Vision loss caused by optic nerve swelling in man with HAE: Report
Treatment with Berinert helped resolve vision loss without nerve damage
A 60-year-old man with hereditary angioedema (HAE) caused by an unknown mutation developed visual loss due to swelling of the optic nerve in both eyes, according to a case reported in Italy.
His symptoms eased after starting treatment with Berinert (human C1 esterase inhibitor), an intravenous (into-the-vein) C1 esterase inhibitor (C1-INH), and were completely resolved within two months, without structural or functional damage to the optic nerves.
“Patients affected by HAE may show atypical presentation with edema [swelling] of the optic nerves,” the researchers wrote. “Persistent vision loss during and between angioedema attacks should be considered a warning sign of edema of the optic nerve.”
These patients “may significantly benefit from prophylactic and chronic treatment with C1-esterase inhibitor,” they wrote.
The case was described in the study, “Vision loss due to atypical bilateral edema of the optic nerve in a patient with hereditary angioedema: A case report,” published in the European Journal of Ophthalmology.
Swelling attacks in HAE
HAE is characterized by sudden and temporary swelling attacks affecting the deeper layers of the skin, commonly in the lips, hands, feet, and the skin around the eyes. Attacks also may occur in the mucosal linings of the respiratory and digestive tracts.
The disease may be caused by mutations in the SERPING1 gene, which carries instructions for making the C1-INH protein, leading to a deficiency in C1-INH levels or function. The lack or dysfunction of C1-INH may cause bradykinin levels to rise too high, resulting in swelling.
HAE also may be caused by mutations in other genes, and some patients have HAE due to unknown mutations. People with HAE commonly report headaches, visual impairment, and pain and swelling around the eyes during attacks. In some cases, the central nervous system, which includes the brain and spinal cord, may also be involved.
“However, no reports are available about optic nerve involvement,” the researchers wrote. The optic nerve is responsible for relaying information from the eyes to the brain, which then processes sensory information to create visual images.
Here, researchers described the case of a 60-year-old man with HAE diagnosed at 33, caused by an unknown mutation, and presenting normal C1-INH levels in the blood. Two members of his family also were affected.
He had around 10 HAE attacks per year, characterized by swelling of the face, eyelids, and neck, pain around the eyes, and visual impairment in one or both eyes. Each episode usually lasted a few hours and was completely resolved after treatment with Berinert.
Almost 20 years ago, the patient had an HAE attack that led to a coma due to cerebral edema, which promptly resolved with Berinert treatment.
Persistent vision impairment in both eyes
Ten months before this presentation, the patient had an HAE attack with swelling of the upper airways, face, and region around the eyes, associated with vision loss in both eyes. Treatment with Berinert resolved the edema, but visual impairment persisted, contrary to previous attacks.
Examination of the inner back surface of the eye, called fundus, revealed a vital optic disc without papilledema, which occurs when optic disc swelling is caused by an increase of intracranial pressure in both eyes. The optic disc is the first segment of the optic nerve.
However, an MRI scan revealed swelling of the optic nerve sheath — the membranes that cover and protect the central nervous system structures, including the optic nerve — in both eyes.
Moreover, the patient had reduced visual acuity in an area of his field of vision in both eyes.
He was then admitted to the hospital. During his hospital stay, his visual acuity worsened in both eyes. Attacks were acutely treated with Berinert, and he also received corticosteroids, but his vision did not improve.
The patient was discharged with a treatment regimen consisting of subcutaneous (under-the-skin) prophylactic treatment with Berinert, given every four days, to prevent HAE attacks. Since then, the number and severity of his angioedema attacks decreased, and his visual acuity improved.
Two months after starting prophylactic treatment, his visual acuity reached normal levels, and an MRI scan revealed complete resolution of optic nerve swelling. Further examinations revealed no structural or functional damage to nerve fibers and the optic disc.
According to researchers, this case highlights the need to consider swelling of the optic nerve in patients with HAE and vision loss during and between attacks.
“In this clinical scenario, MRI and visual field tests are mandatory to detect [structural and] functional alteration of … the optic nerve. Prophylactic chronic treatment with C1-INH may be considered a sight-saving drug in these patients,” they wrote.