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 Table of Contents  
ORIGINAL ARTICLE
Year : 2014  |  Volume : 4  |  Issue : 1  |  Page : 21-27

Choroidal changes by ocular coherence tomography in white dot syndrome


1 Department of Ophthalmology, Changhua Christian Hospital, Changhua, Taiwan
2 Department of Ophthalmology, Changhua Christian Hospital; School of Medicine, Chung Shan Medical University, Taichung, Taiwan

Date of Web Publication4-Mar-2014

Correspondence Address:
San-Ni Chen
Department of Ophthalmology, Changhua Christian Hospital, Changhua
Taiwan
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Source of Support: None, Conflict of Interest: None


DOI: 10.1016/j.tjo.2013.06.002

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  Abstract 

Purpose: To evaluate the findings of optical coherence tomography (OCT) in the acute and convalescent stages in patients with white dot syndrome. Patients were followed up at our clinic for at least 6 months.
Materials and methods: A consecutive case series of patients with white dot syndrome were enrolled in this study. Only patients with disease onset less than 1 week were included in this study. Slit-lamp biomicroscopy, indirect ophthalmoscopy, fluorescein angiography, indocyanine green angiography (ICGA), OCT, visual field test, and corrected decimal visual acuity test were performed on all patients.
Results: A total of eight eyes from eight patients were analyzed in this study, including cases with acute zonal occult outer retinopathy (AZOOR), punctate inner choroidopathy and AZOOR, multiple evanescent white dot syndrome, and multifocal choroiditis. In the acute stage, OCT demonstrated diffuse or segmental attenuation/loss of inner segment/outer segment (IS/OS) signal. Choroidal thickening with increased choroidal vascular porosity as compared with the fellow eyes was noted in all eyes. The ICGA showed hypofluorescence patches in the late phase. In the convalescent stage, complete or partial restoration of photoreceptor IS/OS was noted along with a partial or complete resolution of choroidal thickening and choroidal vascular porosity in OCT. The ICGA also demonstrated resolved choroidal hypofluorescence in the convalescent stage.
Conclusion: Choroidal thickening and increased choroidal vascular porosity in addition to disruption of photoreceptor IS/OS were characteristic OCT features of white dot syndrome. Recovery of vision was accompanied with restoration of OCT findings in both retina and choroid.

Keywords: choroid, indocyanine green angiography, inner segment/outer segment, ocular coherence tomography, white dot syndrome


How to cite this article:
Cheng CY, Hwang JF, Chen SN. Choroidal changes by ocular coherence tomography in white dot syndrome. Taiwan J Ophthalmol 2014;4:21-7

How to cite this URL:
Cheng CY, Hwang JF, Chen SN. Choroidal changes by ocular coherence tomography in white dot syndrome. Taiwan J Ophthalmol [serial online] 2014 [cited 2022 Jan 26];4:21-7. Available from: https://www.e-tjo.org/text.asp?2014/4/1/21/203920




  1. Introduction Top


White dot syndrome is composed of a group of disorders including acute zonal occult outer retinopathy (AZOOR), multiple evanescent white dot syndrome (MEWDS), multifocal choroiditis (MFC), punctate inner choroidopathy (PIC), and acute posterior multifocal placoid pigment epitheliopathy, etc. Inflammation located on the outer retinal layer, retinal pigment epithelia, and inner choroid have been proposed as the etiology.[1] Clinical characteristics include acute deterioration of vision, blind spot enlargement, visual field (VF) loss, and photopsia. Loss of inner segment/outer segment (IS/OS) line and attenuation of outer nuclear layer (ONL) in optical coherence tomography (OCT) have been described in cases with AZOOR, MFC, and MEWDS in previously published reports.[2],[3],[4],[5],[6],[7] To the best of our knowledge, there are still no reports discussing the choroidal changes in OCT. In this study, manifestations of the retina and choroid in Fourier domain OCT and indocyanine green angiography (ICGA) at the acute and convalescent stages are described and discussed.


  2. Materials and methods Top


This prospective study evaluated the consecutive case series of white dot syndrome from June 2010 to December 2011 in Changhua Christian Hospital, Taiwan. Only patients with disease onset less than 1 week were recruited in this study. This study was approved by the Institutional Review Board of Changhua Christian Hospital and was carried out in accordance with the World Medical Association’s Declaration of Helsinki. All patients underwent comprehensive examinations including corrected decimal visual acuity (VA), slit-lamp biomicroscopy, indirect ophthalmoscopy, spectral domain OCT (Cirrus OCT; Carl Zeiss Meditec Inc., Dublin, CA, USA), and color and autofluorescence fundus photography. Fluorescein angiography (FA), ICGA (HRA-2; Heidelberg Engineering, Heidelberg, Germany), and VF test (Humphrey 30-2, Carl Zeiss Meditec, Germany) were also performed.

2.1. Spectral domain OCT

Cirrus HD-OCT (Carl Zeiss Meditec, Inc) was used to obtain spectral domain OCT images. The scanning rate was 27,000 A-scan/ second with an axial resolution of 5 μm. Both 6 mm × 6 mm cubic scan and high-definition one-line raster scan centering on the foveola were performed. Multiple hyper-reflective bands corresponding to the different histological layers of retina were identified and achieved. The subfoveal choroidal thickness was measured according to the horizontal high-definition one-line raster scan for both eyes on every visit. We also performed a comparison of changes in hyper-reflective bands and choroidal thickness between fellow eyes and each visit.

2.2. Fluorescein and ICGA

Simultaneous fluorescein and ICGA were carried out using HRA2 (Heidelberg Engineering).


  3. Results Top


A total of eight eyes from eight patients (3 males and 5 females) who fulfilled the study criteria were analyzed. All eyes were myopic. The average refractive status was −8.91 ± 3.27 D (range from −5.25 D to −13.5 D). The average age of the participants was 35.1 ± 16.0 years (range: 18–43 years). Based on the subclassification of disease entity, one patient had AZOOR, one patient had PIC combined with AZOOR, four patients had MEWDS, and two patients had MFC. All patients complained of blurred vision with or without VF defect. Corrected decimal VA ranged from 20/100 to 20/20 at the initial visit. The IS/OS boundary attenuation or loss was noted in every patient in the acute phase of the disease. The four patients with MEWDS had complete recovery of IS/OS boundary without treatment. The patient with AZOOR had IS/OS boundary that completely recovered after immunomodulation therapy. The patient with AZOOR combined with PIC and the two patients with MFC had partial recovery of IS/OS boundary after immunomodulation therapy. Increased choroidal thickness compared with the fellow eyes was noted in all but one patient (Case 7), in whom MFC occurred 1 year earlier in the fellow eye. Increased choroidal vascular porosity as compared with the fellow eyes was also noted in all eyes. Decreased choroidal thickening was noted in all eyes during the convalescent phase. Hypofluorescence in late-stage ICGA was noted in all eyes at the acute phase and was later partially or completely resolved in all cases. Patients’ demographic data are listed in [Table 1].
Table 1: Demographic data of patients.

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3.1. AZOOR

3.1.1. Case 1

An 18 year-old myopic male patient complained of loss of vision in the left eye for 1 day. His corrected decimal VA in the left eye was 20/100 and 20/20 in the right eye. Relative afferent papillary defect was noted in the left eye. Indirect ophthalmoscopy and slit-lamp microscopy showed a tessellated myopic fundus without any other abnormalities [Figure 1]A. Humphrey 30-2 VF test showed a defect in the temporal lower, upper, and nasal periphery areas in the left eye. Subtle obliteration at the nasal upper area was also noted in the right eye [Figure 1]B. He also had a decreased electroretinographic amplitude in A wave in the left eye. An FA showed no particular findings, and ICGA showed delayed choroidal filling and multiple hypofluorescent patches at the posterior pole at the late phase [Figure 1]C. Spectral domain OCT showed diffuse attenuated signals of IS/OS from the peripapillary area extending to the area temporal to the fovea [Figure 1]D. Increased choroidal thickness and choroidal vascular porosity compared with the fellow eye were also noted [choroidal thickness: oculus dexter (OD) = 68 μm; oculus sinister (OS) = 120 μm]. AZOOR was impressed and the patient was admitted for pulse steroid therapy for 3 days (1000 mg methylprednisolone/day) followed by oral prednisolone administration. The choroidal thickness was further increased with a still diffusely attenuated IS/ OS boundary 10 days later. Progressive restoration of IS/OS boundaries and improvement of VF and VA scores were noted 4 weeks after the initiation of therapy. His decimal VA came back to 20/20 3 months later with a completely recovered IS/OS boundary in OCT [Figure 1]D; choroidal thickness: 96 μm), with some optical densities clustered around the inner aspect of ONL at the perifoveal area. A VF test showed a slightly enlarged blind spot with minimal depressed temporal VF [Figure 1]E. Repeated ICGA showed a resolution of choroidal hypofluorescence at the late phase [Figure 1]F. His condition was stable until the end of follow-up 12 months later.
Figure 1: (A) Color fundus photography in Case 1 with acute zonal occult outer retinopathy at the initial presentation shows a tessellated fundus in the left eye without other abnormality. (B) A visual field test (VF) shows a visual defect at the temporal lower, central, and nasal peripheral area in the left eye. An arcuate VF defect at the nasal upper peripheral area is also noted in the right eye. (C) A fluorescein angiography does not reveal any specific findings, but an indocyanine green angiography (ICGA) shows multiple hypofluorescent patches, which partially fused in the late stage. (D) Diffuse inner segment/outer segment (IS/OS) signal attenuation with some optical densities clustered around the outer nuclear layer at the perifoveal area is noted in the optical coherence tomography of the left eye (c). Increased choroidal thickness is also noted as compared with the right eye (a). Completely recovered IS/OS boundary with decreased choroidal thickness is noted 3 months later (b). (E) After treatment, the VF defect shows a slightly enlarged blind spot with minimally depressed temporal VF defect. (F) The ICGA shows a resolution of the choroidal hypofluorescence in the late phase. OD = oculus dexter; OS = oculus sinister.

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3.2. PIC with AZOOR

3.2.1. Case 2

A 36-year-old myopic female patient complained of paracentral scotoma in the left eye for 3 days. Corrected decimal VA was 20/20 for both eyes. She had an episode of blurred vision in the left eye 1 year prior to her current visit, which spontaneously resolved. A funduscopic examination revealed a tessellated fundus with multiple faint yellowish spots and linear streaks in the left eye [Figure 2]A and tessellated fundus in the right eye. An FA showed multiple hyperfluorescent spots and linear streaks corresponding to the findings in color fundus in the early phase without obvious leakage in the late phase. An ICGA demonstrated multiple hypofluorescent spots and linear, branching lesions with diffuse, patchy, background hypofluorescence [Figure 2]B. A VF test showed temporal scotoma contiguous to the enlarged blind spot [Figure 2]C. An OCT showed diffuse attenuated signals of IS/OS from the nasal fovea to the peripapillary area. Increased subfoveal choroidal thickness [Figure 2]D; OD = 80 μm; OS = 165 μm) and increased choroidal vascular porosity were also noted. Progressive restoration of IS/OS boundary and VF were noted 2 months later. An ICGA performed 3 months later showed a resolution of the background hypofluorescence with persistent hypofluorescent, linear, branched lesions. Partially recovered IS/OS boundary, resolution of choroidal thickening [Figure 2]D; choroidal thickness: 80 mm), mildly depressed light sensitivity, and a mildly enlarged blind spot were left at 10 months of follow-up [Figure 2]E.
Figure 2: (A) Color fundus photography in Case 2 with punctate inner choroidopathy and acute zonal occult outer retinopathy shows a tessellated fundus with multiple yellowish spots and linear streak in the left eye. (B) A fluorescein angiography shows hyperfluorescent spots and linear streak without an obvious leakage in the late stage. An indocyanine green angiography shows multiple hypofluorescent spots and streaks with background hypofluorescence in the late stage. (C) Humphrey 30-2 visual field test shows a large temporal scotoma contiguous with the blind spot and depressed central light sensitivity. (D) An optical coherence tomography in the left eye (c) demonstrates the diffuse attenuation of the inner segment/outer segment (IS/OS) boundary from the peripapillary area to the nasal side of the fovea along with the increased choroidal thickness and choroidal vascular porosity as compared with the right eye (a). Partially recovered IS/OS boundaries are noted along with partial resolution of choroidal thickness 10 months later in the left eye (b). (E) Repeated visual field shows mildly depressed light sensitivity and a mildly enlarged blind spot. OD = oculus dexter; OS = oculus sinister.

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3.3. MEWDS

3.3.1. Case 3

A 43 year-old myopic male patient complained of blurred vision in the left eye for 1 week. Corrected decimal VA was 20/20 in the right eye and 20/40 in the left eye. A funduscopy showed multiple faint, white spots with a blurred margin at the posterior pole and granularity of fovea [Figure 3]A. An FA showed multiple wreath-like leakage in the late phase, whereas an ICGA showed multiple hypofluorescent spots in the late phase. Segmental disruption and triangular elevation of IS/OSs with spotty optical density in the ONL were noted along with an increased choroidal thickness and choroidal vascular porosity [Figure 3]B; choroidal thickness: OD = 244 μm; OS = 316 μm). A VF test showed an enlarged blind spot and depressed central VF sensitivity [Figure 3]C. The corrected decimal VA came back to 20/20 and recovered IS/OS boundary were noted 4 weeks later with recovered VF [Figure 3]D. Choroidal thickening was partially resolved and porosity persisted in OCT [Figure 3]B.
Figure 3: (A) Color fundus photography in Case 4 with multiple evanescent white dot syndrome in the left eye showed multiple faint white spots at posterior pole. (B) An optical coherence tomography (OCT) at the acute phase demonstrated segmental disruption of inner segment/outer segment (IS/OS) boundaries and triangular elevation at some points of IS/OS boundaries in the left eye (c). Some optical densities are noted at the inner aspect of outer nuclear layer (arrow) and inner plexiform layer (arrowhead). Increased choroidal thickness and porosity are also noted in the left eye as compared with the right eye (a). An OCT 2 months later shows completely recovered IS/OS boundaries, mildly decreased choroidal thickness, and persistent increased porosity (b). There were some optical densities clustered around the inner plexiform layer. (C) The initial visual field shows an enlarged blind spot and depressed central visual field sensitivity. (D) Visual field recovered 4 weeks later. OD = oculus dexter; OS = oculus sinister.

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3.3.2. Case 4

A 35-year-old myopic female patient complained of blurred vision in the right eye for 1 day. Her corrected decimal VA was 20/30 in the right eye and 20/20 in the left eye. MEWDS was impressed according to the typical fundus findings. A VF test demonstrated an enlarged blind spot and depressed light sensitivity in the right eye. An OCT showed segment attenuation of IS/OS [Figure 4]. Increased choroidal thickness and porosity were also noted. Her VA came back to 20/20 with recovered IS/OS boundary, resolved choroidal thickening, and choroidal porosity 3 weeks later [Figure 4].
Figure 4: Multiple evanescent white dot syndrome in Case 4. An optical coherence tomography at the acute stage showed segmental disruption of inner segment/outer segment (IS/OS) in the right eye (a). Choroidal thickening and increased choroidal vascular porosity are also noted compared with the fellow eye (c). Recovered IS/OS, resolution of choroidal changes are noted 4 weeks later (b). OD = oculus dexter; OS = oculus sinister.

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3.4. MFC

3.4.1. Case 7

A 31-year-old myopic female patient had sudden visual loss in the left eye for 2 days. One year earlier, she had a sudden loss of vision with progressive deterioration in the right eye. However, she did not receive any treatment then. The patient’s corrected decimal VA was 20/100 in the right eye and 20/400 in the left eye. An ocular examination revealed peripapillary scar, macular scar, multiple chorioretinal atrophic patches, and vitreous cells in the right eye. Multiple white spots with fluffy margins clustered at the posterior pole were noted in the left eye [Figure 5]A. An FA showed multiple hyperfluorescent spots with leakage and an ICGA showed multiple hypofluorescent patches corresponding to the fluffy white patches in color funduscopy in the left eye [Figure 5]B. Spectral domain OCT showed a diffuse loss of IS/OS boundaries in the right eye with a thickened choroid and submacular nodular scar in the right eye. An OCT in the left eye showed an even more thickened choroid, segmental disruption of IS/OS boundaries and transretinal, mildly elevated hyper-reflective nodule [Figure 5]C. She was admitted for pulse steroid therapy for 3 days followed by the administration of immunomodulation agents including oral steroid and azathioprine. A follow-up OCT 1 week later showed partially resolved choroidal thickening, but further deteriorated IS/OS boundaries. Partial restoration of IS/OS was noted 3 month later [Figure 5]C coupled with visual improvement (corrected decimal VA: 20/25) and decreased choroidal hypofluorescence. Unfortunately, disease activity rebounded vigorously during the tapering of the steroid with markedly increased choroidal thickening, loss of IS/OS boundaries [Figure 5]C, and deteriorated vision (corrected decimal VA: 20/700). The transretinal hyper-reflectivity markedly increased in size but decreased in reflectivity with increased choroidal thickening. After re-dosing of immunosuppressive agents, her condition stabilized with a partial resolution of choroidal thickening, reduction in the size of transretinal hyper-reflectivity, and partially recovered but still with attenuated signals of IS/OS boundaries at the macular area [Figure 5]C.
Figure 5: (A) Multiple white spots with fluffy margins clustered at posterior pole are noted in the left eye in Case 7 with multifocal choroiditis. (B) A fluorescein angiography shows a profuse leakage at the late phase and an indocyanine green angiography shows multiple hypofluorescent spots. (C) An optical coherence tomography in the left eye shows a thickened choroid, segmental disruption of inner segment/outer segment (IS/OS) boundaries and a transretinal, mildly elevated hyper-reflective nodule (a). The nodule size changed along with inflammation. Partial restoration of IS/OS is noted (c). Unfortunately, disease activity rebounded vigorously during the tapering of steroid treatment. The transretinal hyper-reflective nodule increased markedly in size with a further increase in choroidal thickening (b). After re-dosing of immunosuppressive agents, the patient's condition stabilized 5 months later, with the thickness of both retina and choroid decreased d). OS = oculus sinister.

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  4. Discussion Top


Retinal changes in OCT have been reported in various diseases of white dot syndrome.[2],[3],[4],[5],[6],[7],[8] Diffuse or segmental disruption of IS/OS boundaries with or without dome-shaped elevations in OCT were reported in previous reports at the acute stage in MEWDS.[2],[3],[4] Literatures about OCT findings of AZOOR involved cases in the chronic or subacute stage, which included a loss of IS/OS junctions, thinning of ONL, and abnormal inner retina lamination.[6],[7] For the OCT findings in MFC, thinning of retina, destructuring of the retinal layers, loss of IS/OSs of photoreceptors, localized thinning of choroid, occlusion of the choroidal vessels, and transretinal hyperreflectivity have been reported.[9],[10] Drusen-like material between retinal pigment epithelium (RPE) and Bruch membrane, localized hyper-reflectivity below the subretinal epithelial material were reported in the acute lesions in MFC.[11]With regard to the choroidal changes of white dot syndrome in OCT, only limited reports are still available. Choroidal thickness was reported to be normal as compared with the control in eyes with AZOOR.[8] It was presumed that the main pathology of AZOOR was confined within the photoreceptor layer, and in some reports, also the inner retina and RPE layer.[8],[12] However, those reported cases with normal choroidal thickness were in the subacute or chronic phases. Our serial examination at the acute and convalescent phases, by contrast, demonstrated that the choroid is either primarily or secondarily involved. In addition, choroidal hypofluorescence patches in the acute phase and resolved hypofluorescence in the convalescent phase shown by ICGA corresponded well to the choroidal thickening and resolution of thickening revealed by OCT. The ICGA abnormalities in AZOOR in the acute phase have been reported in a patient with PIC and AZOOR,[13] in which there were multiple patchy, partially fused, hypofluorescent spots noted in ICGA, which were similar to the findings in our cases. Choroidal thickening and increased choroid vascular porosity in OCT compared with the fellow eyes were also noted in all of the four cases with MEWDS, which, to the best of our knowledge, has not been reported in previous studies. The choroidal thickening and increased vascular porosity may represent the edematous choroid and dilated choriocapillaris resulting from choroidal ischemia or choroidal inflammation, which corresponded to the findings of ICGA. Complete recovery of IS/OS junctions along with complete or partial resolution of choroidal thickening changes were noted in all cases, which corresponded to the clinical improvement in both VA and VF of the patients.

For the two cases of MFC, choroidal thickening in OCT were more pronounced than the changes in the other two disease entities, which reflected the severe degree of choroidal inflammation in MFC. Besides, the choroidal changes evolved along with the disease activity. Because most patients with MFC need long-term immunosuppressive agents, choroidal thickness measured by OCT may serve as an indicator of disease activity.

In summary, OCT findings in white dot syndrome share some common characteristics, including disruption of IS/OSs as well as increased choroidal thickness and choroidal vascular porosity at the acute phase. One of the main limitations of this study is the limited case number. Therefore, a multicenter study with larger case numbers is necessary to further elucidate the OCT findings in choroid with regard to white dot syndrome.

Conflicts of interest: The authors have no conflicts of interest relevant to this article.



 
  References Top

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Gass JDM. Stereoscopic atlas of macular disease. Diagnosis and treatment. 4th ed. St. Louis, MO: Mosby; 1997.  Back to cited text no. 1
    
2.
Li D, Kishi S. Restored photoreceptor outer segment damage in multiple evanescent white dot syndrome. Ophthalmology 2009;116:762–70.  Back to cited text no. 2
    
3.
Kanis MJ, van Norren D. Integrity of foveal cones in multiple evanescent white dot syndrome assessed with OCT and foveal reflection analyser. Br J Ophthalmol 2006;90:795–6.  Back to cited text no. 3
    
4.
Nguyen MH, Witkin AJ, Reichel E, Ko TH, Fujimoto JG, Schuman JS, et al. Microstructural abnormalities in MEWDS demonstrated by ultrahigh resolution optical coherence tomography. Retina 2007;27:414–8.  Back to cited text no. 4
    
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Li D, Kishi S. Loss of photoreceptor outer segment in acute zonal occult outer retinopathy. Arch Ophthalmol 2007;125:1194–200.  Back to cited text no. 5
    
6.
Spaide RF, Koizumi H, Freund KB. Photoreceptor outer segment abnormalities as a cause of blind spot enlargement in acute zonal occult outer retinopathycomplex diseases. Am J Ophthalmol 2008; 146:111–20.  Back to cited text no. 6
    
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Fujiwara T, Imamura Y, Giovinazzo VJ, Spaide RF. Fundus autofluorescence and optical coherence tomographic findings in acute zonal occult outer retinopathy. Retina 2010;30:1206–16.  Back to cited text no. 7
    
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Francis PJ, Marinescu A, Fitzke FW, Bird AC, Holder GE. Acute zonal occult outer retinopathy: towards a set of diagnostic criteria. Br J Ophthalmol 2005;89:70–3.  Back to cited text no. 8
    
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Gallagher MJ, Yilmaz T, Cervantes-Castaneda RA, Foster CS. The characteristic features of optical coherence tomography in posterior uveitis. Br J Ophthalmol 2007;91:1680–5.  Back to cited text no. 9
    
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Yasuno Y, Okamoto F, Kawana K, Yatagai T, Oshika T. Investigation of multifocal choroiditis with panuveitis by three-dimensional high-penetration optical coherence tomography. J Biophotonics 2009;2:435–41.  Back to cited text no. 10
    
11.
Vance SK, Khan S, Klancnik JM, Freund KB. Characteristic spectral-domain optical coherence tomography findings of multifocal choroiditis. Retina 2011;31:717–23.  Back to cited text no. 11
    
12.
Gass JD. Acute zonal occult outer retinopathy. Donders lecture: The Netherlands Ophthalmological Society, Maastricht, Holland, June 19, 1992. J Clin Neuroophthalmol. 1993; 13:79–97.  Back to cited text no. 12
    
13.
Saito A, Saito W, Furudate N, Ohno S. Indocyanine green angiography in a case of punctate inner choroidopathy associated with acute zonal occult outer retinopathy. Jpn J Ophthalmol 2007;51:295–300.  Back to cited text no. 13
    


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