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

Trial Summary

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 data supports the effectiveness of the treatment Intraocular pressure measure, Goldmann Applanation Tonometry, Icare, Accupen for glaucoma?

Research shows that the Icare tonometer, a device used to measure eye pressure, provides results that are in agreement with the Goldmann Applanation Tonometer, which is a standard method for measuring intraocular pressure. This suggests that Icare is effective for monitoring eye pressure in conditions like glaucoma. ^{1 2 3 4 5}

Is intraocular pressure measurement safe for humans?

The studies on intraocular pressure measurement using devices like ICare and Goldmann Applanation Tonometry focus on comparing their accuracy and reliability, but they do not report any safety concerns, suggesting these methods are generally safe for human use. ^{2 6 7 8 9}

How does the treatment for measuring intraocular pressure in glaucoma differ from other treatments?

The treatment for measuring intraocular pressure in glaucoma, using devices like the Goldmann Applanation Tonometry and iCare, is unique because it focuses on accurately measuring eye pressure rather than treating the condition directly. These devices are non-invasive and portable, making them convenient for regular monitoring, unlike other treatments that may involve medication or surgery to manage glaucoma. ^{1 3 4 10 11}

What is the purpose of this trial?

The goal of this prospective controlled study is to measure the reliability of two intraocular pressure (IOP)-measuring instruments in comparison to the gold standard, Goldmann applanation tonometry (GAT) following vitreo-retinal surgery. The main question the current study aims to answer is: are Icare and Accupen as accurate as GAT in measuring IOP one day post eye surgery? Participants in this study will have their IOP measured by the three different instruments one day post-surgery.

Research Team

Mathieu Caissie, MD

Principal Investigator

CHU de Québec - Université Laval

Imad E Hachem, MD

Principal Investigator

CHU de Québec - Université Laval

Eligibility Criteria

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

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

Treatment Details

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.

Participant Groups

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+

Findings from Research

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® 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 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 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]

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 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 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 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]

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]

References

1. United States 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. [2022]

2. United States pubmed.ncbi.nlm.nih.gov

Validity and limits of the rebound tonometer (ICare®): clinical study. [2019]

3. United States pubmed.ncbi.nlm.nih.gov

Agreement of Intraocular Pressure Measurement of Icare ic200 with Goldmann Applanation Tonometer in Adult Eyes with Normal Cornea. [2021]

4. United States pubmed.ncbi.nlm.nih.gov

Agreement of Intraocular Pressure Measurement of Icare ic200 with Goldmann Applanation Tonometer in Adult Eyes with Normal Cornea. [2021]

5. United States pubmed.ncbi.nlm.nih.gov

Icare ONE rebound versus Goldmann applanation tonometry in children with known or suspected glaucoma. [2015]

6. England pubmed.ncbi.nlm.nih.gov

Comparison of intraocular pressure measured by iCare tonometers and Goldmann applanation tonometer. [2023]

7. England pubmed.ncbi.nlm.nih.gov

Comparison of the ICare rebound tonometer with the Goldmann tonometer in a normal population. [2022]

8. England pubmed.ncbi.nlm.nih.gov

Comparison of the ICare rebound tonometer with the Goldmann applanation tonometer by experienced and inexperienced tonometrists. [2022]

9. England pubmed.ncbi.nlm.nih.gov

Comparison of the new rebound tonometer with Goldmann applanation tonometer in a clinical setting. [2022]

10. Germany pubmed.ncbi.nlm.nih.gov

Comparison of the iCare rebound tonometer and the Goldmann applanation tonometer over a wide IOP range. [2018]

11. United States pubmed.ncbi.nlm.nih.gov

Schiotz Scleral Intraocular Pressure Readings Predict Goldmann Applanation Readings Better Than Rebound Tonometry. [2019]