Does general anesthesia have a clinical impact on intraocular pressure in children?

A Prospective Study of the Effects of General Anesthesia on Intraocular Pressure in Healthy Children

Purpose

To determine the effect of general anesthesia on intraocular pressure (IOP) in children with no intraocular pathology and determine which postanesthetic time point is most predictive of preinduction IOP.

Design

Prospective observational study.

Participants

Children with no intraocular pathology ≤ 18 years scheduled for general anesthesia as part of their routine care followed by a pediatric ophthalmologist at Nanjing Medical University.

Methods

Participants underwent a standardized general anesthetic protocol using a mask induction with sevoflurane and propofol maintenance. Intraocular pressure was measured at the following 7 time points: preinduction (taken in the preoperative area), postinduction minutes 1, 3, and 5, and postairway placement minutes 1, 3, and 5 for a total time period of 10 minutes after induction. A generalized estimating equation was used to evaluate the effect of anesthesia on IOP and the effect of patient factors (age, gender, vital signs, and airway type) on preanesthetic and postanesthetic IOP. An IOP prediction model was developed using the postanesthesia IOP measurements for predicting preinduction IOP.

Main Outcome Measures

Intraocular pressure and change in IOP at prespecified time points.

Results

Eighty-five children were enrolled with a mean ± standard deviation (SD) age of 7.5 ± 2.9 years. Mean ± SD preinduction IOP was 20.1 ± 3.7 mmHg. Overall, IOP was lowest at 3 minutes postinduction, decreased to a mean of 13.4 ± 3.7 mmHg (P < 0.001). After this, IOP rose 5 minutes postinduction to 16.5 ± 4.2 mmHg, which did not reach preinduction IOP levels (P < 0.001). The IOP prediction model showed that combining 1 minute postinduction and 3 minutes postairway was most predictive (R2 = 0.13), whereas 1 minute postairway was least predictive of preinduction IOP (R2 = 0.01).

Conclusions

After the induction of general anesthesia in children, IOP temporarily decreases with a trough at 3 minutes postinduction before increasing and remaining stable just below preinduction levels. Intraocular pressure measurements taken 1 minute after induction with 3 minutes after airway placement are most predictive of preinduction IOP, though predictive value is relatively low.

Financial Disclosures

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

Effective concentration (EC50) of sevoflurane for intraocular pressure measurement in anaesthetised children with glaucoma: A dose-finding study

Background and Aim

Sevoflurane, a preferred anaesthetic for children, exhibits a dose-dependent reduction in intraocular pressure (IOP). However, consensus is lacking regarding optimal end-tidal sevoflurane concentration for safe IOP measurement. This study aimed to identify the concentration at which IOP measurement could be attempted without inducing movements in paediatric patients after inhalational induction.

Methods

Two paediatric groups (1-12 months and 12-36 months) with glaucoma undergoing examination under anaesthesia were recruited. After induction with 8% sevoflurane and 100% oxygen, the first child had an end-tidal sevoflurane concentration maintained at 2% for 4 min, followed by IOP measurement. Success was defined as 'no movement', and subsequent concentrations (adjusted in 0.2% steps) were determined using the Dixon and Massey method based on the previous patient's responses.

Results

The study included 75 children. The effective concentration of sevoflurane causing 'no movement' during IOP measurement in 50% of the study population for successful IOP measurement was 1.98% (95% confidence interval [CI] 1.63, 2.17, P = 0.017) for 1-12 months group and 0.55% (95% CI 0.39, 0.66, P = 0.002) for 12-36 months group. Probit regression analysis yielded effective concentration of sevoflurane causing 'no movement' during IOP measurement in 95% of the study population values of 2.47% (95% CI 2.24, 4.58, P = 0.017) for 1-12 months group and 0.94% (95% CI 0.78, 1.57, P = 0.002) for 12-36 months group.

Conclusion

In paediatric patients, a higher end-tidal sevoflurane concentration of 2% is needed for IOP measurement in 1-12 months age group compared to 0.5% required in 12-36 months age group, achieving success in 50% of the study population.

Comparison of the iCare rebound tonometer and the Perkins applanation tonometer in children under general anesthesia

INTRODUCTION

The goal of the study was to compare Perkins applanation tonometry and iCare rebound tonometry, evaluating their correlation and agreement in a diverse pediatric population under general anaesthesia (GA).

MATERIALS AND METHODS

Children undergoing an eye examination under GA between November 2019 and March 2020 were included. Intraocular pressure (IOP) was measured successively using the Perkins applanation tonometer and the iCare IC200 rebound tonometer. Ultrasonic central pachymetry and axial length were measured.

RESULTS

One hundred and thirty-eight eyes of 72 children were included. The mean age was 2.87years. IOP measurements obtained with the two tonometers were statistically and significantly highly correlated (r=0.8, P<0.001), although the iCare overestimated IOP by an average of 3.37mmHg (SD±4.48). The agreement between the two methods was moderate; the 95% agreement limits ranged from -5.41 to +12.15mmHg (r=0.5, P<0.001). The IOP difference between the two tonometers was weakly but significantly correlated with mean IOP (r=0.52; P=0.006). No correlation was found with axial length and pachymetry.

CONCLUSION

In this study, the IOP values obtained using the Perkins applanation tonometer and the iCare IC200 rebound tonometer were well correlated. The iCare tended to overestimate the IOP, especially for high IOP values. However, no underestimation of IOP was found with this device, hence its potential for glaucoma screening in children.

Effect of anesthetic induction with propofol, alfaxalone or ketamine on intraocular pressure in cats: a randomized masked clinical investigation

OBJECTIVE

To compare the effect of propofol, alfaxalone and ketamine on intraocular pressure (IOP) in cats.

STUDY DESIGN

Prospective, masked, randomized clinical trial.

ANIMALS

A total of 43 ophthalmologically normal cats scheduled to undergo general anesthesia for various procedures.

METHODS

Following baseline IOP measurements using applanation tonometry, anesthesia was induced with propofol (n = 15), alfaxalone (n = 14) or ketamine (n = 14) administered intravenously to effect. Then, midazolam (0.3 mg kg^-1) was administered intravenously and endotracheal intubation was performed without application of topical anesthesia. The IOP was measured following each intervention. Data was analyzed using one-way anova and repeated-measures mixed design with post hoc analysis. A p-value <0.05 was considered significant.

RESULTS

Mean ± standard error IOP at baseline was not different among groups (propofol, 18 ± 0.6; alfaxalone, 18 ± 0.7; ketamine, 17 ± 0.5 mmHg). Following induction of anesthesia, IOP increased significantly compared with baseline in the propofol (20 ± 0.7 mmHg), but not in the alfaxalone (19 ± 0.8 mmHg) or ketamine (16 ± 0.7 mmHg) groups. Midazolam administration resulted in significant decrease from the previous measurement in the alfaxalone group (16 ± 0.7 mmHg), but not in the propofol group (19 ± 0.7 mmHg) or the ketamine (16 ± 0.8 mmHg) group. A further decrease was measured after intubation in the alfaxalone group (15 ± 0.9 mmHg).

CONCLUSIONS AND CLINICAL RELEVANCE

Propofol should be used with caution in cats predisposed to perforation or glaucoma, as any increase in IOP should be avoided.

Intraocular Pressure Measurement in Childhood Glaucoma under Standardized General Anaesthesia: The Prospective EyeBIS Study

Objective: We aimed to compare intraocular pressure (IOP) measurements using iCare® PRO rebound tonometry (iCare) and Perkins applanation tonometry (Perkins) in childhood glaucoma subjects and healthy children and the influence of anaesthesia depth, age and corneal thickness. Material: Prospective clinical, case-control study of children who underwent an ophthalmologic examination under general anaesthesia according to our protocol. Children were 45.45 ± 29.76 months old (mean ± SD (standard deviation)). Of all children, 54.05% were female. IOP was taken three times (T1−T3), according to duration and the depth of anaesthesia. The order of measurement alternated, starting with iCare. Agreement between the device measurements was evaluated using Bland−Altman analysis. Results: 53 glaucoma subjects and 22 healthy controls. Glaucoma subjects: IOP measured with iCare was at T1: 27.2 (18.1−33.8), T2: 21.6 (14.8−30.6), T3: 20.4 mmHg (14.5−27.0) and Perkins 17.5 (12.0−23.0), 15.5 (10.5−20.5), 15.0 mmHg (10.5−21.0) (median ± IQR (interquartile range)). Healthy controls: IOP with iCare: T1: 13.3 (11.1−17.0), T2: 10.6 (8.1−12.4), T3: 9.6 mmHg (7.7−11.7) and Perkins 10.3 (8.0−12.0), 7.0 (5.5−10.5), 7.0 mmHg (5.5−8.5) (median ± IQR). The median IOP was statistically significantly higher with iCare than with Perkins (p < 0.001) in both groups. The mean difference (iCare and Perkins) was 6.0 ± 6.1 mmHg for T1−T3, 7.3 at T1, 6.0 at T2, 4.9 mmHg at T3. Conclusion: The IOP was the highest in glaucoma subjects and healthy children at T1 (under sedation), independently of the measurement method. iCare always leads to higher IOP compared to Perkins in glaucoma and healthy subjects, regardless of the duration of anesthesia.

Childhood glaucoma registry in Germany: initial database, clinical care and research (pilot study)

Objective

The aim of this prospective pilot study is to establish an initial database to register patients diagnosed with different types of childhood glaucoma and the set-up of a national registry for childhood glaucoma (ReCG) in Germany. 28 children with different types of diagnosed childhood glaucoma, who were admitted and treated at the Childhood Glaucoma Center of the University Medical Center Mainz, Germany were included. Main outcome measures were the type of childhood glaucoma, mean intraocular pressure (IOP) and genetic data of the patients.

Results

The documents and questionnaires for each individual included: informed consent form of the parents, medical history form of the child, patient’s gestational history questionnaire and general anesthesia examination form. Primary congenital and secondary childhood glaucoma were revealed in 11 (39%) and 17 (61%) patients, respectively. The mean IOP measured with Perkins tonometer in all patients under general anesthesia at the time of inclusion was 17.5 ± 11.8 mmHg in the right and 17 ± 8.9 mmHg in the left eyes. In 33% of children with glaucoma mutations in the CYP1B1, FOXC1, LTBP2 and TEK genes were found. The development of specific questionnaires for childhood glaucoma provides detailed baseline data to establish a ReCG in Germany for the first time.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13104-022-05921-8.

Anaesthetic protocol for paediatric glaucoma examinations: the prospective EyeBIS Study protocol

INTRODUCTION

Neonates and young infants with diagnosed or highly suspected glaucoma require an examination under anaesthesia to achieve accurate intraocular pressure (IOP) measurements, since crying or squinting of the eyes may increase IOP and lead to falsely high values. IOP considerably depends on perioperative variables such as haemodynamic factors, anaesthetics, depth of anaesthesia and airway management. The aim of this paper is to report the design and baseline characteristics of EyeBIS, which is a study to develop a standardised anaesthetic protocol for the measurement of IOP under anaesthesia in childhood glaucoma, by investigating the link between the magnitude of IOP and depth of anaesthesia.

METHODS AND ANALYSIS

This is a single-centre, prospective cohort study in 100 children with diagnosed or highly suspected glaucoma all undergoing ophthalmological examination under general anaesthesia. 20 children, who undergo general anaesthesia for other reasons, are included as controls. The primary outcome measure is the establishment of a standardised anaesthetic protocol for IOP measurement in childhood glaucoma by assessing the relationship between IOP and depth of anaesthesia (calculated as an electroencephalography variable, the bispectral index), with special emphasis on airway management and haemodynamic parameters. The dependence of IOP under anaesthesia on airway management and haemodynamic parameters will be described, using a mixed linear model. Restricting the model to patients with healthy eyes will allow to determine a 95% reference region, in which 95% of the measurement values of patients with healthy eyes can be expected.

ETHICS AND DISSEMINATION

The study has been approved by the local ethics committee of the Medical Association of Rhineland-Palatine (Ethik-Kommisssion der Landesaerztekammer Rheinland-Pfalz), Germany (approval number: 2019-14207). This work will be disseminated by publication of peer-reviewed manuscripts, presentation in abstract form at national and international scientific meetings and data sharing with other investigators.

TRIAL REGISTRATION NUMBER

ClinicalTrials.gov Registry (NCT03972852).

A PRELIMINARY STUDY OF INTRINSIC AND EXTRINSIC FACTORS INFLUENCING INTRAOCULAR PRESSURE IN BROOK TROUT (SALVELINUS FONTINALIS)

Reference intervals of intraocular pressure (IOP) are poorly described in piscine species as the factors that may influence it. Rebound tonometry was used to measure IOP in 28 adult brook trout (Salvelinus fontinalis) anesthetized in a buffered solution of 60 mg/L tricaine methanesulfonate (n = 16) or restrained with electronarcosis (n = 12) at 16 mA. There was no significant effect of the eye side, sex, fish origin, and body weight, but IOP values were significantly higher with electronarcosis (mean ± SD: 16.4 ± 5.0 mm Hg) than with immersion anesthesia (10.8 ± 3.3 mm Hg; P = 0.0017). The same restraint method should be used for comparison with previously published IOP values or when evaluating individual variations over time.

Comparison of endotracheal intubation, laryngeal mask airway, and I-gel in children undergoing strabismus surgery

Background

Insertion of the advanced airway during induction of general anesthesia can cause undesirable sympathetic stimulation such as increased intraocular pressure (IOP) and hemodynamic parameters. In this study, we compared insertion of three different advanced airway devices; endotracheal tube (ETT), laryngeal mask airway (LMA) and I-gel in terms of IOP, hemodynamic changes and postoperative nausea and vomiting (PONV) following induction of general anesthesia with propofol and remifentanil in children undergoing strabismus surgery.

Materials and Methods

A total of 90 children (5.68 ± 1.49 years old) were randomly assigned to one of the three groups, ETT, LMA, or I-gel insertion as advanced airway devices IOP and also hemodynamic variables were measured before (T0 and T1) and immediately after (T2) the insertion of these airway devices, although 2 min (T3) and 5 min (T4) after it. PONV was assessed about 2 h after the completion of surgery in the recovery room.

Results

The mean arterial pressure (MAP), IOP, and systolic and diastolic blood pressures were significantly different between the three groups immediately (T2), 2 min (T3), and 5 min (T4) after the insertion of airway devices. The heart rate (HR) was significantly different between the three groups in all measurement times except of T0. Within-group comparisons showed that the three groups had significant changes in MAP, IOP, HR, systolic and diastolic pressure before and after airway insertion (T1 and T2). The trend in the LMA and ETT groups was descending-ascending-descending, whereas in the I-gel group, it was quite descending. There was no significant difference among the three groups in terms of PONV.

Conclusion

As a result, our study showed that, compared with LMA and ETT, the I-gel had less impact on undesirable stress responses and seems to be superior to LMA and ETT in children undergoing strabismus surgery.

Outcome, influence factor and development of CLS measurement in continuous IOP monitoring: A narrative review

A large fluctuation in intraocular pressure (IOP) and a high peak IOP remain the risk factors for progressive visual field loss in patients with glaucoma, which is a leading cause of irreversible blindness. However, IOP measurements during working time cannot provide sufficient information on IOP to guide clinicians in setting IOP target values. Contact lenses are extensively used in ophthalmology to correct the refractive error, and recently, they are serving as platforms for detection and drug delivery. Contact lens sensor (CLS) is a feasible and promising approach to continuously monitor IOP, with superior tolerance, non-invasiveness, and without sleep disturbance. The present work reviewed the associations between progressive course and Triggerfish® CLS outputs as well as the relationship between treatments and Triggerfish® CLS outputs. Moreover, it further summarized state-of-the-art CLS devices of the past decade.

Effect of general anaesthesia on intraocular pressure in paediatric patients: a systematic review

OBJECTIVES

Assessment of the impact of general anaesthetic agents on intraocular pressure (IOP) in children via systematic review.

METHODS

Pubmed, Embase, and CENTRAL databases were systematically searched to identify randomised controlled trials, prospective, and interventional studies. The search included all studies through October 5, 2018 with no date or language restrictions. A linear mixed-effects regression analysis was performed to study the change in IOP after general anaesthesia (GA).

RESULTS

The strategy identified 518 studies that met search criteria. Six studies (531 eyes) were included for quantitative synthesis. Seven categories of mixed and non-mixed induction and maintenance agents were compared. When assessing all agents utilising a model of mean IOP as a function of time, IOP decreased after induction phase at a rate of -0.59 ± 0.19 mmHg/min (P value = 0.006).

CONCLUSIONS

This systematic review showed that most anaesthetic agents significantly decrease IOP over time after the induction phase of general anaesthesia in children. An understanding of the effects of GA on IOP is critical for those performing paediatric ophthalmic examinations under anaesthesia.

[360° trabeculotomy for pediatric glaucoma]

Congenital glaucoma disease leads to blindness if left untreated. It is estimated that 1 child in 10,000 in Germany is born with congenital glaucoma. In adults the disease develops slowly and insidiously, whereas congenital glaucoma leads to a rapid growth of the eye (buphthalmos) mostly directly after birth due to a very high intraocular pressure. The cause is dysgenesis of the iridocorneal angle. Successful operative treatment of congenital glaucoma is possible in the majority of cases (approximately 80-90%). The treatment of childhood glaucoma is primarily surgical. Since 1960 classical probe trabeculotomy has been the most commonly used procedure, which has the advantage that unlike goniotomy, it can also be performed in cases with clouding of the cornea. In this surgery the canal of Schlemm is probed and the inner wall as well as the trabecular meshwork is opened inwardly over approximately 120°. In recent years the 360° trabeculotomy procedure has become established, in which an illuminated catheter filled with viscoelastic material is used (as with conventional canaloplasty) to dilate the canal of Schlemm. The trabecular meshwork is then inwardly opened by pulling on the ends of the catheter. The results of this method are explained in this article.

Icare-Pro Rebound Tonometer Versus Hand-held Applanation Tonometer for Pediatric Screening

PURPOSE

To compare intraocular pressure (IOP) measurements obtained using the new rebound tonometer Icare-Pro (Icare, Tiolat Oy, Helsinki, Finland) and the hand-held version of the Goldmann applanation tonometer (Perkins; Clement Clarke, Haag-Streit, Harlow, United Kingdom) in healthy children during clinical practice.

METHODS

In this prospective study, three IOP measurements were made using each tonometer in a single session, starting with the Icare-Pro. Participants were 173 non-anesthetized patients aged 1 to 16 years. Measurements were made in both eyes but only data for the right eye were entered in the analysis. Central corneal thickness, anterior chamber depth, and axial length were also measured in each patient. Data were compared by determining interclass correlation coefficients (ICCs) for each tonometer and representing the differences detected as Bland-Altman plots.

RESULTS

Good linear correlation was observed between IOP readings obtained using the Perkins and Icare-Pro tonometers (r = 0.87, P < .001), although the Icare-Pro readings were slightly higher (mean IOP difference: 0.26 ± 1.58 mm Hg, P = .037). The 95% limits of agreement between the two methods were 2.8 to -3.4 mm Hg. The ICC was 0.857 (95% confidence interval: 0.810 to 0.893), indicating good agreement. For both tonometers, a low but significant correlation was detected between IOP and central corneal thickness or age. However, no correlation of IOP was found with axial length or anterior chamber depth.

CONCLUSIONS

Pediatric IOP measurements determined using the new Icare-Pro rebound tonometer showed good correlation with those obtained using the hand-held Perkins applanation tonometer in a routine clinical examination with no need for general anesthesia. [J Pediatr Ophthalmol Strabismus. 2018;55(6):382-386.].

Résultats pressionnels et visuels à long terme de la sclérectomie profonde dans le glaucome congénital primitif

OBJECTIVE

To estimate long term future of pressure and vision of children who underwent DS for CPG.

MATERIAL AND METHODS

Children affected by CPG, aged from 1 day to 3 years at the time of the diagnosis were retrospectively included between 1999 and 2014. All benefited from a DS with use of antimetabolites. Preoperative and long-term post-operative intraocular pressures (IOP), per and postoperative complications as well as visual acuity and refractive status were estimated. Complete IOP control was defined by a postoperative IOP ≤16 mmHg without medical treatment.

RESULTS

141 eyes of 71 children were included (sex ratio: 1.02). Mean follow-up was 56.6 ±9.6 months. Final average IOP among the whole sample was 11.3 +/-7 mmHg. The rate of total success was 69.4 %, partial success 27.6 % and 3 % failure at the last check. No complications were seen in 85.1 % of cases (n=120 eyes). Among 37 children analyzed for visual acuity, maintained visual acuity was found in 50 % of cases (n= 37 eyes).

CONCLUSION

DS allows obtaining good IOP control with a very low rate of complications, and should be considered as a technique of choice in the surgical management of CPG. This study is of particular relevance because it has been led on a long term period and on an important staff considering the rare prevalence of the condition.