i-Onion™ is an instrument that stimulates safely maximal tear secretion in an easy, brief and reliable manner.

How does i-Onion™ do that?

  • Basal tear flow is measured with a Schirmer test strip (ST) placed on the lower lid (3 min.) on the eye.

  • The i-Onion™ instrument is applied on the socket of the contralateral eye, immediately after a ST strip is in place. A CO2 gas puff is directed onto the eye.

  • A CO2 gas puff is directed onto the eye surface for 4 seconds.

  • The i-Onion™ is removed.

  • The ST strip is removed 3 min. later.

  • The numerical value obtained shows the maximal lacrimal secretion capacity.

Scientific Principles and foundations

Disorders leading to reduced eye surface wetness affects 10-20% of the world population. However, the traditional procedures hitherto used for a rapid and simple assessment of the lacrimal production in normal or pathological conditions are rough and limited in the daily clinical practice to the measurement of basal tear secretion by the lacrimal gland at rest using the Schirmer test. This approach does not provide any clue on how far the measured basal tear flow value is from the maximal secretory capacity of the lacrimal glands, neither detects whether the gland still possesses a tearing reserve volume large enough to supply the tear flow required. This is critical information to decide the use drugs (secretagogues) that activate lacrimal gland’s secretion.

The i-Onion™ instrument is a brand-new ophthalmological device conceived and de built up by Tearful SL, that allows to obtain a quantitative evaluation of the maximal tear secretion capacity of the lacrimal glands in human and other mammal’s eyes in healthy or pathological conditions. To obtain this result, the i-Onion™ instrument releases a 3-second, 200ml/min, 99.9% medical grade CO2 gas jet onto the surface of the explored eye, producing a total excitation of the corneo-scleral nerve terminals mediating reflex secretion, thereby causing a controlled, transient maximal reflex production of tears by the lacrimal glands. The volume of tears produced by the stimulus impinging on the cornea of the explored subject, can be measured by qualified health personnel, using Schirmer test strips or any other ophthalmic technique used for tear flow measurement.



Dry Eye Disease (DED) prevention

Assessment of lacrimal gland reserve values with the i-Onion™ procedure can support prediction in advance of several pathologies such as: DED/Sjögren & Video Display Terminal (VDT)- associated DED patients.

Predict patient’s tolerance to contact lens

Exploration with i-Onion™ stimulation prior to contact lens fitting, provides quantitative information about the magnitude of the functional tearing capacity of the patient.
Systematic measurement of this parameter previously to lens use helps optometrists and ophthalmologists to predict patient’s tolerance to contact lens and define appropriate strategies to reduce the risk of complications derived of contact lens use.

Pre-surgery information

Exploration with i-Onion™ of the maximal tear reserve provides useful pre-surgery information of the Photorefractive procedure, information about risks associated to nerve injury-induced decreased tear flow.

Evaluate animal’s lacrimal gland capacity to secrete tear

Use of i-Onion™ to objectively evaluate in pets the lacrimal gland capacity to secrete tear can be useful in veterinary medicine. Yearly health examination for DED in predisposed breeds of dogs has been recommended by specialists in veterinary ophthalmology.