Injectsense FAQs
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ABOUT GLAUCOMA & IOP
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What is intraocular pressure (IOP)?
Intraocular pressure (IOP) is the fluid pressure inside the eye, maintained by the continuous production and drainage of a clear fluid called aqueous humor. Measured in millimeters of mercury (mmHg), IOP plays a central role in eye health — particularly in glaucoma, the second leading cause of blindness worldwide.
Normal IOP typically falls between 10 and 21 mmHg, though the range that is safe for any individual patient depends on the health of their optic nerve and other risk factors. Elevated IOP is the primary modifiable risk factor for glaucoma progression, and reducing it is the primary goal of nearly all glaucoma treatments.
Why does IOP fluctuate?
IOP is not a fixed value — it is a dynamic physiological signal that changes constantly in response to:
- Circadian rhythm — pressure tends to be highest in the early morning hours for most patients
- Body posture — lying down increases IOP relative to sitting or standing
- Physical activity — certain exercises temporarily raise or lower pressure
- Medication timing — topical eye drops reduce IOP, but the effect wears off between doses
- Hydration and fluid intake — large volumes of water consumed quickly can temporarily spike IOP
These fluctuations mean that a single IOP reading taken during a daytime office visit may not reflect a patient's true pressure profile, particularly the nocturnal peaks that may be driving optic nerve damage.
What is glaucoma and how is IOP involved?
Glaucoma is a group of progressive optic neuropathies — conditions in which the optic nerve is damaged over time, leading to irreversible vision loss. It is the second leading cause of blindness globally, affecting an estimated 80 million people worldwide and more than 4 million in the United States. Because glaucoma typically progresses slowly and without pain, many patients are unaware of their disease until significant vision loss has already occurred.
Elevated IOP is the primary modifiable risk factor for glaucoma development and progression. When IOP rises — due to impaired drainage of aqueous humor from the eye — it exerts mechanical stress on the optic nerve head, gradually damaging the nerve fibers responsible for transmitting visual signals to the brain.
However, the relationship between IOP and glaucoma is more complex than a single threshold. Many patients develop glaucoma at IOP levels considered normal (so-called normal-tension glaucoma), while others tolerate elevated pressures without damage. This is why researchers increasingly focus on IOP fluctuation — pressure variability and nocturnal spikes — as a key driver of disease progression, separate from absolute pressure levels.
Why are some patients at risk even when their IOP appears controlled?
Traditional IOP measurements are taken a few times per year during daytime office visits. Studies show that clinically significant IOP elevations frequently occur outside office hours — particularly at night and during early morning hours — and are completely invisible to standard tonometry. Patients whose office IOP appears well-controlled may still be experiencing regular pressure excursions that accelerate optic nerve damage. Continuous IOP monitoring is the only approach that can reliably detect these events.
What is continuous IOP monitoring?
Continuous IOP monitoring is the real-time, autonomous measurement of intraocular pressure over extended periods — hours, days, weeks, or even years — without requiring the patient to visit a clinic for each reading. Unlike traditional tonometry, which captures IOP only a few times a year during office hours, continuous monitoring provides a complete picture of how a patient's eye pressure behaves across all times of day and night, across different activities and body positions, and in response to treatment.
How is continuous IOP monitoring different from home tonometry?
Home tonometry devices allow patients to take IOP readings themselves, typically once or twice a day. While more frequent than office visits, these readings still represent discrete snapshots and require active patient participation — introducing variability from technique differences. Truly continuous monitoring, as enabled by fully implanted autonomous sensors, collects data passively, consistently, and in absolute pressure, producing a richer and more clinically reliable dataset without patient intervention or lifestyle interruption.
THE iOP-CONNECT PLATFORM
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What is the iOP-Connect sensor?
The iOP-Connect is an ultra-miniature, fully implantable wireless intraocular pressure sensor developed by Injectsense. Smaller than a grain of rice (less than 2 cubic millimeters in volume), it is the world's smallest implantable IOP sensor. Once placed inside the eye, it measures pressure continuously and autonomously — without requiring any ongoing action from the patient.
The device is designed to remain in the eye for decades, wirelessly recharged and uploading data weekly via a pair of smart glasses worn by the patient for a few minutes. Data is encrypted and transmitted to a secure cloud platform, where physicians can review each patient's complete IOP history, set pressure thresholds, and receive alerts.
Note: The iOP-Connect is an investigational device limited by federal law to investigational use only. It is not commercially available.
How does the iOP-Connect work?
The iOP-Connect integrates several advanced technologies into a single hermetically sealed silicon package:
- Pressure sensing: A MEMS pressure sensor measures absolute IOP at programmable intervals set by the physician — from once per hour to once per millisecond
- Power: A solid-state lithium microbattery (developed by sister company Injectpower) powers the device; it is recharged wirelessly each week via near-field inductive coupling from the smart glasses
- Data transmission: The smart glasses download stored IOP readings and upload them to the cloud via the patient's smartphone
- Biocompatibility: The device is polymer-free, fully hermetic, and uses well-characterized semiconductor materials designed for decades of in-body operation
The system operates at nanowatt-level power consumption, enabling long operational life between weekly charging sessions.
Where is the device implanted?
The iOP-Connect is implanted in the pars plana — a region near the rear of the eye, close to the optic nerve head, where pressure on the optic nerve is most clinically relevant. The device is self-anchoring and does not require sutures. Implantation is performed in-office via an injection procedure similar to standard intravitreal injections used for wet AMD treatment, which are performed millions of times annually worldwide.
How does iOP-Connect compare to Goldmann applanation tonometry (GAT)?
Goldmann applanation tonometry (GAT) is the current clinical standard for IOP measurement. It requires a trained technician, a slit lamp, and a patient visit — and produces a single IOP reading at that moment in time. Key differences from the iOP-Connect:
- Frequency: GAT captures 3–4 readings per year; iOP-Connect captures data around the clock
- Timing: GAT is limited to daytime office hours; iOP-Connect captures nocturnal peaks and activity-related fluctuations
- Patient burden: GAT requires travel to a clinic; iOP-Connect requires only weekly glasses use at home
- Operator variability: GAT measurements vary by operator; iOP-Connect uses a fixed sensor position
- Data richness: GAT yields individual data points; iOP-Connect yields a continuous waveform suitable for AI and clinical analysis
In three-month in-vitro stability testing, iOP-Connect demonstrated a measured drift of only 0.006 mmHg per month, with a long-term accuracy target of +/- 1 mmHg at system level.
What other medical conditions can implantable pressure sensors address?
While Injectsense's initial clinical focus is glaucoma, the underlying sensor platform is designed for multiple physiological monitoring applications:
- Intracranial pressure (ICP) monitoring: For patients with hydrocephalus, traumatic brain injury, or idiopathic intracranial hypertension
- Cardiovascular pressure monitoring: Continuous measurement of cardiac chamber or vascular pressures for heart failure management
- Urological applications: Bladder pressure monitoring for patients with neurogenic bladder conditions
- Joint pressure sensing: Orthopedic applications following joint replacement or reconstruction
Note: Applications beyond ophthalmic IOP monitoring are at research and development stages. All devices are investigational and not commercially available.
CLINICAL & REGULATORY
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What is FDA Breakthrough Device Designation?
FDA Breakthrough Device Designation is a program that accelerates the development and review of medical devices that provide more effective treatment or diagnosis of life-threatening or irreversibly debilitating diseases. Devices granted this designation receive prioritized, interactive communication with the FDA throughout development — from early design through clinical trials and onto commercialization decisions.
The designation is not FDA clearance or approval. It is a development pathway designation signaling that the technology has the potential to address a serious unmet medical need and warrants expedited attention.
Injectsense received FDA Breakthrough Device Designation for the iOP-Connect chronic continuous IOP monitoring system in 2020. The designation may also enable up to four years of immediate Medicare coverage following FDA market authorization, pending CMS review — which could significantly accelerate patient access once the device is approved.
How is AI being used with continuous IOP data?
Artificial intelligence and machine learning systems improve with large, high-resolution, continuous datasets. The sporadic IOP measurements currently available from clinic visits are insufficient to train AI models that can reliably detect disease progression, predict future events, or personalize treatment. Continuous IOP data from implantable sensors changes this fundamentally.
The analogy is continuous glucose monitoring (CGM) in diabetes. Before CGM, endocrinologists had only a few blood sugar readings per year. Once continuous data became available at scale, machine learning began to meaningfully improve prediction of diabetic complications and personalize insulin management. Glaucoma care is at the same inflection point.
With 24/7 IOP waveforms collected across patient populations, AI systems can begin to:
- Define new metrics of disease control — including pressure variability, nocturnal load, and spike frequency
- Identify patients likely to progress despite apparently controlled daytime IOP
- Detect medication non-adherence through pressure pattern changes
- Correlate IOP dynamics with structural changes on OCT and functional changes on visual field testing
- Build predictive models of glaucoma progression tailored to individual patients
- Analyze pharmacokinetics of IOP-lowering drugs across a full 24-hour cycle
A MarketScope 2023 survey confirmed this is the number-one technology ophthalmologists want integrated into practice — cited by 51% of respondents.
Note: AI-powered IOP analysis tools are in development. The iOP-Connect is investigational and not commercially available.
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All Injectsense devices are investigational and limited by federal law to investigational use only. Not for commercial sale.