Macroaneurysm Rupture after Car Accident

This case report describes a 48-year-old man who developed acute vision loss in the right eye following head trauma from a car accident, found to have a ruptured retinal arterial macroaneurysm (RAM) with associated retinal hemorrhage and exudate. Published in the Journal of Ophthalmology Research Reviews & Reports in 2021, the case illustrates how trauma can precipitate rupture of a pre-existing retinal macroaneurysm and emphasizes the importance of thorough retinal evaluation in patients with post-traumatic visual symptoms.

Background

Retinal arterial macroaneurysm (RAM) is an acquired, focal dilation of a retinal artery that can present with retinal hemorrhage or exudation. It is most commonly associated with systemic hypertension, arteriosclerosis, and cardiovascular disease. RAM can present with a wide variety of clinical appearances, leading to frequent misdiagnosis as other conditions including Coats disease, von Hippel-Lindau disease, retinal vein occlusion, and diabetic retinopathy.

Fluorescein angiography is one of the most useful diagnostic tests for confirming RAM. Management depends on the clinical findings and associated complications. Most patients experience a period of thrombosis or fibrosis, after which visual acuity returns spontaneously. However, complications such as macular hole formation have been reported secondary to ruptured RAM.

While RAM is typically seen in patients with underlying vascular risk factors, trauma can serve as a precipitating event for rupture of an existing macroaneurysm. This case is notable because the patient was otherwise healthy with no known medical history, and the rupture occurred in the setting of head trauma from a motor vehicle accident.

The Patient

A 48-year-old Hispanic man presented to the neuro-ophthalmology clinic with:

• Blurry vision in the right eye
• History of head trauma from a car accident in March 2020
• No loss of consciousness at the time of the accident
• Vision loss in the right eye noticed the day after the car accident
• No associated headaches, diplopia, or other eye-related symptoms
• No past medical history (no hypertension, diabetes, or cardiovascular disease)

Diagnostic Workup

Clinical Examination

• Visual acuity: 20/100 OD (right eye), 20/20 OS (left eye)
• Intraocular pressure: 18 mmHg in both eyes
• Color vision test: 6/11 OD (reduced), 11/11 OS (normal)
• Ocular motility: No nystagmus or intrusion in saccadic or pursuit movements
• Pupil exam: Normal pupillary reaction to light; no relative afferent pupillary defect (RAPD)

Retinal Findings

• Dilated fundus examination: Inferotemporal retinal hemorrhage associated with exudate in the right eye; normal retinal exam in the left eye
• OCT of the retina and optic nerve: Within normal limits
• Fundus photography: Confirmed inferotemporal hemorrhage with exudate in the right eye

Visual Field Testing

• Visual field test: Superior nasal defect in the right eye, anatomically consistent with the inferotemporal retinal hemorrhage location

Results

The clinical presentation -- unilateral retinal hemorrhage with exudate following head trauma in an otherwise healthy patient -- was consistent with a ruptured retinal arterial macroaneurysm. Key diagnostic correlations included:

• Inferotemporal hemorrhage location correlated precisely with the superior nasal visual field defect, following the expected retinotopic mapping
• Absence of RAPD indicated that the optic nerve was not significantly affected
• Normal OCT suggested the hemorrhage and exudate did not cause significant structural macular changes at the time of imaging
• Unilateral involvement (right eye only) is typical for RAM

The temporal relationship between the car accident and onset of visual symptoms strongly suggests that head trauma precipitated the rupture of a pre-existing retinal arterial macroaneurysm.

Clinical Significance

This case highlights several important clinical points:

• Trauma can trigger rupture of a pre-existing retinal arterial macroaneurysm, even in patients without known vascular risk factors
• Post-traumatic visual complaints require thorough retinal evaluation, including dilated fundus examination and visual field testing, to rule out retinal pathology
• RAM is often misdiagnosed due to its variable clinical presentation; differential diagnosis includes Coats disease, von Hippel-Lindau disease, retinal vein occlusion, and diabetic retinopathy
• Prognosis is generally favorable -- most patients with ruptured RAM experience spontaneous thrombosis or fibrosis with gradual return of visual acuity
• Patients with RAM should be monitored for systemic conditions including hypertension, hyperlipidemia, and arteriosclerosis, even when initially presenting without these risk factors

Management Guidelines

• RAMs without hemorrhage or exudate: May be monitored every six months until complete recovery
• Ruptured RAMs with hemorrhage or exudation: Observation is recommended after the first month, then follow-up every 1 to 3 months until improvement
• Complications to watch for: Macular hole formation has been reported secondary to ruptured RAM

Citation

Naser M, Hashemi N. Macroaneurysm Rupture after Car Accident. Journal of Ophthalmology Research Reviews & Reports. 2021;2(1):1-2. SRC/JORRR/109.

References