|Year : 2022 | Volume
| Issue : 2 | Page : 443-444
Fundus autofluorescence in detection of embolus in retinal artery occlusion
Pradeep Sagar, Suchitra Biswal, HN Ravishankar
Department of Vitreo-retina, Sankara Eye Hospital, Shimoga, Karnataka, India
|Date of Submission||01-Jul-2021|
|Date of Acceptance||22-Oct-2021|
|Date of Web Publication||13-Apr-2022|
Sankara Eye Hospital, Harakere, Shimoga, Karnataka - 577 202
Source of Support: None, Conflict of Interest: None
Fundus autofluorescence (FAF) is a noninvasive imaging tool helpful in various retinal and choroidal diseases. In this series, we report the utility of FAF in two cases of retinal artery occlusion (RAO). Cholesterol embolus was seen as a bright hyper autofluorescent foci on FAF in a case of branch RAO. Platelet fibrin embolus exhibited minimal hyper autofluorescence in another case of multiple RAO in contrast to bright hyper autofluorescence of cholesterol embolus. Fundus autofluorescence may be helpful in easier identification of cholesterol embolus in RAO and helps in differentiating it from platelet fibrin embolus.
Keywords: Embolus, fundus autofluorescence, retinal artery occlusion
|How to cite this article:|
Sagar P, Biswal S, Ravishankar H N. Fundus autofluorescence in detection of embolus in retinal artery occlusion. Indian J Ophthalmol Case Rep 2022;2:443-4
|How to cite this URL:|
Sagar P, Biswal S, Ravishankar H N. Fundus autofluorescence in detection of embolus in retinal artery occlusion. Indian J Ophthalmol Case Rep [serial online] 2022 [cited 2022 May 26];2:443-4. Available from: https://www.ijoreports.in/text.asp?2022/2/2/443/342900
Retinal artery occlusion (RAO) is an ocular emergency, which is analogous to a cerebrovascular accident. Early detection of the site of occlusion and type of embolus helps in timely intervention and could prevent other cerebrovascular and cardiovascular events. Retinal embolus can be composed of platelet fibrin, calcium, or atheroma based on the source. On attentive clinical examination, embolus is detectable in 20%–40% of cases of central retinal artery occlusion (CRAO). Fundus autofluorescence (FAF), a noninvasive imaging modality helps in the visualization of fluorophores based on the property of autofluorescence. In this case report, we describe the utility of FAF in identifying the type of embolus in RAO.
| Case Reports|| |
A 54-year-old male presented with sudden onset diminution of vision in the left eye of 1-day duration. The best-corrected visual acuity (BCVA) in the left eye was 20/60. He was hypertensive since 4 years. Fundus evaluation of the left eye showed retinal whitening in the inferior half of the macula. On careful examination, embolus was noted at the proximal end of the inferior branch of the central retinal artery [Figure 1]a. The embolus was visible as a hyper autofluorescent lesion on FAF [Figure 1]b. Optical coherence tomography angiography (OCTA) showed flow void signal in the inferior half of the macula [Figure 1]c. Ocular massage and anterior chamber paracentesis were performed. On day 3 follow-up, multimodal imaging showed distal migration of embolus, normalization of arterial caliber and restoration of flow signal [Figure 1]d,[Figure 1]e,[Figure 1]f. Carotid doppler showed asymmetric circumferential plaque in left carotid artery causing 60% stenosis.
|Figure 1: (a) Color fundus image of left eye showing presence of embolus at bifurcation of retinal artery near the disc. Narrowed retinal artery is seen distal to embolus. (b) Fundus autofluorescence of left eye showing hyper autofluorescent foci corresponding to the embolus. (c) Optical coherence tomography angiography image showing flow void area in inferotemporal quadrant. (d) Color fundus image at day 3 follow-up, showing the distal migration of embolus and restoration of normal caliber of retinal artery. (e) Fundus autofluorescence at day 3 follow-up, showing the distal migration of hyper autofluorescent embolus. (f) Optical coherence tomography angiography image at day 3 follow-up, showing restoration of flow signal in inferotemporal quadrant|
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A 34-year-old male presented with sudden onset diminution of vision in the left eye of 1-day duration. The BCVA in the left eye was 20/40. Fundus evaluation of the left eye showed areas of retinal whitening along the inferonasal quadrant and superior half of macula and superotemporal quadrant. Platelet fibrin embolus was seen along the inferonasal branch of the retinal artery [Figure 2]a. Minimal hyper autofluorescence was seen corresponding to the area of platelet fibrin embolus on FAF [Figure 2]b. Carotid doppler and 2D echocardiogram were normal. Low density lipoprotein was elevated.
|Figure 2: (a) Color fundus image of left eye showing the presence of embolus along the inferonasal branch of retinal artery. (b) Fundus autofluorescence showing minimal hyper autofluorescence corresponding to the embolus. (c) Optical coherence tomography angiography showing flow avoid area corresponding to embolus within the blood vessel|
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| Discussion|| |
Retinal artery occlusions are predominantly due to emboli. Detection of emboli helps in identification of the site of block, planning treatment, and assessment of treatment success.
FAF is a noninvasive imaging modality helpful in various retinal and choroidal disorders. Siddiqi et al. reported that retinal artery emboli exhibit hyper autofluorescence. Majstruk et al. hypothesized that calcification in the arterial wall is responsible for autofluorescence of retinal arterial plaque. Bacquet et al. reported that emboli from an atherosclerotic plaque exhibits hyper autofluorescence. In case 1, the hyper autofluorescent foci migrated after treatment, confirming that it is an embolus. Carotid doppler showed asymmetric circumferential plaque in left carotid artery, which would indicate that the probable source of embolus is atheroma. The autofluorescent property of atheroma is due to glycation products such as carboxymethyl lysine, pentosidine, and erythronic acid. In the second case, the embolus was clinically suggestive of platelet fibrin embolus and was less hyper autofluorescent.
| Conclusion|| |
Our findings indicate that the cholesterol embolus is hyper autofluorescent. Thus, FAF may have a role in easier detection of cholesterol emboli in RAO, which may be missed on clinical examination. FAF may also help in differentiating cholesterol embolus from platelet fibrin embolus.
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
Conflicts of interest
There are no conflicts of interest.
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[Figure 1], [Figure 2]