Browsing by Author "Timucin, Ozgur Bulent"

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Assessment of Corneal Endothelial Cell Density in Patients With Keratoconus Not Using Contact Lenses
(Elsevier Science Bv, 2013) Timucin, Ozgur Bulent; Karadag, Mehmet Fatih; Cinal, Adnan; Asker, Muntecep; Asker, Selvi; Timucin, Damla
Purpose: To assess the corneal endothelial cell density (ECD) in keratoconus patients with no history of contact lens use. Setting: Yuzuncu Yil University, School of Medicine and Van Training and Research Hospital, Department of Ophthalmology, Van, Turkey. Design: Cross-sectional controlled study. Methods: The eyes of 65 patients with the diagnosis of keratoconus with no history of contact lens wear and the eyes of 40 healthy controls were prospectively examined using the Heidelberg Retinal Tomography Rostock Cornea Module (HRT3/RCM). The average ECD from the two groups were then compared. Results: Of the cases with keratoconus, 44(67.7%) were men and 21 (32.3%) were women. The mean age was 20.9 +/- 6.8 (range =10-41) years. Of the controls, 28 (70%) were men and 12(30%) were women. The mean age was 23.9 +/- 5.8 (range = 14-35) years. Of the 65 eyes with keratoconus, 19(29.2%) had mild keratoconus, 21 (32.3%) had moderate keratoconus, and 25 (38.5%) had severe keratoconus. The mean ECD was 2731.6 +/- 303.2 cells/mm(2) in cases with keratoconus and 2664.9 +/- 319.5 cells/mm(2) in controls. There was no difference between the densities (unpaired t-test, P=0.4). No significant relationships were found between the ECD data and central corneal thickness or steepest keratometric. Conclusions: Endothelial cell density was unaltered in keratoconic patients without a history of contact lens use when compared with healthy controls. Change in ECD is independent from the central corneal thickness and the stage of keratoconus. (C) 2012 British Contact Lens Association. Published by Elsevier Ltd. All rights reserved.
Assessment of Keratocyte Density in Patients With Keratoconus Not Using Contact Lenses
(Lippincott Williams & Wilkins, 2011) Timucin, Ozgur Bulent; Karadag, Mehmet Fatih; Cinal, Adnan
Purpose: To assess the keratocyte density (KD) in the cornea of patients with keratoconus not using contact lenses. Method: In this pilot study, the eyes (n = 68) of 35 patients with the diagnosis of keratoconus, who did not use contact lenses and the eyes (n = 70) of 35 healthy controls were prospectively examined using the Heidelberg Retinal Tomography Rostock cornea module (HRT3/RCM). The cases with keratoconus and controls were compared with regard to KD in the anteroposterior stromal layers. Results: Of the cases with keratoconus, 15 (42.9%) were men and 20 (57.1%) were women. The mean age was 21.1 +/- 11.1 (range = 14-41) years. Of the controls, 26 (73.9%) were men and 9 (26.1%) were women. The mean age was 23.9 +/- 12.9 (range = 14-35) years. Of the 68 eyes with keratoconus, 22 (28.2%) had mild keratoconus, 23 (35.9%) had moderate keratoconus, and 23 (35.9%) had severe keratoconus. The mean anterior stromal KD was 651.4 +/- 89 cells per square millimeter in cases with keratoconus and 879.4 +/- 75 cells per square millimeter in controls (P < 0.05). The mean anterior stromal KD decreased by 25.9% in corneas with keratoconus. The mean posterior stromal KD was found to be 363.6 +/- 74 cells per square millimeter in cases with keratoconus and 469.7 +/- 56 cells per square millimeter in controls (P < 0.01). The mean posterior stromal KD decreased by 22.6% in corneas with keratoconus. The anterior stromal KD was higher than the posterior stromal KD (P < 0.001). No significant relationships were found between the stromal KD data and central corneal thickness or steepest keratometric. Conclusions: The KD in the anterior and posterior corneal stroma was decreased in patients with keratoconus, but without the use of contact lens, compared with healthy controls. This density difference was independent from the central corneal thickness and the stage of keratoconus.
The Effects of Light Sources With Different Spectral Structures on Ocular Axial Length in Rainbow Trout (Oncorhynchus Mykiss)
(Academic Press Ltd- Elsevier Science Ltd, 2016) Timucin, Ozgur Bulent; Arabaci, Muhammed; Cuce, Ferhat; Karatas, Boran; Onalan, Sukru; Yasar, Muhterem; Karadag, M. Fatih
Every day, we are acquiring more and more clues regarding the effects of different spectral structures (SS) of light on ocular axial length (OAL). As a step towards understanding this association, this study sought to characterise the effects of light sources of different SS on OAL in fish through comparisons with indoor daylight. The experimental design was completely randomised with 4 treatments and 2 replications. Three hundred and fifty two rainbow trout (Oncorhynchus mykiss) were housed in 8 tanks and fed for 71 days. Differences in the mean values of ocular elongation were determined at the end of the experiment. The daylight group was exposed to indoor daylight in the hatchery environment, the red group was exposed to long wavelength light (600-650 nm), the green group was exposed to mid wavelength light (495-570 nm) and the blue group was exposed to short wavelength light (420-495 nm). The values of the OALs in fish grown under the same light intensity, but with light of different spectral characteristics, demonstrated significant differences (p < 0.05). The mean OAL in the daylight group was determined as 3.64 +/- 0.40 mm, as 3.70 +/- 0.35 mm in the red group, as 3.53 +/- 0.34 mm in the green group and as 3.42 +/- 0.29 mm in the blue group. The mean OAL in the blue group was significantly shorter compared to the red (p = 0.003) and the daylight groups (p = 0.02). When compared with the long wavelength light and indoor daylight, the effect of short wavelength light on OAL in fish was observed to be negative. Exposure to light with modified SS of in indoor environments may be effective in stopping ocular elongation. (C) 2016 Elsevier Ltd. All rights reserved.
The Effects of Light Sources With Different Spectral Structures on Ocular Axial Length in Rainbow Trout (Oncorhynchus Mykiss)
(Academic Press Ltd- Elsevier Science Ltd, 2023) Timucin, Ozgur Bulent; Arabaci, Muhammed; Cuce, Ferhat; Karatas, Boran; Onalan, Sukru; Yasar, Muhterem; Karadag, M. Fatih