This paper aims at providing an up-to-date review of principle and application of various tonometers, and analyzes the new techniques of diurnal IOP monitoring and design of sensor system abroad. Requirements and test methods for GB/T 14710-93.
Equipment Design ; Intraocular Pressure ; Tonometry, Ocular ; instrumentation ; methods

OBJECTIVE: To compare the difference in intraocular pressure (IOP) readings as well as the tolerability between Icare rebound tonometer (Icare RBT) and Goldmann applanation tonometer (GAT), and to evaluate the application of Icare RBT in monitoring the intraocular pressure in children after congenital cataract surgery. METHODS: The IOP was measured with the Icare RBT and GAT respectively in 150 children (262 eyes) after congenital cataract surgery by two experienced ophthalmologists. Correlation and Bland-Altman analysis were used to assess the agreement in IOP readings between the two instruments. The influence of the central corneal thickness (CCT) adjusted for age on IOP readings was analyzed by linear regression analysis. The tolerance of the patients to Icare RBT and GAT measurement were surveyed. RESULTS: The mean age was (44.82 ± 11.56) months in 150 children, including 81 boys and 69 girls. The mean IOP readings by the Icare RBT and GAT were (16.08 ± 5.72) mmHg and (14.17 ± 5.05) mmHg, respectively. The mean difference between the Icare RBT and GAT was (1.91 ± 2.04) mmHg, which was significantly correlated with CCT (r=0.409, P<0.001). The IOP readings by Icare RBT was significantly correlated with that measured by GAT(r= 0.936, P<0.001). The 95% confidence interval of the difference between the two instruments was ?2.10 to 5.91 mmHg. The Icare RBT examination was well tolerated by the children compared to the GAT examination. CONCLUSION The Icare RBT is easy to use and well tolerated by the children after congenital cataract surgery. Compared to GAT, the value measured by the IOPs trends to be overestimated. The difference in readings between the 2 tonometers will magnify with the increase in CCT.
Cataract ; congenital ; Cataract Extraction ; Child, Preschool ; Female ; Humans ; Intraocular Pressure ; Male ; Tonometry, Ocular ; instrumentation

Intraocular pressure detection has a great significance for understanding the status of eye health, prevention and treatment of diseases such as glaucoma. Traditional intraocular pressure detection needs to be held in the hospital. It is not only time-consuming to doctors and patients, but also difficult to achieve 24 hour-continuous detection. Microminiaturization of the intraocular pressure sensor and wearing it as a contact lens, which is convenient, comfortable and noninvasive, can solve this problem because the soft contact lens with an embedded micro fabricated strain gauge allows the measurement of changes in corneal curvature to correlate to variations of intraocular pressure. We fabricated a strain gauge using micro-electron mechanical systems, and integrated with the contact lens made of polydimethylsiloxane (PDMS) using injection molding. The experimental results showed that the sensitivity was 100. 7 µV/µm. When attached to the corneal surface, the average sensitivity of sensor response of intraocular pressure can be 125.8 µV/mm Hg under the ideal condition.
Contact Lenses, Hydrophilic ; Dimethylpolysiloxanes ; Glaucoma ; Humans ; Intraocular Pressure ; Tonometry, Ocular ; instrumentation

The objective of this study was to evaluate and validate the accuracy of the Perkins handheld applanation tonometer for measuring intraocular pressure (IOP) in horses and cattle. Both eyes of 10 adult horses and cattle were evaluated in a postmortem study. The eyes from 10 clinically normal adult horses and cattle were also examined after bilateral auriculopalpebral nerve block and topical anesthesia for an in vivo study. IOP was measured postmortem using direct manometry (measured with an aneroid manometer) and tonometry (measured with a Perkins handheld applanation tonometer). The correlation coefficients (r2 ) for the data from the postmortem manometry and Perkins tonometer study were 0.866 for horses and 0.864 for cattle. In the in vivo study, IOP in horses was 25.1 +/- 2.9 mmHg (range 19.0~30.0 mmHg) as measured by manometry and 23.4 +/- 3.2 mmHg (range 18.6~28.4 mmHg) according to tonometry. In cattle, IOP was found to be 19.7 +/- 1.2 mmHg (range 18.0~22.0 mmHg) by manometry and 18.8 +/- 1.7 mmHg (range 15.9~20.8 mmHg) by tonometry. There was a strong correlation between the IOP values obtained by direct ocular manometry and the tonometer in both horses and cattle. Our results demonstrate that the Perkins handheld tonometer could be an additional tool for accurately measuring IOP in equine and bovine eyes.
Animals ; Cattle/*physiology ; Eye/*physiopathology ; Horses/*physiology ; Intraocular Pressure/*physiology ; Linear Models ; Manometry/instrumentation/veterinary ; Tonometry, Ocular/instrumentation/*veterinary

We evaluated one of the new non-contact tonometers, the Pulsair non-contact tonometer, to assess its accuracy and reliability. Measurements on 101 eyes were used to assess its accuracy against Goldmann tonometry measurements, and another 24 eyes were used to assess its reliability (reproducibility). The results showed the instrument to be highly accurate and reliable in measurement.
Evaluation Studies as Topic ; Female ; Humans ; Intraocular Pressure ; Male ; Ocular Hypertension/diagnosis ; Predictive Value of Tests ; Regression Analysis ; Reproducibility of Results ; Tonometry, Ocular/*instrumentation ; Vision Screening/*methods

PURPOSE: To compare conventional laser peripheral iridotomy (LPI) and LPI combined with laser peripheral iridoplasty in eyes with primary angle closure suspect (PACS) by assessment of anterior chamber dimensional changes using a Pentacam. METHODS: Forty-eight eyes of 24 subjects with bilateral PACS were recruited consecutively. Each eye was randomly allocated to treatment with conventional LPI, argon LPI only, or LPI plus iridoplasty, which consisted of simultaneous argon LPI and peripheral iridoplasty. Anterior chamber measurements were performed on each eye using a Pentacam, both before and after treatment. Mean anterior chamber depth (ACD), anterior chamber volume (ACV), and anterior chamber angle were measured, and topographic ACD analysis was performed. Results were compared between the two treatment groups. RESULTS: After treatment with either conventional LPI or LPI plus iridoplasty, the mean ACD and ACV increased significantly. Topographic ACD analysis revealed that the mid-to-peripheral ACD increase was significantly greater in the LPI plus iridoplasty group than in eyes treated with conventional LPI. Intraocular pressure changes and post-LPI complications did not differ between the groups. CONCLUSIONS: Compared with conventional LPI, our study showed that LPI plus iridoplasty improved the mid-to-peripheral ACD increase. This procedure may have a role as an adjunct for reducing angle closure by simultaneously eliminating pupillary and non-pupillary block components.
Adult ; Aged ; Anterior Chamber/*pathology/surgery ; Diagnostic Techniques, Ophthalmological/*instrumentation ; Equipment Design ; Female ; Follow-Up Studies ; Glaucoma, Angle-Closure/pathology/physiopathology/*surgery ; Gonioscopy ; Humans ; Intraocular Pressure ; Iridectomy/*methods ; Iris/pathology/*surgery ; Laser Therapy/*methods ; Lasers, Solid-State ; Male ; Middle Aged ; Prospective Studies ; Tonometry, Ocular