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8
result(s) for
"Üçer, Mehmet Barış"
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Disc–fovea distance and choroidal thickness: is there a relationship?
2022
Background:
The distance between the optic disc center and the fovea is a biometric parameter; however, it is unclear whether DFD (disc–fovea distance) affects the choroidal thickness.
Objective:
The aim of this study is to investigate the association between DFD and choroidal thickness.
Design:
This is a prospective, and cross-sectional study.
Methods:
Two hundred fifty eyes of 250 healthy participants were examined in terms of DFD, age, axial length, spherical equivalent, and choroidal thickness. Inclusion criteria included aged between 20–40 years, no posterior segment disorders, and participants with best-corrected visual acuity (10/10 according to Snellen’s chart). Participants with high hypermetropia (>4 diopter) or myopia (>6 diopter) or any systemic disease likely to affect choroidal thickness were excluded. Choroidal thickness measurements were performed at subfoveal, 1.0 mm temporal, and 1.0 mm nasal using the enhanced-depth imaging optical coherence tomography.
Results:
The mean age of all the participants was 26.21 ± 5.73 years, mean DFD was 4634.29 ± 274.70 µm, mean axial length was 23.62 ± 0.83 mm, and mean spherical equivalent was −0.61 ± 1.06 diopter. The mean subfoveal, nasal, and temporal choroidal thicknesses were 388.73 ± 90.15 µm, 351.26 ± 88.09 µm, and 366.50 ± 79.56 µm, respectively. A negative correlation was found between subfoveal, nasal, and temporal choroidal thicknesses and axial length (r = −0.157, p = 0.013; r = −0.168, p = 0.008; r = −0.174, p = 0.006, respectively). Insignificant correlation was found between choroidal thicknesses and spherical equivalent (p > 0.05). There was not a statistically significant correlation between DFD and subfoveal, nasal, and temporal choroidal thicknesses (r = −0.028, p = 0.655; r = 0.030, p = 0.641; r = −0.025, p = 0.699, respectively). In addition, there was not a statistically significant correlation between age and choroidal thickness.
Conclusion:
This study shows that DFD and spherical equivalent do not affect choroidal thickness; axial length negatively affects choroidal thickness. In addition, age does not affect choroidal thickness between 20 and 40 years.
Journal Article
How does anisometropia affect the choroidal vascularity index?
2022
Purpose:
To investigate the choroidal vascularity index (CVI) and morphological features of the choroid in anisometropic amblyopia.
Methods:
In this prospective cross-sectional study, 39 patients with unilateral anisometropic amblyopic patients and 33 eyes of 33 healthy control participants were involved. These participants were examined in terms of axial length (AL), spherical equivalent (SE), central macular thickness (CMT), choroidal thickness (CT), total choroidal area (TCA), luminal area (LA), stromal area (SA), LA/SA ratio, and CVI. All parameters were compared between amblyopic eyes, healthy fellow eyes, and healthy control eyes. The Shapiro-Wilk tests, Chi-square test, the paired t-test, Wilcoxon signed-rank test, Mann-Whitney U test, Kruskal-Wallis test, and Pearson/Spearman correlation tests were used.
Results:
In the hyperopic patients; SE, subfoveal CT, nasal CT, temporal CT, TCA, LA, SA, and CMT were greater in amblyopic eyes than in healthy fellow eyes and control eyes (P < 0.001, P < 0.001, P < 0.001, P < 0.001, P < 0.001, P < 0.001, and P < 0.001, respectively), and CVI, LA/SA ratio, and AL were smaller in amblyopic eyes than in healthy fellow eyes and control eyes ([P < 0.001, P = 0.006], P < 0.001, and P < 0.001, respectively). In the myopic patients, subfoveal CT, nasal CT, temporal CT, TCA, LA, SA values were statistically smaller in amblyopic eyes than in healthy eyes and control eyes ([P < 0.001, P = 0.002), [P = 0.004, P = 0.012], [P = 0.012, P = 0.032], [P < 0.001, P = 0.013], [P < 0.001, P = 0.024], and [P < 0.001, P = 0.047], respectively). The differences in the AL and choroidal parameters were due to myopia and hyperopia.
Conclusion:
The choroidal structural parameters of the amblyopic eyes were different from that of the healthy eyes.
Journal Article
How does anisometropia affect the choroidal vascularity index?
by
Şahin, Tayfun
,
Üçer, Mehmet Barış
,
Cevher, Selim
in
Amblyopia
,
Biological markers
,
Care and treatment
2022
To investigate the choroidal vascularity index (CVI) and morphological features of the choroid in anisometropic amblyopia. In this prospective cross-sectional study, 39 patients with unilateral anisometropic amblyopic patients and 33 eyes of 33 healthy control participants were involved. These participants were examined in terms of axial length (AL), spherical equivalent (SE), central macular thickness (CMT), choroidal thickness (CT), total choroidal area (TCA), luminal area (LA), stromal area (SA), LA/SA ratio, and CVI. All parameters were compared between amblyopic eyes, healthy fellow eyes, and healthy control eyes. The Shapiro-Wilk tests, Chi-square test, the paired t-test, Wilcoxon signed-rank test, Mann-Whitney U test, Kruskal-Wallis test, and Pearson/Spearman correlation tests were used. In the hyperopic patients; SE, subfoveal CT, nasal CT, temporal CT, TCA, LA, SA, and CMT were greater in amblyopic eyes than in healthy fellow eyes and control eyes (P < 0.001, P < 0.001, P < 0.001, P < 0.001, P < 0.001, P < 0.001, and P < 0.001, respectively), and CVI, LA/SA ratio, and AL were smaller in amblyopic eyes than in healthy fellow eyes and control eyes ([P < 0.001, P = 0.006], P < 0.001, and P < 0.001, respectively). In the myopic patients, subfoveal CT, nasal CT, temporal CT, TCA, LA, SA values were statistically smaller in amblyopic eyes than in healthy eyes and control eyes ([P < 0.001, P = 0.002), [P = 0.004, P = 0.012], [P = 0.012, P = 0.032], [P < 0.001, P = 0.013], [P < 0.001, P = 0.024], and [P < 0.001, P = 0.047], respectively). The differences in the AL and choroidal parameters were due to myopia and hyperopia. The choroidal structural parameters of the amblyopic eyes were different from that of the healthy eyes.
Journal Article
Comparison of central corneal thickness measurements with three different optical devices
2021
Purpose:
The purpose of this study was to compare and evaluate the agreement of central corneal thickness (CCT) values obtained with three different devices working according to optical principle in healthy eyes.
Methods:
60 eyes of 60 individuals (30 men and 30 women) were enrolled in this study. CCT measurements performed with Scheimpflug–Placido topographer (Sirius), spectral-domain optical coherence tomography (RTVue) with an anterior segment module, and optical biometer (AL-Scan) were compared. Bland–Altman analysis was used to demonstrate agreement between methods.
Results:
The mean age was 30.07 ± 7.313 years (range, 18–47 years). The mean CCT values obtained by RTVue, Sirius, and AL-Scan were 518.25 ± 36.38 µm, 526.08 ± 36.33 µm, and 513.50 ± 39.09 µm, respectively. The mean differences in CCT were 7.83 ± 14.15 µm between Sirius and RTVue, 12.58 ± 11.87 µm between Sirius and AL-Scan, and 4.75 ± 4.50 µm between RTVue and AL-Scan. The mean CCT was statistically different among the three groups (p < 0.05). All three modalities of CCT measurements correlated closely with each other, with Pearson’s correlation coefficients ranging from 0.924 to 0.961. The 95% limits of agreement were −19.90 to 35.56 µm between Sirius and RTVue, −10.69 to 35.85 µm between Sirius and AL-Scan, and −4.07 to 13.58 µm between RTVue and AL-Scan.
Conclusion:
Different results could be obtained through different noncontact devices in CCT measurements. Although the measurement values obtained by these devices show a high level of correlation, it would be a more correct approach to not use them directly interchangeably in clinical practice. Evaluation and follow-up of CCT should be performed using the same device.
Journal Article
Analysis of the Choroidal Structure in the Early Stage of Type 2 Diabetic Retinopathy
2024
Background and Objective:
Our aim was to evaluate the choroidal structure in the early stage of Type 2 diabetic retinopathy (DR).
Materials and Methods:
The study included patients with nonproliferative diabetic retinopathy (NPDR) without edema (n = 30, NPDR group), patients with diabetes without retinopathy (n = 30, No DR group), and healthy subjects (n = 33, control group). Choroidal thickness (CT), total choroidal area (TCA), luminal area (LA), stromal area (SA), and choroidal vascularity index (CVI) were evaluated.
Results:
The hypertension (HT) rate was highest in patients with NPDR (63.3%), and lowest in the control group (27.3%). Subfoveal, nasal, temporal CT, TCA, and LA were thinner in patients with diabetes compared to the control group for both patients with and without HT, although not significantly. CTs, TCA, LA, and SA were lower in hypertensive patients than patients without HT in all groups. CVI and LA/SA were significantly lower in NPDR group compared to the controls for both patients with and without HT.
Conclusion:
In patients with diabetes and before clinical retinopathy develops, the thinning of the CT and CVI begins. A decrease in CVI continues as the retinopathy progresses. HT appears to be a factor that can reduce CT, TCA, LA, and SA.
[Ophthalmic Surg Lasers Imaging Retina 2024;55:xx–xx.]
Journal Article
Anterior segment changes following Nd: YAG laser posterior capsulotomy: a quantitative ultrasound biomicroscopy study
2025
Purpose: To evaluate the effects of neodymium-doped yttrium-aluminum-garnet (Nd: YAG) laser posterior capsulotomy on anterior segment parameters in pseudophakic eyes using ultrasound biomicroscopy (UBM).
Methods: This prospective study included 35 pseudophakic eyes of 34 patients with visually significant posterior capsule opacification (PCO) following uncomplicated phacoemulsification with a one-piece hydrophobic acrylic intraocular lens. UBM was used to assess anterior segment parameters, including anterior chamber angle (ACA), anterior chamber depth (ACD), anterior chamber width (ACW), lens vault (LV), and iris thickness (IT). The angle opening distances (AOD) at 500 μm (AOD500), and at 750 μm (AOD750), the angle recess area (ARA) at 500 μm (ARA 500), the trabecular-iris space area at 500 μm (TISA 500), and at 750 μm (TISA 750) were measured both temporal and nasal area. The measurements were taken three times, the first time before the Nd: YAG capsulotomy, the second time 1 week after and the third time 1 month after the procedure.
Results: No statistically significant changes were found in intraocular pressure (IOP), central corneal thickness, ACD, ACW, LV, or IT following capsulotomy. However, a significant and sustained increase was observed in angle-related parameters (ACA, AOD500/750, ARA500, and TISA500/750) at both 1 week and 1 month post-procedure(
p
< 0.05 for all). No significant changes were detected between the 1st week and 1st month measurements of angle-related parameters (
p
> 0.05 for all).
Conclusion: Nd: YAG laser capsulotomy leads to significant widening of anterior chamber angle structures without affecting IOP or ACD. These findings suggest that the procedure is safe and may positively influence aqueous humor dynamics.
Journal Article
What is the relationship between the choroidal vascularity ındex (CVI) and myopia?
by
Cevher, Selim
,
Öztürk, Caner
,
Üçer, Mehmet Barış
in
Adult
,
Axial Length, Eye - pathology
,
Choroid - blood supply
2025
Purpose
To examine the detailed vascular and morphological characteristics of the choroidal tissue in subjects with myopia.
Methods
A total of 111 subjects with myopia were included in the study. The study was conducted in three groups according to spherical equivalent(SE). Group 1 comprised subjects with low myopia (SE between 0.00 diopter (D) and − 3.00 D), Group 2 included those with moderate myopia (SE between − 3.25 D and − 6.00 D), and Group 3 consisted of subjects with high myopia (SE of − 6.25 D or worse). The following parameters were measured: axial length(AL), SE, central macular thickness (CMT), choroidal thickness(CT), total choroidal area(TCA), luminal area(LA), stromal area(SA), LA/SA ratio, and choroidal vascularity index(CVI). The binarization method was employed to calculate the TCA, LA, SA, LA/SA ratio, and CVI values. A comparison was conducted between the groups with respect to all parameters.
Results
In patients with high myopia, CT values (subfoveal, nasal, and temporal) were significantly thinner than moderate and low myopic patients (< 0.001). The low myopic group exhibited significantly elevated LA, SA, and TCA values in comparison to the moderate and high myopic groups. Conversely, the LA/SA ratio and CVI values were observed to be higher in patients with high myopia than in those with low or moderate myopia. A statistically significant negative correlation was identified between CVI and LA/SA values and SE(r = − 0.270,
P
= 0.004; r = − 0.291,
P
= 0.002, respectively). A statistically significant positive correlation was identified between CVI and LA/SA values and AL (r = 0.269,
P
= 0.004; r = 0.281,
P
= 0.003, respectively).
Conclusion
In young adults, high myopia has been linked to significant choroidal thinning in the macular region. This reduction in choroidal thickness is largely attributed to a decrease in the stromal component of the choroid, rather than the luminal (vascular) component.
Trial registration date and number
08/06/2022, 2022-49.
Journal Article
Choroidal Thickness in Emmetropia: An Enhanced Depth Imaging Spectral-Domain Optical Coherence Tomography-Based Study
2022
To investigate and determine the choroidal thickness (CT) in healthy emmetropic Turkish subjects aged between 20 and 40 years using Enhanced Depth Imaging Spectral-Domain Optical Coherence Tomography (EDI-OCT).
This study included 194 eyes of 194 healthy emmetropic subjects. All participants underwent a detailed ophthalmologic examination. Axial length (AL) was measured with optical biometry. CT measurements were performed at subfoveal, 1.0 mm temporal, and 1.0 mm nasal using the EDI-OCT. Central macular thickness (CMT) measurements were also performed at the same time. Participants were divided into two groups; Group 1 (age between 20 and 30 years) and Group 2 (age between 31 and 40 years). CT and CMT were compared among two groups.
The mean age of all the subjects was 26.61±6.08 years, the mean AL was 23.44±0.72 mm, and the mean spherical equivalent was -0.11±0.28 Diopter. The mean subfoveal, nasal, and temporal CT was 389.27±86.61 μm, 354.54±86.86 μm, and 368.25±78.69 μm, respectively. Subfoveal and nasal CT of female participants were found thinner than male participants (p=0.013 and p=0.008, respectively). CT and CMT were found similar between Group 1 and Group 2.
This study showed that mean subfoveal CT and CMT was 389.27±86.61μm and 268.17±18.76 μm, respectively, among healthy emmetropic Turkish subjects. Females had thinner CT in subfoveal and nasal quadrants. In addition, age did not affect CT between 20 and 40 years.
Journal Article