Optical remote sensing of intraocular pressure by an implantable nanostructured array
Pathological condition of ciliary body (aqueous humor production) or drainage abnormalities cause an abnormal intraocular pressure (IOP) in the eye and most frequently it is an intra-ocular hypertension (elevated IOP), which is the most important risk factor for developing glaucoma. Glaucoma is a severe eye disease known as the major cause for the blindness in developed countries. In the current clinical practice the monitoring of the IOP is the most effective feedback for preventing the further development of glaucoma.
Therefore, nowadays ophthalmologists and biomedical imaging sector continuously demand more precise and non-invasive instruments for intraocular pressure monitoring. IOP is the fluid pressure of the aqueous humour and is maintained by the liquid production of the ciliary body in the eye. The average value of normal intraocular pressure is 15.5 mmHg with fluctuations of about 2.75 mmHg. Pathological IOP can be observed up to 30 mmHg.
In general, two approaches are distinguished for measuring IOP: non-invasive and non-contact. Both non-invasive and non-contact methods are indirectly measuring corneal stiffness as an indication of IOP. The current IOP measurement methods are strongly biased by the ocular mechanical parameters of the eye, e.g. the corneal thickness and rigidity.
Here we propose a novel approach for contactless true (direct) measurement of IOP by inserting a hydrophobic biocompatible nanostructure sample into the anterior chamber.