Reboundtonometrie und Applanationstonometrie während einer Narkoseuntersuchung beim kindlichen Glaukom

Posture-related fluctuations of intraocular pressure in healthy children with suspicion of glaucoma

PURPOSE

Currently, there are no specific data on the circadian course of intraocular pressure (IOP) in children, especially for IOP measurements in the supine position. The study aimed to characterize the diurnal and nocturnal IOP fluctuations in supine and sitting positions in patients less than 18 years of age.

METHODS

Seventy-nine eyes of 79 patients under 18 years of age with suspicious optic nerve heads or ocular hypertension could be included in this study. All included patients showed an inconspicuous retinal nerve fiber layer thickness and Bruch's membrane minimum rim width by coherence tomography. IOP measurements during the 24-h IOP profile were retrospectively evaluated. Measurements were taken at 10:00, 16:00, 20:00, and 23:00 h in the sitting position and at 6:00 h in the morning in the supine position using iCare rebound tonometry on 2 consecutive days.

RESULTS

Thirty-four of 79 children (43.0%) had peak nocturnal IOP values > 25 mmHg. The mean daily IOP was 18.8 ± 5.6 mmHg, and the mean daily fluctuation was 6.1 ± 4.0 mmHg. At 6 am, supine measurements were elevated to 25.1 ± 8.0 mmHg. Extensive fluctuations with values > 40 mmHg in the nocturnal supine measurement occurred in a relevant share of patients (n = 5).

CONCLUSION

There appear to be relevant diurnal and nocturnal IOP fluctuations in healthy children (< 18 years). Nocturnal IOP measurements in supine patients with risk factors for glaucoma may provide important additional information to identify critical patients for further follow-up.

Neck Extension and Intraocular Pressure Elevation During Palatoplasty in a Patient with Patau Syndrome and Congenital Glaucoma: A Case Report

Patau syndrome (trisomy 13) is a severe disorder associated with multiple systemic defects. Patau syndrome is commonly associated with ocular abnormalities but rarely associated with congenital glaucoma. To obtain a better surgical view, palatoplasty requires neck extension during surgery. The intraocular pressure (IOP) of patients with Patau syndrome can increase owing to the neck extension position while undergoing palatoplasty, particularly in those with congenital glaucoma. Here, we describe a case with increased IOP measured using a rebound tonometer during palatoplasty in a pediatric patient with Patau syndrome and congenital glaucoma. This case shows that it may be important to reduce the degree of neck extension and shorten the operation time to minimize any increase in the IOP during palatoplasty in pediatric patients with Patau syndrome accompanied by congenital glaucoma.

Effect of Chloral Hydrate Sedation on Intraocular Pressure in a Pediatric Population

PURPOSE

To determine the effect of oral chloral hydrate (CH) sedation on intraocular pressure (IOP) in an outpatient pediatric population.

DESIGN

Prospective, noncomparative case series.

METHODS

Children aged 1 month to 5 years undergoing CH sedation for ocular imaging/evaluation at a tertiary eye hospital were included. IOP was measured using an Icare tonometer prior to sedation (in some, not all), at 25 minutes after sedation, and then every 10 minutes until sedation completion. Change in IOP over time was assessed using mixed model linear regression to account for correlation of IOP readings.

RESULTS

A total of 112 children were enrolled, 50.9% were female, and mean age was 2.1 (standard deviation [SD]: 1.3) years. Of the total, 83 (74.1%) participants had IOP measurement attempted prior to sedation, with 64 having presedation IOP completed. Among those completing presedation IOP, 46.9% were asleep/calm, and the rest (53.1%) were slightly/more distressed (IOP did not differ by level of agitation). Those with and without presedation IOP available had similar demographics and health status (P > .05). Heart rate, respiratory rate, and oxygen saturation all declined after sedation (P < .001). The mean dose of CH administered was 80.9 (SD: 13.2) mg/kg, and sedation was deemed "adequate" in 97.3% after a single dose. Mean IOP among those with presedation IOP was 19.5 mm Hg and, although not significant, declined to 18.7 mm Hg at 25 minutes (P = .12). There was no trend toward further decline in IOP over time (P > .05).

CONCLUSIONS

CH sedation for outpatient pediatric ophthalmic procedures as administered in this prospective assessment had no impact on IOP.

Agreement profiles for rebound and applanation tonometry in normal and glaucomatous children

Objectives:

To investigate agreement between intraocular pressure measurements by the rebound tonometer and handheld Perkins applanation tonometer in children with and without primary congenital glaucoma and test agreement with intraocular pressure and age variations.

Materials and methods:

A prospective non-interventional comparative study done on 223 eyes of 115 children, 161 normal eyes, and 62 eyes with primary congenital glaucoma. Intraocular pressure measurements were obtained in the upright position by rebound tonometer first, followed by installation of topical anesthetic eye drops (benoxinate), then measured by Perkins applanation tonometer.

Results:

For all eyes, mean difference between Perkins applanation tonometer and rebound tonometer was −0.59 ± 2.59 mmHg, p = 0.001. Regression analysis with (r) = 0.9, (r2) = 0.79, and p < 0.001. In primary congenital glaucoma: there was a mean difference of −.79 ± 2.82 (p = 0.032), a good correlation with (r) = 0.94, (r2) = 0.87%, and 95% level of agreement: –6.34 to +4.76. In normal eyes: mean difference was −.52 ± 2.5 (p = 0.01), correlation: (r) = 0.8, (r2) = 0.64, and p = 0.001. The 95% level of agreement −5.41 and +4.36 mmHg. In intraocular pressure ⩽ 15 mmHg: mean difference −0.89 ± 2.15 mmHg, 95% level of agreement between −5.1 and +3.32 mmHg, p < 0.001. In intraocular pressure >15 mmHg: mean difference was 0.04 ± 3.28 mmHg, 95% level of agreement −6.38 and +6.46 mmHg, p = 0.914.

Conclusion:

There is a good correlation between rebound tonometer and Perkins applanation tonometer in children with and without primary congenital glaucoma; however, rebound tonometer overestimates the intraocular pressure, and in intraocular pressure >15 mmHg there is less agreement between the two devices. Hence, in higher intraocular pressure measurement caution should be taken when interpreting rebound tonometer readings, and a confirmatory measurement using Perkins applanation tonometer is advised.

Effect of anesthesia on intraocular pressure measurement in children

Measurement of the intraocular pressure (IOP) is central to the diagnosis and management of pediatric glaucoma. An examination under anesthesia is often necessary in pediatric patients. Different agents used for sedation or general anesthesia have varied effects on IOP. Hemodynamic factors, methods of airway management, tonometry technique, and body positioning can all affect IOP measurements. The most accurate technique is one that reflects the awake IOP. We review factors affecting IOP measurements in the pediatric population and provide recommendations on the most accurate means to measure IOP under anesthesia based on the present literature.

Features of measurement of intraocular pressure in children

This review discusses the results of various studies conducted in recent years on the comparison of modern methods of measuring intraocular pressure (IOP) in children: pneumotonometry, Maklakov applanation tonometry, and tonometry using Perkins tonometer, Goldmann tonometer, Icare tonometer, Ocular Response Analyzer, TonoPen handheld tonometer, transpalpebral tonometer TIOP01, or a dynamic contour Pascal tonometer. This study discusses the advantages and disadvantages of different methods of measurement of IOP in children, including the evaluation of patients with fibrous lens capsules that might affect the measurement of IOP and an analysis of the characteristics of evaluation of IOP in children with congenital glaucoma.

Comparison of Intraocular Pressure Measurements Obtained by Rebound, Noncontact, and Goldmann Applanation Tonometry in Children

PURPOSE

To compare intraocular pressure (IOP) among rebound, noncontact, and Goldmann applanation tonometry (GAT) and their relationships to central corneal thickness in children.

DESIGN

Diagnostic protocol comparison and evaluation.

METHODS

In right eyes of 419 children, mean IOP, rates of successful measurement with 3 tonometries, and intermethod agreement by Bland-Altman plot were assessed. The influences of central corneal thickness, and of average IOP of 3 tonometries on IOP differences between tonometries, were evaluated.

RESULTS

The mean age was 8.89 ± 3.41 years (3-15 years). There was significant difference in mean IOP of each tonometry; GAT showed the lowest values (P < .05). The IOP was successfully measured by noncontact tonometry in 89%, by rebound tonometry in 75%, and by GAT in 64% of children less than 10 years old, and in 100%, 98%, and 94% of children older than 10 years, respectively. The IOP of each tonometer positively correlated with central corneal thickness (P < .05). The mean differences and limits of agreement were 0.81 ± 6.19 mm Hg (noncontact minus rebound), 2.56 ± 4.62 mm Hg (rebound minus GAT), and 1.81 ± 4.76 mm Hg (noncontact minus GAT). Rebound and noncontact tonometry overestimated IOP relative to GAT for thicker central corneal thicknesses. Rebound tonometry overestimated IOP relative to GAT and noncontact tonometry at higher average IOP of 3 tonometries.

CONCLUSIONS

Rebound, noncontact, and Goldmann applanation tonometries can be considered appropriate methods for children, though noncontact tonometry is the most accessible. Given the risk of false-positive diagnosis of pediatric glaucoma, attention should be devoted to children with IOP within a suspicious range or thicker cornea.

A comparison of Icare PRO and Tono-Pen XL tonometers in anesthetized children

BACKGROUND

Tonometry in the anesthetized child, vital for evaluating known or suspected glaucoma, remains limited to tonometers capable of supine recording. The Icare PRO measures intraocular pressure (IOP) in the sitting or supine patient. The purpose of this study was to compare Icare PRO and Tono-Pen tonometry during examination under anesthesia in eyes of supine children with normal eyes and glaucoma and/or corneal pathology.

METHODS

In this prospective study of children undergoing examination under anesthesia, IOP was recorded in both eyes with Icare PRO and Tono-Pen immediately after mask anesthesia induction, with instrument order randomized.

RESULTS

A total of 100 eyes of 50 children (median age, 58 months) were included. IOP range was 6-50 mm Hg by Icare PRO and 6-53 mm Hg by Tono-Pen. Mean IOP measured by Tono-Pen (18.9 ± 7.5) was higher than that measured by Icare PRO (16.7 ± 7.1 mm Hg) by 2.2 mm Hg (P < 0.001). The presence of corneal edema was associated with IOP measurements higher by Tono-Pen than by Icare PRO (mean difference, 8.4 mm Hg). When eyes with corneal edema were excluded from analysis, there was no correlation between central corneal thickness and the difference in IOP between the two instruments.

CONCLUSIONS

IOP in eyes of supine children under anesthesia measured approximately 2 mm Hg higher by Tono-Pen than Icare PRO and this difference was greater in eyes with frank corneal edema. Icare PRO may become a valuable tool for tonometry in supine infants and children, but a confirmatory test should be considered in eyes with corneal edema.