Real-Time Monitoring of Local Intraocular Pressure Distributions Applied to Retina for Diagnosis and Treatment of Glaucoma

Glaucoma, which causes gradual degeneration and functional abnormality of the optic nerve, is the second leading cause of vision loss. The main cause of glaucoma is known as the damage of the optic nerve due to high intraocular pressure (IOP). Since the damage resulting from glaucoma is hardly recovered, diagnosing in the early stage is significant. Currently, the Goldmann applanation tonometry is the gold standard method for IOP measurements and most methods including this tonometry measured by using the strain of the cornea. However, many glaucoma patients suffer from normal-tension glaucoma, which occurs in the range of normal IOP. This indicates that the IOP measured at the cornea does not properly reflect the damage to the optic nerve. The IOP increase occurs by the disturbance in the flow of aqueous humor. The anterior chamber, where the flow of aqueous humor occurs, is separated from the vitreous chamber which applies pressure to the optic nerve. Thus, the IOP measured at the cornea can be different from the pressure applied to the retina depending on the biomechanics properties of the eyes. Here, we report the local distributions of IOP values measured at the cornea, anterior chamber, and vitreous chamber of live rabbit eyes using a soft probe-type pressure sensor. This highly sensitive and flexible pressure sensor with a soft needle shape can minimize the damage to the eye, with offering a new direction for the diagnosis and treatment of glaucoma.