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Permanent URI for this collectionhttps://hdl.handle.net/11727/10754

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Subject: search.filters.subject.Optical coherence tomography

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    Evaluation of choroidal and retinal thickness measurements in adult hemodialysis patients using spectral-domain optical coherence tomography
    (2016) Kal, Ali; Kal, Oznur; Eroglu, Fatma Corak; Omer, Ozlem; Kucukdonmez, Cem; Yilmaz, Gursel; 0000-0002-2589-7294; 0000-0003-3003-0756; 27626146; AAK-6987-2021; D-5308-2015
    Purpose: To assess the effect of hemodialysis on retinal and choroidal thicknesses using spectral-domain optical coherence tomography (SD-OCT). Methods: In this prospective interventional study, 25 hemodialysis patients (17 male, 8 female) were enrolled. All participants underwent high-speed, high-resolution SD-OCT (lambda=840 mm; 26.000 A-scans/s; 5 mu m resolution) before and after hemodialysis. Choroidal thickness was measured perpendicularly from the outer edge of the retinal pigment epithelium to the choroid-sclera boundary at the fovea and at five additional points: 500 mu m and 1000 mu m nasal to the fovea and 500 mu m, 1000 mu m, and 1500 mu m temporal to the fovea. Two masked physicians performed the measurements. Choroidal and retinal thicknesses before and after hemodialysis were compared. Results: The median choroidal thicknesses before and after hemodialysis were 182 mu m (range, 103-374 mu m) and 161 mu m (range, 90-353 mu m), respectively (P<0.001). The median retinal thicknesses were 246 mu m (range, 179-296 mu m) before and 248 mu m (range, 141-299 mu m) after hemodialysis (P>0.05). Systolic arterial pressure, diastolic arterial pressure, mean arterial pressure, heart rate, and ocular perfusion pressure significantly decreased after hemodialysis (P<0.001). Intraocular pressure did not vary significantly (P=0.540). Conclusion: Hemodialysis seems to cause a significant decrease in choroidal thickness, whereas it has no effect on retinal thickness. This significant decrease in choroidal thickness might be due to the extensive fluid absorption in hemodialysis, which could result in decreased ocular blood flow.
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    Evaluation of the acute effect of haemodialysis on retina and optic nerve with optical coherence tomography
    (2016) Emre, Sinan; Ozturkeri, Anil; Ulusoy, Mahmut Oguz; Cankurtaran, Cem; 28003781; T-5643-2019
    Purpose: The primary objective of haemodialysis (HD) was to correct the composition and volume of body fluids. The aim of this study was to evaluate the acute effect of HD on mean arterial pressure changes and on retina and optic nerve with optical coherence tomography (OCT). Methods: Fifty-three eyes of 28 patients were enrolled in this study. The patients' retinal and RNFL thicknesses were measured by OCT and mean arterial pressure alterations were recorded before and immediately after HD session. Results: The results show that while there was a reduction at central foveal thickness and ganglion cell layer thickness, central sub-field and RNFL thickness were increased with HD session. But none of them were statistically significant (p = 0.320, p = 0.792, p = 0.744, p = 0.390). The mean arterial pressure of the patients decreased significantly (p < 0.05) but it was not correlated with retinal and RNFL values. Conclusion: The changes in retinal and RNFL findings were not significant. But these alterations may effect the long term follow-up of the patients with retinal and optic nerve disease. Therefore it is important to pay attention HD session time for these patients' measurements.
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    Prevalence of Split Nerve Fiber Layer Bundles in Healthy People Imaged with Spectral Domain Optical Coherence Tomography
    (2016) Gungor, Sirel Gur; Akman, Ahmet; Sezenoz, Almila Sarıgul; Tanriasik, Gulsah; 0000-0001-6178-8362; 0000-0002-7030-5454; 28050324; AAD-5967-2021; AAJ-4860-2021
    Objectives: The presence of retinal nerve fiber layer (RNFL) split bundles was recently described in normal eyes scanned using scanning laser polarimetry and by histologic studies. Split bundles may resemble RNFL loss in healthy eyes. The aim of our study was to determine the prevalence of nerve fiber layer split bundles in healthy people. Materials and Methods: We imaged 718 eyes of 359 healthy persons with the spectral domain optical coherence tomography in this cross-sectional study. All eyes had intraocular pressure of 21 mmHg or less, normal appearance of the optic nerve head, and normal visual fields (Humphrey Field Analyzer 24-2 full threshold program). In our study, a bundle was defined as 'split' when there is localized defect not resembling a wedge defect in the RNFL deviation map with a symmetrically divided RNFL appearance on the RNFL thickness map. The classification was performed by two independent observers who used an identical set of reference examples to standardize the classification. Results: Inter-observer consensus was reached in all cases. Bilateral superior split bundles were seen in 19 cases (5.29%) and unilateral superior split was observed in 15 cases (4.16%). In 325 cases (90.52%) there was no split bundle. Conclusion: Split nerve fiber layer bundles, in contrast to single nerve fiber layer bundles, are not common findings in healthy eyes. In eyes with normal optic disc appearance, especially when a superior RNFL defect is observed in RNFL deviation map, the RNLF thickness map and graphs should also be examined for split nerve fiber layer bundles.
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    Corneal, Scleral, Choroidal, and Foveal Thickness in Patients with Rheumatoid Arthritis
    (2017) Akman, Ahmet; Gungor, Sirel Gur; Gokmen, Onur; Yesilirmak, Nilufer; Yucel, Ahmet Eftal; Yesil, Hilmi; Yildiz, Fatih; Sise, Adam; Diakonis, Vasilios; 29326847; I-6542-2012
    Objectives: To investigate corneal, scleral, choroidal, and foveal thicknesses in female patients with rheumatoid arthritis (RA) and compare them with healthy subjects. Materials and Methods: This prospective study included consecutive female patients diagnosed with RA and healthy subjects. Corneal, scleral, choroidal, and retinal (foveal) thicknesses were obtained by using optical coherence tomography and a comparison was performed between groups for all outcome measures. Results: Thirty-six eyes of 36 female patients diagnosed with RA (group 1) and 36 eyes of 36 healthy female volunteers (group 2) were included. Mean corneal, scleral, choroidal thicknesses and retinal thickness at the fovea of group 1 were 543.3 +/- 33.7 mu m, 343.7 +/- 42.2 mu m, 214.6 +/- 50, and 213.5 +/- 18.9 mu m, respectively; in group 2, these values were 549.9 +/- 29.6 mu m, 420.9 +/- 42.4 mu m, 206.4 +/- 41.9 mu m, and 222 +/- 15.5 mu m, respectively. The comparison between group 1 and 2 with respect to corneal, choroidal, and foveal thicknesses did not reveal statistical significant differences (p>0.05). On the contrary, there was a statistically significant difference with respect to scleral thickness between the groups, with the RA patients demonstrating a thinner scleral layer (p<0.001). Conclusion: Female patients with RA seem to demonstrate statistically significant scleral thinning when compared with healthy subjects, while there was no difference concerning corneal, choroidal, and foveal thickness.