Features of measurement of intraocular pressure in children

Possibilities of monitoring intraocular pressure in children using EASYTON transpalpebral tonometer

Purpose

To compare the effectiveness of transpalpebral scleral tonometry (TPST) and corneal pneumotonometry in children, and assess the discomfort level when measuring intraocular pressure (IOP) by these methods.

Methods

TPST using EASYTON tonometer (Russia) and pneumotonometry using Reichert 7 Non-contact AutoTonometer (USA) have been sequentially performed on 84 eyes (42 children aged 5–14, ave. 9.3 ± 2.7), including 64 myopic eyes (-0.5 to 6.75D), 18 hyperopic eyes (+ 0.75 to + 3.75D), and 2 emmetropic eyes. We assessed tolerance to the procedure on a five-point scale using a questionnaire which listed several criteria: discomfort, presence of pain, fear or anxiety during the procedure, the child's resistance to measurement.

Results

EASYTON tonometry demonstrated repeatability of IOP indicators when measuring the same eye three times sequentially and almost the same IOP level in paired eyes of isometropic children. Pneumotonometry reveals a greater individual data variability and a more pronounced asymmetry of the paired eyes’ indicators. IOP measured using the TPST was 18.3 ± 2.3 mmHg across the whole group, 18.2 ± 2.3 mmHg in myopic, and 18.5 ± 2.3 mmHg in hyperopic children. With pneumotonometry, the corresponding indicators were 17.1 ± 3.9 mmHg, 16.9 ± 3.8 mmHg, and 18.2 ± 4.0 mmHg. The average score for the TPST (4.64 ± 0.60 points) was significantly higher than that for pneumotonometry (3.85 ± 0.90 points) (p < 0.05).

Conclusions

TPST provides broader possibilities for IOP control in pediatric practice, yielding more reliable and accurate results than pneumotonometry, eliminating the influence of corneal thickness and irregularity on the measurement result, and ensuring a calmer behavior and more comfort of children during the procedure.

[Central corneal thickness and intraocular pressure in children with congenital glaucoma]

Purpose - to determine the values of central corneal thickness (CCT) in children depending on the level of intraocular pressure (IOP) and the stage of congenital glaucoma (CG).

MATERIAL AND METHODS

Clinical studies were carried out in the eye department of the clinic at the Tashkent Pediatric Medical Institute. The study involved 18 patients (36 eyes) aged 9 to 11 years (mean age 9.3±1.6 years) with confirmed diagnosis of CG. All patients underwent basic ophthalmologic examination prior to surgical and conservative treatment. In addition to basic methods, axial eye length and CCT were determined using an automatic non-contact tonometer/pachymeter manufactured by NIDEK (USA).

RESULTS

Analysis of the obtained data showed that in initial, moderate and advanced stages of glaucoma, the CCT values were significantly lower than the age norm values. This indicates stretching of the fibrous capsule and thinning of the cornea in glaucoma. In terminal stage CG, the CCT values practically did not differ from the age norm, but were higher than in initial, moderate and advanced stages of the disease. The noted thickening of the corneal membrane in terminal stage may be explained by edema of the corneal tissue as a result of elevated IOP.

CONCLUSION

The age norm values of CCT should be taken into account when characterizing the severity of glaucomatous process in children. Compared to the age norm, the cornea is significantly thinner in children aged 9 to 11 years with initial, moderate and advanced stages of CG, and becomes significantly thicker in terminal stage, which is associated with edema caused by elevated IOP.