Design of automated digital eye palpation exam for intraocular pressure measurement

Elevated intraocular pressure (IOP) is a major risk factor for the degenerative eye disease glaucoma. Accurate indirect measurements of IOP are essential for glaucoma diagnosis and screening. This work presents an experiment developed to measure IOP in-vitro by simulating the technique of digital palpitation tonometry, a technique in which a trained examiner palpates the eyeball using the fingertips of both index fingers to "feel" the stiffness of the eye. The qualitative nature of this method and errors introduced by the subjectivity of the examiner mean that it is rarely used in comparison with other modern-day tonometry methods. However, this technique offers several potential advantages in that it can be performed outside of a clinical setting without the need for instrument sterilization or local anesthesia and may be less subject to measurement errors occurring in patients who have undergone refractive laser eye surgery. In order to quantify the mechanics of digital palpation tonometry, an automated experiment to measure the intraocular pressure of enucleated porcine eyeballs using mechanized digital palpation was designed and tested. This experiment has direct applications towards the development of a next-generation tonometer for glaucoma treatment.