Design Of Applanation Tonometer Used A Special Cone Prism And Research On Biomechanical Properties Of Cornea

Intraocular pressure IOP is a very important parameter of clinical medicine. The changes of intraocular pressure may lead to many diseases, Department of Ophthal-mology, Department of Ophthalmology in human disease incidence is highest glauc-oma due to increased intraocular pressure. Because the current approach of clinical medicine is still lack of prevention of glaucoma and reliable, only through early diagnosis, early treatment to prevent the damage of visual function. Patholog-ical high intraocular pressure is the main feature of glaucoma, Department of Ophthalmology physicians for glaucoma therapy to try to reduce intraocular pressu-re to maintain the normal level. Therefore, study of intraocular pressure detec-tion and accurate measurement of intraocular pressure value in the clinical diagnosis and treatment of glaucoma is very important.At the same time, intraocular pressure and stress strain, elastic modulus, creep properties, ocular rigidity and a series of biomechanical properties of the corneah-as close relationship, study on the biomechanical properties of the cornea has very important reference and application value for the current clinical use ofmyopia exci-mer laser corneal refractive operation, the diagnosis and treatment of corneal disea-se. The study on the mechanical properties of the cornea are by in vitro measure-ment methods, this way can often destroy the structure and physiologyical environ-ment inherent in the cornea, and can’t reflect the realcharacteristics in the body of the cornea. Therefore, it has great significance to study the non destructive in the bio-mechanical properties of the cornea of the body.This dissertation reviewed the development and application of intraocular pre-ssure measurement technology and different types of tonometer in clinic, because theapplanation tonometer has the features of non damage, fast measuring speed in the detection of the cornea, emphatically describes the working principle of app-lanation tonometer and concrete application in the detection of cornea. Theapplana-tion intraocular pressure compared to the more the advantages and disadvantages of the corneal deformation test, the dynamic and continuousmeasurement of in vivo co- meal applanation area, corneal flattening pressureand intraocular pressure, and pro-posed a method for pressing plane productsize obtained by using total reflection fru-stum of a cone prism. At the same time,according to the principle of measureing ELWINMARG and R.STUART MACKAY proposed, designed the implementta-tion way of measuring corneal flattening forces, and build a new applanation tono-metry test device, and the experimental results and intraocular pressure measure-ment of the "gold standard" Goldmman tonometer compared to determine the acc-uracy of the measurement,, also proved that the experimental detection device can realize continuous measurement of the dynamic corneal applanation area, corneal fl-attening pressure and intraocular pressure.In determining the accuracy and practicability of the device, use it to carry out some research on the mechanical properties of cornea, corneal tonometry deforma-tion, analyzed the relationship between the corneal elastic modulus and corneal app-lanation area, real intraocular pressure and intraocular pressuremeasured from the theory, based on the use of applanation detection to study thecorneal elastic modulus and the experiment. At the same time, the relationship between corneal applanati-on applanation force, displacement and ocular rigidityare discussed, using the sa-me model applanation tonometry test device for detecting the relationship betw-een force and displacement of different cornealapplanation applanation intraocular pressure. The results of two experimentsshowed that the new applanation to nome-try test device for the biomechanical properties of the cornea of nondestruc tive mea-surement in vivo plays a very important role.