الفهرس 
IntroductionOnly 14 pages are availabe for public view
 |  | from | 86 |  |  |
| | | from | 86 | | |
Abstract
In all parts of the world, glaucoma is considered a major public health problem and cause personal tragedy. It’s the second leading cause of blindness worldwide, and affects more than 50 million people. The intraocular pressure(IOP)plays a major role in the eye safety. Both IOP rise and hypotony can affect the eye.
Glaucoma is a disease characterized by the triad: increased IOP, visual field changes and optic disc cupping.
Many factors affect IOP as general & local factors:
General factors as genetic, age ,sex ,race ,change in body position , blood pressure , Valsalva maneuver, water drinking ,pregnancy ,smoking, alcohols ,drugs, caffeine,exercise ,anesthesia , hormonal factors and diurnal variation
Local factors as ,axial Length , laterality , central corneal thickness ,
corneal curvature, corneal anomalies and accommodation
The diurnal variation in IOP has extremely important clinical implications for glaucoma patients. Asrani et al have shown that large diurnal variation in IOP is a risk factor for progression of glaucoma. Others have shown that the diurnal IOP curve is altered in glaucoma patients compared to normal subjects.
The fact that the pressure can vary dramatically during a given day makes it unreasonable to assume that a single pressure taken at a specific time is representative of the average pressure the patient experiences over time. It is quite possible that this single pressure represents a high or low point, and that the patient’s average pressures are substantially different.
This study included (100) persons from ophthalmology out clinic patients in Beni-Suef University hospital & Assiut ophthalmology hospital non diabetics , non hypertensive , non glaucomatous and there age ranging from 40 -50 years old , (58% female and 42% male), there IOP were measured 4 times per day (8am, 2pm, 8pm, and 12am) for two days by using an Applanation Tonometry , they show diurnal variation of IOP varies from (1-6) mmHg for males and (1-7) for females.