Prospective, open-labeled, randomized, controlled, multicenter study at two clinical investigative sites in Tucson, Arizona. The subjects will undergo intraocular pressure measurement with the CATS tonometer prism and the Goldmann applanation tonometer prism (GAT). Seventy-five (75) Subjects 18 and older and will be enrolled. Subjects will be screened based on standard of care vision examination at the clinical investigation sites. All subjects will undergo a standard ophthalmic exam and informed consent. IOP will be measured using a Goldmann tonometer armature with both the standard flat GAT prism and the modified curved CATS prism alternately inserted. The only additional measurement is central corneal thickness (CCT) which is used to correct for one of the corneal biomechanical errors seen in the GAT prism and is currently standard of care.
Who can participate
Age range
18 Years
Sex
ALL
See this in plain English?
AI-rewrites the medical criteria so a patient or caregiver can understand them. Always confirm with the trial site.
Inclusion Criteria:
* Written informed consent (and assent when applicable) obtained from subject or subject's legal representative and ability for subject to comply with the requirements of the study.
* Male and female patients, at least 18 years of age
Exclusion Criteria:
* Subject has undergone ocular surgery within the last 3 months
* Uncontrolled systemic disease that in the opinion of the Investigator would put the subject's heath at risk
* Pregnant or nursing women
* Subjects with only one functional eye
* Those with one eye having poor or eccentric fixation
* Eyes displaying an oval contact image
* Those with corneal scarring or who have had corneal surgery including corneal laser surgery
* Microphthalmos
* Buphthalmos
* Contact lens wearers
* Severe Dry eyes
* Lid squeezers - blepharospasm
* Nystagmus
* Keratoconus
* Any other corneal or conjunctival pathology or infection.
* Central corneal thickness between 0.600 mm and 0.500 mm (more than 2 standard deviations about the human mean)
Questions worth asking your doctor
Bring these to your next appointment. They're a starting point for a shared conversation — not a sign you qualify or a recommendation to enrol.
1Based on my diagnosis and history, is this trial worth exploring for me — or is there a standard treatment we should try first?
2What does this trial's phase tell us about how much is already known about its safety and benefit?
3What would taking part actually involve for me — visits, tests, time, and travel?
4What are the known and possible risks or side effects I should weigh, and how would they be monitored?
5If this trial isn't the right fit, what other options or trials would you suggest I look into?
Generated to help you prepare — always confirm anything about your own eligibility and care with the study team and your doctor.
Questions for the trial coordinator
The trial coordinator is the person who runs the study day to day. These cover the practical side — logistics, costs, and what taking part would actually mean for your life. The study team confirms whether you meet the criteria; these are questions to ask, not a sign you qualify.
1What does taking part actually involve week to week — how many visits, where, and how long does each one take?
2What costs are covered by the study, and what might I have to pay for myself, including travel, parking, or time off work?
3What happens during screening, and what happens if the study team confirms I don't meet the criteria after those tests?
4Who pays for the scans, blood work, and other tests the trial requires — the study, my insurance, or me?
5How will being in the trial affect my regular care, and will my own doctor stay informed and involved?
6Can I leave the trial at any point if I change my mind, and what would happen to my care if I do?
A starting point for the conversation — always confirm anything about your own eligibility, costs, and care with the study team and your doctor.
What they're measuring
1
All subjects will have CATS tonometer prism intraocular pressure readings compared to Goldmann tonometer prism readings.
Timeframe: From date of randomization until 24 hours
2
All subjects will have corneal thickness measurements performed and the CATS tonometer prism intraocular pressure readings will be compared to Goldmann tonometer readings using a correction value table.
Timeframe: From date of randomization until 24 hours