Researcher:
Hasanreisoğlu, Murat

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Murat

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Hasanreisoğlu

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Hasanreisoğlu, Murat

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2020 - 202325

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    Peripapillary choroidal vasculature in pediatric eyes with type 1 diabetes mellitus
    (Kare Yayıncılık, 2022) N/A; N/A; Hasanreisoğlu, Murat; Kesim, Cem; Uzunay, Nur Sena; Taş, Ayşe Yıldız; Karslıoğlu, Melisa Zişan; Şahin, Afsun; Faculty Member; Teaching Faculty; Undergraduate Student; Faculty Member; Doctor; Faculty Member; Koç University Research Center for Translational Medicine (KUTTAM) / Koç Üniversitesi Translasyonel Tıp Araştırma Merkezi (KUTTAM); School of Medicine; School of Medicine; School of Medicine; School of Medicine; N/A; School of Medicine; N/A; N/A; N/A; N/A; Koç University Hospital; N/A; 182001; 387367; N/A; 200905; N/A; 171267
    Objectives: choroidal vasculature change in children with diabetes mellitus is not investigated enough although it could reflect clinical outcome. Methods: pediatric Type 1 diabetes mellitus (T1DM) patients and healthy controls were retrospectively evaluated. Peripapillary retinal nerve fiber layer optical coherence tomography (OCT) images of the right eyes were analyzed. Choroidal parameters including total choroidal area, luminal area, stromal area, and choroidal vascularity index were measured through image binarization. Results: twenty eyes of 20 patients were compared with 46 eyes of 46 healthy controls. Mean total choroidal area, luminal area, and stromal area were 1.59±0.35, 1.10±0.24, and 0.50±0.13 mm2 in patients’ eyes and 1.52±0.49, 1.05±0.34, and 0.47±0.17 mm2 in healthy eyes. No difference was found in choroidal vascularity indices between patients and healthy eyes (68.8±3.9% vs. 69.4±4.4%, p=0.521). Temporal choroidal vascularity index was significantly higher than its nasal counterpart in healthy eyes (71.8±5.0% vs. 68.6±4.9%, p<0.001) which was not significant in patients’ eyes (70.7±4.0% vs. 68.9±5.1%, p=0.067). Temporal quadrant had the highest choroidal vascularity index score among all quadrants in healthy controls (all p<0.05), whereas no choroidal vascularity index difference between quadrants was detected in patients (p=0.75). Conclusion: peripapillary choroidal vasculature has shown subtle sectoral changes which did not reflect the overall peripapillary OCT section in pediatric T1DM patients when compared with healthy controls.
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    Differences in the characteristics of subjects achieving complete, partial, or no resolution of macular edema in the READ-3 study
    (Springer, 2021) Halim, Muhammad Sohail; Afridi, Rubbia; Hassan, Muhammad; Ibrahim-Ahmed, Mohamed; Do, Diana V.; Sepah, Yasir Jamal; N/A; Hasanreisoğlu, Murat; Faculty Member; Koç University Research Center for Translational Medicine (KUTTAM) / Koç Üniversitesi Translasyonel Tıp Araştırma Merkezi (KUTTAM); School of Medicine; 182001
    Purpose : To identify baseline characteristics of subjects enrolled in the READ-3 study that would predict the response of macular edema to ranibizumab (RBZ) therapy at year 1. Methods : In this post hoc analysis of the READ-3 randomized, multicenter phase 2 clinical trial, subjects with diabetic macular edema (DME) were randomized to receive monthly intravitreal injections of RBZ (0.5 or 2.0 mg) for 6 consecutive injections followed by as-needed treatments based on pre-defined retreatment criteria. In this sub-study, subjects were divided into three groups (persistent, rebound, and resolved) based on edema status at month 12 (M12). Multi-logistic regression was utilized to assess the probability of edema outcomes M12, based on the baseline characteristics. Results : One hundred twenty-three out of 152 subjects were analyzed for this sub-study. A significant difference was observed in the baseline (BL) central subfield thickness (CST) among the study groups (p < 0.05). BL CST was a significant predictor for edema outcome at M12 with > 80% probability of the subject having persistent edema if BL CST was > 570 mu m (p < 0.05). This association persisted when controlled for the dose of RBZ (relative risk (RR), 1.007; p < 0.05). BL CST was also a significant predictor for having persistent edema at M12 in subjects without vitreomacular adhesion (VMA) (> 80% probability of edema persistence at CST > 570 mu m [RR, 1.006; p < 0.05]). However, in the presence of VMA, BL CST was no longer a significant predictor of having persistent edema at month 12 (RR, 1.005; p > 0.05). Conclusions : Subjects with high CST (> 570 mu m) at baseline may not benefit from repeated intravitreal injections of anti-VEGF for resolution of edema.
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    Directed fine tuning using feature clustering for instance segmentation of toxoplasmosis fundus images
    (IEEE, 2020) Abeyrathna, Dilanga; Subramaniam, Mahadevan; Chundi, Parvathi; Halim, Muhammad Sohail; Ozdal, Pinar Cakar; Nguyen, Quan Dong; N/A; Hasanreisoğlu, Murat; Faculty Member; School of Medicine; 182001
    Medical image segmentation is a challenging problem for computer vision approaches where deep learning networks have achieved impressive successes in recent years. In this paper, we propose a directed, fine tuning approach for instance segmentation networks by using feature clustering of predictions along with labeled training instances to improve network performance. The approach directs and limits analyses of predicted instances by experts to similar training instances only and reduces manual overheads by managing the number of instances that need to be examined. Sub-optimal network predictions are handled either by retraining the networks on data augmented with the relevant training instances, correcting training labels, and/or by readjusting network inference parameters. We first develop a state-of-the-art Mask R-CNN based network for instance segmentation of fundus images with retinal lesions and scars caused by Ocular Toxoplasmosis. Then, we show how the proposed approach can be applied to fine tune this network in a directed manner using feature clustering using a pre-trained CNN network. We demonstrate the robustness of our proposed approach with the evaluation results - mask average IoU increased by 7% and mAP under 0.5 IoU threshold increased by 20%. Our experiments also show that fine tuning by analyzing 66% of the predicted instances achieves the same improvement as that obtained by all of the predicted instances, a significant reduction of the manual overheads for fine tuning
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    Automated diagnosis of keratoconus from corneal topography
    (Assoc Research Vision Ophthalmology Inc, 2021) N/A; N/A; N/A; Department of Industrial Engineering; N/A; Taş, Ayşe Yıldız; Hasanreisoğlu, Murat; Balım, Haldun; Gönen, Mehmet; Şahin, Afsun; Faculty Member; Faculty Member; Master Student; Faculty Member; Faculty Member; Department of Industrial Engineering; School of Medicine; School of Medicine; Graduate School of Sciences and Engineering; College of Engineering; School of Medicine; 200905; 182001; N/A; 237468; 171267
    Purpose: Although visual inspection of corneal topography maps by trained experts can be powerful, this method is inherently subjective. Quantitative classification methods that can detect and classify abnormal topographic patterns would be useful. An automated system was developed to differentiate keratoconus patterns from other conditions using computer-assisted videokeratoscopy. Methods: This system combined a classification tree with a linear discriminant function derived from discriminant analysis of eight indices obtained from TMS-1 videokeratoscope data. One hundred corneas with a variety of diagnoses (keratoconus, normal, keratoplasty, epikeratophakia, excimer laser photorefractive keratectomy, radial keratotomy, contact lens-induced warpage, and others) were used for training, and a validation set of 100 additional corneas was used to evaluate the results. Results: In the training set, all 22 cases of clinically diagnosed keratoconus were detected with three false-positive cases (sensitivity 100%, specificity 96%, and accuracy 97%). With the validation set, 25 out of 28 keratoconus cases were detected with one false-positive case, which was a transplanted cornea (sensitivity 89%, specificity 99%, and accuracy 96%). Conclusions: This system can be used as a screening procedure to distinguish clinical keratoconus from other corneal topographies. This quantitative classification method may also aid in refining the clinical interpretation of topographic maps.
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    Posterior uveitis associated with large vessel giant cell arteritis
    (Taylor & Francis, 2022) Nguyen, Nam V.; Karkhur, Samendra; Yuksel, Murat; Hassan, Muhammed; Halim, Muhammad Sohail; Nguyen, Quan Dong; N/A; Hasanreisoğlu, Murat; Faculty Member; School of Medicine; 182001
    Purpose: To report a case of acute unilateral posterior uveitis as a rare manifestation of giant cell arteritis (GCA). Observation: A 62-year-old male presented to the clinic for evaluation of decreased vision in the right eye (OD). BCVA in OD was 20/60, and fundus examination revealed 3+ vitreous cells along with several inflammatory precipitates located in posterior vitreous and on surface of retina. Although TAB was inconclusive for GCA, the clinical diagnosis of GCA was made according to the GCA diagnostic criteria. This diagnosis was further supported by (18)FDG-PET scan. The patient was started on corticosteroids, and the symptoms improved significantly after first week of treatment. At follow-up visit one month and half later, BCVA improved to 20/40 in the right eye. Conclusion: Although GCA is rarely present with uveitis, in case of unilateral posterior uveitis in elderly patient, it should be considered in the differential diagnosis.
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    Effect of light backscattering from anterior segment structures on automated flare meter measurements
    (Sage Publications Ltd, 2022) Yalınbaş, Duygu; Yılmaz, Mervenur; Zeynep; Halim, Muhammad Sohail; Sepah, Yasir J.; Nguyen, Quan Dong; N/A; Hasanreisoğlu, Murat; Kesim, Cem; Uzunay, Nur Sena; Şahin, Afsun; Faculty Member; Teaching Faculty; Undergraduated Student; Faculty Member; Koç University Research Center for Translational Medicine (KUTTAM) / Koç Üniversitesi Translasyonel Tıp Araştırma Merkezi (KUTTAM); School of Medicine; School of Medicine; School of Medicine; School of Medicine; 182001; 387367; N/A; 171267
    Background: To evaluate effect of maximal anterior cortical lens density, iris scatter and anterior chamber depth on laser flare photometry. Methods: Patients diagnosed with clinical uveitis were enrolled in the study. Clinical flare gradings were recorded upon the Standardization of Uveitis Nomenclature. Aqueous flare was measured with an automated device (Kowa FM700). Back-scattering from anterior cortical lens and anterior iris surface was calculated from Scheimpflug images. A curvilinear regression model was used to calculate estimated values for each clinical grade. These values were used to split cases in Group I (laser flare photometry lower than estimated) and Group II (laser flare photometry higher than estimated). Mean anterior chamber depth, pupil aperture, maximal anterior cortical lens density and iris scatter values were compared between two groups. A stepwise multiple regression analysis was performed to determine the effect of clinical flare gradings and ocular parameters on aqueous flare measurements. Results: The study included 228 eyes of 114 cases. Scheimpflug images were obtained from 105 eyes. Estimated aqueous flare measurements (in photons/milliseconds) were 4.87, 8.50, 14.81, 25.83, 45.04 and 136.93 for 0, 0.5+, 1+, 1.5+, 2+ and 3+ clinical flare respectively. Group II had higher maximal anterior cortical lens density than Group I (96.6 ± 37.1 vs 77.9 ± 17.1 pixel unit, p = 0.001). The measured aqueous flare was significantly related to clinical flare, maximal anterior cortical lens density and pupil aperture (adjusted R2: 0.480, p < 0.001). Conclusion: The back-scattered light from anterior cortical lens could affect laser flare photometry measurements. This effect might be quantified by Scheimpflug imaging.
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    Femtosecond laser ablation assisted nfc antenna fabrication for smart contact lenses
    (Wiley, 2022) N/A; Department of Mechanical Engineering; Department of Mechanical Engineering; N/A; N/A; N/A; N/A; Department of Mechanical Engineering; Mirzajani, Hadi; İstif, Emin; Abbasiasl, Taher; Mirlou, Fariborz; Özkahraman, Ecem Ezgi; Hasanreisoğlu, Murat; Beker, Levent; Researcher; Other; PhD Student; PhD Student; N/A; Faculty Member; Faculty Member; Department of Mechanical Engineering; Koç University Research Center for Translational Medicine (KUTTAM) / Koç Üniversitesi Translasyonel Tıp Araştırma Merkezi (KUTTAM); n2STAR-Koç University Nanofabrication and Nanocharacterization Center for Scientifc and Technological Advanced Research; College of Engineering; College of Engineering; Graduate School of Sciences and Engineering; Graduate School of Sciences and Engineering; N/A; School of Medicine; College of Engineering; N/A; N/A; N/A; N/A; N/A; 182001; 308798
    Smart contact lenses (SCLs) have drawn substantial interest for continuous health monitoring applications. Even though most of the reported works utilize near-field communication (NFC) or inductive coupling for wireless powering and data transmission, developing a scalable and rapid fabrication technique for annular ring antennas confined in a small contact lens area is still an unsolved challenge. Here, femtosecond laser ablation is employed for the first time as a simple, single-step, and highly precise fabrication technique for NFC antennas using conventional flexible printed circuit board materials. Antenna lines with depth and width of 9 and 35 mu m are achieved, respectively. The antenna with a footprint of 19.5 mm(2) is characterized in biological solution followed by aging, and bending tests, and a frequency deviation of less than %1 is recorded. A real-life application is demonstrated by fabricating an SCL embedded with the antenna, an NFC chip, and an electrochemical sensor for wireless monitoring of glucose in artificial tear solution by a smartphone. The device could successfully quantify biologically relevant glucose concentrations ranging from 0.2 to 1 mM with a limit-of-detection of 66 mu M. In addition, device response to interfering molecules is less than +/- 1 nA, and the spike-and-recovery test is successfully demonstrated.
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    Correlation of clinical aqueous flare grading to semi-automated flare measurements using laser flare photometry
    (Taylor & Francis, 2022) Halim, Muhammad Sohail; Onghanseng, Neil; Tran, Anh N. T.; Hassan, Muhammad; Yilmaz, Mervenur; Segawa, Asadu; Gurelik, Gokhan; Afridi, Rubbia; Ormaechea, Maria Soledad; Uludag, Gunay; Nguyen, Nam, V; Bae, Jeong Hun; Park, Jung Huynh; Do, Diana, V; Ibrahim, Mohamed A.; Sepah, Yasir J.; Quan Dong Nguyen; N/A; Hasanreisoğlu, Murat; Kesim, Cem; Faculty Member; Teaching Faculty; Koç University Research Center for Translational Medicine (KUTTAM) / Koç Üniversitesi Translasyonel Tıp Araştırma Merkezi (KUTTAM); School of Medicine; School of Medicine; 182001; 387367
    Purpose: To compare laser flare photometry (LFP) measurements of aqueous flare with Standardization of Uveitis Nomenclature (SUN) and modified SUN grading.Methods: In this prospective study with multicenter design, uveitis patients were classified according to SUN and modified SUN grading scales. LFP was performed with Kowa FM-700 flaremeter. Mean LFP values were compared with SUN and MSUN scores.Results: The study included 475 LFP measurements, of which 216, 48, 150, 31, 28 and 2 had 0, 0.5+, 1+, 1.5 +, 2+ and 3+ flare, respectively. LFP values were significantly different between each two consecutive steps for both clinical gradings (all P < .05). Cut-off values for modified SUN grading steps were defined as 5.7, 9.7, 15.7 and 43.2 for 0/0.5+, 0.5+/ 1+, 1+/1.5+ and 1.5/2+ borders of clinical flare, respectively.Conclusions: LFP proves to be an objective measurement in analyzing aqueous flare comparable to both SUN and MSUN clinical grading systems.
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    Comparison of pediatric patients with idiopathic uveitis, and uveitis due to juvenile idiopathic arthritis and Behçet's disease
    (Taylor & Francis, 2023) Yildirim, Deniz Gezgin; Bakkaloglu, Sevcan A.; N/A; Hasanreisoğlu, Murat; Faculty Member; School of Medicine; 182001
    Objectives: The aim of this study is to compare the demographic, clinical features, treatment results and outcomes in pediatric patients with idiopathic uveitis and uveitis due to juvenile idiopathic arthritis (JIA) and Behçet’s disease (BD).Methods: 97 pediatric uveitis patients were divided into three groups according to the etiology of uveitis: Group 1 comprised idiopathic uveitis patients, Group 2 uveitis patients who had JIA, and Group 3 uveitis patients with BD.Results: Symptomatic presentation and intermediate uveitis were more common in Group 1 (p < 0.005). Asymptomatic presentation and anterior uveitis in Group 2 (p < 0.005), whereas sympto-matic presentation and posterior uveitis in Group 3 (p < 0.005). Erythrocyte sedimentation rate (ESR) was higher in patients with BD or JIA uveitis than those with idiopathic uveitis (p < 0.005). Biologic therapy was more commonly used in JIA group compared to other groups (p < 0.005). Patients who had a complication related with uveitis were more common in females, asymptomatic disease course, and needed use of biologic treatment than in those without any complication (p < 0.005).Conclusion: Uveitis accompanying rheumatologic diseases may have asymptomatic and insidious course but have higher ESR as an important notice.
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    Henle fiber layer mapping with directional optical coherence tomography
    (Lippincott Williams & Wilkins, 2022) N/A; N/A; N/A; N/A; N/A; N/A; N/A; Department of Computer Engineering; N/A; Kesim, Cem; Bektaş, Şevval Nur; Kulalı, Zeynep Umut; Yıldız, Erdost; Ersöz, Mehmet Giray; Şahin, Afsun; Demir, Çiğdem Gündüz; Hasanreisoğlu, Murat; Doctor; Undergraduate Student; Undergraduate Student; PhD Student; Doctor; Faculty Member; Faculty Member; Faculty Member; Department of Computer Engineering; Koç University Research Center for Translational Medicine (KUTTAM) / Koç Üniversitesi Translasyonel Tıp Araştırma Merkezi (KUTTAM); N/A; School of Medicine; School of Medicine; N/A; School of Medicine; School of Medicine; College of Engineering; School of Medicine; Koç University Hospital; N/A; N/A; N/A; Koç University Hospital; N/A; N/A; N/A; 387367; N/A; N/A; N/A; 324533; 171267; 43402; 182001
    Purpose: To perform a macular volumetric and topographic analysis of Henle fiber layer (HFL) from retinal scans acquired by directional optical coherence tomography. Methods: Thirty healthy eyes of 17 subjects were imaged using the Heidelberg spectral-domain optical coherence tomography (Spectralis, Heidelberg Engineering, Heidelberg, Germany) with varied horizontal and vertical pupil entry. Manual segmentation of HFL was performed from retinal sections of horizontally and vertically tilted optical coherence tomography images acquired within macular 20 x 20 degrees area. Total HFL volume, mean HFL thickness, and HFL coverage area within Early Treatment for Diabetic Retinopathy Study grid were calculated from mapped images. Results: Henle fiber layer of 30 eyes were imaged, segmented and mapped. The mean total HFL volume was 0.74 +/- 0.08 mm(3) with 0.16 +/- 0.02 mm(3), 0.18 +/- 0.03 mm(3), 0.17 +/- 0.02 mm(3), and 0.19 +/- 0.03 mm(3) for superior, temporal, inferior, and nasal quadrants, respectively. The mean HFL thickness was 26.5 +/- 2.9 mu m. Central 1-mm macular zone had the highest mean HFL thickness with 51.0 +/- 7.6 mu m. The HFL coverage that have thickness equal or above to the mean value had a mean 10.771 +/- 0.574 mm(2) of surface area. Conclusion: Henle fiber layer mapping is a promising tool for structural analysis of HFL. Identifying a normative data of HFL morphology will allow further studies to investigate HFL involvement in various ocular and systemic disorders.