Publications by authors named "Selim Orgul"

Our aim was to analyze the intraocular pressure (IOP) changes following different intravitreous injection (IVI) procedures with or without prefilled syringes (PFS) and to elaborate their possible causes. Clinical study and laboratory assessment. 173 eyes of 141 patients.

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Human organoids recapitulating the cell-type diversity and function of their target organ are valuable for basic and translational research. We developed light-sensitive human retinal organoids with multiple nuclear and synaptic layers and functional synapses. We sequenced the RNA of 285,441 single cells from these organoids at seven developmental time points and from the periphery, fovea, pigment epithelium and choroid of light-responsive adult human retinas, and performed histochemistry.

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Purpose: To evaluate the correlation between retinal venous blood flow parameters and glaucomatous visual field damage in a retrospective analysis.

Methods: Fifty-five (24 male, 31 female) glaucoma patients, under intraocular pressure (IOP) reducing treatment, aged (mean ± SD) 69 ± 10 years, 29 with primary open-angle and 26 with normal-tension glaucoma, were evaluated with regard to the correlation between IOP, color Doppler retinal venous blood flow velocity and glaucomatous damage.

Results: Univariate regression analysis disclosed statistically significant correlations of the visual field index MD with age, IOP and venous blood flow (p ≤ 0.

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Monitoring subtle choroidal thickness changes in the human eye delivers insight into the pathogenesis of various ocular diseases such as myopia and helps planning their treatment. However, a thorough evaluation of detection-performance is challenging as a ground truth for comparison is not available. Alternatively, an artificial ground truth can be generated by averaging the manual expert segmentations.

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Background: The broad spectrum of uveitis disorders requires a multimodal imaging approach in the daily practice of an ophthalmologist. As inflammatory conditions, they have in common an alteration in leukocyte migration. In this context, optical coherence tomography angiography (OCTA) might be of great value for diagnosing or following up patients with these disorders.

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Purpose: To analyse a prognostic value of initial retinal vessel flicker response for the 3-year development of functional (visual field) and morphological (nerve fibre layer thickness) damage progression in primary open-angle glaucoma patients.

Patients And Methods: Initially, 70 patients were recruited, and flicker response was measured by standardized procedure with the retinal vessel analyser (RVA). Ocular coherence tomography of retinal nerve fibre layer (OCT RNFL) and a visual field testing were performed at beginning and every 6 months for 3 years; 56 patients completed the study.

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It is widely accepted that cold exposure increases peripheral vascular resistance and arterial blood pressure (BP) and, hence, increases cardiovascular risk primarily in the elderly. However, there is a lack of concomitantly longitudinal recordings at personal level of environmental temperature (PET) and cardiophysiological variables together with skin temperatures (STs, the “interface-variable” between the body core and ambient temperature). To investigate the intra-individual temporal relationships between PET, STs and BP 60 healthy young women (52 completed the entire study) were prospectively studied in a winter/summer design for 26 h under real life conditions.

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Purpose: To investigate relationship between the peripapillary retinal vessel diameter and the residual retinal function, measured by mfERG, in patients with retinitis pigmentosa (RP).

Patients And Methods: A cross-sectional study based on 23 patients with RP (43 eyes) and 20 controls (40 eyes) was performed. Retinal vessel diameters were measured using a computer-based program of the retinal vessel analyser (RVA; IMEDOS Systems UG, Jena, Germany).

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Purpose: Retinal oximetry (RO) has been established as a non-invasive method to analyse oxygen saturation in retinal vessels. The aim of our study was to determine the reproducibility of RO images in healthy and in diseased retinas.

Methods: A total of 61 right eyes (244 RO images) in 61 subjects (35♀, 26♂) were examined: 22 controls, 18 patients with glaucoma and 21 patients with inherited retinal diseases (IRDs).

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Purpose: To study the influence of retinal structural changes on oxygen saturation in retinitis pigmentosa (RP) patients.

Methods: Oximetry measurements were performed on 21 eyes of 11 RP patients and compared to 24 eyes of 12 controls. Retinal oxygen saturation was measured in all major retinal arterioles (A-SO₂) and venules (V-SO₂) with an oximetry unit of the retinal vessel analyser (IMEDOS Systems UG, Jena, Germany).

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Purpose: Purpose Differences in the gene expression of leukocytes between patients with normal-tension glaucoma (NTG) and controls have been described. This study was performed in order to detect the differences in gene expression in peripheral lymphocytes in patients with primary open-angle glaucoma (POAG), patients with pseudoexfoliation glaucoma (PEX), and patients with NTG, and in healthy subjects.

Methods: Ten patients with POAG, 11 patients with PEX, 10 patients with NTG, and 42 sex- and age-matched healthy persons were recruited.

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Aim: To evaluate the effect of ageing on the retinal vascular responsiveness to flicker light in glaucoma and ocular hypertension (OHT).

Methods: Retinal vascular response to flicker was measured with the retinal vessel analyser in 56 healthy subjects (59 ± 9 years), 50 primary open-angle glaucoma (POAG) (60 ± 10 years) and 46 OHT patients (62 ± 9 years). In the glaucoma group, the less damaged eye; in the OHT group, the eye with the higher intraocular pressure; and in healthy controls, one randomly selected eye was considered.

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Purpose: To study the impact of the mitochondrial ubiquitin ligase MARCH5 on mitochondrial morphology and induction of apoptosis using an in vitro model of neuronal precursor cells exposed to glaucoma-relevant stress conditions.

Methods: RGC5 cells transfected with expression constructs for MARCH5, MARCH5(H43W), Dpr1(K38A) or vector control were exposed to either elevated pressure of 30 mmHg, oxidative stress caused by mitochondrial electron transport chain (ETC) inhibition, or hypoxia-reoxygenation conditions. Mitochondrial morphology of RGC5 cells was analyzed following staining of the mitochondrial marker cytochrome c and photoactivatable GFP (PAGFP) diffusion assay.

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It is generally assumed that skin vascular resistance contributes only to a small extent to total peripheral resistance and hence to blood pressure (BP). However, little is known about the impact of skin blood flow (SBF) changes on the diurnal variations of BP under ambulatory conditions. The main aim of the study was to determine whether diurnal patterns of distal SBF are related to mean arterial BP (MAP).

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Purpose: To analyze an association between the presumed risk factors for glaucoma and the actual extent of glaucomatous damage in untreated primary open-angle glaucoma.

Patients And Methods: In 50 untreated open-angle glaucoma patients, we analyzed an association between the level of glaucomatous damage and presumed glaucoma risk factors: mean untreated intraocular pressure (IOP) and short-term IOP variability, ocular pulse amplitude, corneal thickness, acral and corneal temperature, retinal arterial diameter and retinal venous diameter, choroidal blood flow (laser Doppler flowmetry flow, velocity, volume), heart rate, and ocular perfusion pressure. Morphologic damage (mean retinal nerve fiber layer thickness, measured by ocular coherence tomography) and functional damage (visual field mean defect) were evaluated separately in 2 forward-stepwise multiple regression models.

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Purpose: To assess risk factors for failure in canaloplasty.

Methods:   Nonrandomized prospective study involving 51 eyes of 51 patients with medically uncontrolled primary open-angle glaucoma undergoing canaloplasty. Visual acuity, intraocular pressure (IOP) and slit-lamp examinations were performed before and after surgery at 1 and 7 days, and at 1 month and every 3 months thereafter.

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The main objective of this report is to encourage consistent quality of testing and reporting within and between centres that use colour Doppler imaging (CDI) for assessment of retrobulbar blood flow. The intention of this review is to standardize methods in CDI assessment that are used widely, but not to exclude other approaches or additional tests that individual laboratories may choose or continue to use.

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Purpose: To determine the possibility of plasma citrate as a biomarker in patients with glaucoma.

Methods: Twenty-one consecutive Caucasian patients with glaucoma and 21 sex- and age-matched controls were investigated. Plasma citrate, plasma creatinine, urine citrate, and urine creatinine were analyzed by ion chromatography.

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Purpose: To analyze submacular choroidal blood flow (ChBF) response to isometric exercise in untreated patients with glaucoma and ocular hypertension.

Methods: ChBF was examined by means of confocal laser Doppler flowmetry during 5 minutes of baseline, during 90 seconds of isometric exercise with a Martin's vigorimeter and during 15 minutes of recovery. Values from one randomly chosen eye of 45 healthy subjects, the eye with more advanced damage in 45 primary open-angle glaucoma (POAG) patients, and the eye with higher native intraocular pressure in 45 patients with ocular hypertension (OHT) were acquired, and parameters of ChBF as well as blood pressure response were analyzed.

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Purpose: To evaluate the influence of menopausal status and age on peripheral and ocular circulation assessed by means of continuous laser Doppler flowmetry (LDF).

Methods: Fifty-three healthy participants were recruited randomly. Twenty-six men and 27 women were divided into two age groups.

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The aim of the study was to investigate whether women with primary vascular dysregulation (VD; main symptoms of thermal discomfort with cold extremities) and difficulties initiating sleep (DIS) exhibit a disturbed phase of entrainment (Ψ) under everyday life conditions. The authors predicted a phase delay of the distal-proximal skin temperature gradient and salivary melatonin rhythms with respect to the sleep-wake cycle in women with VD and DIS (WVD) compared to controls (CON), similar to that found in their previous constant-routine laboratory data. A total of 41 young healthy women, 20 with WVD and 21 matched CON without VD and normal sleep onset latency (SOL), were investigated under ambulatory conditions (following their habitual bedtimes) during 7 days of continuous recording of skin temperatures, sleep-wake cycles monitored by actimetry and sleep-wake diaries, and single evening saliva collections for determining the circadian marker of dim light melatonin onset (DLMO).

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Heart-rate variability patterns of 18 women during a 40-h constant routine of prolonged wakefulness under controlled laboratory conditions were analyzed. The authors tested the circadian timing of the autonomic nervous system and the relationship between the sympathetic and vagal branches in women with both a functional disorder of vascular regulation (main symptom: cold hands and feet) and prolonged sleep onset and controls without these symptoms. Spectral analysis of R-R intervals during paced breathing episodes revealed significantly lower power values in the high-frequency band (HF; 0.

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Purpose: To assess the safety and efficacy of canaloplasty (360-degree viscodilation and tensioning of the Schlemm canal) in Whites with open-angle glaucoma (OAG).

Methods: In a prospective study, 32 consecutive patients with medically uncontrolled OAG underwent primary canaloplasty with a follow-up time of more than 1 year. Laser goniopuncture was performed if postoperative intraocular pressure (IOP) was above 16 mmHg.

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