Abstract
Purpose: :
To evaluate the differences in tonometry readings in pediatric patients under sevoflurane anesthesia induction with and without glaucoma using three different tonometers.
Methods: :
Intraocular pressure was measured in random order with three different tonometers: TonoPen XL, Perkins, and Schiotz in pediatric patients for evaluation due to glaucoma or other procedures (nasolacrimal probe, strabismus surgery). IOP was measured under spontaneous ventilation (no relaxed patient). Ultrasonic pachymetry was recorded in all cases. A coefficient of variance <5% was used for Tonopen measures and 5,5 grams for Schiotz tonometer. The right eye was the first one to be evaluated.
Results: :
15 patients without glaucoma and 8 patients with glaucoma (5 aphakic/pseudophakic glaucoma, 2 congenital glaucoma and 1 aniridia glaucoma) were included. Average age 4.2±3,4 and 5.5±3.6 years respectively.No statistical difference was found in basal pachymetry between rigth eye (OD) 578±52 vs 585±105 and left eye (OS) 597±54 vs 639±84, in patients without or with glucoma, respectively.IOP between patients without and with glaucoma was statistically significant (p<0.01). The highest IOP readings were obtained using TonoPen in both groups (p<0.01), and the lowest ones with Schiotz tonometer (p< 0.01).The IOP readings were different with TonoPen vs Perkins or Schiotz (p< 0.01), but not between Perkins vs Schiotz. There was a statistical significance in all tonometers when a comparison between patients with pachymetry >600µm vs <600 µm was made (Tonopen>Perkins>Schiotz).
Conclusions: :
In pediatric patients with or without glaucoma, intraocular pressure readings were higher with Tonopen vs Perkins or Schiotz, and there was no statistical difference between Perkins vs Schiotz.
Keywords: intraocular pressure