The Effects of Mydriatic Eye Drops in Retinopathy of Prematurity Examinations

Istanbul Training and Research Hospital62 enrolled

Overview

Retinopathy of prematurity (ROP) is a retinal disorder of preterm neonates and a potential cause of blindness. As early diagnosis and treatment preserve vision, very low birth weight infants must be screened for ROP. Mydriatic eye drop administration is essential to perform funduscopic evaluations. The most commonly used mydriatic drops for pupil dilatation are 0.5-1.0% tropicamide and/or 0.5-1.0% phenylephrine or 0.2-1.0% cyclopentolate. Phenylephrine, an alpha-1 sympathomimetic agonist, is readily absorbed from conjunctival mucosa and has a potent systemic vasopressor effect. Tropicamide causes cycloplegia by inhibition of ciliary muscle contraction and has a short acting para-sympatholytic effect. Systemic absorption of mydriatic eye drops has been associated with cardiovascular, respiratory and gastrointestinal adverse effects. Systemic side effects include apnea, desaturation, increased heart rate and blood pressure, delayed gastric emptying, and feeding intolerance. The data about the effects of mydriatics on cerebral blood flow and tissue oxygenation are sparse. Cerebral blood flow autoregulation depends in part on the adrenergic and cholinergic control of cerebral vasculature, but whether mydriatics have an effect on cerebral haemodynamics is unknown. Near-infrared spectroscopy and Doppler ultrasonography (US) are non-invasive methods commonly used for neuromonitorization in NICUs. The regional blood flow changes measured using Doppler US have been reported to be associated with cerebral oxygenation and indicate a high correlation with NIRS in newborns. The aim of this study was to evaluate the effects of mydriatic eye drops on cerebral oxygenation and blood flow in preterm infants by NIRS and Doppler US.

Study Type

OBSERVATIONAL

Enrollment

Conditions

Retinopathy of Prematurity Mydriasis

Interventions

NIRS(INVOS 5100; Covidien Somanetics, Troy, MIDEVICE

NIRS (Near Infrared Spectroscopy) is a non-invasive, bedside device that measures the concentration of oxygenated and deoxygenated hemoglobin in tissue, providing information about tissue oxygenation. Its working mechanism is based on the ability of light with wavelengths between 700-1000 nm to penetrate up to 8 cm into the skin and brain tissue. It offers continuous information about tissue oxygenation in different regions using probes attached to the skin. While pulse oximeters indicate arterial oxygen saturation, they are insufficient in detecting tissue-level hypoxia. Therefore, NIRS, being a painless method, is frequently used in the monitoring of newborns in the intensive care unit.

Eligibility

Sex: ALLMin age: 28 DaysMax age: 31 Days

Medical Language ↔ Plain English

Inclusion Criteria: * Babies born at gestational age less than 34 weeks and/or birth weight below 2000 grams. Infants undergoing their first retinopathy examination. Exclusion Criteria: * Congenital anomaly * Continued mechanical ventilation support * Having pain from a different cause and/or requiring concurrent analgesic use * Sedation analgesia administered within the last 24 hours * Hemodynamically unstable * Intraventricular hemorrhage, neurological dysfunction * Receiving anticonvulsant therapy.

Outcomes

Primary Outcomes

NIRS

Absolute change in rScO2 after mydriatic eye drops instillation with NIRS

Time frame: Data were started to get recorded 60 minutes before the instillation of eye drops for pupil dilation. The recording was continued uninterruptedly till 1 hour after the instillation through study completion, an average of 2 hours.

Doppler US measurements

Absolute change in MCA blood flow after mydriatic eye drops instillation with Doppler USG

Time frame: The initial and second assessment were conducted before the application and at the 60th minute of instillation of the first drop, respectively - an average of 2 hours.

Secondary Outcomes

Changes in heart rate (beats per minute)

Heart rate was recorded continuously, starting 60 minutes before and after mydriatic eye drop instillation.

Time frame: starting 60 minutes before and after mydriatic eye drop instillation,through study completion, an average of 2 hours.

Changes in blood pressure

Mean arterial pressure values was recorded for every 5 minutes, starting 60 minutes before and after mydriatic eye drop instillation,through study completion, an average of 2 hours.

Time frame: Starting 60 minutes before and after mydriatic eye drop instillation,through study completion, an average of 2 hours.

Changes in oxygen saturation.

Oxygen saturation was recorded continuously, starting 60 minutes before and after mydriatic eye drop instillation, through study completion, an average of 2 hours.