OBJECTIVE: The purpose of the study was to determine the accuracy of applanation tonometry, pneumatonometry, and TonoPen tonometry in adults and children and the effect of age on tonometer error. DESIGN: The design was divided into four parts: part 1 was prospective and cross-sectional, and parts 2 through 4 were prospective, cross-sectional, and masked. PARTICIPANTS: This study contained 72 patients representing 74 data points. INTERVENTION: Tonometry with simultaneous manometry was performed. MAIN OUTCOME MEASURES: Intraocular pressure (i.o.p.) and the tonometric estimate of IOP were obtained. RESULTS: The normal pediatric IOP follows the line Ta = 0.71 age(years) + 10 up to age 10. Applanation tonometry under anesthesia differs from pneumatonometry by an average of -8.6 mmHg and is age related by the equation Ta = Tpn + 2.6 log(age) - 10.3. The TonoPen was the most accurate instrument for enucleated eyes, and the pneumatonometer was the most accurate in anesthetized living eyes. CONCLUSIONS: Applanation tonometry markedly underestimated IOP in young eyes. TonoPen tonometry performed well with enucleated eyes but was not adequately accurate for clinical use. The pneumatonometer performed the best clinically and the best overall.
OBJECTIVE: The purpose of the study was to determine the accuracy of applanation tonometry, pneumatonometry, and TonoPen tonometry in adults and children and the effect of age on tonometer error. DESIGN: The design was divided into four parts: part 1 was prospective and cross-sectional, and parts 2 through 4 were prospective, cross-sectional, and masked. PARTICIPANTS: This study contained 72 patients representing 74 data points. INTERVENTION: Tonometry with simultaneous manometry was performed. MAIN OUTCOME MEASURES: Intraocular pressure (i.o.p.) and the tonometric estimate of IOP were obtained. RESULTS: The normal pediatric IOP follows the line Ta = 0.71 age(years) + 10 up to age 10. Applanation tonometry under anesthesia differs from pneumatonometry by an average of -8.6 mmHg and is age related by the equation Ta = Tpn + 2.6 log(age) - 10.3. The TonoPen was the most accurate instrument for enucleated eyes, and the pneumatonometer was the most accurate in anesthetized living eyes. CONCLUSIONS: Applanation tonometry markedly underestimated IOP in young eyes. TonoPen tonometry performed well with enucleated eyes but was not adequately accurate for clinical use. The pneumatonometer performed the best clinically and the best overall.
Authors: P-A Tonnu; T Ho; T Newson; A El Sheikh; K Sharma; E White; C Bunce; D Garway-Heath Journal: Br J Ophthalmol Date: 2005-07 Impact factor: 4.638
Authors: Per Hallberg; Anders Eklund; Kenneth Santala; Timo Koskela; Olof Lindahl; Christina Lindén Journal: Med Biol Eng Comput Date: 2006-07-26 Impact factor: 2.602
Authors: Gauti Jóhannesson; Christina Lindén; Anders Eklund; Anders Behndig; Per Hallberg Journal: Graefes Arch Clin Exp Ophthalmol Date: 2014-07-17 Impact factor: 3.117
Authors: J M González-Méijome; J Jorge; A Queirós; P Fernandes; R Montés-Micó; J B Almeida; M A Parafita Journal: Br J Ophthalmol Date: 2006-08-02 Impact factor: 4.638