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 Table of Contents  
CASE REPORT
Year : 2022  |  Volume : 2  |  Issue : 2  |  Page : 430-433

Serial swept-source optical coherence tomography angiography changes within deeper choroid in tubercular serpiginous-like choroiditis: A case report


Department of Vitreo Retina, Netralaya Superspeciality Eye Hospital, Ahmedabad, Gujarat, India

Date of Submission29-Jul-2021
Date of Acceptance01-Nov-2021
Date of Web Publication13-Apr-2022

Correspondence Address:
Kushal Delhiwala
Netralaya Superspeciality Eye Hospital, KD House, 1st Floor, Above Andhra Bank, Parimal Cross Roads, Ellisbridge, Ahmedabad - 380 006, Gujarat
India
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Source of Support: None, Conflict of Interest: None


DOI: 10.4103/ijo.IJO_2004_21

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  Abstract 


A 31-year-old female was diagnosed with active placoid tubercular serpiginous-like choroiditis (TB-SLC) in the right eye. Serial swept-source optical coherence tomography angiography (SS-OCTA) of deeper choroid revealed unique dilated, tortuous, and disorganized tangled network of medium-sized choroidal vessels (MCV) at presentation (mimicking bag-of-worms) with increased compactness on paradoxical worsening and significant reorganization on resolution. SS-OCTA of choriocapillaris (CC) revealed extensive flow void at presentation, which increased on paradoxical worsening and its reversal with minimal CC atrophy on resolution. Visual acuity improved from 20/200 to 20/30. Serial changes from presentation till resolution provide hypothesis about unique appearance within choroid in TB-SLC lesion.

Keywords: Anti-tubercular therapy, choriocapillaris, deeper choroid, placoid tubercular serpiginous-like choroiditis, swept-source optical coherence tomography angiography


How to cite this article:
Patel R, Delhiwala K, Khamar B. Serial swept-source optical coherence tomography angiography changes within deeper choroid in tubercular serpiginous-like choroiditis: A case report. Indian J Ophthalmol Case Rep 2022;2:430-3

How to cite this URL:
Patel R, Delhiwala K, Khamar B. Serial swept-source optical coherence tomography angiography changes within deeper choroid in tubercular serpiginous-like choroiditis: A case report. Indian J Ophthalmol Case Rep [serial online] 2022 [cited 2022 May 18];2:430-3. Available from: https://www.ijoreports.in/text.asp?2022/2/2/430/342919



Optical coherence tomography angiography (OCTA) is a noninvasive diagnostic tool used for analyzing layer specific vascular architecture and perfusion of retina and choroid in posterior uveitis.[1] Swept source (SS)-OCTA uses longer wavelength (1050 nm), allowing deeper choroidal penetration.[2] This enables choroidal vascular imaging in greater detail and has become increasingly relevant in managing choroidal inflammations. OCTA in granulomatous choroiditis has shown flow voids in choriocapillaris (CC) corresponding to true CC ischemia, secondary to choroidal granuloma and/or focal choroidal arteriolitis.[3] In cases of tubercular serpiginous-like choroiditis (TB-SLC), serial SS-OCTA has demonstrated flow voids at CC level in active lesion, followed by either CC atrophy and/or reversal of CC flow voids with minimal atrophy on resolution.[4],[5] However, changes in deeper choroid (DC) on SS-OCTA have not been well described in TB-SLC. Utilizing SS-OCTA technology (DRI-Triton plus™; Topcon, Tokyo, Japan), we describe an unusual appearance of medium-sized choroidal vessels (MCV) of DC in a case of active placoid TB-SLC mimicking bag-of-worms at initial presentation and serial changes observed in MCV on resolution in response to therapy.


  Case Report Top


A 31-year-old female presented with blurred vision in the right eye (OD) for 2 days. Best-corrected visual acuity (BCVA) was 20/200 in OD and 20/20 in the left eye (OS). Anterior segment evaluation of both eyes and fundus in OS were unremarkable. Fundus evaluation in OD revealed amoeboid placoid lesion overlying macula without evidence of vitritis [Figure 1]a. The lesion showed outer creamy-yellow edges surrounding orange ring. Autofluorescence (AF) of placoid lesion showed patchy hyper-AF surrounded by hyper-AF dual margins (lesional area 34.25 mm2 measured using Topcon built-in proprietary software ImageNet 6; [Figure 1]e]). Fluorescein angiography (FA) revealed early hypofluorescence and visible choroidal vessels followed by late hyperfluorescence [Figure 2]a,[Figure 2]b,[Figure 2]c. SS-optical coherence tomography (SS-OCT) B-scan through lesion revealed hyperreflective bumps involving RPE, ellipsoid zone loss, and external limiting membrane disruption [Figure 2]d. Corresponding SS-OCTA (9 mm by 9 mm scan) showed flow voids in CC slab and dilated, tortuous, and disorganized tangled network of bright MCV mimicking bag-of-worms in DC slab [Figure 3]a and [Figure 4]a. There was no signal attenuation on corresponding en-face SS-OCT [Figure 3]e and [Figure 4]e. Retinal vasculature was normal on FA and SS-OCTA.
Figure 1: Serial color fundus photos (a–d) of the right eye placoid TB-SLC involving macula: (a) Active outer edges and inner orange ring (white arrow) at baseline. (b) Paradoxical worsening (PW) with increased lesion size. (c) Partial resolution. (d) Complete resolution with pigmentation and scarring. Serial fundus autofluorescence (AF) images (e–h) of lesion: (e) Central hyper-AF, hyper-AF dual margins (yellow arrows) with hypo-AF zone (white asterisk) in between at baseline. (f) Centrifugal migration of hyper-AF dual margins on PW. (g) Increased hypo-AF on partial resolution. (h) Predominantly hypo-AF on complete resolution

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Figure 2: Baseline fundus fluorescein angiography (a–c) of the right eye active placoid TB-SLC lesion showing: (a) Hypofluorescence with visible underlying choroidal vessels (yellow arrow) in early phase. (b) Central hyperfluorescence in mid phase. (c) Increase in leakage at edges with increased hyperfluorescence of the lesion in late phase. (d) Swept-source optical coherence tomography B-scan through active lesion at baseline revealed hyperreflective bumps involving retinal pigment epithelium, ellipsoid zone loss, and external limiting membrane disruption

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Figure 3: Serial SS-OCTA images of choriocapillaris (CC) slab (a–d) in the right eye placoid TB-SLC lesion: (a) Hyporeflective flow void area (white arrow) and minimal unmasking of deeper medium sized choroidal vessel (MCV; white arrowhead) at baseline. (b) Increased flow void area and unmasking of MCV on paradoxical worsening. (c) Reversal of flow voids on partial resolution. (d) Patchy residual flow voids related to CC atrophy on complete resolution. Corresponding en-face structural SS-OCT scans (e–h) do not show any signal attenuation in lesional area. The CC slab was defined as 10.4 μm below Bruch's membrane (BM)

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Figure 4: Serial SS-OCTA images of deeper choroid (DC) slab (a–d) in the right eye: (a) Dilated, tortuous, and disorganized tangled network of medium-sized choroidal vessels (MCV; white arrows) at baseline mimicking bag-of-worms. (b) Increased compactness of disorganized MCV on paradoxical worsening. (c) Partial MCV reorganization on partial resolution. (d) Near normal MCV on complete resolution. Corresponding en-face structural SS-OCT scans (e–h) do not show any signal attenuation in lesional area. DC slab was defined below CC, with inner and outer boundaries at 31.2 and 98.8 m beneath BM, respectively

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Based on clinical diagnosis of TB-SLC (positive Quantiferon-TB Gold test-9.56 IU/mL interferon difference of TB antigen-Nil, <0.35 IU/mL-negative; Mantoux test showing 17 mm by 17 mm of induration and normal chest X-ray), antitubercular treatment (4-drug ATT) along with oral prednisolone (1 mg/kg body weight/day) was initiated after pulmonologist opinion.

Two weeks later, there was centrifugal expansion of placoid lesion [Figure 1]b with increased area of flow voids in CC, increased compactness of disorganized MCV in DC on SS-OCTA (12 mm by 12 mm scan; [Figure 3]b and [Figure 4]b]), and no signal attenuation on corresponding en-face SS-OCT [Figure 3]f and [Figure 4]f. AF showed increased patchy hyper-AF with centrifugal migration of hyper-AF dual margins (lesional area 43.04 mm2; [Figure 1]f). Documented BCVA was 20/180.

Considering paradoxical worsening, intravenous methylprednisolone (IVMP) 1 g/day was administered for 3 days and oral mycophenolate mofetil 500 mg twice a day was added to ongoing treatment followed by gradual oral prednisolone tapering.

At 8 weeks post IVMP, fundus showed pigmentation and scarring of placoid lesion suggestive of resolving TB-SLC [Figure 1]c, with reversal of flow void in CC, partial reorganization of MCV in DC on SS-OCTA (12 mm by 12 mm scan; [Figure 3]c and [Figure 4]c), and no signal attenuation on corresponding en-face SS-OCT [Figure 3]g and [Figure 4]g. AF showed increased hypo-AF with stippled pattern and disappearance of hyper-AF dual margins [Figure 1]g. BCVA improved to 20/30. She was advised to discontinue all oral medications except ATT.

At 6 months follow-up, BCVA was stable at 20/30 with increased pigmentation and scarring, suggestive of complete resolution of TB-SLC [Figure 1]d and [Figure 1]h. SS-OCTA showed patchy residual flow voids in CC and near normal reorganization of MCV in DC (12 mm by 12 mm scan; [Figure 3]d, [Figure 4]d, [Figure 3]h, and [Figure 4]h).

Serial choroidal vessel density (CVD) measurement in lesional area of TB-SLC was done with binarized OCTA image of DC slab.[2] Using ImageJ software, CVD was calculated as the proportion of white pixels from the total number of pixels of lesional area in a binarized OCTA image. CVD in area of lesion was 26.39% on presentation, 39.08% on paradoxical worsening, 52.64% at 8 weeks post IVMP, and 53.41% at 6 months follow-up. CVD in unaffected area was 76%.


  Discussion Top


Index case describes dilated, tortuous, and disorganized tangled network of MCV in DC mimicking bag-of-worms appearance and flow voids in overlying CC on SS-OCTA during the active phase of central placoid TB-SLC, which progressed on paradoxical worsening and showed reversal with appropriate treatment. Bag-of-worms appearance has been reported previously for retinal blood vessels.[6] However, the similar appearance of MCV on SS-OCTA has not been reported earlier to the best of our knowledge. Disorganization of MCV was noticeable during the early phase of FA also.

Mere CC flow voids may unmask MCV with increased MCV visibility in CC OCTA slab. In our case, MCV was best demonstrated in DC slab and only minimally visible in CC. This may suggest a possible etiology beyond unmasking. Since initial MCV alterations (dilated, tortuous, and tangled choroidal vessel network) underwent subsequent partial reorganization following resolution of granulomatous lesion in our case, this may suggest possible role of stromal modelling following initial probable loss of intervascular connective tissue, in addition to overlying CC flow voids secondary to ischemia/compression of CC. Biopsy proven granulomatous choroidal lesions are known to be associated with choroidal connective tissue loss as well as compression and shift of the surrounding vascular tissue.[7]

Significant reversal of CC flow void noted with TB-SLC resolution can be secondary to decreased CC compression, while patchy residual CC flow voids can be related to CC atrophy secondary to ischemia.[4]

Deeper choroidal vessels appear dark on SS-OCTA in the presence of intact RPE and normal CC.[8],[9] Alterations in RPE morphology due to inflammation and overlying CC flow void may have contributed to brightness of MCV in our case.

Previous report of TB-SLC showed remarkable visual improvement associated with reversal of multifocal CC flow void areas in response to treatment.[5] The present case also showed significant visual recovery associated with remarkable reversal of large flow void area in CC and partial MCV reorganization following response to therapy.


  Conclusion Top


In conclusion, unique dilated, tortuous, and disorganized tangled network of MCV mimicking bag-of-worms appearance associated with large flow void in overlying CC was observed at initial presentation in a patient with active placoid TB-SLC. With appropriate treatment, it showed remarkable reversal in association with near normal visual recovery.

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.



 
  References Top

1.
Tranos P, Karasavvidou EM, Gkorou O, Pavesio C. Optical coherence tomography angiography in uveitis. J Ophthalmic Inflamm Infect 2019;9:21.  Back to cited text no. 1
    
2.
Wang E, Zhao X, Yang J, Chen Y. Visualization of deep choroidal vasculatures and measurement of choroidal vascular density: A swept-source optical coherence tomography angiography approach. BMC Ophthalmol 2020;20:321.  Back to cited text no. 2
    
3.
Tugal-Tutkun I, Herbort CP Jr, Mantovani A, Neri P, Khairallah M. Advances and potential new developments in imaging techniques for posterior uveitis. Part 1: Noninvasive imaging methods. Eye (Lond) 2021;35:33-51.  Back to cited text no. 3
    
4.
Agarwal A, Aggarwal K, Mandadi SKR, Kumar A, Grewal D, Invernizzi A, et al. For OCTA Study Group. Longitudinal follow-up of tubercular serpiginous-like choroiditis using optical coherence tomography angiography. Retina 2021;41:793-803.  Back to cited text no. 4
    
5.
Tummala GC, Chu Z, Weinstein JE, Wang RK, Pepple KL. Swept source OCTA reveals a link between choriocapillaris blood flow and vision loss in a case of tubercular serpiginous-like choroiditis. Am J Ophthalmol Case Rep 2021;21:101018.  Back to cited text no. 5
    
6.
Katoch D, Rana V, Dogra MR. Isolated retinal racemose hemangioma with a “Bag of Worms” appearance. Ophthalmol Retina 2020;4:1145.  Back to cited text no. 6
    
7.
Chen L, Xu G. Extensive choroidal infiltrates in choroidal biopsy proven ocular sarcoidosis. Retin Cases Brief Rep 2013;7:69-70.  Back to cited text no. 7
    
8.
Diaz JD, Wang JC, Oellers P, Lains I, Sobrin L, Husain D, et al. Imaging the deep choroidal vasculature using spectral domain and swept source optical coherence tomography angiography. J Vitreoretin Dis 2018;2:146-54.  Back to cited text no. 8
    
9.
Wang JC, Laíns I, Silverman RF, Sobrin L, Vavvas DG, Miller JW, et al. Visualization of choriocapillaris and choroidal vasculature in healthy eyes with en face swept-source optical coherence tomography versus angiography. Transl Vis Sci Technol 2018;7:25.  Back to cited text no. 9
    


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  [Figure 1], [Figure 2], [Figure 3], [Figure 4]



 

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