Browsing by Author "Ozdemir, M"

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Age-Related Differences in Normal Corneal Topography
(Slack inc, 2004) Topuz, H; Ozdemir, M; Cinal, A; Gumusalan, Y
BACKGROUND AND OBJECTIVE: The aim of this study was to compare age-related differences in the corneal topography of a normal population using a computerized corneal topography system. PATIENTS AND METHODS: The randomized comparative study included 240 eyes of 120 subjects with normal corneas. Subjects were divided into six age groups: 5 to 10 years (group 1), 11 to 20 years (group 2), 21 to 30 years (group 3), 31 to 40 years (group 4), 41 to 50 years (group 5), and 51 years or older (group 6). Average corneal power and corneal astigmatism were examined. An average corneal topography map was constructed and the astigmatism pattern was determined in each age group. RESULTS: Average corneal power values were 41.64 +/- 0.85 diopters (D), 42.35 +/- 0.90 D, 42.63 +/- 0.99 D, 42.94 +/- 0.93 D, 43.38 +/- 0.77 D, and 43.53 +/- 0.88 D in groups 1 to 6, respectively (P <.001). Mean astigmatism values were similar in all age groups (P = .225). Younger subjects had with-the-rule astigmatism, but older subjects showed a shift to oblique or against-the-rule astigmatism. The averaged maps of groups 1 to 3 showed a vertical bow-tie pattern, but the central steep area gradually extended horizontally and it became a round configuration in groups 4 to 6. CONCLUSION: This study suggests that the normal cornea becomes steeper in the horizontal line and superior vertical quadrant and shifts from with-the-rule to against-the-rule astigmatism, but the amount of physiological corneal astigmatism does not change with age.
Early and Late Effects of Pterygium Surgery on Corneal Topography
(Slack inc, 2005) Ozdemir, M; Cinal, A
Square Backround and Objective: The aim of this study was to compare the corneal topographic changes at the early and late postoperative period after pterygium surgery. square PATIENTS AND METHODS: Sixteen eyes of 15 patients with primary pterygium were included in the study. All of the pterygia were excised primarily. Computerized corneal topography measurements were taken before surgery and at the second week (postoperative early period) and third month (postoperative late period) after the operation. Keratometric astigmatism, total mean corneal refractive power, and flattened or steepened areas of the cornea were detected at each visit. The topographical changes were evaluated using the analysis of variance. Multiple comparison analyses were made with the Tukey HSD test. square RESULTS: Keratometric astigmatism was 2.58 +/- 2.33 diopters (D) at the preoperative period, 1.30 +/- 1.24 D at the postoperative early period, and 0.61 0.38 D at the postoperative late period (P < .001). The surgically induced corneal astigmatism was 3.23 +/- 2.33 D (range, 0.52 to 8.32 D) at the postoperative early period and 2.70 +/- 2.24 D (range, 0.47 to 7.72 D) at the postoperative late period (P = .287). Astigmatism was 81.25% with-the-rule at the preoperative period, 43.75% oblique and 37.50% against-the-rule at the postoperative early period, and 62.50% with-the-rule at the postoperative late period. Total mean corneal refractive power was 42.51 +/- 1.99 D at the preoperative period, 43.95 +/- 1.58 D at the postoperative early period, and 43.89 +/- 1.80 D at the postoperative late period (P = .014). square CONCLUSION: Corneal topographic changes induced by pterygium greatly improve at the postoperative early period. However, normal corneal topography patterns are formed at the postoperative late period.
Effects of Fibrovascular Traction and Pooling of Tears on Corneal Topographic Changes Induced by Pterygium
(Nature Publishing Group, 2003) Yasar, T; Ozdemir, M; Cinal, A; Demirok, A; Ilhan, B; Durmus, AC
Aim To investigate the effects of fibrovascular traction and the pooling of tears at the pterygium apex on the corneal topographic changes induced by pterygium. Methods A total of 16 eyes of 14 cases with primary pterygium were included in the study. A computerized corneal topography system was used for corneal topography examinations. Baseline keratographs were taken two times at straight gaze. A repeat corneoscope photograph was immediately obtained in temporal gaze. Then the tears at the pterygium apex were dried with a cellulose sponge, and a new corneoscope photograph was immediately obtained without allowing one to blink. Corneal topographic maps ( numeric maps) were divided into 301 fields in 24 meridians. One colour was allocated to each field, representing its mean refractive power for all groups. In all eyes, keratometric astigmatism at the 3 mm central cornea and total mean corneal refractive power were found. Data were compared using paired-samples two-tailed t-tests. Results Keratometric astigmatism at the 3 mm central cornea was significantly reduced at the temporal gaze (3.10 +/- 2.34 D, t = 3.40, P = 0.027) and dried eyes (2.12 +/- 1.01 D, t = 4.74, P = 0.001) according to the first baseline measurement (4.31 +/- 1.91 D) of the total mean corneal refractive power was found to be 43.45 +/- 1.28 D (39.29-45.87) at the first baseline measurement. There was no change at the temporal gaze (43.54 +/- 1.06 D, P>0.05). However, the total corneal refractive power was significantly higher in dried eyes (44.26 +/- 0.93 D, t = 34.92, P<0.001). The steepest region of corneal topography was a superior quadrant, and the flattest area was a nasal quadrant at the baseline. At the temporal gaze, the cornea was significantly flatter in the superior and inferior sides of the pterygium meridian. After dried pooling of tears, topographic abnormalities returned, and the cornea became more uniform and symmetric. Conclusion We conclude that the pooling of tears at the pterygium apex plays an important role, but fibrovascular traction has no effect on the corneal topographical changes induced by pterygium.
Latanoprost Therapy in Patients With Glaucoma and Ocular Hypertension Inadequately Controlled With Carteolol
(Springer Japan Kk, 2004) Yasar, T; Ozdemir, M; Andi, I; Ozdemir, G; Simsek, S
A Newbom With Lipemia Retinalis
(Slack inc, 2003) Ozdemir, M; Bay, A; Yasar, T; Cinal, A
Lipemia retinalis is a rare ocular manifestation of certain types of hyperlipidemia. A case of a newborn with lipemia retinalis evaluated by laboratory and clinical findings is described. A creamy white appearance of all retinal blood vessels was demonstrated by color fundus photographs. The patient had elevated levels of triglycerides (29,000 mg/dL) and cholesterol (1,470 mg/dL). Lipid electrophoresis indicated hyperprebetalipoproteinemia. Type IV primary hyperlipoproteinemia was diagnosed.
Organochlorine Pesticide Residues in Human Breast Milk From Agricultural Regions of Turkey, 1995-1996
(Springer, 1997) Cok, I; Bilgili, A; Ozdemir, M; Ozbek, H; Bilgili, N; Burgaz, S