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Comparison of the Icare tonometer and the hand-held goldmann applanation tonometer in pediatric aphakia
Yunping Li1, Luosheng Tang, Manyi Xiao
1Department of Ophthalmology, 2nd Xiangya Hospital, Central South University, Hunan, China.
Insights
The Icare tonometer is well-tolerated by pediatric aphakia patients, though it may overestimate intraocular pressure (IOP) compared to the Perkins tonometer, especially with increased central corneal thickness.
Area of Science:
- Ophthalmology
- Pediatric Ophthalmology
- Medical Devices
Background:
- Congenital cataract surgery can lead to aphakia, necessitating regular intraocular pressure (IOP) monitoring.
- Accurate IOP measurement is crucial for managing glaucoma risk in pediatric aphakic eyes.
- Traditional tonometry methods can be challenging in young children, often requiring sedation.
Purpose of the Study:
- To compare intraocular pressure (IOP) measurements between the Icare tonometer and the hand-held Goldmann applanation tonometer (Perkins tonometer).
- To evaluate the usability and tolerance of the Icare tonometer in children with aphakia post-congenital cataract surgery.
Main Methods:
- A study involving 125 children with aphakia following congenital cataract surgery.
- Patients were divided into younger (3-30 months) and older (31-72 months) age groups.
- IOP, axial length, and central corneal thickness (CCT) were measured; younger children underwent measurements under sedation.
Main Results:
- A strong positive correlation was found between IOP readings from the Icare and Perkins tonometers (r=0.943, P<0.001).
- The 95% limits of agreement ranged from -1.6 to 5.6 mm Hg.
- Icare IOP measurements increased disproportionately with increasing CCT (r=0.408, P<0.001), while axial length showed no correlation with IOP.
Conclusions:
- The Icare tonometer is generally better tolerated in pediatric aphakic patients, particularly under unsedated conditions.
- The Icare tonometer may overestimate IOP compared to the Perkins tonometer.
- The discrepancy between Icare and Perkins IOP measurements increases with greater central corneal thickness.
Purpose:
To compare the intraocular pressure (IOP) measurements obtained by the Icare and the hand-held Goldmann applanation tonometer (also called Perkins) in aphakic children after congenital cataract surgery.
Methods:
We investigated 125 children with aphakia after congenital cataract surgery in this study. A younger group (3 to 30 mo) and an elder group (31 to 72 mo) were divided in those patients by their age. In the younger group, all measurements were performed under sedation using chloral hydrate. Axial length of the eye and central corneal thickness (CCT) were also measured from all patients.
Results:
Significant correlation was found on IOP readings obtained by the Icare and the Perkins tonometers (r=0.943, P<0.001). After establishing a Bland-Altman plot, we found that 95% limit of the agreement between the 2 methods distributed between -1.6 to 5.6 mm Hg. The IOPs recorded from the Icare increased faster than that from the Perkins tonometer with the increase of the CCT thickness; a significant association relationship was found on the IOP difference between the 2 measurements (r=0.408, P<0.001). However, no statistical correlation was identified between the axial length and the IOPs recorded by either tonometer.
Conclusions:
Most of the young patients accepted the Icare tonometer under unsedated conditions. This significant advantage indicated that the Icare tonometer will be overall better tolerated in pediatric aphakia population, although it could overestimate the IOPs compared with the measurements obtained from the Perkins tonometer. Differences in readings between the 2 tonometers become bigger as the CCT increase.
