Systemic effects of mydriatics in low weight infants

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.

Systemic adverse events after screening of retinopathy of prematurity with mydriatic

Purpose

To evaluate systemic adverse events after screening for retinopathy of prematurity (ROP) performed with mydriatic.

Methods

This was a retrospective case series study. Medical records of consecutive patients who underwent screening for ROP with 0.5% phenylephrine and 0.5% tropicamide eyedrops were retrospectively reviewed. The score of abdominal distention (0–5), volume of milk sucked and volume of stool, along with systemic details (pulse and respiration rates, blood pressure and number of periods of apnea) were collected at 1 week and 1 day before ROP examination, and at 1 day after examination. Results were compared between the days before and after examination. Correlation between body weight at the time of examination and the score of abdominal distention was examined. The numbers of infants with abdominal and/or systemic adverse events were compared between pre- and post-examination periods.

Results

Eighty-six infants met the inclusion criteria. The score of abdominal distention increased from 2.0 at 1 day before examination to 2.3 at 1 day after examination (p = 0.005), and the number of infants who had worsened abdominal distension increased after examination (p = 0.01). Infants with lower body weight had a higher score of abdominal distention (p < 0.0001, r = −0.57). The number of infants with reduced milk consumption increased after examination (p = 0.0001), as did the number of infants with decreased pulse rate (p = 0.0008).

Conclusions

Screening for ROP with mydriatic may have adverse effects on systemic conditions. Infants should be carefully monitored after ROP screening with mydriatic.

Systematic review of mydriatics used for screening of retinopathy in premature infants

INTRODUCTION

Routine retinopathy of prematurity eye examinations are an important part of neonatal care, and mydriatic medicines are essential in dilating the pupil for the eye examination. There are concerns about the level of evidence for efficacy and safety of these mydriatic medicines.

OBJECTIVE

This review evaluates both efficacy and safety evidence of mydriatics used during the retinopathy of prematurity eye examination.

METHOD

Systematic literature review.

RESULTS

There is limited evidence guiding clinical practice for safety and efficacy of mydriatics. The majority of publications are underpowered and with an unclear to high level of bias. There are a wide variety of mydriatic regimens evaluated for efficacy and safety, and multiple regimens are associated with case reports.

CONCLUSIONS

Current international guideline seems unnecessarily high, especially when the reviewed literature suggest that lower doses are effective, albiet from underpowered studies. The lowest effective combination regimen appears to be phenylephrine 1% and cyclopentolate 0.2% (1 drop). Microdrop administration of this regimen would further increase the safety profile, however, efficacy needs to be assessed.

Effects and Side Effects of Mydriatic Eyedrops in Neonates

The pupils of neonates and premature infants often need to be dilated for retinal examination. The drops used for this purpose have some known side effects. This study investigated the effects and side effects of these drops. In this prospective randomized study, 80 healthy neonates were randomly assigned to eight groups. In Group A 1% cyclopentolate was used; in Group B 1% tropicamide; in Group C 2.5% phenylephrine; in Group D 1% cyclopentolate and 1% tropicamide; in Group E 2.5% phenylephrine and 1% tropicamide; in Group F 0.5% cyclopentolate, 0.5% tropicamide and 2.5% phenylephrine; in Group G 1% cyclopentolate and 2.5% phenylephrine and in Group H 0.9% NaCl. Heart rate, systolic and diastolic blood pressures were recorded before, and 5, 10, 15, 30, 45, 60 minutes after instillation of the drops. Pupillary size was measured at baseline, 30 and 60 minutes. To stimulate the conditions of indirect ophthalmoscopic examination, the pupil sizes were measured under the intense beam of a halogen light. The results were analyzed statistically. Maximum side effects were seen in group C; the safest was group B and maximum mydriasis was achieved in group F.

Hemodynamic responses and plasma phenylephrine concentrations associated with intranasal phenylephrine in children

INTRODUCTION

Intranasal phenylephrine, an alpha-1 adrenergic agonist, causes vasoconstriction of the nasal mucosa and is used to reduce bleeding associated with nasotracheal intubation or endoscopic sinus surgery. The purpose of this study was to describe the hemodynamic effects associated with plasma phenylephrine concentrations following topical intranasal administration of 0.25% and 0.5% phenylephrine in children.

METHODS

After Institutional Review Board and parental approval, 77 children between the ages of 2 and 12 years were studied in a prospective, double-blind manner and randomized into three groups. Group 1 received intranasal saline, while groups 2 and 3 received 0.1 mL/kg of 0.25% or 0.5% phenylephrine, respectively. All received the same anesthetic of halothane, N₂ O, O₂ , and vecuronium. After inhalation induction, endtidal halothane and PaCO₂ were maintained at 1.5% and 35 mm Hg, respectively. Heart rate and rhythm, systolic, diastolic, and mean, noninvasive arterial blood pressures were recorded and venous blood was obtained for measurement of plasma phenylephrine concentration by high-performance liquid chromatography at baseline and at 2, 5, 10, and 20 minutes following intranasal spray application of the study drug. Nasotracheal intubation was performed immediately following the 5-minute measurements, and the presence of bleeding was assessed. Hemodynamic data were compared by analysis of variance for repeated measures. Bleeding and arrhythmia incidence among groups were analyzed using chi-squared tests. Phenylephrine levels were correlated with hemodynamic values via regression analysis.

RESULTS

Fifty-two patients received intranasal phenylephrine. Increases in blood pressure correlated with increasing plasma phenylephrine concentration. Systolic blood pressure increased 8%, and mean blood pressure increased 14%, which were statistically significant but clinically insignificant. Heart rate did not change, and the incidence of arrhythmia was low and similar among groups. Bleeding following nasotracheal intubation was less frequent in Group 3 (11/27 subjects) than in Group 1 (17/25). Peak plasma phenylephrine concentrations were observed by 14±7 minutes following intranasal administration, and were highly variable among individuals (37.8±39.7 and 49.6±93.9 ng/mL [mean±SD] in Groups 2 and 3).

DISCUSSION

Administration of intranasal phenylephrine, 0.25% and 0.50%, results in rapid but highly variable systemic absorption that is associated with mild increases of blood pressure that are clinically insignificant. Bleeding associated with nasotracheal intubation was less following administration of 0.5% intranasal phenylephrine than following intranasal saline.

[Serious adverse side effects after pupillary dilation in preterm infants]

PURPOSE

This study aimed at investigating serious side effects of the pupillary dilation protocol used in Caen University Hospital for the screening of retinopathy of prematurity. This protocol includes one drop of phenylephrine 5% and two drops of tropicamide 0.5% instilled at a 5-minute interval.

PATIENTS AND METHODS

This retrospective study included all premature infants with a birth weight less than or equal to 1500 g and/or a gestational age less than or equal to 30 gestational weeks, hospitalized in the neonatal intensive care unit of Caen University Medical Center, having ocular fundus examinations for retinopathy of prematurity screening between 2009 and 2014. The medical records of patients who died or developed necrotizing enterocolitis were reviewed to analyze the imputability of the two eye drops used for pupil dilation.

RESULTS

Five-hundred and twelve infants were included, corresponding to 1033 ocular fundus examinations. No case of death could be ascribed to the use of eye drops. Two cases of necrotizing enterocolitis could be ascribed to the use of tropicamide with a doubtful and plausible intrinsic imputability according to French imputability criteria.

CONCLUSION

The pupillary dilation protocol used in Caen University Hospital for screening of retinopathy of prematurity might be implicated in two cases of necrotizing enterocolitis with an uncertain imputability of tropicamide 0.5% eye drops. No serious side effect could be ascribed to the use of phenylephrine 5% eye drops in this study.

Transient ileus associated with the use of mydriatics after screening for retinopathy of prematurity in a very low birth weight infant

Very low birth weight (VLBW) infants have ophthalmologic examinations for retinopathy of prematurity (ROP) prior to discharge, with appropriate follow-up and intervention where appropriate. Eye drops such as cylopentolate, tropicamide, and phenylephrine are used at different concentrations to provide proper pupil dilation for screening ROP. Topical instillation of eye drops may cause mild or severe ocular or systemic adverse effects. Early recognition of systemic toxicity after eye drop instillation is important. The authors present a case of a VLBW infant who developed significant abdominal symptoms (mimicking ileus) that were significant enough to discontinue oral feeding after ocular instillation of 0.5% tropicamide and 2.5% phenylephrine eye drops for routine examination of ROP. After structural and functional gastrointestinal disorders and sepsis were excluded, symptoms resolved completely after discontinuation of the drug. This report is thought to be the first in the medical literature to address 5% tropicamide and 2.5% phenylephrine eye drops, and the combination that may lead to serious complication after ROP examinations.

Inability to walk, disequilibrium, incoherent speech, disorientation following the instillation of 1% cyclopentolate eyedrops: case report

A 4-year-old boy, who had no prior history of convulsions, presented with inability to walk, disequilibrium, dysarthria (incoherent speech), and impaired cognition (disorientation) following the instillation of 1% cyclopentolate, a commonly used mydriatic in pediatric practice. This case demonstrates the uncommon, although serious, atropine-like adverse effect of cyclopentolate eyedrops in usual dosage in child.

The retinopathy of prematurity screening examination: ensuring a safe and efficient examination while minimizing infant discomfort

Retinopathy of prematurity (ROP) examinations in the NICU are necessary to protect vision in premature infants, but the examinations are associated with risk and discomfort. ROP examination risks include adverse effects from mydriatic agents, systemic responses to the stress of examination, and nosocomial infection. Infant discomfort may be lessened by limiting examination length and possibly by measures such as topical anesthetic, oral sucrose, and certain nonpharmacologic techniques. A well-organized ROP service facilitates appropriate scheduling of examinations and education of the infant's parents. This article addresses causes of risk and infant discomfort, providing a framework for developing a safe and efficient ROP service while minimizing infant discomfort.

Comparison of mydriatic regimens used in screening for retinopathy of prematurity in preterm infants with dark irides

PURPOSE

To determine the mydriatic regimen that provides optimal dilation of the pupil with minimal systemic side effects for screening of retinopathy of prematurity.

METHODS

This cross-sectional, randomized, double-masked clinical trial compared cyclopentolate 1% + phenylephrine 2.5%, tropicamide 1% + phenylephrine 2.5%, and a prepared combination of cyclopentolate 0.2% with phenylephrine 1% for pupillary dilation in preterm infants with dark irides. Thirteen infants were randomized to each regimen. Outcomes measured were pupillary dilation, heart rate, blood pressure, abdominal girth, and intolerance to feeds.

RESULTS

All three mydriatic regimens provided adequate pupillary dilation at 45 minutes, with dilation sustained at 60 minutes. There was a significant increase in mean blood pressure in the cyclopentolate 1% + phenylephrine 2.5% and the tropicamide 1% + phenylephrine 2.5% groups. Although there was no significant change of abdominal girth in any of the three groups, a total of eight patients developed intolerance to feeds; four (50%) of these infants were from the cyclopentolate 1% + phenylephrine 2.5% group.

CONCLUSION

The prepared combination of cyclopentolate 0.2% + phenylephrine 1% appears to be the mydriatic of choice for preterm infants with dark irides as it provided adequate pupillary dilation with the least systemic side effects.

Systemic adverse effects of topical ocular treatments

Some eyedrops, gels or ointments may cause adverse effects as serious as those observed with systemic therapies. Because of their relatively poor penetration into eye tissue, ophthalmic drugs usually contain high concentrations of their active ingredient. Asking patients about these drugs to prevent interactions is useful when prescribing a new systemic treatment. Conversely, it is advisable to ask about ophthalmic drugs during the etiological investigation of possible iatrogenic effects.

Cycloplegic and mydriatic agents for routine ophthalmologic examination: a survey of pediatric ophthalmologists

INTRODUCTION

We have used a mixture of tropicamide 1% and cyclopentolate 2% for routine cycloplegia in children. Because our hospital pharmacy expressed reluctance to prepare this mixture, we were interested in the current standard of care among pediatric ophthalmologists.

METHODS

A survey was mailed to all members and associate members of the American Association for Pediatric Ophthalmology and Strabismus. Responses were tabulated from 522 respondents (62%).

RESULTS

Mixtures were used by 22% of respondents for neonates and by 40% for older children. The most popular mixtures were cyclopentolate and phenylephrine for neonates and cyclopentolate, phenylephrine, and tropicamide for older children.

CONCLUSION

Although a commercially available mixture (Cyclomydril; Alcon, Ft. Worth, TX) has found wide acceptance for treatment of neonates, ophthalmologists seeking stronger concentrations for older children must rely on alternate sources. There would appear to be a market for such a product.

Does valsalva retinopathy occur in infants? An initial investigation in infants with vomiting caused by pyloric stenosis

OBJECTIVE

Retinal hemorrhages (RHs) are 1 manifestation of child abuse, and although they often are considered to be diagnostic of abuse in a young child, there are other potential causes. RHs have been described in association with valsalva maneuver, such as forceful vomiting or coughing. Our aim was to describe the incidence of RH in infants with vomiting caused by pyloric stenosis.

METHODS

A prospective, descriptive study was conducted of infants who underwent pyloromyotomy for hypertrophic pyloric stenosis (HPS). Dilated retinal examinations were performed, and the findings were documented.

RESULTS

A total of 100 infants with HPS were evaluated. Eighty-four infants were male, 92 were white, and 21 had a family history of pyloric stenosis. Thirty-seven examinations were performed in the operating room. Eighteen examinations were confirmed by a second investigator, and 3 children had dilated eye examinations documented independently by a pediatric ophthalmologist. No RHs were identified (0 of 100; 95% confidence interval: 0%-3%). One patient had facial petechiae, and 2 had subconjunctival hemorrhage. Electrolyte levels were abnormal in 63 patients. In 89 cases, the emesis was described as projectile. Patients varied in the number of episodes of emesis, with 30% of patients having >100 episodes of emesis before diagnosis. One patient had a respiratory arrest associated with vomiting in the emergency department and required bag-valve mask ventilation.

CONCLUSIONS

No RHs were identified in 100 infants with vomiting caused by HPS. These results suggest that RHs do not result from forceful vomiting in infants.

SYSTEMIC MANIFESTATIONS IN RESPONSE TO MYDRIASIS AND PHYSICAL EXAMINATION DURING SCREENING FOR RETINOPATHY OF PREMATURITY

OBJECTIVE

To determine whether adverse effects manifested via vital sign changes during the screening examination for retinopathy of prematurity (ROP) are due to the pharmacologic properties of the eye drops or to physical manipulation of the eyes. The authors also investigated the relationship between distress during the screening process and the severity of prematurity of the infant.

DESIGN AND METHODS

A prospective observational study was designed that enrolled all infants either weighing < or =1500 g or who were < or =32 weeks gestational age at birth who were admitted to the neonatal intensive care unit (NICU) at Northwest Texas Hospital or Baptist St. Anthony's Hospital from June 2002 to February 2003. Thirty participants were enrolled in this study. Blood pressure, pulse, temperature, respiratory rate, and O2 saturation were recorded at different time intervals during the examination. Infants were excluded from the study if they were on the ventilator, considered acutely ill, born with significant birth defects, or currently taking inotropic drugs, or had received albuterol 2 hours before the examination.

RESULTS

Oxygen saturation and pulse rate following physical manipulation of the eyes significantly varied from baseline values and the values obtained during the three instillations of topical mydriatics. No significant changes in blood pressure, temperature, or respiratory rate from their respective baseline values were observed throughout the ROP screening examination. Gestational age of the infant did not correlate with level of distress during the examination.

CONCLUSION

Regardless of the severity of prematurity, infants seem to undergo significant distress during the eyelid speculum examination. Thus ophthalmologists should take into consideration the infant's discomfort caused by physical manipulation of the eyes and attempt to perform the examination as swiftly, yet safely, as possible using topical anesthetic.

Rétinopathie du prématuré : résultats de l’examen du fond d’œil chez 94 enfants à risque

PURPOSE

The purpose of this study was to evaluate the incidence and severity of retinopathy of prematurity (ROP) in infants of birth weight less than 1.500 g and/or under 32 weeks'gestation.

METHODS

Ninety-four preterm infants were examined following the Royal College of Ophthalmologists guidelines and retinopathy was graded using the International Classification of ROP. Screening limits were 1 500 g birth weight or 32 weeks'gestational age. Fundus examinations for ROP were performed at 5 weeks'chronological age from birth. Pupil dilation was obtained with instillation of 1% tropicamide three times at 15-minute intervals.

RESULTS

The 94 infants examined for ROP had a median gestational age of 292.3 weeks and a median birth weight of 1 110340 g. ROP was diagnosed in 21 of 94 subjects (22.3%) by fundus examination. ROP stage 3 developed in one preterm infant, ROP stage 2 developed in five preterm infants, and ROP stage 1 developed in 15 preterm infants. No premature babies developed stage 4 or stage 5 ROP. The disease regressed spontaneously in all cases and none of the infants required cryo/laser therapy. In the most premature infants, 23-26 weeks'gestation, 57% developed ROP and one developed severe ROP (stage 3). No disease more posterior to peripheral zone 2 was observed. The incidence of ROP was higher in infants exposed to greater than 21% oxygen (24.2%) than in infants who did not receive oxygen (17.8%). Oxygen, blood transfusion, and cardiopathy appear to be associated with an increased incidence of retinopathy of prematurity.

CONCLUSIONS

ROP continues to be a common problem associated with prematurity in France. This study found a similar incidence of prethreshold ROP when compared to recent studies. The data showed that blood transfusion and cardiopathy may play a role in the development of ROP in premature infants.

Cardiovascular effects of topical ophthalmic 10% phenylephrine in dogs

OBJECTIVE

To evaluate the effect of topical ophthalmic 10% phenylephrine on systolic arterial pressure (SAP), diastolic arterial pressure (DAP), mean arterial pressure (MAP), pulse rate (PR) and electrocardiogram (ECG) in dogs.

ANIMALS STUDIED

Nine clinically normal dogs.

PROCEDURE

Arterial catheters were placed in the dorsal pedal artery of awake dogs and ECG leads were attached. After a 15-min acclimatization period, baseline PR, SAP, DAP and MAP were recorded every 5 min for 20 min. Two treatment groups (eight dogs each) were studied. Group I: one drop of phenylephrine was placed in each eye once. Group II: one drop of phenylephrine was placed in each eye three times at 5-min intervals. Following treatment, PR, SAP, DAP and MAP were recorded every 5 min for 90 min. The mixed procedure of the SAS system was used to perform a repeated measures analysis of variance to test for linear and quadratic trends across time.

RESULTS

Group I: There was a significant quadratic decrease in PR across time (P = 0.0051). Systolic arterial pressure increased linearly with time (P = 0.0002), MAP increased linearly with time (P = 0.0131), and DAP increased linearly with time (P = 0.0001). Group II: There was a significant quadratic decrease in PR across time (P = 0.0023). There was a significant quadratic increase in SAP (P = 0.0324), MAP (P = 0.0103) and DAP (P = 0.0131) across time.

CONCLUSIONS

Topical ophthalmic application of 10% phenylephrine in normal dogs results in elevation of arterial blood pressure and reflex bradycardia.

Combination cyclopentolate and phenylephrine for mydriasis in premature infants with heavily pigmented irides

PURPOSE

This study examined whether safe and effective mydriasis can be achieved in premature infants with heavily pigmented irides using combination cyclopentolate 0.2% and phenylephrine 1% eyedrops.

METHODS

A prospective, randomized double-blind study was performed to compare combination cyclopentolate 0.2% and phenylephrine 1% eye-drops with triple instillation of tropicamide 0.5% and phenylephrine 2.5%. Twenty-eight consecutive babies with dark irides and birthweight <1600 g referred for screening for retinopathy of prematurity comprised the study population. Infants' eyes were randomly dilated twice with both regimens within a 2-week period. Blood pressure, heart rate, and pupil size were measured.

RESULTS

Good mydriasis was achieved in both groups with no significant differences in pupil size or blood pressure (systolic, diastolic, or mean arterial pressures) over starting baseline values. Pulse rates decelerated below the baseline values in both groups, but these differences were not large.

CONCLUSION

The single combination eyedrop of cyclopentolate 0.2% and phenylephrine 1% is as effective and safe a mydriatic for infants with dark irides as both tropicamide 0.5% and phenylephrine 2.5%.

The influence of drop size of cyclopentolate, phenylephrine and tropicamide on pupil dilatation and systemic side effects in infants

In this prospective study, microdrops (mean drop volume 5.6 microl) and commercially available standard drops (mean drop volume 35.4 microl) of cyclopentolate, phenylephrine and tropicamide's clinical efficacy and systemic side effects were compared. Sixty-one infants requiring diagnostic pupil dilatation were studied for pupillary diameter, systemic blood pressure, heart rate and skin flushing changes related to the instillation of mydriatic drops. Both microdrops and standard drops of the drugs produced significant increase in pupillary diameter compared with the baseline (p<0.01). In cyclopentolate and phenylephrine groups, there was no significant pupillary diameter changes between microdrops and standard drops (p>0.05). Mean blood pressure increased significantly in infants given standard drops. There was no significant change in the group that was given microdrops. In our opinion, reduced volume of mydriatics can prevent possible side effects.

Cardiovascular effects of commonly used ophthalmic medications

Eye disease and cardiovascular disease frequently coexist. As a result, cardiologists and ophthalmologists often treat the same patients. Among ophthalmologists it is well known that topical ophthalmic medications are capable of producing serious cardiovascular effects, including congestive heart failure, arrhythmias, and death. However, cardiologists may not be aware of these potential complications. This article reviews the cardiovascular effects of commonly prescribed topical ocular medications and describes important contraindications to their use in patients with cardiovascular disease. Cardiologists, by making themselves and their patients more aware of the cardiovascular effects of topical ocular medications, may be able to avoid the adverse and potentially fatal complications of these agents.

A mydriatic eye-drop combination without systemic effects for premature infants: a prospective double-blind study

Eye drops used for diagnostic mydriasis may produce systemic side effects in preterm infants. Studies on the pupil dilating and systemic effect of various mydriatic agents yielded conflicting results. We conducted a prospective randomized double-blind study on the systemic effect of two mydriatic eye-drop combinations. Thirty-nine preterm infants were randomly assigned to two groups. An eye-drop combination of 2.5% phenylephrine and 0.5% tropicamide (group D) was compared with the combination of 0.5% cyclopentolate and 0.5% tropicamide (group F). Either eye-drop combination was followed by 0.5% tropicamide given 20 minutes later. Heart rate (HR) and the systolic, mean, and diastolic blood pressure (BP) were recorded before and after eye-drop instillation and after ophthalmoscopy. A control session with NaCl eye drops was added for each infant. A significant increase of BP and HR peak values was observed within 7 to 10 minutes after the cyclopentolate/tropicamide combination only. On the other hand, the mydriatic effect of the phenylephrine/tropicamide combination was significantly superior to that of the cyclopentolate/tropicamide combination. We recommend the combination of 2.5% phenylephrine and 0.5% tropicamide to achieve a sufficient diagnostic mydriasis without systemic side effects in preterm infants.

Systemic reactions to ophthalmic drug preparations

Adverse systemic reactions associated with the use of topical ophthalmic timolol, chloramphenicol, phenylephrine and cyclopentolate are surveyed, with special emphasis on precautions and contraindications for these ophthalmic drug preparations. Systemic reactions secondary to timolol, a beta-adrenergic antagonist indicate that it should be used with caution in patients with asthma or a history of asthma, chronic obstructive pulmonary disease or cardiovascular disease and in those patients receiving systemic administration of beta-blockers or verapamil. Because significant blood dyscrasias or aplastic anaemia have been reported following topical ophthalmic chloramphenicol, the only absolute indication in ocular conditions is an organism that is resistant to all other antibiotics. Both 2.5% and 10% phenylephrine have been associated with cardiovascular effects and should be used with caution in selected patients on monoamine oxidase inhibitors, tricyclic antidepressants or atropine or in those with hypertension, advanced arteriosclerotic changes, aneurysms, orthostatic hypotension, long-standing insulin-dependent diabetes and in children with low bodyweights. Central nervous system toxicity secondary to cyclopentolate is dose-related and can be avoided by use of minimal concentrations and avoidance of unnecessary repetition of administration. Occlusion of the nasolacrimal passage with finger pressure immediately after instillation of any eyedrop also decreases the amount of drug that is absorbed systemically.

A comparison of the pupillary and cardiovascular effects of various mydriatic agents in preterm infants

We conducted a randomized, masked study of pupillary dilating capabilities and associated cardiovascular effects of three solutions. Thirty-four babies less than 1500 grams at birth were studied at six to eight weeks. Group A (n = 10) received phenylephrine (PE) 2.5% and tropicamide 1.0%; Group B (n = 10) PE 2.5%, tropicamide 0.5%, and cyclopentolate 0.5%, Group C (n = 10) PE 1.0% and tropicamide 1.0%; Group D (n = 4) saline 0.9%. One drop was placed in each eye and repeated five minutes later. Pupillary dilation was measured with a metric ruler by direct observation at one hour. Blood pressure (BP) and heart rate (HR) were monitored, using an oscillometer, immediately prior to the instillation of the drops and at five-minute intervals, for 60 minutes. BP and HR increased transiently in all groups receiving mydriatics but returned to baseline values in 25 minutes. This increase was significant in Groups A and B (2.5% PE: p less than 0.02). Group D (saline) showed no change in BP or HR. Postdrop pupillary size was largest in Group A but the differences were not significant. On exposure to bright light, the pupillary size in Group C was significantly smaller than Groups A or B (7.35 +/- 0.59 mm, 7.23 +/- 0.38 mm and 6.75 +/- 0.57 mm in Groups A, B and C, p less than .01). Nevertheless, dilation was sufficient to allow appropriate examination in all infants (pupillary diameter greater than 6.0 mm). Solutions containing 2.5% PE are most effective for use in LBW infants, but produce cardiovascular effects. Solutions containing 1% PE provide adequate dilation with minimum cardiovascular effects.

Effects of cyclopentolate eyedrops on gastric secretory function in pre-term infants

Because of a report of necrotizing enterocolitis and death of a neonate from cyclopentolate eyedrops, we prospectively studied the effects of cyclopentolate 0.5% and 0.25% ophthalmic solutions and of a placebo on gastric volume and acid secretions in 20 pre-term infants. Placebo and cyclopentolate 0.25% eyedrops had no significant effect on the tested gastric functions. However, cyclopentolate 0.5% eyedrops significantly decreased gastric acid secretion and volume. Since this effect may predispose to the development of gastroenteritis, we recommend that cyclopentolate 0.5% be avoided in preterm infants; a weaker concentration of cyclopentolate eyedrops, however, can be used for mydriasis.

A comparison of mydriatic eyedrops in low-weight infants

The pupils of neonates often need to be dilated to examine the retina for retinopathy of prematurity and other disorders. It is known that low-weight infants (less than 1600 grams) are susceptible to systemic hypertension when 10% or 2.5% phenylephrine eye drops are used. To find the safest and best commercially available mydriatic agent in neonates, 30 low-weight infants were divided evenly into three groups. The drops tested were cyclopentolate 0.5% alone, cyclopentolate 0.5% plus mydriacyl 0.5%, and a combination drop of phenylephrine 1% and cyclopentolate 0.2%. There was no clinically significant effect of any of the drops on systolic blood pressure or pulse rate. The cyclopentolate and phenylephrine combination dilated the pupils by a mean of 2.8 mm which was statistically greater than the other groups (P less than 0.01) and had a longer duration of maximal dilation than the other drops (P less than 0.05).