Differential effects of the retinopathy of prematurity exam on the physiology of premature infants

Isolated Retinal Neovascularization in Retinopathy of Prematurity: Clinical Associations and Prognostic Implications

OBJECTIVE

Isolated retinal neovascularization (IRNV) is a common finding in patients with stage 2 and 3 retinopathy of prematurity (ROP). This study aimed to further classify the clinical course and significance of these lesions (previously described as "popcorn" based on clinical appearance) in patients with ROP as visualized with ultrawidefield OCT (UWF-OCT).

DESIGN

Single center, retrospective case series.

PARTICIPANTS

Images were collected from 136 babies in the Oregon Health and Science University neonatal intensive care unit.

METHODS

A prototype UWF-OCT device captured en face scans (>140°), which were reviewed for the presence of IRNV along with standard zone, stage, and plus classification. In a cross-sectional analysis we compared demographics and the clinical course of eyes with and without IRNV. Longitudinally, we compared ROP severity using a clinician-assigned vascular severity score (VSS) and compared the risk of progression among eyes with and without IRNV using multivariable logistic regression.

MAIN OUTCOME MEASURES

Differences in clinical demographics and disease progression between patients with and without IRNV.

RESULTS

Of the 136 patients, 60 developed stage 2 or worse ROP during their disease course, 22 of whom had IRNV visualized on UWF-OCT (37%). On average, patients with IRNV had lower birth weights (BWs) (660.1 vs. 916.8 g, P = 0.001), gestational age (GA) (24.9 vs. 26.1 weeks, P = 0.01), and were more likely to present with ROP in zone I (63.4% vs. 15.8%, P < 0.001). They were also more likely to progress to stage 3 (68.2% vs. 13.2%, P < 0.001) and receive treatment (54.5% vs. 15.8%, P = 0.002). Eyes with IRNV had a higher peak VSS (5.61 vs. 3.73, P < 0.001) and averaged a higher VSS throughout their disease course. On multivariable logistic regression, IRNV was independently associated with progression to stage 3 (P = 0.02) and requiring treatment (P = 0.03), controlling for GA, BW, and initial zone 1 disease.

CONCLUSIONS

In this single center study, we found that IRNV occurs in higher risk babies and was an independent risk factor for ROP progression and treatment. These findings may have implications for OCT-based ROP classifications in the future.

FINANCIAL DISCLOSURE(S)

Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Interdisciplinary collaborative eye examinations to protect preterm infant neurodevelopment: a quality improvement project

Introduction

Infants born <31 weeks gestational age with birth weight ≤ 1,500 grams receive routine eye examinations to screen for Retinopathy of Prematurity (ROP) while in the Neonatal Intensive Care Unit (NICU) to help prevent vision threatening complications; however, preterm infants' sensory systems are underdeveloped, and repeated exposure to painful stimuli is associated with worse developmental outcomes.

Methods

An interdisciplinary NICU team designed a collaborative eye exam model (CEEM) incorporating best practice recommendations for infant pain control during exams. Pain scores and vital signs were recorded before, during, and after exams. Two sets of mixed-effects regression models with a random intercept on infants were established to investigate relationships between the intervention, birth gestational age (BGA), postmenstrual age (PMA), and outcomes associated with painful stimuli. Survey feedback was elicited from NICU stakeholders about the CEEM.

Results

Thirty standard of care (SC) and 35 CEEM exams of 37 infants were included in final analysis. In infants of the same BGA, the number of desaturation events was significantly reduced in the CEEM group (p = 0.003) and became 1.53 times smaller with each additional week of BGA (p = 0.009). Probability of heart rate recovery within 15 min lowered significantly in the CEEM group (p = 0.04). In SC or CEEM or between infants of the same PMA, no differences were observed for bradycardia, heart rate range, chance of heart rate recovery, or pain scores. Increases in tachycardia (p < 0.001) events and desaturations p = 0.006 were discovered in the CEEM group. When considering interaction effects, the CEEM appeared to reduce the number of desaturations to a greater degree for infants at earliest BGAs with attenuation of this effect with greater BGA. Regarding PMA, bradycardia and tachycardia events were reduced for infants across PMAs in the CEEM, but the effect for tachycardia improves with age, while the effect for bradycardia diminishes with age. Stakeholders agreed that the infant's eye exam experience and the staff experience was "very much" improved by the CEEM.

Discussion

Despite variable findings in selected outcome measures, the CEEM was positively viewed by staff. Infants may benefit from the CEEM differently based on BGA and PMA.

Implementation of optical coherence tomography in retinopathy of prematurity screening

PURPOSE OF REVIEW

In this review, we explore the investigational applications of optical coherence tomography (OCT) in retinopathy of prematurity (ROP), the insights they have delivered thus far, and key milestones for its integration into the standard of care.

RECENT FINDINGS

While OCT has been widely integrated into clinical management of common retinal diseases, its use in pediatric contexts has been undermined by limitations in ergonomics, image acquisition time, and field of view. Recently, investigational handheld OCT devices have been reported with advancements including ultra-widefield view, noncontact use, and high-speed image capture permitting real-time en face visualization. These developments are compelling for OCT as a more objective alternative with reduced neonatal stress compared to indirect ophthalmoscopy and/or fundus photography as a means of classifying and monitoring ROP.

SUMMARY

OCT may become a viable modality in management of ROP. Ongoing innovation surrounding handheld devices should aim to optimize patient comfort and image resolution in the retinal periphery. Future clinical investigations may seek to objectively characterize features of peripheral stage and explore novel biomarkers of disease activity.

The effects of mydriatic eye drops on cerebral blood flow and oxygenation in retinopathy of prematurity examinations

Mydriatic eye drops used during retinopathy examination have been associated with cardiovascular, respiratory, and gastrointestinal side effects. The aim of our study was to investigate the effects of the drops used for pupil dilatation on cerebral blood flow and cerebral oxygenation. The study included 62 infants who underwent retinopathy screening exams. Vital signs, heart rate (HR), arterial oxygen saturation (SpO2), and mean arterial pressure (MAP) were recorded. Cerebral oxygenation and middle cerebral artery blood flow velocity were evaluated using near-infrared spectroscopy (NIRS) and Doppler ultrasonography, respectively, and the cerebral metabolic rate of oxygen (CMRO2) was also calculated. The mean gestational age of the infants included was 31.29 ± 1.42 weeks, and the mean birth weight was 1620 ± 265 g. Heart rate was found to be significantly decreased after mydriatic eye drop instillation; however, there were no significant differences regarding blood pressure and oxygen saturation levels (HR: p < 0.001; MAP: p = 0.851; SpO2: p = 0.986, respectively). After instillation while cerebral regional oxygen saturation (rScO2) measurements were significantly decreased at the 60th minute (p = 0.01), no significant difference was found in Vmax and Vmean of MCA before and after mydriatic eye drop instillation (p = 0.755, p = 0.515, respectively). Regarding CMRO2 measurements, we also did not find any statistical difference (p = 0.442).    Conclusion: Our study has shown that although eye drops may affect heart rate and regional cerebral oxygen saturation, they do not alter cerebral blood flow velocities and metabolic rate of oxygen consumption. Current recommendations for mydriatic eye drop use in retinopathy exam appear to be safe. What is Known: • Mydriatic eye drop installation is recommended for pupil dilatation during ROP screening exams. • It's known that mydriatics used in ROP examination have affects on the vital signs, cerebral oxygenation and blood flow. What is New: • This is the first study evaluating the changes in cerebral oxygenation and blood flow velocity after mydriatic drop instillation using NIRS and Doppler US concomitantly. • While the eye drops may affect heart rate and regional cerebral oxygen saturation, they do not alter cerebral blood flow velocities and metabolic rate of oxygen consumption.

Effects of fentanyl and sucrose on pain in retinopathy examinations with pain scale, near-infrared spectroscopy, and ultrasonography: a randomized trial

BACKGROUND

This study aimed to compare the efficacy of intravenous, intranasal fentanyl and oral sucrose in reducing the pain response during retinopathy of prematurity examinations using premature infant pain profile (PIPP) scores.

METHOD

The study included 42 infants who underwent retinopathy screening examinations. The infants were divided into three groups: oral sucrose, intranasal fentanyl, and intravenous fentanyl. Vital signs (heart rate, arterial oxygen saturation, and mean arterial pressure) were recorded. The PIPP was used to determine pain severity. Cerebral oxygenation and middle cerebral artery blood flow were evaluated using near-infrared spectroscopy and Doppler ultrasonography, respectively. The data obtained were compared between groups.

RESULTS

There was no significant difference between the three groups regarding postconceptional and postnatal ages or birth weights and weight at the time of examination. All babies had moderate pain during the examination. No correlation was observed between analgesia method and pain scores (P = 0.159). In all three groups, heart rate and mean arterial pressure increased, whereas oxygen saturation decreased during the exam compared with pre-examination values. However, heart rate (HR), mean arterial pressure (MAP) and arterial oxygen saturation (sPO2) values did not differ between groups (HR, P = 0.150; MAP, P = 0.245; sPO2, P = 0.140). The cerebral oxygenation (rSO2) values between the three groups were found to be similar [rSO2: P = 0.545, P = 0.247, P = 0.803; fractional tissue oxygen extraction (FTOE): P = 0.553, P = 0.278]. Regarding cerebral blood flow values, we also did not find any difference between the three groups [mean blood flow velocity (Vmean): P = 0.569, P = 0.975; maximum flow velocity (Vmax): P = 0.820, P = 0.997].

CONCLUSIONS

Intravenous and intranasal fentanyl and oral sucrose were not superior to each other in preventing pain during the examination for retinopathy of prematurity (ROP). Sucrose may be a good alternative for pain control during ROP examination. Our findings suggest that ROP exam may not affect cerebral oxygenation or cerebral blood flow. Larger scale studies are needed to determine the best pharmacological option to reduce pain during ROP exams and evaluate the effects of this procedure on cerebral oxygenation and blood flow.

Autonomic measures identify stress, pain, and instability associated with retinopathy of prematurity ophthalmologic examinations

BACKGROUND

Retinopathy of prematurity (ROP) ophthalmologic examinations cause stress and pain. Infants' stress and pain can be measured non-invasively using skin conductance (SC) and high frequency heart rate variability (HF-HRV), reflecting sympathetic-mediated sweating and parasympathetic activity, respectively.

OBJECTIVES

To test the utility of SC to detect sympathetic activation during ROP examination, and the contribution of HF-HRV to predict stability post-examination.

METHODS

In this prospective, single center study, we measured SC continuously pre-, during, and post-examination, and HRV at 24 h pre-ROP examination. Clinical data included stability [apneas, bradycardias, and desaturations (A/B/Ds)], and interventions post-examination.

RESULTS

SC increased 56% above baseline during ROP examination (p = 0.001) and remained elevated post-examination (p = 0.02). Post-hoc analysis showed higher illness acuity, represented by need for respiratory support, was associated with lower HF-HRV at 24 h pre-ROP examination (p = 0.001). Linear regression indicated lower HF-HRV at 24 h pre-examination contributed to the need for higher intervention (i.e., stimulation to breathe, oxygen support) particularly among infants with higher illness acuity [F(1, 15) = 5.05, p = 0.04; β = -1.33, p = 0.04].

CONCLUSION

ROP examination induced a 2-fold increase in sympathetic activation which remained above baseline in recovery. Also, we propose that the low parasympathetic tone associated with autonomic imbalance contributes to instability and need for higher intervention to assure stabilization with A/B/D events. Our findings provide insight into the underestimation of adverse events associated with ROP examination and identification of infants who may be more vulnerable to potential sequelae following ROP examinations.

Development of Sensory Processing in Premature Infants and Implications for Evidence-Based Music Therapy in the NICU

The purpose of this article is to provide an overview of the development of sensory processing in premature infants with implications for music therapists providing evidence-based care in a NICU. An overview of sensory processing and sensory processing disorders in premature infants is included, with specific emphasis on development of sensory systems of premature infants. Implications for developmentally appropriate music as therapy for premature infants are identified. Evidence-based NICU-MT can be combined with nursing care to reduce the risks of sensory processing disorder for the developing premature infant.

Major cardiorespiratory events do not increase after immunizations, eye exams, and other stressors in most very low birth weight infants

BACKGROUND

Increased cardiorespiratory events with bradycardia and oxygen desaturation have been reported in very low birthweight (VLBW) infants following stressors such as immunizations. These events are difficult to quantify and may be mild. Our group developed an automated algorithm to analyze bedside monitor data from NICU patients for events with bradycardia and prolonged oxygen desaturation (BDs) and used this to compare BDs 24 hours before and after potentially stressful interventions.

METHODS

We included VLBW infants from 2012-2017 with data available around at least one of four interventions: two-month immunizations, retinopathy of prematurity (ROP) examinations, ROP therapy, and inguinal hernia surgery. We used a validated algorithm to analyze electrocardiogram heart rate and pulse oximeter saturation data (HR, SpO2) to quantify BD events of HR <  100 beats/minute for≥4 seconds with oxygen desaturation <  80%SpO2 for≥10 seconds. BDs were analyzed 24 hours before and after interventions using Wilcoxon rank-sum tests.

RESULTS

In 354 of 493 (72%) interventions, BD frequency stayed the same or decreased in the 24 hours after the event. An increase of at least five BD's occurred in 17/146 (12%) after immunizations, 85/290 (29%) after ROP examinations, 4/33 (12%) after ROP therapy, and 3/25 (12%) after hernia surgery. Infants with an increase in BDs after interventions had similar demographics compared to those without. More infants with an increase in BDs following immunizations were on CPAP or caffeine than those without.

CONCLUSIONS

Most VLBW infants in our cohort had no increase in significant cardiorespiratory events in the 24 hours following potentially stressful interventions.

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.

Oculocardiac Reflex During ROP Exams

Purpose

Reducing physiologic stress including bradycardia during staging eye exams for retinopathy of prematurity (ROP) is desirable. We observed heart rate change during routine retinopathy of prematurity eye examinations and compared the response with our ongoing study of oculocardiac reflex (OCR) elicited by uniform EOM tension during strabismus surgery.

Patients and Methods

Electrocardiograph was prospectively monitored during ROP exams featuring indirect ophthalmoscopy with Alfonso lid speculum and see-through scleral depressor without topical anesthesia. Clinical data were retrieved from ROP-Check software. OCR was defined as maximally changed heart rate (HR) as a percent of baseline. Strabismus surgery patients under general anesthesia served as controls.

Results

From 10/2017 to 9/2020, 281 infants had ROP exams, and the median OCR was 55.9% of baseline HR (IQR 41.4% to 72.6%), the kurtosis 0.93 and skewness 1.01 representing a drop from HR 169 ± 16 bpm to 102 ± 39 bpm. In comparison, 1493 adult and pediatric strabismus surgery patients had less OCR median bradycardia 87.8% (IQR 72–98%), kurtosis 1.60 and skewness −1.18. ROP %OCR correlated with birth gestational age (%OCR = 2.5 (GA) – 11, r(279)=0.33, p<0.01) and with birthweight (%OCR = 0.02 (BW) + 38, r(279) =0.35, p<0.01). The duration of bradycardia induced by ROP exam averaged 92 ± 34 seconds (range 34–240 seconds).

Conclusion

Bradycardia is common during eye exams in the smallest premature infants with greater degree, more rapid onset and longer duration than OCR during strabismus surgery.

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Prediction of retinopathy of prematurity using the screening algorithm WINROP in a Saudi cohort of preterm infants

OBJECTIVES

To validate the web weight gain-based WINROP (weight, insulin-like growth factor I, neonatal, retinopathy of prematurity [ROP]) algorithm retrospectively to identify type 1 ROP in a Saudi cohort of premature infants.  Methods: The records of preterm infants (greater than 23 and less than 32 weeks gestation) born between August 2013 and October 2018, were reviewed. Birth weight, gestational age, and weekly weight measurements of the premature infants were entered online. Based on weekly weight gain, the WINROP algorithm alerted clinicians whether infants were at high-risk for vision‑threatening type 1 ROP. Sensitivity, specificity, positive and negative predictive values were calculated. Results: The median gestational age of the infants at birth was 28 weeks, with median birth weight at 1085 g. Of the 175 infants included in the study, 13 (7.4%) developed type 1 ROP. WINROP positive alarm was triggered in 70.9% (124/175) of all infants and 100% (13/13) of those treated for type 1 ROP. The specificity of the algorithm was 31.5%. Positive predictive values was 10.5% and negative was 100%. Conclusion: The general WINROP sensitivity in identifying type 1 ROP was 100% similar to that reported in developed countries; however, its specificity was low at 31.5%. Tweaking of the algorithm based on the population may increase the specificity and promote the practical utility of this non-invasive screening tool for ophthalmologists and neonatologists in this population.