الفهرس | Only 14 pages are availabe for public view |
Abstract This is a descriptive study with cross-section design which was performed to characterize the thinnest point of the cornea in myopic Egyptian adults between the age of 21 and 50 years who do not have any diseases (ocular or systemic) that may affect their corneal thickness. All subjects included in this study were with clear corneas with no history of recent contact lens wear or previous corneal surgery. Full medical and ophthalmological history were taken, then full ophthalmogical examination, followed by measuring of Corneal thickness by Orbscan in one group targeting outpatient clinic in Kalawoon hospital and by using of ultrasonographic pachymetry in another group targeting outpatient clinic in Suez Canal University. The data of corneal thickness measures from Ultrasonographic pachymetry and Orbscan were analyzed statistically. The study included 98 patients with 196 eyes (49 patient in each group) 70 females and 28 males, with mean age 28 years, average spherical equivalent of -2.1diopters and average intraocular pressure of 16.4mmHg. Central corneal thickness by Ultrasonographic pahymetry was 546μm in right eye and 550μm in the left eye. Central corneal thickness by Orbscan was 551μm in right eye and 550μm in the left eye. Corneal thickness at the thinnest point of the cornea Orbscan was 546μm in both eyes. In 49 (50%) right eyes, the thinnest point of the cornea was located temporally inferior in 29 (59.2%) eyes; nasally inferior in 2 (4.1%) eyes; temporally superior in 3 (6.1%) and nasally superior in 2 (4.1%) eyes, however in 9 eyes (18.4%) the thinnest point of the cornea was located at the center of the cornea. In 49 (50%) left eyes, the thinnest point of the cornea was located temporally inferior in 27 (55.1%) eyes; temporally superior in 3 (6.1%) and nasally inferior in 2 (4.1%) eyes; however in 5 (10.2%) eyes the thinnest point of the cornea was located at the center of the cornea The difference between the central corneal thickness and the thinnest point of the cornea is not influenced by factors such as age, sex, refraction, and intraocular pressure. Concerning corneal pachymetry , it is better to determine the thinnest point of the cornea (which can be at the centre or elsewhere) and build our calculations on it , and this point can be easily characterized by recent devices like Orbscan. |