|SYMPOSIUM - RETINOCHOROIDAL IMAGING
|Year : 2015 | Volume
| Issue : 5 | Page : 406-415
Fundus autofluorescence applications in retinal imaging
Andrea Gabai1, Daniele Veritti2, Paolo Lanzetta2
1 Department of Medical and Biological Sciences - Ophthalmology, University of Udine, Udine, Italy
2 Department of Medical and Biological Sciences - Ophthalmology, University of Udine, Udine; Istituto Europeo di Microchirurgia Oculare, Udine, Italy
|Date of Submission||09-Jan-2015|
|Date of Acceptance||24-May-2015|
|Date of Web Publication||2-Jul-2015|
Prof. Paolo Lanzetta
Department of Ophthalmology, University of Udine, Piazzale S. Maria della Misericordia, 33100 Udine
Source of Support: None, Conflict of Interest: None
Fundus autofluorescence (FAF) is a relatively new imaging technique that can be used to study retinal diseases. It provides information on retinal metabolism and health. Several different pathologies can be detected. Peculiar AF alterations can help the clinician to monitor disease progression and to better understand its pathogenesis. In the present article, we review FAF principles and clinical applications.
Keywords: Fundus autofluorescence, lipofuscin, retina, retinal imaging
|How to cite this article:|
Gabai A, Veritti D, Lanzetta P. Fundus autofluorescence applications in retinal imaging. Indian J Ophthalmol 2015;63:406-15
|How to cite this URL:|
Gabai A, Veritti D, Lanzetta P. Fundus autofluorescence applications in retinal imaging. Indian J Ophthalmol [serial online] 2015 [cited 2019 Jul 15];63:406-15. Available from: http://www.ijo.in/text.asp?2015/63/5/406/159868
Fundus autofluorescence (FAF) is a novel noninvasive imaging technique providing in-vivo information on retinal status. It is commonly employed in clinical practice to diagnose and study several pathologies. , Lipofuscin (LF) and melanolipofuscin are the main sources of retinal AF. These fluorophores are endogenous, thereafter there is no need to inject any dye to acquire FAF images. Because of age-related or pathologic accumulation/depletion of fluorophores within the retinal pigment epithelium (RPE) cells and retinal tissue, FAF can show changes in the integrity and metabolism of retinal cells. ,, In this review, we summarize the basic principles and clinical applications of FAF.
| Retinal Pigment Epithelium and Lipofuscin|| |
Retinal pigment epithelium is a monolayer of approximately hexagonal cells located between the neurosensory retina and the choroid. Its functions include rod's outer segment (OS) phagocytosis. Each RPE cell supports approximately 45 photoreceptors and phagocytes approximately 3 billion OSs over a lifetime. The byproducts of this process are stored in lysosome residual bodies as LF. , LFs are ubiquitous lipoproteic pigments accumulating in postmitotic cells in nervous, myocardial and retinal cells during ageing. LF occupies approximately one-third of the RPE cells cytoplasm over the age of 70 and emits AF when excited by specific wavelengths. N-retynilidene-N-retynilethanolamine (A2E) represents the LF's major fluorophore. , It accumulates in the lysosomes because it is not recognized by lytic enzymes as a consequence of photo-oxidative alterations.  Its chemical structure is responsible for the detergent-like action on the RPE cells membranes, and its conjugated double bonds promote light absorption and fluorescence emission. 
| Fundus Autofluorescence Imaging Techniques and Instrumentation|| |
In-vivo FAF was observed for the first time during vitreous fluorophotometry.  Subsequently von Rückmann et al. introduced the confocal scanning laser ophthalmoscope (cSLO) that elicits retinal AF by scanning the retina with a low-powered laser beam. ,, By adopting confocal optics, this technology overcomes the interference of autofluorescent preretinal structures, such as the lens. Confocal optics ensure that the reflectance of the scanning laser and the retinal fluorescence are derived from the same optical plane. The exciting and emission filters of standard confocal ophthalmoscopes are 488 nm (blue light), and 500-520 nm respectively so that cSLO-AF is called also blue-AF or short-wavelength (SW)-AF. Near infra-red (NIR)-AF also uses confocal optics, but with longer exciting wavelength (790 nm). The emission is above 800 nm and its signal is 60-100 times weaker than what seen in blue light AF. Melanin is the main fluorophore in NIR-AF, so fluorescence is more intense in choroidal tissue and RPE cells due to higher melanin density. 
Besides cSLO, fundus cameras can also be adapted to provide FAF images projecting a single flashlight on the entire retina at 1 time. Differently from cSLO-AF, fundus cameras don't have a confocal optics system, so the AF gets elicited also from preretinal structures, such as crystalline lens. Potential interferences may be overcome using specific filters with longer wavelength (excitation filter 535-580 nm, barrier filter 615-715 nm) developed by Schmitz-Valckenberg et al.  This type of FAF is also called green AF.
| Fundus Autofluorescence Appearance and Distribution|| |
In the healthy eye, cSLO-AF shows a hypofluorescent area in the foveal region due to the high concentration of xanthophylls and melanin. Xanthophylls (lutein and zeaxanthin) protect the foveal photoreceptors and RPE cells filtering blue light, scavenging free-radicals and masking the natural AF of the subfoveal RPE cells. ,, AF in the macular area is more intense between 5° and 15° from the fovea, but it still less intense than in the peripheral retina. This is due to a lower LF content and higher melanin deposition in the macular RPE cells when compared to the peripheral ones. , Optic disc and retinal vessels appear dark, because of the absence of RPE in the optic disc and the blood blocking AF where vessels lie [Figure 1]. Normal FAF appears slightly different with green-AF showing a less evident AF blockage by the macular pigments and less signal decreasing over the optic disc and blood vessels.  The high foveal autofuorescence with NIR-AF imaging in the normal retina corresponds to the higher concentration of melanin in that area, due to the higher and more cylindric shape of RPE cells [Figure 2]. 
|Figure 1: Confocal scanning laser ophthalmoscope short-wavelength-autofluorescence image of a normal right eye|
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| Fundus Autofluorescence Images Interpretation|| |
By evaluating abnormalities in FAF images, several retinal alterations can be identified. A lower AF signal can express a reduction in the RPE cells number and/or low LF concentration. Areas, where RPE is atrophic, will appear hypoautofluorescent. , Fibrosis, the presence of intraretinal fluid, the accumulation of pigment and blood can reduce the AF as well. Conversely, areas of LF accumulation (such as in Stargardt's disease, Best's disease, and other dystrophies) correspond to an increased AF signal. A FAF enhancement can also be observed in the presence of some types of drusen and macular edema. 
| Clinical Applications of Fundus Autofluorescence Imaging|| |
Autofluorescent material deposition characterizes several retinal dystrophies. An increased background AF and focal hyper-AF are common in these disorders.
Autosomal recessive Stargardt disease
Autosomal recessive Stargardt disease-fundus flavimaculatus (STGD1) is caused by mutation occurring in the ABCA4 gene on the chromosome 1 that leads to an excessive LF formation. By irradiating the juxtafoveal retina of STGD1 patients with a 510 nm wavelength, Delori et al. found a 3 times higher AF signal than controls.  By using SW-AF, Boon et al. observed focal hyper-AF in patients affected by STGD1, not necessarily corresponding to ophthalmoscopically evident flecks and associated to nearby areas of normal or reduced macular AF. In other cases, they found a diffusely increased FAF with hypoautofluorescent speckles and macular areas showing a reduced AF.  Recently Burke et al. found STGD1 hyper-AF (488 nm excitation) to characterize certain phenotypes. They observed the G1916E and G851D genetic mutations to be associated with a slower LF accumulation and less intense AF as compared to other genotypes. , These evidences indicate how FAF findings may be used to detect candidates for the genetic screening of ABCA4 mutations. The presence of peripapillary sparing, that is present in most cases and was considered pathognomonic of Stargardt disease in the past  can be assessed using FAF. This finding correlates with better general retinal function as observed by electroretinogram (ERG). Conversely peripapillary atrophy and hypo-AF are associated with lower photopic and scotopic response on ERG  and may indicate a worst prognosis. Furthermore, NIR-AF can help to diagnose STGD1.  Hence, FAF is useful to study STGD1 and generally shows focal hyper-AF in the affected eyes, although other FAF abnormalities can also be found.
Bull's eye maculopathy
Typically, Bull's eye maculopathy (BEM) shows concentric parafoveal rings of enhanced and diminished AF. Duncker et al. observed that in eyes with BEM studied with SW-AF, AF was higher in the presence of ABCA4 mutations.  For this reason, FAF can be helpful in deciding whether or not to prescribe genetic investigations.
The term retinitis pigmentosa (RP) encompasses a heterogeneous group of progressive retinal degenerations leading to a gradual loss of photoreceptors and vision. , RP presents with a ring or arc of high AF enclosing a zone of normal fluorescence where photoreceptors are preserved. ,, A correlation between the ring diameter and the inner segment/OS junction length and between the diameter and the retinal sensitivity has been reported. ,,,,,,,, Greenstein et al. found that in 12 out of 21 eyes affected by RP, SW-AF was normal outside the ring/arc.  According to published evidences, FAF in RP not only shows the LF distribution in the RPE, but also the presence of other fluorophores in the photoreceptors layer. , Hence, the hyper-AF could also correspond to degenerating photoreceptors with subsequent increased production of LF.  In RP NIR-AF appearance resemble a ring or arc probably due to the separation of melanosomes by the interspersion of increased numbers of LF granules. , Therefore, NIR-AF may reveal pathological processes earlier than SW-AF [Figure 3].
|Figure 3: Short-wavelength-autofluorescence (AF) (on the left) and near infra-red-AF (on the right) images showing a ring shaped AF in retinitis pigmentosa|
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Best vitelliform macular dystrophy
Lipofuscin deposition in the subretinal space is a typical sign of best vitelliform macular dystrophy. This early-onset autosomal dominant dystrophy is caused by a mutation in the BEST1 gene expressing the protein called bestrophin. , Clinically the disease presents with large LF-like subretinal deposits in both eyes, progressing to atrophy in advanced stages. , Several studies showed that SW-AF patterns in Best dystrophy are variable, ranging from an increased AF in the early phases of the disease to hypo-AF in the later stages [Figure 4]. ,,,,, By using NIR-AF, some authors found early signs of the disease at a preclinical stage. They observed central hypo-AF surrounded by a hyperautofluorescent ring in patients presenting BEST1 mutation with preserved visual acuity and lack of fundus alterations at biomicroscopy. The authors speculate that bestrophin, a calcium-activated chloride channel, mutation may cause electrolytic imbalances in the RPE, with calcium binding melanin and altering the normal AF. ,, This could explain the central low-intensity signal on NIR-AF. A classification of the auofluorescence patterns in Best vitelliform macular dystrophy has been proposed by Parodi et al. They observed six patterns at SW-AF and NIR-AF: Normal, multifocal, hyper- autofluorescent, hypoautofluorescent, patchy, spoke-like and multifocal. The patchy was the most frequent and could be observed in various disease stages. 
|Figure 4: Short-wavelength-autofluorescence image of a hyperautofluorescent juxtafoveal lipofuscin accumulation in Best dystrophy|
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Oishi et al. examined patients affected by cone dystrophy and cone-rod dystrophy. By using ultra-wild field FAF (excitation 532 nm, absorption 570-580 nm) they found that the extent of areas of hyper or hypo-AF reflected the severity of functional loss in patients affected by cone-dominant retinal dystrophies. The scotoma they observed on the visual field examination corresponded to areas of altered AF.  A relationship was also observed between FAF and ERG findings under dark and light-adapted conditions. The rod function showed a stronger association with areas of abnormal FAF, confirming that AF matches the distribution of this type of photoreceptors. ,
Age-related macular degeneration
Age-related macular degeneration (AMD) represents the most frequent cause of legal blindness in the developed countries. Early AMD is characterized by drusen and approximately one patient out of five progresses to geographic atrophy (GA) and/or to neovascular AMD (nAMD). ,,
Lipofuscin accumulation may play an important role in AMD pathogenesis, but the exact mechanisms of this process have not been completely established yet. In general lysosomal dysfunction due to lipid accumulation and protein peroxidation in the RPE cells may accelerate the LF formation in AMD. , A2E, the major component of LF, impairs the lysosomal and mithocondrial function in aged RPE cells. In particular A2E seems to obstacle the degradation processes inside the lysosomes and to increase the formation of mithocondrial oxygen reactive species subsequently compromising the autophagic processes and the energy supply that are essential for the cellular homeostasis and survival. 
Early age-related macular degeneration
The clinical features of early AMD include pigmentary RPE alterations and drusen. FAF abnormalities not always correspond to funduscopically visible lesions and not all visible lesions correspond to notable AF alterations. However, hyperpigmentated areas tend to show increased SW-FAF signals due to melanolipofuscin accumulation, whereas hypopigmentation is often associated to a reduced AF expressing a degenerated or lacking RPE. , Drusen may present as intrinsically hyperautofluorescent lesions. Actually, autofluorescent elements have been observed within drusen in postmortem specimens.  However, a normal FAF appearance can be observed in patients with small drusen due to low image resolution or when FAF alterations are masked by macular pigments. Overall, large drusen are more frequently associated with abnormal AF. With cSLO-AF large confluent drusen and drusenoid retinal pigment epithelium detachments (PEDs) present an increased AF areas whereas, when using fundus cameras large drusen show a dark center surrounded by a faint hyperautofluorescent area. Crystalline drusen are often seen as decreased AF spots.  Delori et al. observed that the rarefaction of RPE cells at the center of the drusen and the increased LF concentration at their edges can appear as a ring-shaped hyper-AF surrounding an hypoautofluorescent space.  Specific types of drusen demonstrate peculiar FAF patterns: Cuticular drusen are hyperautofluorescent, reticular drusen appear as elongated, roundish hypoautofluorescent areas included in a network of normal AF. , The retina surrounding drusen can present increased FAF due to melanolipofuscin accumulation. 
Bindewald et al. proposed a classification of the abnormal AF patterns in early AMD, classifying them as normal, minimal change, focal increased, patchy, linear, lace like, reticular and speckled. 
Interestingly, Midena et al. observed a correlation between altered AF and reduction in retinal sensitivity in early AMD.  In summary, there are various possible FAF changes in early AMD. FAF alterations can precede the appearance of visible lesions. Therefore, FAF may represent a valuable imaging technique to diagnose early AMD and to monitor its progression.
Geographic atrophy results from the death of RPE cells. The loss of EPR cells and their LF content results in a dramatic decrease in AF. SW-AF is able to more distinctly discriminate areas where RPE is atrophic than color fundus photography (CFP). These areas appear as sharply defined regions with no AF. Although CFP and FAF findings demonstrate a strong intraobserver agreement, FAF gives more reproducible images and is more accurate in detecting smaller atrophic areas. , On the downside, media opacities, such as advanced cataract, and AF absorption from macular xanthophylls may be obstacles in FAF imaging in the central macula.  NIR-AF can help to overcome some limitations of conventional FAF such as the overestimation of atrophy in the foveal area, allowing a better distinction among true atrophy, drusen, and RPE hypopigmentation. 
Fundus AF also provides valuable help to predict GA progression. An increased AF surrounding the GA has been reported to precede its extension, and more hyper-autofluorescent GA borders seem to correlate with a higher extension rate [Figure 5]. ,, Schmitz-Valckenberg et al. observed a diminished retinal sensitivity where the AF is increased on the borders of GA.  Different FAF classifications of GA have been proposed. Lois et al. classified GA as focal, increased, reticular, combined and homogeneous.  Subsequently, a classification of GA patterns based on the SW-AF appearance around the atrophy was proposed by the FAM study group. The authors defined the different patterns as focal, banded, patchy or diffused. Some of them showed a higher risk of GA progression.  In the presence of diffuse and banded AF pattern atrophy seems to progress more rapidly as compared to other patterns, with the diffuse trickling pattern being the rapidest. 
|Figure 5: Geographic retinal pigment epithelium atrophy extension in 2 years (from left to right). Hyperautofluorescence at the atrophy margins indicates the direction in which it will extend|
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Neovascular age-related macular degeneration
Specific FAF alterations can be observed in nAMD, adding specific information to that offered by other imaging techniques like optical coherence tomography (OCT), fluorescein angiography (FA) and indocyanine green angiography (ICGA). LF granules were identified around the lumen of choroidal neovessels in bioptic specimens and AF alterations in correspondence of choroidal neovascularization (CNV) have been reported. ,,, In nAMD eyes treated with anti-vascular endothelial growth factor Heimes et al. found a poorer functional response in the presence of higher pretreatment central AF, by using a cSLO-AF system.  According to McBain et al. FAF can be reduced in classic CNVs due to the AF blockade by growing neovessels.  Occult CNVs aspect at FAF is variable depending on the co-existence of heterogenous RPE alterations and atrophy. Both classic and occult CNVs can show enhanced AF next to the CNV expressing the presence of phagocytized RPE remnants and chronic accumulation of sub-retinal fluid.  Retinal PED may present with different AF patterns. In most cases, PED presents as a hyperautofluorescent area surrounded by a less autofluorescent halo. Within the PED, subretinal fluid and atrophy usually result in hypo-AF signal. RPE tears appear as an area of absent AF where the RPE has been displaced and hyper-AF in correspondence of folded RPE at the edge of the tear. Scarring in the late phase nAMD is usually hypoautofluorescent.  A SW-AF enhancement can be observed around the scar, probably due to an irregular pigment deposition within a multilayered RPE. 
Lipofuscin accumulation in diabetic retinopathy (DR) occurs more in the microglia than in the RPE.  Currently, studies on FAF imaging in patients with DR are scant and mostly focused on diabetic macular edema (DME). Cystoid macular edema locates in the outer plexiform layer and the inner nuclear layer where it displaces the macular pigments that normally block the AF. This could explain the increased macular AF in the presence of cystoid DME. ,, Vujosevic et al. observed SW-AF alterations that correlate with OCT and microperimetry.  In a study conducted by Yoshitake et al. on NIR-AF negative correlations between central subfield retinal thickness and AF intensity, and between the latter and visual acuity were reported.  By using cSLO-AF Pece et al. observed that patients with hyperautofluorescent edema had a worse visual acuity as compared to those presenting a single-lobulated pattern. They also reported hyper-AF to increase with the retinal thickness.  A relation between SW-AF, OCT and visual acuity in DME was also described by Chung et al. 
Central serous chorioretinopathy
Fundus AF can complement other imaging techniques such as FA, ICGA and OCT in showing alterations in eyes affected by central serous chorioretinopathy (CSCR). ,, CSCR is characterized by an idiopathic subretinal leakage leading to serous retinal detachment with an accumulation of material derived from the photoreceptors catabolism. It typically shows high AF (excitation 500-610 nm, absorption 675-715 nm) with a punctate diffuse distribution. 
Teke et al. found a reduced AF in correspondence of the focal leakage site detected by FFA in nearly 90% of acute and chronic CSCR patients. This finding may express a reduced retinal metabolism in that area. Differently, by using SW-AF, in the serous detachment area, they observed hypo-AF in acute disease, subsequently to blockage of AF by subretinal effusion, and hyper-AF in the chronic cases, due to the accumulation of dispersed chromophores and OSs of photoreceptors.  Hypo-AF at the focal leakage site was also reported by other authors using SW-AF and may correspond to disrupted RPE cells and/or to AF blockade by subretinal fluid.  Differently, von Rückmann et al. noticed an increased AF at the leakage point possibly reflecting the accumulation of autofluorescent phagosomal material.  To summarize, CSCR can present with various FAF patterns reflecting the metabolic state of the RPE, accumulation of photoreceptor-derived material and masking by serous detachment [Figure 6].
|Figure 6: Serous neuroretinal detachment in central serous chorioretinopathy masks the normal retinal autofluorescence|
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Chorioretinal inflammatory and infective diseases
Lipofuscin accumulation resulting from lysosomal oxidative damage could be an indicator of the disease activity in chorioretinal inflammatory conditions.  Generally, FAF shows increased signal in the presence of an active inflammatory response, whereas quiescent phases and final chorioretinal scarring or atrophy are hypoautofluorescent.  Specific AF pattern can help to distinguish among different types of chorioretinitis.
White dots syndromes
White dots syndromes include a group of inflammatory conditions affecting the choroid, RPE and outer retina. , In most cases, they present ophthalmoscopically with white-yellow spots in the RPE and inner choroid. Differential diagnosis may be clinically challenging due to this common appearance. Several authors reported specific FAF alterations in patients with different types of white dot syndromes. ,,,,,,, Multifocal choroiditis (MFC) and punctate inner choroidopathy (PIC) exhibit raised or low AF within the dots and in the surrounding area. , Inflammation and photoreceptor phagocytosis causes initial hyper-AF in PIC, which may then be followed by hypo-AF due to RPE atrophy.  When PIC patients are treated with immunemodulatory drugs, hyperautofluorescent and active lesions turn hypoautofluorescent in response to therapy, with the persistence of hyper-AF indicating a higher risk of recurrences.  Birdshot chorioretinopathy (BSC) shows defined hypoautofluorescent areas that often do not correspond to ophthalmoscopically visible lesions, being larger and more diffused and becoming hypoautofluorescent in the advanced stages. , The presence of placoid macular hypo-AF in BSC represents an unfavorable prognostic indicator and requires an aggressive immunemodulatory treatment. , In acute multiple evanescent white dots syndrome FAF shows multiple ill-defined hyperautofluorescent spots corresponding to ophthalmoscopically evident dots [Figure 7]. These findings disappear as the inflammation resolves.  Acute posterior multifocal placoid pigment epitheliopathy also shows a biphasic appearance on AF. In the acute phase, there is hypo-AF due to macular edema masking natural AF. Later, as the edema resolves, placoid areas appear hyperautofluorescent due to LF accumulation. 
|Figure 7: Short-wavelength-autofluorescence (AF) image (on the left) and fundus photograph (on the right) in multiple evanescent white dots syndrome showing the dots mild hyper-AF|
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Vogt-Koyanagi-Harada (VKH) disease is a bilateral granulomatous autoimmune panuveitis complicated by exudative retinal detachments. It presents with an acute phase sometimes followed by a chronic stage with choroidal depigmentation and RPE clumping configuring the "sunset glow" fundus appearance. ,,, Koizumi et al. analyzed the FAF appearance in acute VKH patients receiving prompt immunosuppressive treatment and in untreated or late-treated patients. The first group shows a transitory mild hyper-AF, the second group exhibits an initial widespread scattered hyper-AF then progressing to a mixed pattern showing both hyper- and hypo-AF areas.  Chronic VKH is not associated with FAF alterations since the typical depigmentation, resulting from the autoimmune process against the choroidal melanocytes, spares the RPE cells. ,
Serpiginous and serpiginous like choroiditis
An association between foveal hypo-AF and visual impairment was demonstrated in patients with serpiginous choroidopathy (SPC) [Figure 8].  Hyper-AF can anticipate the development of CNV in some patients with SPC and MFC. , Serpiginous like choroiditis is presumed to be caused by tuberculosis and starts with ophthalmoscopically evident placoid lesions that tend to progressively coalesce with a serpiginous appearance. , FAF typically shows ill-defined predominantly hyperautofluorescent lesions in the acute phase. Later the lesions appear more defined with a subtle hypo-AF at the borders and prevalence of enhanced AF internally. When the lesion evolves, hypofluorescent areas may appear due to the presence of damaged RPE cells. ,
|Figure 8: Short-wavelength-autofluorescence image of an eye affected by serpiginous choroidopathy|
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Primary vitreoretinal lymphoma
Non-Hodgkin's lymphomas arising in the eye are commonly B-cell derived and known as primary vitreoretinal lymphoma (PVRL) or primary intraocular lymphoma. ,, A granular AF was reported in PVRL affected eyes with hyper-AF resulting from the accumulation of LF next to the tumoral infiltration under the RPE and hypo-AF from the blockage by the invading tumor or due to the RPE damage and atrophy. 
Choroidal melanocytic lesions
Lipofuscin accumulation and RPE alterations are often present in choroidal melanocytic lesions. Therefore FAF is useful in documenting their presence. Hyperautofluorescent pigment and LF were found in nearly 90% of choroidal melanocytic lesions by Gündüz et al. using SW-FAF.  FAF can also help to characterize malignant lesions. According to Shields et al. choroidal melanomas show a variably increased AF with a typical granular pattern by using the standard FAF technique (580 nm excitation and 695 nm barrier filters). They observed higher AF in larger tumors, pigmented tumors and tumors with disrupted overlying RPE.  The sources of hyper-AF within malignant melanomas include remnants of LF granules and macrophages.  RPE alterations such as hyperplasia, fibrous metaplasia and atrophy overlying the tumors can be seen as an hypoautofluorescent area.  Chronic alterations of the RPE over a choroidal melanoma usually let the intrinsic AF of the lesion to appear. ,, The orange pigment, representing LF within the macrophages in the subretinal space is a subclinical sign of malignancy and appears hyperautofluorescent. 
| Clinical Limitations and Future Directions of Fundus Autofluorescence|| |
Fundus AF represents a rapid and noninvasive imaging technique. Thanks to FAF, it is possible to expand the comprehension of retinal diseases' pathogenesis and to monitor their course. Fluorescence reference systems have been developed to compare objectively FAF images taken in different subjects or at different times. For a more precise measurement, AF can also be averaged between different retinal zones or acquired at specific desired points.  Optical aberrations may be reduced incorporating adaptive optical systems in the FAF devices allowing to observe the retinal cells with a cellular-level of resolution. Ultra-widefield noncontact imaging system are now available enabling the clinician to visualize the retina with a 200° field of view.  Retinal metabolism has been recently investigated with a novel technique named fluorescent lifetime imaging ophthalmoscopy. It employs a modified SLO device that detects the alterations in the lifetime of the AF signal by measuring it with a single-photon counter. The AF lifetime appears to become longer with age and to be shorter in the central retina than in the periphery in healthy eyes. It represents a promising new tool to investigate the retinal metabolism in response to pathological changes.  Despite these considerations FAF remains a complementary technique in many retinal conditions where AF is just a pathological ephiphenomenon and shows several limitations that cannot be overstated. At present, there are no reference databases to classify consistently the normal and pathological FAF phenotypes. The interindividual and intraindividual variability of media opacities, refractive error and cellular LF content and genetic expression during the ageing process, make the possibility to develop such database likely challenging. , Differences in the acquisition system, such as between cSLO and fundus camera, and in other equipment and settings like excitation and emission filters, laser power, laser amplification and photodetectors gain also limit an objective AF measurement and the possibility to compare images from different patients and operators. , Therefore further technologic advances, the implementation of standard image acquisition procedures and the creation of a comprehensive classification systems of the normal and pathological phenotypes, could largely empower the impact of FAF imaging on the diagnosis and management of retinal diseases.
| References|| |
Delori F, Keilhauer C, Sparrow JR, Staurenghi G. Origin of fundus autofluorescence. In: Holz FG, Schmitz-Valckenberg S, Spaide RF, Bird AC, editors. Atlas of Fundus Autofluorescence Imaging. Berlin, Heidelberg: Springer-Verlag; 2007. p. 17-29.
Eldred GE, Katz ML. Fluorophores of the human retinal pigment epithelium: Separation and spectral characterization. Exp Eye Res 1988;47:71-86.
Schütt F, Davies S, Kopitz J, Holz FG, Boulton ME. Photodamage to human RPE cells by A2-E, a retinoid component of lipofuscin. Invest Ophthalmol Vis Sci 2000;41:2303-8.
Sparrow JR, Zhou J, Ben-Shabat S, Vollmer H, Itagaki Y, Nakanishi K. Involvement of oxidative mechanisms in blue-light-induced damage to A2E-laden RPE. Invest Ophthalmol Vis Sci 2002;43:1222-7.
Delori FC, Dorey CK, Staurenghi G, Arend O, Goger DG, Weiter JJ. In vivo
fluorescence of the ocular fundus exhibits retinal pigment epithelium lipofuscin characteristics. Invest Ophthalmol Vis Sci 1995;36:718-29.
Bosch E, Horwitz J, Bok D. Phagocytosis of outer segments by retinal pigment epithelium: Phagosome-lysosome interaction. J Histochem Cytochem 1993;41:253-63.
Herman KG, Steinberg RH. Phagosome movement and the diurnal pattern of phagocytosis in the tapetal retinal pigment epithelium of the opossum. Invest Ophthalmol Vis Sci 1982;23:277-90.
Feeney-Burns L, Hilderbrand ES, Eldridge S. Aging human RPE: Morphometric analysis of macular, equatorial, and peripheral cells. Invest Ophthalmol Vis Sci 1984;25:195-200.
Boyer NP, Higbee D, Currin MB, Blakeley LR, Chen C, Ablonczy Z, et al.
Lipofuscin and N-retinylidene-N-retinylethanolamine (A2E) accumulate in retinal pigment epithelium in absence of light exposure: Their origin is 11-cis-retinal. J Biol Chem 2012;287:22276-86.
Schütt F, Bergmann M, Kopitz J, Holz FG. Mechanism of the inhibition of lysosomal functions in the retinal pigment epithelium by lipofuscin retinoid component A2-E. Ophthalmologe 2001;98:721-4.
Schütt F, Bergmann M, Kopitz J, Holz FG. Detergent-like effects of the lipofuscin retinoid component A2-E in retinal pigment epithelial cells. Ophthalmologe 2002;99:861-5.
von Rückmann A, Schmidt KG, Fitzke FW, Bird AC, Jacobi KW. Dynamics of accumulation and degradation of lipofuscin in retinal pigment epithelium in senile macular degeneration. Klin Monbl Augenheilkd 1998;213:32-7.
Bellmann C, Rubin GS, Kabanarou SA, Bird AC, Fitzke FW. Fundus autofluorescence imaging compared with different confocal scanning laser ophthalmoscopes. Br J Ophthalmol 2003;87:1381-6.
Bindewald A, Jorzik JJ, Roth F, Holz FG. cSLO digital fundus autofluorescence imaging. Ophthalmologe 2005;102:259-64.
Keilhauer CN, Delori FC. Near-infrared autofluorescence imaging of the fundus: Visualization of ocular melanin. Invest Ophthalmol Vis Sci 2006;47:3556-64.
Schmitz-Valckenberg S, Holz FG, Bird AC, Spaide RF. Fundus autofluorescence imaging: Review and perspectives. Retina 2008;28:385-409.
Whitehead AJ, Mares JA, Danis RP. Macular pigment: A review of current knowledge. Arch Ophthalmol 2006;124:1038-45.
Delori FC, Fleckner MR, Goger DG, Weiter JJ, Dorey CK. Autofluorescence distribution associated with drusen in age-related macular degeneration. Invest Ophthalmol Vis Sci 2000;41:496-504.
Rothenbuehler SP, Wolf-Schnurrbusch UE, Wolf S. Macular pigment density at the site of altered fundus autofluorescence. Graefes Arch Clin Exp Ophthalmol 2011;249:499-504.
Weiter JJ, Delori FC, Wing GL, Fitch KA. Retinal pigment epithelial lipofuscin and melanin and choroidal melanin in human eyes. Invest Ophthalmol Vis Sci 1986;27:145-52.
Holz FG, Bellman C, Staudt S, Schütt F, Völcker HE. Fundus autofluorescence and development of geographic atrophy in age-related macular degeneration. Invest Ophthalmol Vis Sci 2001;42:1051-6.
Holz FG, Bindewald-Wittich A, Fleckenstein M, Dreyhaupt J, Scholl HP, Schmitz-Valckenberg S, et al
. Progression of geographic atrophy and impact of fundus autofluorescence patterns in age-related macular degeneration. Am J Ophthalmol 2007;143:463-72.
Delori FC, Staurenghi G, Arend O, Dorey CK, Goger DG, Weiter JJ. In vivo
measurement of lipofuscin in Stargardt′s disease - Fundus flavimaculatus. Invest Ophthalmol Vis Sci 1995;36:2327-31.
Boon CJ, Jeroen Klevering B, Keunen JE, Hoyng CB, Theelen T. Fundus autofluorescence imaging of retinal dystrophies. Vision Res 2008;48:2569-77.
Burke TR, Duncker T, Woods RL, Greenberg JP, Zernant J, Tsang SH, et al.
Quantitative fundus autofluorescence in recessive Stargardt disease. Invest Ophthalmol Vis Sci 2014;55:2841-52.
Fishman GA, Stone EM, Grover S, Derlacki DJ, Haines HL, Hock Variation of clinical expression in patients with Stargardt dystrophy and sequence variations in the ABCR gene. Arch Ophthalmol 1999;117:504-10.
Duncker T, Lee W, Tsang SH, Greenberg JP, Zernant J, Allikmets R, et al.
Distinct characteristics of inferonasal fundus autofluorescence patterns in stargardt disease and retinitis pigmentosa. Invest Ophthalmol Vis Sci 2013;54:6820-6.
Duncker T, Tsang SH, Lee W, Zernant J, Allikmets R, Delori FC, et al.
Quantitative fundus autofluorescence distinguishes ABCA4-associated and non-ABCA4-associated bull′s-eye maculopathy. Ophthalmology 2015;122:345-55.
Hartong DT, Berson EL, Dryja TP. Retinitis pigmentosa. Lancet 2006;368:1795-809.
Bhatti MT. Retinitis pigmentosa, pigmentary retinopathies, and neurologic diseases. Curr Neurol Neurosci Rep 2006;6:403-13.
Fleckenstein M, Charbel Issa P, Fuchs HA, Finger RP, Helb HM, Scholl HP, et al.
Discrete arcs of increased fundus autofluorescence in retinal dystrophies and functional correlate on microperimetry. Eye (Lond) 2009;23:567-75.
Robson AG, Michaelides M, Saihan Z, Bird AC, Webster AR, Moore AT, et al.
Functional characteristics of patients with retinal dystrophy that manifest abnormal parafoveal annuli of high density fundus autofluorescence; a review and update. Doc Ophthalmol 2008;116:79-89.
Lima LH, Cella W, Greenstein VC, Wang NK, Busuioc M, Smith RT, et al.
Structural assessment of hyperautofluorescent ring in patients with retinitis pigmentosa. Retina 2009;29:1025-31.
Aizawa S, Mitamura Y, Hagiwara A, Sugawara T, Yamamoto S. Changes of fundus autofluorescence, photoreceptor inner and outer segment junction line, and visual function in patients with retinitis pigmentosa. Clin Experiment Ophthalmol 2010;38:597-604.
Murakami T, Akimoto M, Ooto S, Suzuki T, Ikeda H, Kawagoe N, et al.
Association between abnormal autofluorescence and photoreceptor disorganization in retinitis pigmentosa. Am J Ophthalmol 2008;145:687-94.
Lima LH, Burke T, Greenstein VC, Chou CL, Cella W, Yannuzzi LA, et al.
Progressive constriction of the hyperautofluorescent ring in retinitis pigmentosa. Am J Ophthalmol 2012;153:718-27, 727.e1.
Robson AG, El-Amir A, Bailey C, Egan CA, Fitzke FW, Webster AR, et al.
Pattern ERG correlates of abnormal fundus autofluorescence in patients with retinitis pigmentosa and normal visual acuity. Invest Ophthalmol Vis Sci 2003;44:3544-50.
Robson AG, Egan CA, Luong VA, Bird AC, Holder GE, Fitzke FW. Comparison of fundus autofluorescence with photopic and scotopic fine-matrix mapping in patients with retinitis pigmentosa and normal visual acuity. Invest Ophthalmol Vis Sci 2004;45:4119-25.
Popovic P, Jarc-Vidmar M, Hawlina M. Abnormal fundus autofluorescence in relation to retinal function in patients with retinitis pigmentosa. Graefes Arch Clin Exp Ophthalmol 2005;243:1018-27.
Greenstein VC, Duncker T, Holopigian K, Carr RE, Greenberg JP, Tsang SH, et al.
Structural and functional changes associated with normal and abnormal fundus autofluorescence in patients with retinitis pigmentosa. Retina 2012;32:349-57.
Sawa M, Gomi F, Ohji M, Tsujikawa M, Fujikado T, Tano Y. Fundus autofluorescence after full macular translocation surgery for myopic choroidal neovascularization. Graefes Arch Clin Exp Ophthalmol 2008;246:1087-95.
Sparrow JR, Yoon KD, Wu Y, Yamamoto K. Interpretations of fundus autofluorescence from studies of the bisretinoids of the retina. Invest Ophthalmol Vis Sci 2010;51:4351-7.
Kellner U, Kellner S, Weber BH, Fiebig B, Weinitz S, Ruether K. Lipofuscin-and melanin-related fundus autofluorescence visualize different retinal pigment epithelial alterations in patients with retinitis pigmentosa. Eye (Lond) 2009;23:1349-59.
Duncker T, Tabacaru MR, Lee W, Tsang SH, Sparrow JR, Greenstein VC. Comparison of near-infrared and short-wavelength autofluorescence in retinitis pigmentosa. Invest Ophthalmol Vis Sci 2013;54:585-91.
Best F. Uber eine hereditare Maculaafektion; Beitrage zur Verergslehre. Zschr Augenheilk 1905;13:199-212.
Stone EM, Nichols BE, Streb LM, Kimura AE, Sheffield VC. Genetic linkage of vitelliform macular degeneration (Best′s disease) to chromosome 11q13. Nat Genet 1992;1:246-50.
Arnold JJ, Sarks JP, Killingsworth MC, Kettle EK, Sarks SH. Adult vitelliform macular degeneration: A clinicopathological study. Eye (Lond) 2003;17:717-26.
Kay CN, Abramoff MD, Mullins RF, Kinnick TR, Lee K, Eyestone ME, et al.
Three-dimensional distribution of the vitelliform lesion, photoreceptors, and retinal pigment epithelium in the macula of patients with best vitelliform macular dystrophy. Arch Ophthalmol 2012;130:357-64.
Ferrara DC, Costa RA, Tsang S, Calucci D, Jorge R, Freund KB. Multimodal fundus imaging in Best vitelliform macular dystrophy. Graefes Arch Clin Exp Ophthalmol 2010;248:1377-86.
Wabbels B, Preising MN, Kretschmann U, Demmler A, Lorenz B. Genotype-phenotype correlation and longitudinal course in ten families with Best vitelliform macular dystrophy. Graefes Arch Clin Exp Ophthalmol 2006;244:1453-66.
Renner AB, Tillack H, Kraus H, Krämer F, Mohr N, Weber BH, et al.
Late onset is common in best macular dystrophy associated with VMD2 gene mutations. Ophthalmology 2005;112:586-92.
Spaide RF, Noble K, Morgan A, Freund KB. Vitelliform macular dystrophy. Ophthalmology 2006;113:1392-400.
Parodi MB, Iacono P, Campa C, Del Turco C, Bandello F. Fundus autofluorescence patterns in Best vitelliform macular dystrophy. Am J Ophthalmol 2014;158:1086-92.
Sun H, Tsunenari T, Yau KW, Nathans J. The vitelliform macular dystrophy protein defines a new family of chloride channels. Proc Natl Acad Sci U S A 2002;99:4008-13.
Davidson AE, Millar ID, Burgess-Mullan R, Maher GJ, Urquhart JE, Brown PD, et al.
Functional characterization of bestrophin-1 missense mutations associated with autosomal recessive bestrophinopathy. Invest Ophthalmol Vis Sci 2011;52:3730-6.
Oishi M, Oishi A, Ogino K, Makiyama Y, Gotoh N, Kurimoto M, et al.
Wide-field fundus autofluorescence abnormalities and visual function in patients with cone and cone-rod dystrophies. Invest Ophthalmol Vis Sci 2014;55:3572-7.
Curcio CA, Sloan KR, Kalina RE, Hendrickson AE. Human photoreceptor topography. J Comp Neurol 1990;292:497-523.
Schmitz-Valckenberg S, Fleckenstein M, Scholl HP, Holz FG. Fundus autofluorescence and progression of age-related macular degeneration. Surv Ophthalmol 2009;54:96-117.
Schmitz-Valckenberg S, Bindewald-Wittich A, Dolar-Szczasny J, Dreyhaupt J, Wolf S, Scholl HP, et al.
Correlation between the area of increased autofluorescence surrounding geographic atrophy and disease progression in patients with AMD. Invest Ophthalmol Vis Sci 2006;47:2648-54.
Schmitz-Valckenberg S, Bültmann S, Dreyhaupt J, Bindewald A, Holz FG, Rohrschneider K. Fundus autofluorescence and fundus perimetry in the junctional zone of geographic atrophy in patients with age-related macular degeneration. Invest Ophthalmol Vis Sci 2004;45:4470-6.
Lim LS, Mitchell P, Seddon JM, Holz FG, Wong TY. Age-related macular degeneration. Lancet 2012;379:1728-38.
Hopkins J, Walsh A, Chakravarthy U. Fundus autofluorescence in age-related macular degeneration: An epiphenomenon? Invest Ophthalmol Vis Sci 2006;47:2269-71.
Arnold JJ, Sarks SH, Killingsworth MC, Sarks JP. Reticular pseudodrusen. A risk factor in age-related maculopathy. Retina 1995;15:183-91.
Bindewald A, Bird AC, Dandekar SS, Dolar-Szczasny J, Dreyhaupt J, Fitzke FW, et al.
Classification of fundus autofluorescence patterns in early age-related macular disease. Invest Ophthalmol Vis Sci 2005;46:3309-14.
Midena E, Vujosevic S, Convento E, Manfre′ A, Cavarzeran F, Pilotto E. Microperimetry and fundus autofluorescence in patients with early age-related macular degeneration. Br J Ophthalmol 2007;91:1499-503.
Sunness JS, Bressler NM, Tian Y, Alexander J, Applegate CA. Measuring geographic atrophy in advanced age-related macular degeneration. Invest Ophthalmol Vis Sci 1999;40:1761-9.
Khanifar AA, Lederer DE, Ghodasra JH, Stinnett SS, Lee JJ, Cousins SW, et al.
Comparison of color fundus photographs and fundus autofluorescence images in measuring geographic atrophy area. Retina 2012;32:1884-91.
Schmitz-Valckenberg S, Fleckenstein M, Göbel AP, Sehmi K, Fitzke FW, Holz FG, et al.
Evaluation of autofluorescence imaging with the scanning laser ophthalmoscope and the fundus camera in age-related geographic atrophy. Am J Ophthalmol 2008;146:183-92.
Pilotto E, Vujosevic S, Melis R, Convento E, Sportiello P, Alemany-Rubio E, et al.
Short wavelength fundus autofluorescence versus near-infrared fundus autofluorescence, with microperimetric correspondence, in patients with geographic atrophy due to age-related macular degeneration. Br J Ophthalmol 2011;95:1140-4.
Holz FG, Bellmann C, Margaritidis M, Schütt F, Otto TP, Völcker HE. Patterns of increased in vivo
fundus autofluorescence in the junctional zone of geographic atrophy of the retinal pigment epithelium associated with age-related macular degeneration. Graefes Arch Clin Exp Ophthalmol 1999;237:145-52.
Bearelly S, Khanifar AA, Lederer DE, Lee JJ, Ghodasra JH, Stinnett SS, et al.
Use of fundus autofluorescence images to predict geographic atrophy progression. Retina 2011;31:81-6.
Lois N, Owens SL, Coco R, Hopkins J, Fitzke FW, Bird AC. Fundus autofluorescence in patients with age-related macular degeneration and high risk of visual loss. Am J Ophthalmol 2002;133:341-9.
Bindewald A, Schmitz-Valckenberg S, Jorzik JJ, Dolar-Szczasny J, Sieber H, Keilhauer C, et al.
Classification of abnormal fundus autofluorescence patterns in the junctional zone of geographic atrophy in patients with age related macular degeneration. Br J Ophthalmol 2005;89:874-8.
Hashimoto T, Harada T. Confocal scanning laser microscopic findings of excised choroidal neovascular membranes of age-related macular degeneration and their comparison with the clinical features. Jpn J Ophthalmol 1999;43:375-85.
McBain VA, Townend J, Lois N. Fundus autofluorescence in exudative age-related macular degeneration. Br J Ophthalmol 2007;91:491-6.
von Rückmann A, Fitzke FW, Bird AC. Fundus autofluorescence in age-related macular disease imaged with a laser scanning ophthalmoscope. Invest Ophthalmol Vis Sci 1997;38:478-86.
von Rückmann A, Fitzke FW, Bird AC. Distribution of pigment epithelium autofluorescence in retinal disease state recorded in vivo
and its change over time. Graefes Arch Clin Exp Ophthalmol 1999;237:1-9.
Heimes B, Lommatzsch A, Zeimer M, Gutfleisch M, Spital G, Bird AC, et al.
Foveal RPE autofluorescence as a prognostic factor for anti-VEGF therapy in exudative AMD. Graefes Arch Clin Exp Ophthalmol 2008;246:1229-34.
Karadimas P, Bouzas EA. Fundus autofluorescence imaging in serous and drusenoid pigment epithelial detachments associated with age-related macular degeneration. Am J Ophthalmol 2005;140:1163-5.
Batioglu F, Demirel S, Özmert E. Fundus autofluorescence imaging in age-related macular degeneration. Semin Ophthalmol 2015;30:65-73.
Xu H, Chen M, Manivannan A, Lois N, Forrester JV. Age-dependent accumulation of lipofuscin in perivascular and subretinal microglia in experimental mice. Aging Cell 2008;7:58-68.
McBain VA, Forrester JV, Lois N. Fundus autofluorescence in the diagnosis of cystoid macular oedema. Br J Ophthalmol 2008;92:946-9.
Bessho K, Gomi F, Harino S, Sawa M, Sayanagi K, Tsujikawa M, et al.
Macular autofluorescence in eyes with cystoid macula edema, detected with 488 nm-excitation but not with 580 nm-excitation. Graefes Arch Clin Exp Ophthalmol 2009;247:729-34.
Pece A, Isola V, Holz F, Milani P, Brancato R. Autofluorescence imaging of cystoid macular edema in diabetic retinopathy. Ophthalmologica 2010;224:230-5.
Vujosevic S, Casciano M, Pilotto E, Boccassini B, Varano M, Midena E. Diabetic macular edema: Fundus autofluorescence and functional correlations. Invest Ophthalmol Vis Sci 2011;52:442-8.
Yoshitake S, Murakami T, Horii T, Uji A, Ogino K, Unoki N, et al.
Qualitative and quantitative characteristics of near-infrared autofluorescence in diabetic macular edema. Ophthalmology 2014;121:1036-44.
Chung H, Park B, Shin HJ, Kim HC. Correlation of fundus autofluorescence with spectral-domain optical coherence tomography and vision in diabetic macular edema. Ophthalmology 2012;119:1056-65.
Gemenetzi M, De Salvo G, Lotery AJ. Central serous chorioretinopathy: An update on pathogenesis and treatment. Eye (Lond) 2010;24:1743-56.
Wang M, Munch IC, Hasler PW, Prünte C, Larsen M. Central serous chorioretinopathy. Acta Ophthalmol 2008;86:126-45.
Ross A, Ross AH, Mohamed Q. Review and update of central serous chorioretinopathy. Curr Opin Ophthalmol 2011;22:166-73.
Spaide RF, Klancnik JM Jr. Fundus autofluorescence and central serous chorioretinopathy. Ophthalmology 2005;112:825-33.
Teke MY, Elgin U, Nalcacioglu-Yuksekkaya P, Sen E, Ozdal P, Ozturk F. Comparison of autofluorescence and optical coherence tomography findings in acute and chronic central serous chorioretinopathy. Int J Ophthalmol 2014;7:350-4.
Dinc UA, Tatlipinar S, Yenerel M, Görgün E, Ciftci F. Fundus autofluorescence in acute and chronic central serous chorioretinopathy. Clin Exp Optom 2011;94:452-7.
von Rückmann A, Fitzke FW, Fan J, Halfyard A, Bird AC. Abnormalities of fundus autofluorescence in central serous retinopathy. Am J Ophthalmol 2002;133:780-6.
Okada AA, Goto H, Mizusawa T, Morimoto K, Ebihara Y, Usui M. Angiography of experimental autoimmune uveoretinitis with ultrastructural correlation. Graefes Arch Clin Exp Ophthalmol 1998;236:865-72.
Yeh S, Faia LJ, Nussenblatt RB. Advances in the diagnosis and immunotherapy for ocular inflammatory disease. Semin Immunopathol 2008;30:145-64.
Matsumoto Y, Haen SP, Spaide RF. The white dot syndromes. Compr Ophthalmol Update 2007;8:179-200.
Yeh S, Forooghian F, Wong WT, Faia LJ, Cukras C, Lew JC, et al.
Fundus autofluorescence imaging of the white dot syndromes. Arch Ophthalmol 2010;128:46-56.
Koizumi H, Pozzoni MC, Spaide RF. Fundus autofluorescence in birdshot chorioretinopathy. Ophthalmology 2008;115:e15-20.
Haen SP, Spaide RF. Fundus autofluorescence in multifocal choroiditis and panuveitis. Am J Ophthalmol 2008;145:847-53.
Furino C, Boscia F, Cardascia N, Alessio G, Sborgia C. Fundus autofluorescence and multiple evanescent white dot syndrome. Retina 2009;29:60-3.
Yenerel NM, Kucumen B, Gorgun E, Dinc UA. Atypical presentation of multiple evanescent white dot syndrome (MEWDS). Ocul Immunol Inflamm 2008;16:113-5.
Spaide RF. Autofluorescence imaging of acute posterior multifocal placoid pigment epitheliopathy. Retina 2006;26:479-82.
Souka AA, Hillenkamp J, Gora F, Gabel VP, Framme C. Correlation between optical coherence tomography and autofluorescence in acute posterior multifocal placoid pigment epitheliopathy. Graefes Arch Clin Exp Ophthalmol 2006;244:1219-23.
Cardillo Piccolino F, Grosso A, Savini E. Fundus autofluorescence in serpiginous choroiditis. Graefes Arch Clin Exp Ophthalmol 2009;247:179-85.
Penha FM, Navajas EV, Bom Aggio F, Rodrigues EB, Farah ME. Fundus autofluorescence in multiple evanescent white dot syndrome. Case Rep Ophthalmol Med 2011;2011:807565.
Hua R, Liu L, Chen L. Evaluation of the progression rate of atrophy lesions in punctate inner choroidopathy (PIC) based on autofluorescence analysis. Photodiagnosis Photodyn Ther 2014;11:565-9.
Lee CS, Lee AY, Forooghian F, Bergstrom CS, Yan J, Yeh S. Fundus autofluorescence features in the inflammatory maculopathies. Clin Ophthalmol 2014;8:2001-12.
Turkcuoglu P, Chang PY, Rentiya ZS, Channa R, Ibrahim M, Hatef E, et al.
Mycophenolate mofetil and fundus autofluorescence in the management of recurrent punctate inner choroidopathy. Ocul Immunol Inflamm 2011;19:286-92.
Giuliari G, Hinkle DM, Foster CS. The spectrum of fundus autofluorescence findings in birdshot chorioretinopathy. J Ophthalmol 2009;2009:567693.
Tomkins-Netzer O, Taylor SR, Lightman S. Long-term clinical and anatomic outcome of birdshot chorioretinopathy. JAMA Ophthalmol 2014;132:57-62.
Moorthy RS, Inomata H, Rao NA. Vogt-Koyanagi-Harada syndrome. Surv Ophthalmol 1995;39:265-92.
Rao NA. Mechanisms of inflammatory response in sympathetic ophthalmia and VKH syndrome. Eye (Lond) 1997;11 (Pt 2):213-6.
Read RW, Holland GN, Rao NA, Tabbara KF, Ohno S, Arellanes-Garcia L, et al.
Revised diagnostic criteria for Vogt-Koyanagi-Harada disease: Report of an international committee on nomenclature. Am J Ophthalmol 2001;131:647-52.
Beniz J, Forster DJ, Lean JS, Smith RE, Rao NA. Variations in clinical features of the Vogt-Koyanagi-Harada syndrome. Retina 1991;11:275-80.
Koizumi H, Maruyama K, Kinoshita S. Blue light and near-infrared fundus autofluorescence in acute Vogt-Koyanagi-Harada disease. Br J Ophthalmol 2010;94:1499-505.
Rao NA. Pathology of Vogt-Koyanagi-Harada disease. Int Ophthalmol 2007;27:81-5.
Inomata H, Sakamoto T. Immunohistochemical studies of Vogt-Koyanagi-Harada disease with sunset sky fundus. Curr Eye Res 1990;9 Suppl:35-40.
Gupta A, Bansal R, Gupta V, Sharma A, Bambery P. Ocular signs predictive of tubercular uveitis. Am J Ophthalmol 2010;149:562-70.
Vasconcelos-Santos DV, Rao PK, Davies JB, Sohn EH, Rao NA. Clinical features of tuberculous serpiginouslike choroiditis in contrast to classic serpiginous choroiditis. Arch Ophthalmol 2010;128:853-8.
Bansal R, Kulkarni P, Gupta A, Gupta V, Dogra MR. High-resolution spectral domain optical coherence tomography and fundus autofluorescence correlation in tubercular serpiginouslike choroiditis. J Ophthalmic Inflamm Infect 2011;1:157-63.
Carreño E, Portero A, Herreras JM, López MI. Assesment of fundus autofluorescence in serpiginous and serpiginous-like choroidopathy. Eye (Lond) 2012;26:1232-6.
Grimm SA, McCannel CA, Omuro AM, Ferreri AJ, Blay JY, Neuwelt EA, et al.
Primary CNS lymphoma with intraocular involvement: International PCNSL Collaborative Group Report. Neurology 2008;71:1355-60.
Chan CC, Rubenstein JL, Coupland SE, Davis JL, Harbour JW, Johnston PB, et al.
Primary vitreoretinal lymphoma: A report from an International Primary Central Nervous System Lymphoma Collaborative Group symposium. Oncologist 2011;16:1589-99.
Ishida T, Ohno-Matsui K, Kaneko Y, Tobita H, Shimada N, Takase H, et al.
Fundus autofluorescence patterns in eyes with primary intraocular lymphoma. Retina 2010;30:23-32.
Casady M, Faia L, Nazemzadeh M, Nussenblatt R, Chan CC, Sen HN. Fundus autofluorescence patterns in primary intraocular lymphoma. Retina 2014;34:366-72.
Gündüz K, Pulido JS, Bakri SJ, Petit-Fond E. Fundus autofluorescence in choroidal melanocytic lesions. Retina 2007;27:681-7.
Shields CL, Bianciotto C, Pirondini C, Materin MA, Harmon SA, Shields JA. Autofluorescence of choroidal melanoma in 51 cases. Br J Ophthalmol 2008;92:617-22.
Lohmann W, Wiegand W, Stolwijk TR, van Delft JL, van Best JA. Endogenous fluorescence of ocular malignant melanomas. Ophthalmologica 1995;209:7-10.
Shields CL, Pirondini C, Bianciotto C, Materin MA, Harmon SA, Shields JA. Autofluorescence of choroidal nevus in 64 cases. Retina 2008;28:1035-43.
Lavinsky D, Belfort RN, Navajas E, Torres V, Martins MC, Belfort R Jr. Fundus autofluorescence of choroidal nevus and melanoma. Br J Ophthalmol 2007;91:1299-302.
Shields CL, Bianciotto C, Pirondini C, Materin MA, Harmon SA, Shields JA. Autofluorescence of orange pigment overlying small choroidal melanoma. Retina 2007;27:1107-11.
Greenberg JP, Duncker T, Woods RL, Smith RT, Sparrow JR, Delori FC. Quantitative fundus autofluorescence in healthy eyes. Invest Ophthalmol Vis Sci 2013;54:5684-93.
Witmer MT, Kiss S. Wide-field imaging of the retina. Surv Ophthalmol 2013;58:143-54.
Klemm M, Dietzel A, Haueisen J, Nagel E, Hammer M, Schweitzer D. Repeatability of autofluorescence lifetime imaging at the human fundus in healthy volunteers. Curr Eye Res 2013;38:793-801.
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