Cyclopentolate associated with two cases of grand mal seizure

Machine-learning random forest algorithms predict post-cycloplegic myopic corrections from noncycloplegic clinical data

SIGNIFICANCE

Machine learning random forest algorithms were used to predict objective refractive outcomes after cycloplegic refraction using noncycloplegic clinical data. A classification model predicted post-cycloplegic myopia and could be useful in screening, and a second regression model predicted post-cycloplegic refractive and could provide a useful objective starting point in noncycloplegic subjective refractions.

PURPOSE

A classification model sought to predict post-cycloplegic myopia using noncycloplegic clinical data to enhance myopia screening accuracy, whereas the regression model looked to predict objective refraction outcomes after cycloplegia for use as a starting point for noncycloplegic subjective refraction.

METHODS

A cross-sectional study included data from 2483 eyes. Pre-refraction measurements, such as uncorrected visual acuity, axial length, and corneal curvature radius, were recorded. After cycloplegia, the spherical equivalent was measured. Random forest-based classification and regression models were established with input variables including age, gender, axial length, corneal curvature radius, axial length-to-corneal curvature radius ratio, spherical equivalent, and uncorrected visual acuity. Model performance was assessed using various metrics.

RESULTS

The random forest classification model achieved high out-of-bag validation accuracy (92%), cross-validation accuracy (93%), external validation accuracy (94%), and precision (95%). The external validation sensitivity was 93%, and specificity was 95%. The regression model internal validation showed an out-of-bag validation R2 of 0.86, root mean square error (RMSE) of 0.66, and mean absolute error of 0.49. The 10-fold cross-validation R2 was 0.87, the RMSE was 0.64, and the mean absolute error was 0.48. In the external validation, R2 was 0.88, the RMSE was 0.63, and the mean absolute error was 0.48.

CONCLUSIONS

By analyzing noncycloplegic clinical data, the classification model enables earlier detection of myopia, supporting timely intervention and management. The regression model aims to accurately predict post-cycloplegia myopic corrections, providing reliable initial data for subjective refraction. This could help optometrists perform noncycloplegic subjective refraction more efficiently and is particularly relevant in China, where retinoscopy is not yet fully popularized and many school students decline cycloplegic refraction due to academic pressures and limited free time, primarily because it requires a follow-up the next day.

Ocular Cyclopentolate: A Mini Review Concerning Its Benefits and Risks

Cycloplegic and mydriatic agents are essential in ophthalmological clinical practice since they provide the means for diagnosing and treating certain eye conditions. In addition, cyclopentolate has proven to possess certain benefits compared to other available cycloplegics and mydriatics. Still, the incidence of some adverse drug reactions related to this drug, especially in susceptible patients, has created interest in reviewing the literature about the benefits and risks of using cyclopentolate. A literature search was conducted in Medline/PubMed and Google Scholar, focusing on identifying cyclopentolate's benefits and risks; the most important benefit was its usefulness for evaluating refractive errors, especially for hyperopic children, pseudomyopia, anterior uveitis, treatment of childhood myopia, idiopathic vision loss, and during examinations before refractive surgery, with particular advantages compared to other cycloplegics. While the risks were divided into local adverse drug reactions such as burning sensation, photophobia, hyperemia, punctate keratitis, synechiae, and blurred vision, which are relatively frequent but mild and temporary; and systemic adverse drug reactions such as language problems, visual or tactile hallucinations and ataxia, but unlike ocular, systemic adverse drug reactions are rare and occur mainly in patients with risk factors. In addition, six cases of abuse were found. The treatment with cyclopentolate is effective and safe in most cases; nevertheless, special care must be taken due to the potential severe ADRs that may occur, especially in susceptible patients like children, geriatrics, patients with neurological disorders or Down's syndrome, patients with a low blood level of pseudocholinesterase, users of substances with CNS effects, and patients with a history of drug addiction. The recommendations are avoiding the use of 2% cyclopentolate and instead employing solutions with lower concentrations, preferably with another mydriatic such as phenylephrine. Likewise, the occlusion of the nasolacrimal duct after instillation limits the drug's absorption, reducing the risk of systemic adverse events.

Prediction for Cycloplegic Refractive Error in Chinese School Students: Model Development and Validation

Purpose

To predict cycloplegic refractive error using measurements obtained under noncycloplegic conditions.

Method

Refractive error was measured in 5- to 18-year-old Chinese students using a NIDEK autorefractor before and after administration of 0.5% tropicamide. Spherical equivalent (SER) in diopters (D) was calculated as sphere plus half cylinder. A multivariable prediction model for cycloplegic SER was developed using data from students in Jinyun (n = 1938) and was validated using data from students in Hangzhou (n = 1498). The performance of the prediction model was evaluated using R², mean difference between predicted and measured cycloplegic SER, and sensitivity and specificity for predicting myopia (cycloplegic SER ≤ −0.5 D).

Results

Among 3436 students (mean age, 9.7 years; 51% female), the mean (SD) noncycloplegic and cycloplegic SER values were −1.12 (1.97) D and −0.20 (2.19) D, respectively. The prediction model that included demographics, noncycloplegic SER, axial length/corneal curvature radius ratio, uncorrected visual acuity (UCVA), and intraocular pressure predicted cycloplegic SER with R² of 0.93 in the development dataset and 0.92 in the validation dataset. The mean (SD) differences between predicted and measured cycloplegic SER were 0.0 (0.55) D in the development dataset and 0.06 (0.64) D in the validation dataset. In both the development and validation datasets, the combination of predicted SER and UCVA yielded high sensitivity (91.4% and 91.9%, respectively) and specificity (95.0% and 90.1%, respectively) for detecting myopia.

Conclusions

Cycloplegic refractive error can be predicted using measurements obtained under noncycloplegic conditions. The prediction model could potentially be used to correct the myopia prevalence in epidemiological studies in which administering cycloplegic agent on all participants is not feasible.

Translational Relevance

The prediction model may provide a tool for correcting the overestimation of myopia from noncycloplegic refractive error in future epidemiological studies in which administering cycloplegic agent on all participants is not feasible.

Prediction of cycloplegic refraction for noninvasive screening of children for refractive error

Detection of refractive error in children is crucial to avoid amblyopia and its impact on quality of life. We here performed a retrospective study in order to develop prediction models for spherical and cylinder refraction in children. The enrolled 1221 eyes of 617 children were divided into three groups: the development group (710 eyes of 359 children), the validation group (385 eyes of 194 children), and the comparison group (126 eyes of 64 children). We determined noncycloplegic and cycloplegic refraction values by autorefractometry. In addition, several noncycloplegic parameters were assessed with the use of ocular biometry. On the basis of the information obtained from the development group, we developed prediction models for cycloplegic spherical and cylinder refraction in children with the use of stepwise multiple regression analysis. The prediction formulas were validated by their application to the validation group. The similarity of noncycloplegic and predicted refraction to cycloplegic refraction in individual eyes was evaluated in the comparison group. Application of the developed prediction models for spherical and cylinder refraction to the validation group revealed that predicted refraction was significantly correlated with measured values for cycloplegic spherical refraction (R = 0.961, P < 0.001) or cylinder refraction (R = 0.894, P < 0.001). Comparison of noncycloplegic, cycloplegic, and predicted refraction in the comparison group revealed that cycloplegic spherical refraction did not differ significantly from predicted refraction but was significantly different from noncycloplegic refraction, whereas cycloplegic cylinder refraction did not differ significantly from predicted or noncycloplegic values. Our prediction models based on ocular biometry provide estimates of refraction in children similar to measured cycloplegic spherical and cylinder refraction values without the application of cycloplegic eyedrops.

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.

Cycloplegic Refraction in Hyperopic Children: Effectiveness of a 0.5% Tropicamide and 0.5% Phenylephrine Addition to 1% Cyclopentolate Regimen

Purpose

To evaluate the effectiveness of a cycloplegic regimen using 0.5% tropicamide and 0.5% phenylephrine (Tropherine, Hanmi Pharm), in addition to 1% cyclopentolate, in hyperopic children.

Methods

The medical records of hyperopic patients below the age of 14 years who had undergone cycloplegic retinoscopy were retrospectively reviewed. Cycloplegic refractions were performed using one of two cycloplegic regimens. Regimen 1 was a Tropherine-added regimen comprising the administration of one drop of 1% cyclopentolate followed by two to three drops of Tropherine added at 15-minute intervals. Regimen 2 was a cyclopentolate-only regimen comprising the administration of three to four drops of 1% cyclopentolate at 15-minute intervals. The mean difference between noncycloplegic and cycloplegic refraction was compared between the two regimens.

Results

A total of 308 eyes of 308 hyperopic children were included. The mean difference (±standard deviation) in the spherical equivalent (SE) between cycloplegic and noncycloplegic refraction was significantly larger in regimen 2 than in regimen 1, with values of +1.70 ± 1.03 diopters (D) and +1.25 ± 0.89 D, respectively (p=0.001). The SE change after cycloplegia was significantly different between the two regimens only in patients aged 5 years or younger (p=0.001), particularly in those with high hyperopia with an SE ≥5 D (p=0.005) or fully accommodative esotropia (p=0.009). There was no significant difference between the two regimens in patients older than 5 years, regardless of the presence of high hyperopia or fully accommodative esotropia.

Conclusions

The Tropherine-added regimen exerted a weaker cycloplegic effect than the cyclopentolate-only regimen, particularly in children under the age of 5 years with high hyperopia or fully accommodative esotropia. However, the difference in refraction between the two regimens was small. A Tropherine-added regimen can be effective in hyperopic children, with less associated discomfort than the instillation of cyclopentolate.

Epileptic seizures induced by cycloplegic eye drops

OBJECTIVE

To assess the incidence of seizures induced by cycloplegic ophthalmic drops.

MATERIALS AND METHODS

A survey among members of the American Association for Pediatric Ophthalmology and Strabismus yielded five patients who received cycloplegic eye drops between 1998 and 2010 and who consequently developed a seizure.

RESULTS

The median age of the patients was 5 years (range 3 months to 12 years). Cyclopentolate hydrochloride 1% was the only causative agent. The seizure happened on average 12 min after the instillation of dilating eye drops. Three were generalized convulsions, and two patients had a focal seizure. Past medical history was unremarkable in four cases. In total, 16 previous cases of seizures induced by cycloplegic drugs were identified in reports published between 1890 and 2004, implicating atropine in nine reports, tropicamide and phenylephrine eye drops in one and cyclopentolate in six.

DISCUSSION

A small amount of cyclopentolate drops could induce convulsions in young children after only minutes to less than an hour, while a larger dosage of atropine over the span of several hours could cause this rare and unpredictable complication. Predisposing factors were rare and those developing the seizures were healthy subjects. Generalized seizures were much more frequent than focal convulsions.

CONCLUSIONS

Seizures after instillation of cycloplegic drops are extremely rare.

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.

Comparing homatropine and atropine in pediatric cycloplegic refractions

PURPOSE

To compare cycloplegic efficacy of homatropine and atropine in pediatric refractions and derive a regression formula to calculate refraction findings for both agents.

METHODS

Children between the ages of 4 to 10 years with refractive error underwent cycloplegic refraction with 2% homatropine and 1% atropine by retinoscopy and automated refraction. Refractive data were compared by the use of power vector analysis. Primary outcome measures were spherical equivalent (SE), astigmatic components of refractive error (J(0) and J(45)), overall blur strength of refractive error, and residual accommodation.

RESULTS

A total of 63 children with refractive error were enrolled (mean age, 6.7 ± 1.6 years). Compared with homatropine, atropine uncovered significantly greater hyperopic SE in patients with hypermetropia (4.2 ± 2.5 D [atropine] vs 3.5 ± 2.3 D [homatropine]; P < 0.001) as well as myopia (-1.8 ± 1.4 D [atropine] vs -2.1 ± 1.4 D [homatropine]; P < 0.001). Overall blur strength was significantly greater with atropine (3.1 ± 2.1 [atropine] vs 2.9 ± 1.9 [homatropine]; P = 0.003). Homatropine had a significantly greater residual accommodation (1.8 ± 0.4 D [atropine] vs 3.1 ± 0.5 D [homatropine]; P < 0.001). A regression formula was derived.

CONCLUSIONS

Of the 2 cycloplegic agents, atropine yielded more consistent results than homatropine; however atropine had a relatively slow onset and prolonged effect. Our regression formula may make it possible to derive atropine-like results while using the clinically more versatile homatropine.

Comparative study on the safety and efficacy of different cycloplegic agents in children with darkly pigmented irides

BACKGROUND

The ideal cycloplegic drug that is safe, effective and convenient in children is not yet available. This study aimed to evaluate the safety and efficacy of three cycloplegic regimens in hyperopic children with pigmented irides. The responses to cycloplegia in different age groups and presence of strabismus were also compared.

METHODS

Tropicamide 0.5% and phenylephrine 0.5% (regimen I), tropicamide 1.0% and cyclopentolate 1.0% (regimen II), and atropine 1.0% (regimen III) were evaluated in 25 children using a crossover study design. Cycloplegic refractions were assessed.

RESULTS

The mean age of the children was 5.7 +/- 2.0 years (range 2.5-10.8 years). Six (24.0%) of them had strabismus. The spherical equivalent (SE) refraction for regimens I, II and III were +5.11 +/- 2.04 D, +5.29 +/- 1.89 D and +5.71 +/- 1.90 D, respectively, and were significant different from the manifest SE (+3.95 +/- 2.17 D) (P < 0.001). There was no statistical difference between regimen I and II in children without strabismus (P = 0.258) or aged older than 5 years (P > 0.050).

CONCLUSION

In older children, regimen I was as effective as regimen II and can be used to avoid cyclopentolate toxicity.

Topical mydriatic and cycloplegic spray for Chinese children

PURPOSE

To assess the efficacy and tolerance of mydriatic and cycloplegic spray versus drops for Chinese children.

METHODS

The effects of the spray (cyclopentolate 0.25%, phenylephrine 0.625%, and tropicamide 0.5%) and the drops (cyclopentolate 1%, phenylephrine 0.5%, and tropicamide 0.5%) were evaluated in 29 children (58 eyes) in two separate sessions. There was a 1-week period between the applications of the spray and the drops. Dilated pupil size and refraction after cycloplegia were the primary outcome variables used to assess the efficacy. A subjective discomfort score was used to assess acceptance of the spray and the drops.

RESULTS

The mean age of the study population was 4.33 +/- 1.39 years (range, 3 to 8 years). The mean pupil size was 6.9 mm for the spray and 6.6 mm for the drops. The spray appeared to be slightly more effective than the drops, with a mean difference of 0.3 mm that was statistically significant (P = .001, two-tailed t test). No statistically significant difference in cycloplegic response was found between the spray and the drops (P = .535, two-tailed t test). Administration of the spray caused less discomfort than did administration of the drops (P < .001, Wilcoxon signed-rank test).

CONCLUSIONS

The spray system appears to be clinically equivalent to the drops for achieving effective pupil dilation and cycloplegia, even in a population with dark irides such as ours. Tolerability and acceptance improved because the spray was applied to the closed eyelids.

Acute psychotic reaction caused by topical cyclopentolate use for cycloplegic refraction before refractive surgery: case report and review of the literature

A 56-year-old woman was evaluated for the surgical correction of hyperopia (+3.0 diopters). Two drops of cyclopentolate 1% were instilled in both eyes for measurement of the cycloplegic refraction and wavefront analysis. Immediately after the second instillation, the patient reported drowsiness, dizziness, nausea, and fatigue. Ten minutes later, stimulatory central nervous system symptoms in the form of restlessness, cheerfulness, and a 20-minute-long roar of laughter were observed, interrupted by a new sedative phase. Basic medical and neurologic examinations were unremarkable except for gait ataxia. Four hours later, the examination was continued uneventfully. As surgical treatment of refractive errors and measurement of cycloplegic refraction using cyclopentolate become more frequent, ophthalmologists should be aware of this unusual acute event.

Mydriatics slow gastric emptying in preterm infants

OBJECTIVE

Preterm infants are more likely to have episodes of abdominal distention, emesis, and gastric residuals 24 hours after their first screening examination for retinopathy of prematurity (ROP) than on the day preceding the examination. Because these feeding problems reflect abnormalities in motor function, the purpose of this study was to compare antral and duodenal motor activity and gastric emptying in preterm infants before and after the instillation of mydriatics.

STUDY DESIGN

Using a low compliance continuous perfusion manometric system, we recorded antral and duodenal fasting motor activity in 11 preterm infants before and after the instillation of mydriatics for their first screening examination for ROP. Gastric emptying was compared before and after the eye examination.

RESULTS

Although the number of antral motor contractions remained relatively constant throughout the study, duodenal motor contractions decreased nearly fourfold after the instillation of mydriatics versus that seen before (P <.01). Gastric emptying was significantly delayed after the completion of the eye examination compared with that seen before the examination (P <.05).

CONCLUSION

Current doses of mydriatics inhibit duodenal motor activity and delay gastric emptying, and these gastrointestinal effects of mydriatics may underlie the feeding difficulties seen in preterm infants on the day of screening examinations for ROP.

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%.

Ocular medications in children

Many ocular medications are used by pediatricians or ophthalmologists caring for pediatric patients. Topical antibiotics are commonly prescribed for bacterial conjunctivitis, nasolacrimal duct obstructions, and ophthalmia neonatorum. Many new antiallergy eye drops are now available for the treatment of seasonal (hay fever) conjunctivitis. Dilating eye drops and antiglaucoma medications are generally used or prescribed by ophthalmologists, but pediatricians must be aware of their potentially serious systemic side effects. Before initiating treatment, physicians should evaluate the risks and benefits of ophthalmic medications, establish minimum dosages necessary to achieve a therapeutic benefit, and monitor children for local and systemic side effects.

Systemic adverse effects of topical ophthalmic agents. Implications for older patients

Topical ophthalmic medications are widely prescribed by growing numbers of eye-care professionals. Increasingly, these agents are being prescribed by optometrists and ophthalmic-trained nurses in addition to ophthalmologists and general practitioners. As the number and variety of topical agents on the market rises, and as the number of clinicians involved in prescribing those agents increases; the risk of systemic adverse effects will also increase. Thus, professionals involved in the care of these patients must be aware of the risks associated with these drugs in order to minimise the likelihood of complications. Moreover, inadequate training may result in the clinician failing to associate a topical medication with a systemic condition, allowing an adverse effect to pass unrecognised. It is therefore in the interest of the ophthalmic and pharmaceutical communities to improve awareness of the potential dangers intrinsic in the use of topical eye medications. It is the elderly population who are at greatest risk of experiencing systemic adverse effects of topical agents. Chronic ophthalmic diseases, and hence long term ophthalmic drop treatments, are more prevalent among older people. Such individuals are also likely to have other medical conditions (e.g. cardiac, respiratory or neurological disease) that may be induced or exacerbated by topical ophthalmic agents. Moreover, polypharmacy is common in elderly people, and this is associated with an increased risk of drug interactions.

Eye drops--the hidden poison

Eye drops are very commonly prescribed but their potential for systemic absorption and serious toxicity may be forgotten. This paper examines patterns of prescription of eye drops in Scotland by general practitioners. A review of the serious systemic features and toxicity, and their management, of commonly used eye drops is undertaken. Practical recommendations for the monitoring of such effects in clinical practice are made.

Cycloplegic refraction in children: single-dose-atropinization versus three-day-atropinization

A new scheme for refractive measurements under atropine cycloplegia was tested in 90 strabismic children aged two to several years. Refraction was determined by an autorefractor (CANON R 10) 90 minutes after application of two drops of atropine (0.5% atropine children < 2 1/2 years; 1.0% atropine children > 2 1/2 years) and compared with the results after 3 days of receiving 1 atropine eyedrop 3 times daily. In 86.5% the spherical equivalents differ not more than 1.0 diopter (p = 0.05); the correlation was 0.99. Astigmatic corrections were in agreement in 95.5%, the axis of cylinders in 93.0% (p = 0.05); the correlations were 0.95 and 0.97. The residual accommodation 90 minutes after 2 drops of atropine was not more than 1 diopter in all children. The additional cycloplegic effect of the three-day-atropinization was only 0.5 diopters. This new type of application allows a more rapid and less toxic assessment of refraction than the usual three-day-atropinization.

Seizures associated with 1% cyclopentolate eyedrops

A 4.5 year old boy with cerebral palsy presented with seizures associated with facial flushing and tachycardia following the instillation of 1% cyclopentolate, a commonly used mydriatic in paediatric practice. He had no prior history of convulsions. This case demonstrates the uncommon, though serious, atropine-like side effect of cyclopentolate eyedrops (Cyclogyl, Alcon) in usual dosage in a brain damaged child without an epileptic focus.

Principles of ophthalmic anesthesia

Ophthalmic surgery presents the anesthesiologist with many unique challenges. The exigencies of this subspecialty include a comprehensive knowledge of ocular physiology and pharmacology and an understanding of the anesthetic implications intrinsic to a wide variety of ophthalmic procedures.

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.

How safe are ocular drugs in pediatrics?

In comparison with that of adults, the smaller body mass of children raises questions of dosage. In addition, manifestations of ocular drug toxicity are different in some respects. The ocular drugs causing serious adverse ocular or systemic side effects in children include glaucoma medications, corticosteroids, phenylephrine, and the anticholinergic cycloplegics. The reported complications from using these medications in children will be briefly reviewed, and strategies for minimizing the risk of their adverse effects will be suggested, including a discussion of dosages and techniques of administration.

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).

The problem of cycloplegia in the pediatric age group: a combination formula for refraction

Cycloplegic refraction and indirect ophthalmoscopy are essential to evaluation of the pediatric patient. Unfortunately, along with this practice occur the attendant risks of toxicity and the unpleasantness of instillation. The literature that documents the development of cycloplegic agents is often contradictory regarding efficacy and side effects. It is presented for perspective. We have found that efficacy and discomfort are inseparable; however, as with efficacy and toxicity they are directly related to the concentration used. The case is therefore made to use each agent in its minimal effective concentration and thereby minimize both discomfort and toxicity. Our combination of 1.3% cyclogyl, .167% mydriacil, and 1.6% phenylephrine accomplishes effective cycloplegia for refraction and indirect ophthalmoscopy, has a rapid onset and short duration, works reliably in dark irides, is accomplished in a single encounter with the patient, and exhibits none of the side effects of the individual agents in our series.

Systemic response to mydriatic eyedrops in neonates: mydriatics in neonates

During routine dilation of 48 newborns, systemic responses and pupil dilation were monitored. Both 10 percent aqueous and viscous phenylephrine caused blanching around the eyes and produced considerable rise in blood pressure. Dilatation average 4.7 mm. In a double blind study, a 2.5 percent solution caused no skin blanching and no change in pressure or heart rate. Average dilation was 4.5 mm. No blood pressure changes were observed with either one percent cyclopentolate or one percent tropicamide. Average dilatations were 5.0 mm and 5.3 mm respectively. The above agents, used individually for a total dosage of three drops in each eye did not provide adequate dilation for a thorough funduscopic examination. Our protocol at United Hospitals Medical Center is a safe combination of drugs and provides excellent dilatation averaging greater th an 7 mm. No skin blanching or change in heart rate was observed.