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Intraocular pressure (IOP) is the fluid pressure inside the eye. This article is about pressure in the physical sciences. ...
For other uses, see Eye (disambiguation). ...
Physiology and measurement Intraocular pressure is mainly determined by the coupling of the production of aqueous humor from the eye's ciliary body and its drainage through the trabecular meshwork and Schlemm's canal located in the anterior chamber angle. The aqueous humour is the clear, watery fluid that fills the complex space in the front of the eye which is bounded at the front by the cornea and at the rear by the front surface or face of the vitreous humour. ...
Schematic diagram of the human eye The ciliary body is the part of the eye containing the ciliary muscle and ciliary processes. ...
This is an area of tissue located around the base of the cornea, near the ciliary body, and is responsible for draining the aqueous humour from the eye via the anterior chamber (the chamber on the front of the eye covered by the cornea). ...
Schlemms canal, also known as canal of Schlemm or the scleral venous sinus, is a circular channel in the eye that collects aqueous humor from the anterior chamber and delivers it into the bloodstream. ...
The anterior chamber if the fluid-filled space inside the eye between the iris and the corneas innermost surface, the endothelium . ...
Intraocular pressure is measured with a tonometer. A Tonometer is a device used to measure Intraocular pressure. ...
Influencing factors Intraocular pressure measurement is also influenced by corneal thickness and rigidity.[1][2]
Significance Ocular hypertension (OHT) is defined by intraocular pressure being higher than normal, in the absence of optic nerve damage or visual field loss.[3][4] Current consensus in ophthalmology defines normal introcular pressure as that between 1 mmHg and 2 mmHg.[5][6] Ocular hypertension (OHT) is intraocular pressure higher than normal in the absence of optic nerve damage or visual field loss . Current consensus in ophthalmology defines normal introcular pressure (IOP) as that between 10 mmHg and 21 mmHg . Elevated IOP is the most important risk factor for glaucoma, so those with...
This article is about the anatomical structure. ...
The term visual field is sometimes used as a synonym to field of view, though they do not designate the same thing. ...
This article is about the branch of medicine. ...
One way of defining pressure is in terms of the height of a column of fluid that may be supported by that pressure; or the height of a column of fluid that exerts that pressure at its base. ...
The average value of intraocular pressure is 1.5 mmHg with fluctuations of about 0.25 mmHg. Intraocular pressure varies throughout the night and day. The diurnal variation for normal eyes is between 3 and 6 mmHg and it increases in glaucomatous eyes. During the night, intraocular pressure usually decreases due to the slower production of aqueous humour. Intraocular pressure also varies with a number of other factors such as heart rate, respiration, exercise, fluid intake, systemic medication and topical drugs. Alcohol consumption leads to a transient decrease in intraocular pressure and caffeine may increase intaocular pressure. [7]
Ocular hypertension is the most important risk factor for glaucoma.
Differences in pressure between the two eyes is often clinically significant, and potentially associated with certain types of glaucoma, as well as iritis or retinal detachment. Iritis is a form of anterior uveitis and refers to the inflammation of the iris of the eye. ...
Retinal detachment is a disorder of the eye in which the retina peels away from its underlying layer of support tissue. ...
Because of the effect of corneal thickness and rigidity on intraocular pressure, 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. Refractive eye surgery is any eye surgery used to improve the refractive state of the eye and decrease dependency on glasses or contact lenses. ...
// Photorefractive keratectomy (PRK) and Laser-Assisted Sub-Epithelial Keratectomy (LASEK) are laser eye surgery procedures intended to correct a persons vision and reduce their dependency on glasses or contact lenses. ...
Intraocular pressure may become elevated due to anatomical problems, inflammation of the eye, genetic factors, as a side-effect from medication, or during exercise.[8] Intaocular pressure usually increases with age and is genetically influenced.[9] An abscess on the skin, showing the redness and swelling characteristic of inflammation. ...
Adverse effect, in medicine, is an abnormal, harmful, undesired and/or unintended side-effect, although not necessarily unexpected, which is obtained as the result of a therapy or other medical intervention, such as drug/chemotherapy, physical therapy, surgery, medical procedure, use of a medical device, etc. ...
This article does not cite any references or sources. ...
Hypotony, or ocular hypotony, is typically defined as intraocular pressure equal to or less than 5 mmHg.[10][11] Such low intraocular pressure could indicate fluid leakage and deflation of the eyeball.
Case History | This article needs additional references or sources for verification.
Please help improve this article by adding reliable references. Unverifiable material may be challenged and removed. | One of the most extensive intraocular pressure case history records assembled to date is available online.[12] As of December 29, 2006, this case history included over 12,755 intraocular pressure measurements over a period of 170 days under a wide variety of real life situations. is the 363rd day of the year (364th in leap years) in the Gregorian calendar. ...
Year 2006 (MMVI) was a common year starting on Sunday of the Gregorian calendar. ...
Additional intraocular pressure measurements are continuing to be recorded at a rate of up to 100 per day and this case history web site is updated regularly. The size of the data set and the frequency with which measurements are recorded may lead to additional insights into intraocular pressure changes in response to a diverse number of factors. One interesting recent discussion that arose directly from data mining the large data set involved the timing of using glaucoma eye drop medications.[13]
Another question that is extensively discussed in the patient's commentary at the Case History site is the relationship between psychological stress and intraocular pressure. According to conventional wisdom, a patient's stress (e.g. nervousness or anxiousness) does not increase the patient's intraocular pressure the way it might increase their blood pressure. The data of the Case History challenges this convention wisdom, although a single case history will certainly not settle the question. What can be said at this point is that stress can seemingly increase intraocular pressure in at least the one individual being followed in this ambitious Case History project. Researchers will have to continue investigating the connection between stress and intraocular pressure.
References - ^ Effect of Central Corneal Thickness on Dynamic Contour Tonometry and Goldmann Applanation Tonometry in Primary Open-angle Glaucoma by Matthias C. Grieshaber, MD; Andreas Schoetzau, MS; Claudia Zawinka, MD; Josef Flammer, MD; Selim Orgul, MD in Arch Ophthalmol. 2007;125:740-744.
- ^ Corneal Pachymetry: A Prerequisite for Applanation Tonometry? by Tanaka in Arch Ophthalmol.1998; 116: 544-545
- ^ Archives of Opthalmology
- ^ American Optometric Association
- ^ webMD
- ^ Glaucoma Overview from eMedicine
- ^ Intaocular pressure measure on normal eyes by Pardianto G et al., in Mimbar Ilmiah Oftalmologi Indonesia.2005;2: 78-9.
- ^ Intraocular Pressure Variation During Weight Lifting by Vieira et al., in Arch Ophthalmol.2006; 124: 1251-1254.
- ^ Intaocular pressure measure on normal eyes by Pardianto G et al., in Mimbar Ilmiah Oftalmologi Indonesia.2005;2: 80.
- ^ http://www.emedicine.com/oph/topic579.htm
- ^ http://archopht.ama-assn.org/cgi/content/abstract/117/2/189
- ^ fiteyes.com/blogs/dave
- ^ Combining-Timoptic-and-Xalatan
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