Abstract:
Background: Central retinal Artery occlusion (CRAO) is an
ophthalmic emergency and the ocular analogue of the cerebral stroke.
Atrial myxomas are the most common benign primary cardiac tumor. We
report a case of undiagnosed left atrium (LA) myxoma who presented with
sudden onset blindness in right eye due to CRAO as a sole manifestation
and echocardiographic characteristics of myxoma which increases the risk
of embolism.
Methods: A 52-year old woman presented with history of sudden
onset blindness in right eye. Fundus examination was suggestive of CRAO.
Transthoracic and transesophageal echocardiogram showed a mass in LA
compatible with LA myxoma. Complete surgical resection of myxoma was
done although vision could not be restored to normal.
Conclusion: Detailed history and complete systemic examination
should be done in every patient with embolic phenomena and early
neuroimaging with echocardiography using newer modality like 3D imaging
should be used even in absence of electrocardiographic or auscultatory
abnormalities.
Key words : Myxoma, retinal artery occlusion, embolism, 3
dimensional echocardiography
Introduction: Myxomas are the most common benign primary
cardiac tumor in adults. Most myxomas (> 80%) are found in
Left atrium (LA), although also reported in right atrium, right
ventricle and left ventricle with decreasing
frequency1. Incidence of cardiac myxoma peak at 40 to
60 years of age with male to female ratio of approximately
1:31. Cardiac myxoma may present with obstructive,
embolic and constitutional symptoms including fever, weight loss,
fatigue or combination of these1. We report a case of
sudden onset painless loss of vision in the right eye due to central
retinal artery occlusion (CRAO) as an isolated manifestation of
undiagnosed LA myxoma.
Materials and methods: Written informed consent for this work
to be published (including case history, images and data) was obtained
from the patient for publication of this case report, including
accompanying images. A 52-year-old woman presented with history of
sudden onset painless loss of vision in right eye, one month back in
September 2020. She was previously evaluated by an ophthalmologist at a
nearby centre, diagnosed as a case of central retinal artery occlusion
(CRAO) of the right eye and was being treated with corticosteroids,
aspirin, and atorvastatin. On admission, her visual acuity in right eye
was limited to only perception of light with inaccurate projection of
rays. Visual field of right eye was defective with absent pupillary
light reflex. Applanation tonometry was normal and there was no ocular
movement limitation. Left eye vision was normal. Her blood pressure was
110/70 mmHg and pulse rate was 68 beats per minutes. Her systemic
examination was within normal limits, including normal cardiovascular
system examination with no abnormal murmur, bruit or tumor plop. Fundus
examination of right eye was suggestive of CRAO with whitening and
opacification of the retina especially at posterior pole with a cherry
red spot in the fovea (Figure 1a). Fluorescein angiography of right eye
was also suggestive of CRAO with arterial phase being extremely delayed
and masking of choroidal circulation due to swelling of overlying retina
(Figure 1b.). Neuroimaging including diffusion weighted MRI scan showed
no significant abnormalities. Her electrocardiogram showed normal sinus
rhythm. Bilateral carotid artery doppler revealed no significant
abnormalities. Her blood investigations including complete blood count
with erythrocyte sedimentation rate (ESR), renal function test was
within normal limits. Transthoracic echocardiogram (TTE) was done which
revealed a soft gelatinous mass of 31 x 21 mm size in LA, attached to
atrial septum through a stalk suggestive of LA myxoma (Figure 2).
Transesophageal echocardiogram (TEE) was done for morphological
detailing of LA myxoma, revealed a soft gelatinous mass attached to left
atrium septum by stalk and having multiple irregular fragile villous
extensions from the surface of tumor (Figure 3 a. and 3 b). Live 3
Dimensional (3D) echocardiographic images provided more detailing of
morphological characteristics of tumor, including multiple small
irregular fragile extensions from the surface of myxoma which make the
patient prone for embolic phenomenon (Figure 4). To prevent recurrence
of embolic event, she underwent complete surgical resection of LA myxoma
via median sternotomy. The tumor was completely resected along with part
of atrial septum, and the defect was repaired with autologus pericardium
patch (Figure 5). Histopathological analysis of the resected mass was
consistent with myxoma. The patient recovered uneventfully from cardiac
surgery but unfortunately her right eye sight did not recover.
Discussion: Central retina artery occlusion is an end artery
occlusion causing acute ischemia of retina, and leads to sudden onset
irreversible visual impairment in the affected eye. Once the central
retinal artery is occluded, the ability of the retina to recover depends
on whether the offending embolus or thrombus is dislodged and more
importantly retinal ischemic tolerance time2. The
exact retinal ischemic tolerance time when irreversible damage occurs is
not known but would be appear to be no longer than 4 hours2. Histologically, myxomas are composed of spindle and
stellate shaped cells with myxoid stroma, may also contain endothelial
cells, smooth muscle cells and surrounded by mucopolysaccharide
substance 3. Cardiac myxoma could be asymptomatic and
may be diagnosed as an incidental finding on echocardiogram. When
symptomatic, it may present with features of mitral valve obstruction
(54-95%), systemic embolism (10-45%) and constitutional symptoms such
as fatigue, fever and weight loss 4. In laboratory
findings, there could be anemia, raised erythrocyte sedimentation rate
(ESR), C-reactive protein (CRP) and gamma globulin level4. In this case, the patient was having normal
laboratory investigations and normal cardiovascular system examination.
Pinede et al. reported cardiac auscultation abnormalities only in 64%
of patient 4. So absence of auscultatory abnormalities
does not rule out cardiac myxomas, as in our case. Vascular disturbance
in the eye due to cardiac myxoma are rare, however embolism in
ophthalmic circulation due to cardiac tumor has been reported in
literature5. Acebo et al. previously reported the
morphological features of myxomas which were associated with embolic
phenomena. Villous or papillary forms of myxomas with fragile extension
have a tendency to fragment spontaneously and associated with embolic
phenomena 6. In our case also the myxomas was having
soft gelatinous consistency with multiple fragile villous extensions,
which caused the retinal artery embolism as a primary manifestation.
Echocardiography is the primary diagnostic imaging modality for
intracardiac tumors. Beside transthoracic and transesophageal echo, 3D
echocardiogram adds incremental value to the morphological assessment of
myxomas and correlates very well with the surgical and histopathological
findings, as in our case. The tumors with morphological features
associated embolic phenomena should be intervened on urgent basis. Yu et
al. reported a 43 year old woman with retinal artery occlusion with
syncope caused by atrial myxoma, rapid diagnosis and exact treatment of
myxomas improved patient’s visual capacity7. But in
our case, patient presented late to us for the cardiac evaluation as a
part of diagnostic work-up of CRAO and vision of affected eye could not
be restored, although complete resection of myxomas curtailed the future
risk of embolic phenomena. Lifelong follow-up is needed in these cases
as myxomas have some tendency to recur with rate of 5-14%. The time to
recurrence varied from 0.5 to 6.5 years in different series1, 4.
Conclusion: In summary, we report this case of isolated retinal
artery occlusion as a presenting manifestation of undiagnosed LA Myxoma.
Ophthalmologist should consider the possibility of myxomas in patient
with sudden loss of visual acuity, as timely management is essential for
better outcome and prognosis in these patients. The detailed medical
history with systemic examination is essential in all patients and
normal cardiac auscultation does not rule out cardiac pathology. We also
recommend to always look for high risk morphological features in cardiac
myxomas for embolism with use of less invasive and newer modalities like
3D Echocardiography which provides better morphological
characterization.