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Morphogenesis of the anterior segment in the zebrafish eye
Kelly A Soules, Brian A Link
BMC Developmental Biology , 2005, DOI: 10.1186/1471-213x-5-12
Abstract: As in other vertebrates, the zebrafish anterior segment derives from diverse origins including surface ectoderm, periocular mesenchyme, and neuroepithelium. Similarly, the relative timing of tissue differentiation in the anterior segment is also conserved with other vertebrates. However, several morphogenic features of the zebrafish anterior segment differ with those of higher vertebrates. These include lens delamination as opposed to invagination, lack of iris muscles and ciliary folds, and altered organization in the iridocorneal angle. In addition, substantial dorsal-ventral differences exist within the zebrafish anterior segment.Cumulatively, our anatomical findings provide a reference point to utilize zebrafish for genetic studies into the mechanisms of development and maintenance of the anterior segment.The anterior segment of the vertebrate eye is comprised of the cornea, lens, iris, ciliary body, and highly specialized tissue at the iridocorneal angle. Two main functions are ascribed to the ocular anterior segment. The first is to focus incoming light onto the neural retina and the second is to regulate intraocular pressure. For mammals and other higher vertebrates, refraction of light entering the eye is accomplished by both the transparent cornea and lens. In many aquatic vertebrates, including fish, the lens is solely responsible for focusing incoming light [1,2]. In all vertebrates, intraocular pressure is maintained by the balance between aqueous humor production and outflow [3]. The dynamics of aqueous humor have been best characterized in mammals where ciliary epithelial cells produce the clear ocular fluid while the trabecular meshwork, which is situated at the iridocorneal angle overlying Schlemm's canal, regulates drainage.The structures of the anterior segment arise from diverse embryonic lineages and there is exquisite coordination among the different compartments during development. Studies in avian and mammalian species have shown that tissues
Diagnostics of anterior eye segment in cats and dogs  [PDF]
Had?i-Mili? Milan
Veterinarski Glasnik , 2006, DOI: 10.2298/vetgl0606407h
Abstract: Diagnostics of the anterior segment of the eye present the most frequent diagnostics implemented in ophthalmology and by most veterinary practicians as well. This paper presents the complete diagnostics in the most concise form possible. The procedure with animals is presented first, followed by the equipment, and then anamnesis. The following diagnostic methods are presented: examination in a lighted room which include an examination from a distance, taking a smear, the Schirmer tear test (STT), an examination from close by, examination in a dark room which comprises the elementary examinations, such as the use of focal lighting and examination using a direct ophthalmoscope, and special examination in a dark room, such as biomicroscopy, gonioscopy and keratoscopy. Additional examination methods are also included.
Evaluation of ultrasonic biomicroscopy results in anterior eye segment before and after cataract surgery
Simsek A, Ciftci S
Clinical Ophthalmology , 2012, DOI: http://dx.doi.org/10.2147/OPTH.S37614
Abstract: luation of ultrasonic biomicroscopy results in anterior eye segment before and after cataract surgery Original Research (977) Total Article Views Authors: Simsek A, Ciftci S Published Date November 2012 Volume 2012:6 Pages 1931 - 1934 DOI: http://dx.doi.org/10.2147/OPTH.S37614 Received: 02 September 2012 Accepted: 10 October 2012 Published: 21 November 2012 Ali Simsek,1 Süleyman Ciftci2 1Department of Ophthalmology, Faculty of Medicine, Adiyaman University, Adiyaman, Turkey; 2Department of Ophthalmology, Diyarbakir Training and Research Hospital, Diyarbakir, Turkey Background: The aim of this study was to assess the value of ultrasonic biomicroscopy in reporting decreases in intraocular pressure resulting from changes in anterior chamber depth and angle after phacoemulsification and intracapsular lens implantation in patients with cataract. Methods: This prospective interventional case series included 50 eyes of 50 consecutive subjects operated at the same center. Patients with eye disease affecting visual acuity, a history of eye surgery, corneal surface irregularities, a pupil diameter < 5 mm after preoperative dilation, aged younger than 35 years, posterior capsule perforation, iris dialysis during surgery, intensive postoperative corneal edema, and inability to attend adequate follow-up were excluded. Intraocular pressure, anterior chamber depth and angle, and corneal thickness were measured before and one month after surgery. Results: The mean preoperative intraocular pressure was 14 mmHg and postoperatively was 11 mmHg. Mean anterior chamber depth preoperatively was 2.8 mm and increased to 3.7 mm postoperatively. The mean anterior chamber angle was measured as 27° preoperatively and as 42° postoperatively. Conclusion: After phacoemulsification and intracapsular lens implantation, ultrasonic biomicroscopy showed that the iris diaphragm had shifted backwards, widening the angle of the anterior chamber and decreasing intraocular pressure.
Accessory optical device for the Heidelberg retina angiograph ( HRA classic ) to perform angiography of the vitreous cavity and the anterior eye segment  [cached]
Mennel Stefan,Schwendinger Rudolf,Hausmann Norbert,Peter Silvia
Indian Journal of Ophthalmology , 2007,
Abstract: The Heidelberg retina angiograph ( HRA) classic enables fluorescein angiography (FA) and indocyanine green angiography (ICG-A) of the retina and choroid. The goal of this study was to design an accessory device to adapt the HRA classic for application on structures anterior to the retina. The optical device consisted of a cylindrical two-piece plastic frame holding a magnifying lens commonly used with the indirect ophthalmoscope. A 60-diopters lens was inserted in this frame to enable the angiography of the anterior segment. A less strong lens of 30 diopters was used for the visualization of pathologic findings in the vitreous cavity. We designed an easy-to-use and low-cost device to adapt the HRA classic for angiography of the fundus, vitreous cavity and anterior segment in the same session and without delay. FA and ICG-A images of two patients with rubeosis iridis and of one patient with choroidal melanoma are described.
Evaluation of ultrasonic biomicroscopy results in anterior eye segment before and after cataract surgery  [cached]
Simsek A,Ciftci S
Clinical Ophthalmology , 2012,
Abstract: Ali Simsek,1 Süleyman Ciftci21Department of Ophthalmology, Faculty of Medicine, Adiyaman University, Adiyaman, Turkey; 2Department of Ophthalmology, Diyarbakir Training and Research Hospital, Diyarbakir, TurkeyBackground: The aim of this study was to assess the value of ultrasonic biomicroscopy in reporting decreases in intraocular pressure resulting from changes in anterior chamber depth and angle after phacoemulsification and intracapsular lens implantation in patients with cataract.Methods: This prospective interventional case series included 50 eyes of 50 consecutive subjects operated at the same center. Patients with eye disease affecting visual acuity, a history of eye surgery, corneal surface irregularities, a pupil diameter < 5 mm after preoperative dilation, aged younger than 35 years, posterior capsule perforation, iris dialysis during surgery, intensive postoperative corneal edema, and inability to attend adequate follow-up were excluded. Intraocular pressure, anterior chamber depth and angle, and corneal thickness were measured before and one month after surgery.Results: The mean preoperative intraocular pressure was 14 mmHg and postoperatively was 11 mmHg. Mean anterior chamber depth preoperatively was 2.8 mm and increased to 3.7 mm postoperatively. The mean anterior chamber angle was measured as 27° preoperatively and as 42° postoperatively.Conclusion: After phacoemulsification and intracapsular lens implantation, ultrasonic biomicroscopy showed that the iris diaphragm had shifted backwards, widening the angle of the anterior chamber and decreasing intraocular pressure.Keywords: anterior chamber depth, anterior chamber angle, ultrasonic biomicroscopy
Lesiones traumáticas de los anexos y del segmento anterior del ojo en los boxeadores Traumatic lesions of the adnexa and of the anterior segment of the eye in fighters
Agustín Fernández Sánchez,Beatriz N. Rodríguez Rodríguez,Eddy Mesa Hernández
Revista Cubana de Oftalmolog?-a , 2003,
Abstract: Se realizó un estudio retrospectivo con una muestra de 71 boxeadores a los cuales se les examinaron las estructuras de referencia mediante oftalmoscopia directa y biomicroscopia ocular, antes de las 6 horas posteriores al término de sus peleas; donde se obtuvo como resultado que los anexos afectados fueron los párpados con 5 hematomas, 4 edemas y 1 excoriación; y la conjuntiva con 4 hiperemias y 8 hemorragias. En el segmento anterior del ojo sólo se afectó la córnea con 13 lesiones en total, divididas en 10 excoriaciones superficiales y 3 profundas. Las lesiones traumáticas predominantes en los anexos del ojo son las de los párpados y las de la conjuntiva y las del segmento anterior del ojo, las de la córnea. El ojo más afectado fue el izquierdo y las lesiones más frecuentes fueron en las categorías de 13 y 14, 17 y 18 y 19 y 34 a os las corneales, las conjuntivales y la de los párpados, respectivamente. A retrospective study was carried out with a sample of 71 fighters, whose reference structures were examined by direct ophthalmoscopy and ocular biomicroscopy within the 6 hours following their fights. As a result, it was observed that the affected adnexa were the eyelids with 5 hematomas, 4 edemas and 1 excoriation; and the conjunctiva with 4 hyperemias and 8 hemorrhages. In the anteriro segment, only the cornea was affected with 13 lesions in all, divided into 10 superficial and 3 deep excoriations.The traumatic lesions prevailing in the adnexa of the eye are those of the eyelids and the conjunctiva, whereas the predominating traumatic lesions of the anterior segment of the eye are those of the cornea. The left eye was the most affected and the most frequent lesions were in the categories 13 and 14, 17 and 18 and 19 and 34 years old in the cornea, the conjunctiva and the eyelids, respectively.
Severe anterior uveitis associated with idiopathic dacryoadenitis in diabetes mellitus patient
Takahashi YY, Kakizaki H, Ichinose AA, Iwaki M
Clinical Ophthalmology , 2011, DOI: http://dx.doi.org/10.2147/OPTH.S20863
Abstract: e anterior uveitis associated with idiopathic dacryoadenitis in diabetes mellitus patient Case report (3654) Total Article Views Authors: Takahashi YY, Kakizaki H, Ichinose AA, Iwaki M Published Date May 2011 Volume 2011:5 Pages 619 - 621 DOI: http://dx.doi.org/10.2147/OPTH.S20863 Yasuhiro Takahashi1, Hirohiko Kakizaki1, Akihiro Ichinose2, Masayoshi Iwaki1 1Department of Ophthalmology, Aichi Medical University, Nagakute, Aichi, Japan; 2Department of Plastic Surgery, Kobe University, Kobe, Hyogo, Japan Abstract: A 38-year-old woman with diabetes mellitus complained of acute visual loss in the left eye (20/200) and swollen left upper eyelid. Slit lamp examination of the left eye revealed ciliary injection, posterior synechia iritis, numerous inflammatory cells, and fibrin exudates in the anterior chamber. T1-weighted enhanced magnetic resonance imaging demonstrated left lacrimal gland enhancement with inflammatory spread to the left anterior ocular segment. Blood examination showed increased blood sugar but the other components were within normal limits. The patient was treated with steroid pulse therapy (methylprednisolone 1 g/day × 3 days) under a blood sugar control regimen in consultation with an endocrinologist, after which additional peribulbar injection of triamcinolone acetonide (40 mg) was performed. Resolution of the anterior uveitis and the dacryoadenitis was obtained after 2 months and there was no recurrence 1 year after the therapy. This is a rare case of severe anterior uveitis caused by idiopathic dacryoadenitis in a patient with diabetes mellitus.
Severe anterior uveitis associated with idiopathic dacryoadenitis in diabetes mellitus patient  [cached]
Takahashi YY,Kakizaki H,Ichinose AA,Iwaki M
Clinical Ophthalmology , 2011,
Abstract: Yasuhiro Takahashi1, Hirohiko Kakizaki1, Akihiro Ichinose2, Masayoshi Iwaki11Department of Ophthalmology, Aichi Medical University, Nagakute, Aichi, Japan; 2Department of Plastic Surgery, Kobe University, Kobe, Hyogo, JapanAbstract: A 38-year-old woman with diabetes mellitus complained of acute visual loss in the left eye (20/200) and swollen left upper eyelid. Slit lamp examination of the left eye revealed ciliary injection, posterior synechia iritis, numerous inflammatory cells, and fibrin exudates in the anterior chamber. T1-weighted enhanced magnetic resonance imaging demonstrated left lacrimal gland enhancement with inflammatory spread to the left anterior ocular segment. Blood examination showed increased blood sugar but the other components were within normal limits. The patient was treated with steroid pulse therapy (methylprednisolone 1 g/day × 3 days) under a blood sugar control regimen in consultation with an endocrinologist, after which additional peribulbar injection of triamcinolone acetonide (40 mg) was performed. Resolution of the anterior uveitis and the dacryoadenitis was obtained after 2 months and there was no recurrence 1 year after the therapy. This is a rare case of severe anterior uveitis caused by idiopathic dacryoadenitis in a patient with diabetes mellitus.Keywords: anterior uveitis, idiopathic dacryoadenitis, diabetes mellitus, magnetic resonance imaging, steroid
The Role of Anterior Segment Optical Coherence Tomography in Glaucoma  [PDF]
Sarwat Salim
Journal of Ophthalmology , 2012, DOI: 10.1155/2012/476801
Abstract: The anterior segment optical coherence tomography provides an objective method to assess the anterior segment of the eye, including the anatomy of the anterior chamber angle. This technology allows both qualitative and quantitative analyses of the angle and has shown potential in detecting and managing angle-closure glaucoma. In addition, it has a role in identifying pathology in some forms of secondary open-angle glaucoma and postsurgical management of glaucoma. Limitations of this technology include its cost and inability to visualize well structures posterior to the iris, such as the ciliary body. This paper focuses on potential benefits and limitations of anterior segment optical coherence tomography when compared with conventional gonioscopy and ultrasound biomicroscopy. Various clinical entities will be described to discuss its potential role in glaucoma practice.
Anterior Segment Imaging in Combat Ocular Trauma  [PDF]
Denise S. Ryan,Rose K. Sia,Marcus Colyer,Richard D. Stutzman,Keith J. Wroblewski,Michael J. Mines,Kraig S. Bower
Journal of Ophthalmology , 2013, DOI: 10.1155/2013/308259
Abstract: Purpose. To evaluate the use of ocular imaging to enhance management and diagnosis of war-related anterior segment ocular injuries. Methods. This study was a prospective observational case series from an ongoing IRB-approved combat ocular trauma tracking study. Subjects with anterior segment ocular injury were imaged, when possible, using anterior segment optical coherence tomography (AS-OCT), confocal microscopy (CM), and slit lamp biomicroscopy. Results. Images captured from participants with combat ocular trauma on different systems provided comprehensive and alternate views of anterior segment injury to investigators. Conclusion. In combat-related trauma of the anterior segment, adjunct image acquisition enhances slit lamp examination and enables real time In vivo observation of the cornea facilitating injury characterization, progression, and management. 1. Introduction Improvised explosive devices, rocket propelled grenades, and mortars expose a large number of soldiers and civilians to dangerous blasts that can damage the eye despite its small surface area [1]. Fragmentary projectiles, a secondary blast effect, are the most common cause of ocular injuries resulting in open-globe and adnexal lacerations [1–8]. The extent of injury from penetrating fragments depends on the size and velocity of the fragment, the depth of penetration, and site of impact [5]. While comprehensive knowledge of the patient’s history and ocular examination is critical in the management of ocular injuries, ocular imaging modalities add valuable information for the course of clinical and surgical care of wounded soldiers. Furthermore, current imaging tools can monitor corneal wound healing, foreign body location, and if left in the cornea, foreign body migration. Anterior segment optical coherence tomography (AS-OCT) provides qualitative and quantitative assessment of the anterior segment [9]. Advantages of the AS-OCT include the noncontact capture system that causes minimal discomfort in trauma patients while providing high resolution cross-sections of the anterior segment. Corneal foreign body images provide information regarding the foreign body type (i.e., metallic versus nonmetallic), location, size, and depth. Another valuable imaging tool is the confocal corneal microscope, which can visualize cellular changes in the cornea. As seen in studies on donor corneas by Bourne and McLaren [10] and Waring et al. [11], the microscopic analysis of endothelial cells provides morphological characteristics that can be used to gauge corneal health. Also, a review by Jalbert et al.
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