E- cases, 36 of 40 reviews (90.0%) agreed with readers that zone I ROP was present, 23 of 40 (57.5%) agreed with readers that stage 3 ROP was present, and 4 of 16 (25.0%) agreed that plus disease was present. Based on the consensus review results of the sampled cases, we estimated that review would agree with clinical examination findings in 46.5% of the 161 G-/E+ cases (95% CI, 41.6-51.6) and agree with trained reader grading in 70.0% of the 854 G+/E- cases (95% CI, 67.3-72.8) for the presence of RW-ROP.

Conclusions and Relevance

This report highlights limitations and strengths of both the remote evaluation of fundus images and bedside clinical examination of infants at risk for ROP. These findings highlight the need for standardized approaches as ROP telemedicine becomes more widespread.

Timely implementation of a retinopathy of prematurity telemedicine system

PURPOSE

To examine the feasibility of a retinopathy of prematurity (ROP) telemedicine evaluation system of providing timely feedback to a neonatal intensive care unit (NICU) with at-risk premature infants.

METHODS

This was a prospective observational study of premature infants with birth weights of <1251 g in five NICUs in the United States. Infants scheduled for clinically indicated ROP evaluations underwent indirect ophthalmoscopic examinations and digital imaging on the same day. Imaging was performed by nonphysician retinal imagers. Times required were determined from obtaining digital images of both eyes to submission via web-based system to a secure server for grading by trained readers at a central reading center to sending back grading results to the clinical center.

RESULTS

A total of 1,642 image sets of eyes of 292 infants were obtained, from 823 imaging sessions. The mean turnaround time from submission of image sets of both eyes to return of the grading results to the clinical center was 10.1 ± 11.3 hours (standard deviation), with a median of 12.0 hours (1st quartile, 0.9 hours; 3rd quartile, 16 hours). Overall, 95.5% of gradings (95% CI, 93.9%-96.7%) were returned within 24 hours. Subgroup analyses found, for image sets submitted to the reading center before 2 p.m. Eastern Standard Time, median time to report was 1.7 hours (1st quartile, 0.7 hours; 3rd quartile, 15.5 hours) compared with those submitted after 2pm (median, 14.1 hours; 1st quartile, 11.2, hours; 3rd quartile, 16.3 hours).

CONCLUSIONS

An ROP telemedicine approach can provide timely feedback to the NICU regarding the detection of potentially serious ROP and thus referral to an ophthalmologist for examination and consideration of treatment.

Risk Score for Predicting Treatment-Requiring Retinopathy of Prematurity (ROP) in the Telemedicine Approaches to Evaluating Acute-Phase ROP Study

PURPOSE

To develop a risk score for predicting treatment-requiring retinopathy of prematurity (TR-ROP) in the Telemedicine Approaches to Evaluating Acute-Phase Retinopathy of Prematurity (e-ROP) study.

DESIGN

Second analyses of an observational cohort study.

PARTICIPANTS

Infants with birth weight (BW) <1251 g who had ≥1 imaging session by 34 weeks of postmenstrual age (PMA) and ≥1 subsequent retinopathy of prematurity (ROP) examination for determining TR-ROP by study-certified ophthalmologists.

METHODS

Nonphysician trained readers evaluated wide-field retinal image sets for characteristics of ROP, pre-plus/plus disease, and retinal hemorrhage. Risk score points for predicting TR-ROP were derived from the regression coefficients of significant predictors in a multivariate logistic regression model.

MAIN OUTCOME MEASURES

TR-ROP.

RESULTS

Eighty-five of 771 infants (11.0%) developed TR-ROP. In a multivariate model, significant predictors for TR-ROP were gestational age (GA) (odds ratio [OR], 5.7; 95% confidence interval [CI], 1.7-18.9 for ≤25 vs. ≥28 weeks), need for respiratory support (OR, 7.0; 95% CI, 1.3-37.1 for high-frequency oscillatory ventilation vs. no respiratory support), slow weight gain (OR, 2.4; 95% CI, 1.2-4.6 for weight gain ≤12 g/day vs. >15 g/day), and image findings at the first image session including number of quadrants with pre-plus (OR, 3.8; 95% CI, 1.5-9.7 for 4 pre-plus quadrants vs. no pre-plus), stage and zone of ROP (OR, 4.7; 95% CI, 2.1-11.8 for stage 1-2 zone I, OR, 5.9; 95% CI, 2.1-16.6 for stage 3 zone I vs. no ROP), and presence of blot hemorrhage (OR, 3.1; 95% CI, 1.4-6.7). Image findings predicted TR-ROP better than GA (area under receiver operating characteristic curve [AUC] = 0.82 vs. 0.75, P = 0.03). The risk of TR-ROP steadily increased with higher risk score and predicted TR-ROP well (AUC = 0.88; 95% CI, 0.85-0.92). Risk score ≥3 points for predicting TR-ROP had a sensitivity of 98.8%, specificity of 40.1%, and positive and negative predictive values of 17.0% and 99.6%, respectively.

CONCLUSIONS

Image characteristics at 34 PMA weeks or earlier independently predict TR-ROP. If externally validated in other infants, risk score, calculated from image findings, GA, weight gain, and respiratory support, enables early identification of infants in need of increased surveillance for TR-ROP.

Training retinal imagers for retinopathy of prematurity (ROP) screening

PURPOSE

To report the training/certification process of nonphysician imagers, image quality, and factors that affected image quality in the National Eye Institute sponsored multicentered e-ROP study.

METHODS

Nonphysician imagers underwent rigorous training and certification in obtaining retinal images, with attention to clarity, focus, and optic disk placement. Image readers measured pupil size in pupil image and graded posterior pole, temporal, nasal, superior, and inferior retinal images and classified them as good, adequate, poor, or missing. Good and adequate images were deemed acceptable.

RESULTS

In 4,003 image sessions of 1,257 infants, 3,453 (86.8%) were complete. Of 39,550 retinal images, 91.7% had acceptable quality, 5.6% poor, and 2.7% were missing. Inadequate pupil dilation negatively affected acceptable image quality: 54% acceptable images for pupil <5 mm versus 93% for >6 mm (P < 0.0001). When ventilatory equipment obstructed access to imaged infant, the percent of acceptable image quality decreased: 94% for no support versus 66.6% for oscillatory ventilation (P < 0.0001). Acceptable image quality rates improved from 87% to 90% (P = 0.03) from first 6 months to last 6 months at low patient volume centers, while high patient volume centers remained stable at 95%.

CONCLUSIONS

Nonphysicians successfully obtained acceptable quality images for ROP evaluation. Skills improved with experience. Image quality was negatively affected by inadequate pupil dilation and the presence of obstructive ventilatory equipment.