Umut Karaca

Dr. Umut Karaca

orcid

Research Focus & Metrics

Academic Career Length

8Years (2019-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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5 January 2022 in BMC Ophthalmology
Verified
Journal Article
Open access
PDF file
UKUmut Karaca
Umut Karaca
MKMurat Kucukevcilioglu
Murat Kucukevcilioglu
ADAli Hakan Durukan
Ali Hakan Durukan
DADorukcan Akincioglu
Dorukcan Akincioglu
Background: The study aims to evaluate peripapillary retinal nerve fiber layer thickness (RNFL-T), central macular thickness (MT), choroidal thickness (CT), and thickness of each retinal layer after automatic segmentation in patients who underwent retinal detachment (RD) repair with longstanding silicone oil tamponade. Methods: We enrolled 33 patients who underwent complicated primary rhegmatogenous RD surgery and followed up with a long-term silicone tamponade were included in this retrospective comparative (case–control) study. RNFL-T, CT, and thickness of each retinal layer after automatic segmentation analysis were measured after the longstanding silicone removal surgery. Results: The mean silicone oil removal time was 15.1 ± 15.2 (7–70) months. The overall average thickness of the RNFL was 90.7 ± 13.6 μm in the operated eyes and 118.3 ± 35.6 μm in the sound eyes, with a statistically significant difference. The overall average central MT was 186.3 ± 57.7 μm and was significantly lower in the operated eyes than in the sound eyes. Inner retinal layers of the study group showed a significant thinning in the nerve fiber layer, ganglion cell layer, inner plexiform layer, and inner nuclear layer as compared to that of the sound eyes. The subfoveal CT was 213.7 ± 86.6 μm in the study eyes and 217.7 ± 115.5 μm in the control eyes. There was no significant difference between the study eyes and controls. Conclusion: The effects of silicone oil on the retina remain uncertain; however, morphological results in our study have shown direct or indirect silicone oil–induced toxicity, especially in the inner retinal layers.

8 March 2021 in BMC Ophthalmology
Verified
Journal Article
Open access
PDF file
UKUmut Karaca
Umut Karaca
EKEngin Kaya
Engin Kaya
OAOnder Ayyildiz
Onder Ayyildiz
GOGokhan Ozge
Gokhan Ozge
MKMurat Kucukevcilioglu
Murat Kucukevcilioglu
FMFatih Mehmet Mutlu
Fatih Mehmet Mutlu
Background: Intraoperative floppy iris syndrome is a variant of the small pupil syndrome that has been observed during cataract surgery in some patients currently or previously treated with α1 adrenergic blockers. It is important for cataract surgeons to predict the probable complications preoperatively. Our study aims to evaluate the static and dynamic pupil characteristics of patients treated with silodosin—a selective α1 adrenergic blocker—for benign prostate hypertrophy (BPH) and to compare these values with healthy subjects using an automatic quantitative pupillometry system. Methods: A total of 74 BPH patients treated with silodosin for six months (group 1) and 30 healthy subjects (group 2) were enrolled in this prospective multidisciplinary cross-sectional study. Static and dynamic pupillometric measurements were obtained under optimized conditions, and the results were compared between the two groups. Results: Seventy-four male patients with a mean age of 63,35 ± 7,21 (46–77) years with BPH treated with silodosin and 30 normal male subjects with a mean age of 63,07 ± 4,73 (52–71) years were analyzed. There were statistically significant differences between the groups with regard to scotopic pupil diameter (PD), high photopic PD, and low photopic PD (p < 0.001, for each one). The patient group had statistically significant higher values of amplitude and velocity of pupil contraction and lower values of duration of pupil contraction and latency as well as duration and velocity of pupil dilation. Conclusion: The static and dynamic pupil characteristics of subjects treated with silodosin for BPH are different from those of healthy eyes. In addition, our results may have shed light on the risk for intraoperative floppy iris syndrome (IFIS) before cataract surgery; thus, surgeons can be alert and take precautions.

4 March 2022 in Journal of Medical Case Reports
Verified
Journal Article
Open access
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UKUmut Karaca
Umut Karaca
Background: Scedosporium apiospermum, an opportunistic and filamentous fungus, is a rarely seen ocular entity that is difficult to identify and heal. We report a challenging case of S. apiospermium keratitis and discuss the treatment modalities in light of previous studies. Case presentation: A 30-year-old Turkish farmer with a history of contact lens misuse presented to our clinic with a painful corneal abscess and severe vision loss in his left eye. S. apiospermum was identified by spectrophotometric analysis. The patient was successfully treated with therapeutic penetrating keratoplasty, but was resistant to fluconazole and amphotericin B and susceptible but unresponsive to voriconazole. Conclusion: S. apiospermum keratitis should be considered in the differential diagnosis of immunocompromised and immunocompetent patients with history of ocular trauma and contact lens use, especially those who do not respond to treatment.

4 September 2022 in European Journal of Ophthalmology
Verified
Journal Article
Closed access
GUGulsah USTA
Gulsah USTA
YEYalcın Erzurumlu
Yalcın Erzurumlu
UKUmut Karaca
Umut Karaca
ICIbrahim Aydın Candan
Ibrahim Aydın Candan
MSMehtap Savran
Mehtap Savran
NHNursel Hasseyid
Nursel Hasseyid
Purpose: Ramelteon (RML) is a potent, selective agonist of the high-affinity melatonin receptor 1 and 2 receptors. In addition, RML is known to have antioxidant and anti-inflammatory effects. In this study, we aimed to investigate the effects of RML on HIF-1α, VEGF and e-NOS signaling pathway in a rat model of endotoxin-induced uveitis (EIU). Methods: Twenty-eight Wistar albino rats were divided into 4 groups as controls, lypopolysaccharide (LPS) group (5 mg/kg i.p.), LPS + RML group (5 mg/kg i.p and 8 mg/kg orally, respectively) and RML group (8 mg/kg orally). EIU was induced by a single intraperitoneal LPS injection. Histopathological and genetical analyses were performed. Results: In histopathological analysis, LPS caused mild anterior uveitis characterized by increased surface area of iris leaflets and ciliary body due to edema, mild to moderate congestion, and inflammatory infiltrate 6 h following the injection. The pathological findings were reduced by RML. Higher inflammation levels seen in LPS group were significantly reduced in LPS + RML group. Also, HIF-1 α, eNOS and VEGF expressions increased in LPS and decreased in LPS + RML group. Conclusion: RML treatment reversed the changes in the HIF-1α /eNOS/ VEGF signaling pathway in LPS-induced uveitis in rats, preventing the progression of the damage and showed positive effects.

9 February 2023 in Medicina
Verified
Journal Article
Open access
PDF file
GOGokhan Ozge
Gokhan Ozge
UKUmut Karaca
Umut Karaca
MSMehtap Savran
Mehtap Savran
GUGulsah USTA
Gulsah USTA
KGKanat Gulle
Kanat Gulle
HAHalil Asci
Halil Asci
Background and Objectives: Ocular alkaline burn is a clinical emergency that can cause permanent vision loss due to limbal stem cell deficiency and corneal neovascularization (CNV). Although the basic pathogenetic mechanisms are considered to be acute oxidative stress and corneal neovascularization triggered by inflammation, the underlying intracellular mechanisms have not been clearly elucidated. The aim of this study was to investigate the role of endoplasmic reticulum (ER) stress on inflammation and neovascularization, and the effect of the ER stress inhibitor salubrinal (SLB), as a novel treatment in a corneal alkaline burn model in rats. Methods: Chemical burns were created by cautery for 4 s using a rod coated with 75% silver nitrate and 25% potassium nitrate in the corneal center for the corneal neovascularization (CNV) model. Twenty-eight Wistar albino rats were divided into four groups: SHAM, CNV, CNV + SLB, and CNV + bevacizumab (BVC). After the CNV model was applied to the right eye, a single subconjunctival dose (0.05 mL) of 1 mg/kg salubrinal was injected into both eyes in the CNV + SLB group. A total of 1.25 mg/mL of subconjunctival BVC was administered to the CNV + BVC group. Fourteen days after experimental modeling and drug administration, half of the globes were placed in liquid nitrogen and stored at −20 °C until biochemical analysis. The remaining tissues were collected and fixed in 10% buffered formalin for histopathological and immunohistochemical analysis. Three qualitative agents from three different pathways were chosen: TNFR for inflammation, endothelial nitric oxide synthase (e-NOS) for vascular endothelial growth factor (VEGF)-mediated vascular permeability, and caspase-3 for cellular apoptosis. Results: Significantly lower caspase-3 and eNOS levels were detected in the CNV + SLB and CNV + BVC groups than in the CNV group. Additionally, histopathological evaluation revealed a significant decrease in neovascularization, inflammatory cell infiltration, and fibroblast activity in the CNV + SLB and CNV + BVC groups. The endoplasmic reticulum stress inhibitor, salubrinal, administered to the treatment group, attenuated apoptosis (caspase-3) and inflammation (e-NOS). In the control group (left eyes of the SLB group), salubrinal did not have a toxic effect on the healthy corneas. Conclusion: The ER stress pathway plays an important role in angiogenesis after alkaline corneal burns, and treatment with SLB modulates this pathway, reducing caspase-3 and eNOS levels. Further studies are needed to understand the molecular mechanisms altered by SLB-mediated therapy. The fact that more than one mechanism plays a role in the pathogenesis of CNV may require the use of more than one molecule in treatment. SLB has the potential to affect multiple steps in CNV pathogenesis, both in terms of reducing ER stress and regulating cellular homeostasis by inhibiting the core event of integrated stress response (ISR). Therefore, it can be used as a new treatment option and as a strengthening agent for existing treatments. Although blockade of intracellular organelle stress pathways has shown promising results in experimental studies, more in-depth research is needed before it can be used in routine practice. To the best of our knowledge, this study is the first to report the role of ER stress in corneal injury.

9 March 2021 in Seminars in Ophthalmology
Verified
Journal Article
Closed access
DÖDilek ÖZKAYA
Dilek ÖZKAYA
GUGulsah USTA
Gulsah USTA
UKUmut Karaca
Umut Karaca
MÖMehmet Okan Özkaya
Mehmet Okan Özkaya
To evaluate the anterior segment changes of eye during pregnancy according to the trimesters and compare them with non-pregnant subjects.This prospective study included 90 pregnant women (1.trimest...