Intraocular Pressure Measurement for Glaucoma

Overseen By Julie Mauger, BSc

Age: 18+

Sex: Any

Trial Phase: Academic

Sponsor: CHU de Quebec-Universite Laval

Disqualifiers: Corneal dystrophy, Corneal surgery, others

No Placebo Group All trial participants will receive the active study treatment (no placebo)

Compensation: Varies

Number of Visits: 1

67 Participants Needed

What You Need to Know Before You Apply

What is the purpose of this trial?

This trial evaluates the accuracy of two new tools for measuring eye pressure after glaucoma surgery, compared to the usual method, Goldmann Applanation Tonometry. The researchers aim to determine if these tools can reliably measure intraocular pressure, which is crucial to control after surgery. Candidates include those who have recently undergone eye surgery for conditions like glaucoma and do not have specific corneal issues. Participants will have their eye pressure measured by three different tools the day after surgery. As an unphased trial, this study allows patients to contribute to research that could enhance post-surgery care for glaucoma.

Will I have to stop taking my current medications?

The trial information does not specify whether you need to stop taking your current medications.

What prior data suggests that these intraocular pressure-measuring instruments are safe for use post-surgery?

Research shows that tools like iCare and Accupen, used to measure eye pressure, are generally safe and easy for patients to handle. Studies have found that iCare's method, called rebound tonometry, accurately tracks changes over time, making it reliable and safe. Additionally, Goldmann applanation tonometry (GAT), regarded as the best method for these measurements, has been trusted for its accuracy and used safely for many years.

Trials and studies have reported no significant harm or discomfort from using these tools. Overall, these instruments are considered safe for patients, including those who have undergone eye surgery. ^{1 2 3 4 5}

Why are researchers excited about this trial?

Researchers are excited about this trial because it explores a new method for measuring intraocular pressure (IOP) in glaucoma patients. Unlike traditional methods that can be invasive or uncomfortable, this new approach could offer a more patient-friendly experience. The goal is to provide more accurate and consistent readings, which is critical for managing and treating glaucoma effectively. By enhancing the precision of IOP measurement, this method could lead to better treatment outcomes and improved quality of life for those affected by glaucoma.

What evidence suggests that these intraocular pressure measurement methods are effective for glaucoma?

Studies have shown that the iCare tonometer effectively measures eye pressure, especially over time. It provides accurate readings, which is crucial for monitoring eye health. Goldmann applanation tonometry (GAT) is considered the best method for these measurements due to its high accuracy and reliability. Some research suggests that iCare's method might be more reliable than others for detecting changes in eye pressure. Prospective trial participants should know that both iCare and GAT are trusted tools in eye care. ^{2 3 6 7 8}

Who Is on the Research Team?

Mathieu Caissie, MD

Principal Investigator

CHU de Québec - Université Laval

Imad E Hachem, MD

Principal Investigator

CHU de Québec - Université Laval

Are You a Good Fit for This Trial?

This trial is for individuals who have undergone vitreoretinal surgery and need their intraocular pressure (IOP) measured the following day. The study aims to include participants who can safely undergo IOP measurements with different instruments.

Inclusion Criteria

I have had eye surgery on the retina.

Exclusion Criteria

I have not had corneal surgery in the last 6 months.

I have been diagnosed with corneal dystrophy.

I have had a scleral buckle procedure.

Timeline for a Trial Participant

Screening

Participants are screened for eligibility to participate in the trial

1-2 weeks

Post-operative Measurement

Participants have their intraocular pressure measured by Goldmann applanation tonometry, Icare, and Accupen one day after vitreo-retinal surgery

1 day

1 visit (in-person)

Follow-up

Participants are monitored for safety and effectiveness after the post-operative measurement

2-4 weeks

What Are the Treatments Tested in This Trial?

Interventions

• Intraocular pressure measure

Trial Overview The study is testing the accuracy of two IOP-measuring devices, Icare and Accupen, against the gold standard Goldmann applanation tonometry (GAT), after eye surgery. Participants will have their IOP checked by all three methods one day post-operation.

How Is the Trial Designed?

Group I: Intraocular pressure measure Experimental Treatment 1 Intervention

Who Is Running the Clinical Trial?

CHU de Quebec-Universite Laval

Lead Sponsor

Trials

177

Recruited

110,000+

Published Research Related to This Trial

In a study involving 101 eyes from participants with glaucoma or glaucoma suspect, the iCare PRO and iCare IC200 tonometers showed good agreement with the Goldmann applanation tonometer (GAT) in measuring intraocular pressure (IOP), with an intraclass correlation coefficient (ICC) of 0.95 between the iCare devices.

However, both iCare tonometers consistently underestimated IOP by about 2 mm Hg compared to the GAT, while participants reported that the iCare tonometers were more comfortable to use than the GAT.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Comparison of intraocular pressure measured by iCare tonometers and Goldmann applanation tonometer. Sachdeva, R., Iordanous, Y., Lin, T.[2023]

The ICare® tonometer provides slightly higher intraocular pressure (IOP) readings compared to the Goldmann applanation tonometer (GAT), with a bias of 0.78 mmHg, which is not clinically significant, making it a reliable alternative for measuring IOP.

With a sensitivity of 90% and specificity of 95%, the ICare® tonometer is effective in identifying patients with elevated IOP (21 mmHg or more) and can be used by nonophthalmologists for screening, especially in settings where GAT is unavailable.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Validity and limits of the rebound tonometer (ICare®): clinical study. Scuderi, GL., Cascone, NC., Regine, F., et al.[2019]

The iCare rebound tonometer provides measurements of intraocular pressure (IOP) that are generally comparable to the Goldmann applanation tonometer (GAT) in low to moderate IOP ranges (7-22 mmHg), with 62.7% of measurements within +/-3 mmHg of GAT results.

However, in higher IOP ranges (23-60 mmHg), the iCare tonometer showed greater deviation from GAT measurements, indicating it may not be as reliable for high IOP values, although it was well tolerated by all patients with no reported discomfort.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Comparison of the iCare rebound tonometer and the Goldmann applanation tonometer over a wide IOP range. Munkwitz, S., Elkarmouty, A., Hoffmann, EM., et al.[2018]

In a study of 83 eyes from 55 subjects, the Schiotz tonometer provided the closest agreement to the Goldmann applanation tonometer (GAT) for measuring intraocular pressure (IOP), with a mean underestimation of -1.21 mm Hg.

The ICare and ICare PRO tonometers significantly overestimated GAT IOP, indicating that while Schiotz is more reliable, the predictive model developed from Schiotz readings could help estimate GAT IOP in eyes with scarred or prosthetic corneas.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Schiotz Scleral Intraocular Pressure Readings Predict Goldmann Applanation Readings Better Than Rebound Tonometry. Senthil, S., Chary, R., Ali, MH., et al.[2019]

The ICare rebound tonometer (ICT) shows good agreement with the Goldmann applanation tonometer (GAT) for measuring intraocular pressure (IOP), with 80% of patients having a difference of 2 mmHg or less when measured by experienced tonometrists.

ICT is user-friendly and portable, making it suitable for inexperienced operators, and its accuracy suggests it could be a valuable tool for healthcare workers with limited experience in ophthalmology.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Comparison of the ICare rebound tonometer with the Goldmann applanation tonometer by experienced and inexperienced tonometrists. Abraham, LM., Epasinghe, NC., Selva, D., et al.[2022]

The iCare ic100 tonometer measures intraocular pressure (IOP) effectively, showing a mean IOP of 13.8 mmHg compared to 12.5 mmHg with the conventional TA01i device, indicating that the ic100 tends to report higher values.

The study involved 149 participants and demonstrated a good agreement between the two devices, suggesting that the ic100 is reliable for IOP measurement in large cohort studies, although central corneal thickness (CCT) may affect the readings.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Correlation of iCare ic100 tonometry with iCare TA01i in screening of unselected population in Northern Finland Birth Cohort Eye study. Liinamaa, MJ., Stoor, K., Leiviskä, I., et al.[2022]

The Icare ic200 tonometer tends to overestimate intraocular pressure (IOP) compared to the Goldmann Applanation Tonometer (GAT), with a mean difference of -1.27 mmHg, indicating that Icare readings are generally higher.

Despite the overestimation, the Icare ic200 shows good agreement with GAT measurements, especially for IOP values below 21 mmHg, making it a reliable alternative for measuring IOP in that range.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Agreement of Intraocular Pressure Measurement of Icare ic200 with Goldmann Applanation Tonometer in Adult Eyes with Normal Cornea. Badakere, SV., Chary, R., Choudhari, NS., et al.[2021]

Icare ONE tonometry is a reliable method for measuring intraocular pressure (IOP) in children, showing a mean difference of only 3.3 mm Hg compared to the Goldmann applanation method, with 68% of measurements within 3 mm Hg of the Goldmann results.

The study found that IOP measurements using Icare ONE tended to decrease with repeated use, suggesting that the device may help children relax during testing, and 98% of parents found it easy to learn how to use the device.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Icare ONE rebound versus Goldmann applanation tonometry in children with known or suspected glaucoma. Gandhi, NG., Prakalapakorn, SG., El-Dairi, MA., et al.[2015]

The Icare ic200 tonometer tends to overestimate intraocular pressure (IOP) compared to the Goldmann Applanation Tonometer (GAT), with a mean difference of -1.27 mmHg, indicating that Icare readings are generally higher.

Despite the overestimation, the Icare ic200 shows good agreement with GAT measurements, especially for IOP values below 21 mmHg, making it a reliable alternative for measuring IOP in that range.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Agreement of Intraocular Pressure Measurement of Icare ic200 with Goldmann Applanation Tonometer in Adult Eyes with Normal Cornea. Badakere, SV., Chary, R., Choudhari, NS., et al.[2021]

The ICare rebound tonometer shows a statistically significant difference in intraocular pressure (IOP) measurements compared to the Goldmann applanation tonometer, with an average overestimation of 1.34 mmHg.

Despite the overestimation, the ICare tonometer can be a useful screening tool, providing IOP estimates within +/-3.00 mmHg of the Goldmann tonometer in over 80% of cases, making it suitable for situations where the Goldmann method is not feasible.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Comparison of the ICare rebound tonometer with the Goldmann tonometer in a normal population. Fernandes, P., Díaz-Rey, JA., Queirós, A., et al.[2022]

The Icare PRO rebound tonometer showed a good correlation with the Goldmann applanation tonometry (GAT) in measuring intraocular pressure (IOP) in a study involving 172 eyes from 86 subjects, indicating its reliability as a measurement tool.

While Icare PRO recorded slightly higher IOP values compared to GAT, the differences were consistent across various factors like central corneal thickness and age, suggesting that Icare PRO could serve as an effective alternative or screening tool for IOP measurement.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Comparison of the new rebound tonometer with Goldmann applanation tonometer in a clinical setting. Kim, KN., Jeoung, JW., Park, KH., et al.[2022]

Citations

1. sciencedirect.com sciencedirect.com/science/article/abs/pii/S0002939425005458

Effectiveness and Accuracy of iCare HOME tonometer in ... This systematic review evaluates the effectiveness and accuracy of the iCare HOME tonometer for intraocular pressure (IOP) monitoring in ...

2. ajo.com ajo.com/article/S0002-9394(25)00545-8/abstract

Effectiveness and Accuracy of iCare HOME tonometer in ... This systematic review evaluates the effectiveness and accuracy of the iCare HOME tonometer for intraocular pressure (IOP) monitoring in ...

3. pmc.ncbi.nlm.nih.gov pmc.ncbi.nlm.nih.gov/articles/PMC10391371/

Assessment of intraocular pressure measurement between ... All tonometers showed a statistically significant correlation with CCT, but it was observed that the NCT had a stronger correlation (0.4037).

4. icare-world.com icare-world.com/us/rebound-tonometry-offers-excellent-reliability/

Recent scientific publications show that iCare rebound ... iCare's rebound tonometry provides sufficient accuracy regarding absolute IOP and potentially superior reliability when monitoring IOP changes over time.

5. mdpi.com mdpi.com/2077-0383/14/10/3338

Comparison of Intraocular Pressure Measurements with ... Goldmann applanation tonometry (GAT) is widely regarded as the gold standard for IOP measurement in adults due to its high accuracy and reliability [1].

6. pmc.ncbi.nlm.nih.gov pmc.ncbi.nlm.nih.gov/articles/PMC8456330/

How to Measure Intraocular Pressure: An Updated Review of ... Recent studies have shown that the ORA IOPcc values were superior to the GAT IOP measurements in predicting rates of glaucoma progression [53,54]. The CH ...

7. aao.org aao.org/eyenet/article/checking-iop-comparing-icare-and-gat-results

Checking IOP: Comparing iCare and GAT Results Specifically, there were significantly more patients with an IOP difference greater than 3 mm Hg among those with IOP ≥21 mm Hg than among those ...

8. glaucomatoday.com glaucomatoday.com/articles/2024-july-aug/continuous-iop-monitoring

Continuous IOP Monitoring Telemetric non-contact intraocular pressure monitoring with an implanted sensor in patients with glaucoma: long-term safety report and monitoring data. Br J ...