Fluorescein Angiography Authors:
نویسندگان
چکیده
Introduction Fluorescein angiography (FA) was introduced in ophthalmology by Novotny and Alvis in the sixties of the last century. They took serial fundus photographs after intravenous injection of sodium fluorescein to study the retinal and choroidal circulation(1). Initially, they used this technique in diabetic and hypertensive patients and after, the technique was used in age-related macular degeneration (AMD). Although the clinical diagnosis of AMD can be established based on patient’s history and fundus examination, FA is the most important ancillary test for classifying the disease in its different subtypes, especially in its wet form. Nowadays, optical coherence tomography (OCT) is being more used than FA for monitoring the response to treatment, although FA is still very useful in some cases. Sodium fluorescein is a small molecule, with a molecular weight of 376.27 daltons, and it is highly soluble in water. It is stimulated by light in the range of 465-490 nm and then it enters into a higher energy state. The molecule emits longer wavelength fluorescence, between 520 and 530 nm, as it decays to a lower energy state. In clinical application, two filters are used. An excitation filter allows the passage of blue light, which stimulates the fluorescein in the eye, which emits yellow-green light. In addition, a barrier filter is used to block some reflected blue light, allowing only the yellow-green light to pass through. This resultant fluorescence is recorded by a camera as an image(2). Sodium fluorescein diffuses through the fenestrated vessels of the choriocapillaris, but does not cross the internal and the external blood-retinal barriers. Thus, any condition that compromises these barriers, obstructs blood flow, or changes the normal pigmentation of the retinal pigment epithelium (RPE) can cause abnormalities on FA. The dye is removed from the vascular compartment by the kidney. It is relatively inert, making intravenous injection safe and severe adverse reactions rare. Nevertheless, the patient should be properly informed of the potential risks of FA injection(3).
منابع مشابه
Fundus fluorescein angiography in retinopathy of prematurity.
In this issue of the Journal of Pediatric Ophthalmology & Strabismus, Ng, Lanigan, and O’Keefe present their findings regarding fundus fluorescein angiography in the management and screening of retinopathy of prematurity (ROP). Recently, there has been interest in photographic documentation of ROP in hospitals lacking sufficient ophthalmologic staff. Images created in the intensive care nursery...
متن کاملValidation of concentric rings method as a topographical measure of retinal non- perfusion in ultra wide-field fluorescein angiography Short Title Concentric rings method in wide-field image analysis Authors
متن کامل
Early Detection of Diabetic Retinopathy in Fluorescent Angiography Retinal Images Using Image Processing Methods
Introduction: Diabetic retinopathy (DR) is the single largest cause of sight loss and blindness in the working age population of Western countries; it is the most common cause of blindness in adults between 20 and 60 years of age. Early diagnosis of DR is critical for preventing vision loss so early detection of microaneurysms (MAs) as the first signs of DR is important. This paper addresses th...
متن کامل[Butterfly-shaped pattern dystrophy: case report].
The authors present a case of butterfly-shaped pattern dystrophy diagnosed in a male patient, with retinal pigmented epithelium atrophy and central visual acuity decrease in one of the eyes. The evolution of this case was not benign as described in previous reports. A well-defined lesion located in the posterior pole of both eyes associated with fluorescein angiography allowed the diagnosis of ...
متن کاملComparison of indocyanine green and fluorescein angiography of choroidal neovascularization.
We compared indocyanine green (ICG) and fluorescein angiography for evaluation of choroidal neovascularization (CNV). Cast preparations of CNV induced in monkey eyes by laser photocoagulation were correlated with ICG and fluorescein angiographies of the same CNV formations. Fluorescein angiography was more effective, in general, than ICG angiography in detecting CNV; however, CNVs with subretin...
متن کاملOptical coherence tomography, fluorescein angiography, and the management of neovascular age-related macular degeneration.
In the article by Castillo et al (http://www.aaojournal.org/ article/S0161-6420(14)00728-3/fulltext), the authors provide a thoughtful review of “the accuracy of optical coherence tomography (OCT) [compared] with alternative tests for monitoring neovascular age-related macular degeneration (nAMD) and detecting disease activity among eyes previously treated for this condition.” The topic is impo...
متن کامل