Search results
Results from the WOW.Com Content Network
Corneal pachymetry is the process of measuring the thickness of the cornea.A pachymeter is a medical device used to measure the thickness of the eye's cornea.It is used to perform corneal pachymetry prior to refractive surgery, for Keratoconus screening, LRI surgery [1] and is useful in screening for patients suspected of developing glaucoma among other uses.
Impression tonometry (also known as indentation tonometry) measures the depth of corneal indentation made by a small plunger carrying a known weight. The higher the intraocular pressure, the harder it is to push against and indent the cornea. For very high levels of IOP, extra weights can be added to make the plunger push harder. [14]
Theoretically, average corneal rigidity (taken as 520 μm for GAT) and the capillary attraction of the tear meniscus cancel each other out when the flattened area has the 3.06 mm diameter contact surface of the Goldmann prism, which is applied to the cornea using the Goldmann tonometer with a measurable amount of force from which the IOP is ...
medium spring-open used to cut the external side of the cornea, fine sutures; iris, etc. •de' Wecker's iris scissors small slender spring-open scissors for intraoccular maneuvers (iris and deeper and more delicate structures); has two wings to operate it and one sharp and one blunt blade.
open angle between cornea and iris AC 3/4: Grade 3 anterior chamber angle: AC 2/4: Grade 2 anterior chamber angle: AC 1/4: Grade 1 anterior chamber angle: AC 0/4: Grade 0 anterior chamber angle: closed angle between cornea and iris AC/A: Accommodative convergence / Accommodation ratio the portion of the range of convergence that occurs in ...
The Schiotz tonometer consists of a curved footplate which is placed on the cornea of a supine patient. A weighted plunger attached to the footplate sinks into the cornea. A scale then gives a reading depending on how much the plunger sinks into the cornea, and a conversion table converts the scale reading into IOP measured in mmHg.
Measured values of intraocular pressure are influenced by corneal thickness and rigidity. [ 5 ] [ 6 ] As a result, some forms of refractive surgery (such as photorefractive keratectomy ) can cause traditional intraocular pressure measurements to appear normal when in fact the pressure may be abnormally high.
The baseline glaucoma evaluation tests include intraocular pressure measurement by using tonometry, anterior chamber angle assessment by optical coherence tomography, inspecting the drainage angle , and retinal nerve fiber layer assessment with a fundus examination, measuring corneal thickness , and visual field testing. [50]