UC San Diego

Today, glaucoma is the leading cause of irreversible blindness in the world. Its highest risk factor is related to an elevated intraocular pressure (IOP) within the eye that can cause stress on the optic nerve and deteriorate the visual field in patients. Regular IOP monitoring can be crucial in detecting early onset of glaucoma, especially since surgical cures might not exist in the later stages. To improve the prospect of self-examining ophthalmic devices, we have developed a handheld 3-in-1 device consisting of 3 commonly used glaucoma screening instruments. This includes a compact slit lamp biomicroscope, visual acuity tester, and a non-contact tonometer. The aim of this device is to enable easy self-examination of the eye more frequently, especially for patients physically unable to travel to in-person clinic appointments to perform them.

To validate the tonometer measurement principle, this thesis investigates the development of an artificial cornea using silicone materials to study corneal deflection as a function of the IOP. Samples were fabricated using 2-part 3D-printed molds that accurately capture the geometry of the human cornea. Young’s moduli for a range of selected silicones were evaluated and compared with that of human cornea as well. Eye pressure was simulated using a water-filled manometer channel and readings were obtained from both a commercial and the 3-in-1 device’s tonometer to test the designed artificial corneas. Results from both devices validate the use of such a phantom eye apparatus to test similar ophthalmic instrumentation before clinical testing on humans.