Effects of different types of refractive errors on bilateral amblyopia

Objectives: Identifying effects of different types of refractiveerrors on final visual acuity and stereopsis levels inpatients with bilateral amblyopia.Materials and methods: Patients with bilateral amblyopialower than ≥1.5 D anisometropia were included. Thepatients were classified according to the level of sphericalequivalent (0-4 D and >4 D of hypermetropia), the levelof astigmatism (below and above 2D in positive cylinder)and type of composed refractive error [<4 D of hypermetropiaand < 2 D of astigmatism (group I), > 4 D of hypermetropiaand < 2 D of astigmatism (group II), and < 4 Dhypermetropia and > 2 D of astigmatism (group III)]. Initialand final binocular best corrected visual acuities (BCVA)were compared between groups.Results: The initial binocular BCVA levels were significantlylower in patients with > 4 D of hypermetropia(p=0.028), without correction after treatment (p=0.235).The initial binocular BCVA was not different betweenastigmatism groups, but final BCVA levels were significantlylower in 4-6D of astigmatism compared with 2-4D of astigmatism (p=0.001). During comparison of composedrefractive errors, only the initial binocular BCVAwas significantly lower in group I compared to group II(p=0.015). The final binocular BCVA levels were not differentbetween groups I and III (p>0.05).Conclusions: Although the initial BCVA is lower in patientswith higher levels of hypermetropia, the response ofpatients to treatment with glasses is good. The responseof patients with high levels of astigmatism seems to belimited. J Clin Exp Invest 2012; 3(4): 467-471Key words: Amblyopia, isoametropic amblyopia, hypermetropia,refractive amblyopia, visual acuit

Effects of Stobadine and Vitamin E in Diabetes-Induced Retinal Abnormalities: Involvement of Oxidative Stress

Background. Because hyperglycemia-induced oxidative stress may be a cause of retinopathy, this study examined the hypothesis that administration of exogenous antioxidants, stobadine (ST) and vitamin E (vitE), can restore retinal abnormalities in experimental diabetes. Methods. Normal and streptozotocin (STZ)-induced male Wistar rats received daily intraoral doses of ST (24.7 mg/kg) and vitE (a-dl-tocopherol acetate, 400e500 IU/kg) individually or in combinations for 8 months. The biochemical parameters including aldose reductase enzyme (AR) activity and lipid peroxidation (MDA), and histopathological changes such as retinal capillary basement membrane thickness (RCBMT) and vascular endothelial growth factor (VEGF) expression were evaluated. Results. A 37.99% increase in RCBMT was observed in rats after 8 months diabetes duration. The increase in RCBMT was 12.34% in diabetic rats treated with ST and 23.07% in diabetic rats treated with vitE. In diabetic rats treated with antioxidant combination, just a 4.38% increase was observed in RCBMT. The excess VEGF immunoreactivity and increased MDA and AR activity determined in diabetic retina were significantly attenuated by individual antioxidant treatments. Although both antioxidants decreased blood glucose, HbA1c, fructosamine and triglyceride levels in diabetic rats, poor glycemic control was maintained in all experimental groups during the treatment period. However, the antioxidant combination led to almost complete amelioration in retinal MDA and RCBMT in diabetic rats. Conclusions. The ability of antioxidant combination to arrest retinal abnormalities and lipid peroxidation even in the presence of poor glycemic control might advocate the key role of direct oxidative damage and the protective action of antioxidants in retinal alterations associated with diabetic retinopathy. Ó 2007 IMSS. Published by Elsevier Inc

Extraocular Muscle Regeneratıon By Decellularızed Bovıne Extraocular Muscle And Pcl-Muscle Matrıx Composıte Tıssue Scaffolds

This study has been financially supported by TÜBİTAK under the project named "Extraocular Muscle Regeneration by Decellurized Bovine Extraocular Muscle and PCL-Extraocular Muscle Matrix Composite Tissue Skeleton" (1002 short term R&D support program, project number: 119S915). The aim of this thesis is to develop ideal tissue skeletons suitable for practical use in pathological conditions like severe muscle loss and thyroid ophthalmopathy. Initially, a new hybrid synthetic tissue skeleton composed of poly(caprolactone) (PCL), poly(lactic-co-glycolic acid) (PLGA) and extracellular matrix powder (ECM) was fabricated and characterized. For this purpose, PLGA membranes were produced by solvent casting method and PCL nanofibers were collected on these membranes by electrospinning (PCL-PLGA). Then, the decellularized ECM was lyophilized, pulverized into powder form, and coated on PCL-PLGA membranes by gelation of ECM (ECM-PCL-PLGA). Membranes were characterized by various analysis methods such as scanning electron microscopy (SEM), energy dispersive X-ray analysis (XRD), Fourier transform infrared spectroscopy (ATR-FTIR) and mechanical strength tests, and the success of production was confirmed. Potency of these skeletal materials to support muscle regeneration was assessed by in vitro and in vivo analyses. In vitro experiments revealed that these materials support attachment and proliferation of mouse myoblast cells (C2C12) according to 3-[4,5-dimethylthiazol-2-yl]-diphenyltetrazolium bromide (MTT) analysis. In SEM imaging, C2C12 cells were observed to be adhered in an aligned manner similar to muscle tissue along the fibrous network of scaffolds. Real Time Polymerase Chain Reaction (RT-PCR) analyzes were used to examine for differentiation and it was thought that the effect of ECM contents used in the study on differentiation occurred in the first 7 days, and that the cell proliferation mechanism might be more dominant than differentiation in the following days. After ethical approval from Kobay D.H.L. AŞ. (date: 17.01.2019 and number: 336) in vivo experiments were carried out using 30 rabbits and whole thickness defects of 5 mm in length from the insertion were created in vertical recti of both eyes. The grafts produced were sutured to these defects. Muscle tissues were taken from rabbits on the 15th day to follow the early healing response and on the 45th day for the late phase of healing. The muscle tissue forming potentials of the scaffolds was tested by electrophysiology tests and histological staining. No infection was observed in any groups during the surgical procedures, and it was observed that suturing of HK grafts was much easier as compared to others. In the early period, edema and swelling in the graft were evident in some cases of HK grafts, while intense inflammatory reaction, vascular fullness and increased vascularization were observed in the histopathological examination. In the late phase, the upper rectus muscles of the rabbits were separated from the insertion and the contractile responses to the electrical stimulus were evaluated. The best single twitch responses were obtained in the positive control group, while the HK, PCL-PLGA and ECM-PCL-PLGA groups showed similar responses and the response of the PLGA group was found to be low. In the late histopathological examinations, muscle tissue development was similar in the HK, PCL-PLGA and ECM-PCL-PLGA groups, and the corneal distance of the healed muscle fibers was found to be the best in the positive control group, and the furthest distance was detected in the PLGA group. In the late period, the development and differentiation of muscle tissue lagged behind the other groups in the negative control group. The organization of tissue and muscle fibers were observed to be better in HK grafts. In conclusion, decellularized bovine eye muscle and synthetic hybrid tissue scaffolds were found to be biomaterials promoting muscle tissue regeneration. It has been shown that HK, which is a natural material, provides convenience in surgical procedures and can be used as an alternative to autograft by accelerating the development of regular fibers in the late period.Bu çalışma, “Hücresizleştirilmiş Sığır Gözü Kası ve PCL-Kas Matrisi Kompozit Doku İskeleleriyle Göz Kası Rejenerasyonu” başlıklı 1002 Hızlı Destek Projesi (Proje no: 119S915) kapsamında TÜBİTAK tarafından desteklenmiştir. Sunulan tez çalışması kapsamında, ciddi kas dokusu kaybı ve tiroid oftalmopati gibi patolojik durumlarda pratik uygulamalara elverişli ideal doku iskelesinin geliştirilmesi amaçlanmıştır. Çalışma kapsamında öncelikle, sağlıklı göz kası dokusu rejenerasyonunu desteklemek için poli(kaprolakton) (PCL), poli(laktik-ko-glikolik asit) (PLGA) ve hücresizleştirilmiş dana gözü kasından (HK) elde edilen ekstraselüler matris (ECM) tozu kullanılarak yeni bir hibrit doku iskelesi (greft) geliştirilmeye çalışılmıştır. Bu amaçla, PLGA membranları çözücü döküm yöntemi ile üretilmiş ve PCL nanofiberler bu membranlar üzerine elektroeğirme yöntemiyle toplanmıştır (PCL-PLGA). Ardından hücresizleştirilmiş ECM, liyofilizatörde kurutulmuş, toz haline getirilmiş ve jelleştirme yöntemi ile PCL-PLGA membranlar üzerine kaplanmıştır (ECM-PCL-PLGA). Taramalı elektron mikroskopi (SEM), enerji yayılımlı X-ışını analizi (XRD), Fourier transform kızılötesi spektroskopisi (ATR-FTIR) ve mekanik dayanım testleri gibi çeşitli analiz yöntemleriyle membranların karakterizasyonu yapılmış ve üretim başarısı doğrulanmıştır. Geliştirilen doku iskelelerinin kas doku oluşturma potansiyelleri in vitro ve in vivo analizlerle değerlendirilmiştir. İn vitro deneylerde geliştirilen malzemelerin fare miyoblast hücrelerinin (C2C12) tutunup çoğalmasını desteklediği görülmüş, 3-[4,5-dimetiltiyazol-2-il]-difeniltetrazolyum bromür (MTT) analizinde tüm doku iskelelerinin hücre proliferasyonunu desteklediği belirlenmiştir. Taramalı elektron mikroskobu ile yapılan görüntülemelerde ise C2C12 hücrelerinin, fiber yapıdaki doku iskeleleri boyunca kas dokusuna benzer şekilde hizalı bir şekilde tutunduğu görülmüştür. Gerçek Zamanlı Polimeraz Zincir Reaksiyonu (RT-PCR) analizleri ile çalışma kapsamında kullanılan ECM içeriklerinin farklılaşmaya olan etkisinin ilk 7 günde gerçekleştiği, sonraki günlerde farklılaşmadan ziyade hücre proliferasyon mekanizmasının daha baskın olabileceği düşünülmüştür. Kobay D.H.L. AŞ. Yerel Etik Kurulu'ndan 17.01.2019 tarih ve 336 numaralı onay kararı alındıktan sonra in vivo hayvan deneyleri 30 adet tavşan kullanılarak gerçekleştirilmiş ve tavşanların her iki gözünde vertikal rektus kaslarında insersiyodan itibaren 5 mm'lik tam kat defektler oluşturularak defektlere greftler sütüre edilmiştir. Erken dönem rejenerasyonu takip etmek için 15. gün sonunda, geç dönem için de 45.gün sonunda tavşanlardan kas dokuları alınmış ve elektrofizyoloji testleri ve histolojik analizlerle geliştirilen iskelelerin kas doku oluşturma potansiyelleri incelenmiştir. Cerrahi işlem sırasında hiçbir grupta enfeksiyon gözlenmemiş ve özellikle HK greftlerin sütürasyonunun diğer tüm greftlere göre çok daha kolay olduğu görülmüştür. Erken dönemde HK greftlerinde bazı olgularda ödem ve greftte şişlik belirginken, histopatolojik incelemede bu kaslarda yoğun inflamatuar reaksiyon, damarlarda dolgunluk ve vaskülarizasyonda artış görülmüştür. Geç dönemde tavşanların üst rektus kasları insersiyodan ayrılarak elektriksel uyarıya kasılma cevapları değerlendirildiğinde en iyi tek sarsı cevapları pozitif kontrol grubunda alınırken, HK, PCL-PLGA ve ECM-PCL-PLGA grupları benzer cevaplar sergilemiş ve PLGA grubunun cevabı düşük olarak bulunmuştur. Geç dönem histopatolojik incelemelerde ise kas dokusu gelişmesi HK, PCL-PLGA ve ECM-PCL-PLGA gruplarında benzer olup iyileşen kas fiberlerinin kornea uzaklığı en iyi pozitif kontrol grubunda bulunmuş ve PLGA grubunda ise en uzakta iyileşme tespit edilmiştir. Geç dönemde kas dokunun gelişmesi ve farklılaşması negatif kontrol grubunda diğer grupların gerisinde kalmıştır. Doku ve kas fiberlerinin organizasyonu geç dönemde HK greftlerinde daha iyi izlenmiştir. Sonuç olarak, hücresizleştirilmiş dana göz kası ve sentetik hibrit doku iskelelerinin kas doku rejenerasyonunu destekleyen biyomalzemeler olduğu görülmüştür. Doğal bir malzeme olan HK'nin hem cerrahi işlemlerde kolaylıklar sağladığı hem de geç dönemde düzenli fiberlerin gelişmesini hızlandırarak otogrefte alternatif olarak kullanılabileceği gösterilmiştir

Accommodation Palsy in Multiple Sclerosis

In patients with multiple sclerosis and disturbed near vision, accommodation palsy can be observed as a relatively rare ocular complication. After ruling out other causes that may cause accommodation palsy, these patients may benefit from near glasses and the palsy may be self-limited with complete recovery over tim

Accommodation Palsy in Multiple Sclerosis

In patients with multiple sclerosis and disturbed near vision, accommodation palsy can be observed as a relatively rare ocular complication. After ruling out other causes that may cause accommodation palsy, these patients may benefit from near glasses and the palsy may be self-limited with complete recovery over time

Pilomatrixoma on the Upper Eyelid

Pilomatrixoma is a rare, benign, calcified, adnexial soft tissue tumor of the eyelid which originates from the matrix of hair follicle. In this study, we aimed to present a pilomatrixoma case which presented as a benign mass at the lower part of the eyebrow. An 8-yearold child patient referred to our clinic with a painless mass at the right superior eyelid which had appeared 1,5 month before and seemed to be increasing in size for the last week. The ophthalmologic examination revealed a lobular, 0,7x1 cm sized, pink–violet, solid, swollen mass at the lower part of the right eyebrow. The position of globe was normal and the ocular motility was unrestricted. Orbital computed tomography (CT) revealed 7 mm sized, smooth, noninvasive, benign, homogeneous, well-contoured mass lesion. The lesion was totally excised with sharp dissection under general anesthesia. Benign pilomatrixoma (Malherbe tumor), which is frequently seen especially in the initial two decades, is to be kept in mind in the differential diagnosis of eyelid masses. We should follow up the patients for long term due to possible malignant transformation of pilomatrixoma.(Turk J Ophthalmol 2013; 43: 213-5

Orthokeratologic Lens Applications in the Correction of Low to Moderate Myopia

Purpose: To evaluate the efficacy and safety of orthokeratology in patients with low and medium myopia. Material and Method: Twenty six eyes of 6 male and 7 female patients were evaluated prospectively. The mean spherical equivalent was -3.87±1.35 D (-7 - -2.25) in 26 eyes. Individual semi-rigid, gas-permeable night Gelflex lenses (Australia) were performed based on keratometry values, ambient pupil, mesopic pupil, and autorefractometry values providing best-corrected visual acuity (BCVA). In all cases, uncorrected and best-corrected visual acuity, refraction, keratometry, corneal topography, slit lamp and intraocular pressure measurements were evaluated on first day, at first week, and at first, third and sixth months. Results: While the mean uncorrected visual acuity (UCVA) before orthokeratology (Ortho-K) was 1.08±0.24 (0.4-1.3) logMAR, first week after Ortho-K, it was 0.24±0.27 (0-1) logMAR. The BCVA was 0.01±0.07 (0-0.4) logMAR prior and first week after Ortho-K. First week after Ortho-K, it was 0.22 logMAR at right and 1 logMAR at left. While the average UCVA of our cases at first month was 0.11±0.19 (0-0.8) logMAR, the average BCVA at first month was 0.018±0.08 (0-0.4) logMAR. No ophthalmological complications were noted. Discussion: Ortho-K is a safe and effective method for correction of low and moderate myopia in patients who do not prefer surgery and do not wish to wear glasses or contact lenses during the day. (Turk J Ophthalmol 2013; 43: 317-20

Geçmişten günümüze Devlet Malzeme Ofisi ve yarım asırlık faaliyetleri

Ankara : İhsan Doğramacı Bilkent Üniversitesi İktisadi, İdari ve Sosyal Bilimler Fakültesi, Tarih Bölümü, 2016.This work is a student project of the The Department of History, Faculty of Economics, Administrative and Social Sciences, İhsan Doğramacı Bilkent University.by Yeni, Harun