Device for in-vivo determination of eye moisture

A device for evaluation of a moisture characterization parameter associated with moisture of soft tissue on an inner surface of an eyelid of a subject, the device comprising:

• (a) an alternating current source, adapted to connect to a power supply and to produce an alternating current;
• (b) an electrode arrangement having at least a first electrode and a second electrode, said first electrode electrically separated from said second electrode by an electrically insulating region, said electrode arrangement having an at least semi-rigid region fixing said first electrodes and said second electrode in a spaced-apart manner,
• said electrode arrangement adapted to contact the soft tissue on the inner surface of the eyelid, said electrodes and said electrically insulating region composed of biocompatible materials;
• and
• (c) a processor, associated with said electrode arrangement,
• said first and second electrodes being electrically connected to said alternating current source,
• wherein, when said electrode arrangement is provided with said alternating current, and is disposed against the soft tissue, the soft tissue electrically bridges between said electrodes to form an electrical circuit, such that an electrical signal is produced by said alternating current passing from said first electrode to said second electrode via the soft tissue,
• said processor being adapted to receive in-vivo based electrical information originating from said electrical signal, via said electrical circuit, and to produce an output relating to, or derived from, the moisture characterization parameter associated with the moisture of the soft tissue on the inner surface of the eyelid, based on said in-vivo electrical information,
• said processor being designed and configured to compute the moisture characterization parameter associated with the moisture of the soft tissue on the inner surface of the eyelid, at least partially based on said in-vivo electrical information, and based on an empirical correlation between said in-vivo electrical information and said moisture characterization parameter associated with the moisture of the soft tissue on the inner surface of the eyelid,
• said empirical correlation including an inverse relationship between an electrical impedance derived from said electrical signal or from said in-vivo electrical information, and said moisture characterization parameter associated with the moisture of the soft tissue on the inner surface of the eyelid, such that an increasing level of moisture of soft tissue on the inner surface of the eyelid is correlated, by said processor, with a decreasing of said electrical impedance,
• wherein said moisture characterization parameter associated with the moisture of the soft tissue on the inner surface of the eyelid includes an eye-moisture characterization parameter selected from the group of parameters consisting of a calculated in-vitro osmolarity, a calculated Schirmer's Test absorption length, a calculated Meibomian Grading Score, an ocular surface disease index (OSDI), a corneal and conjunctival staining result, and an eye dryness severity value.