Potential link between sporadic cerebral amyloid angiopathy and vision loss: a case report.

Abstract

Amyloids have been linked to the development of various diseases. Cerebral amyloid angiopathy (CAA) is one of the conditions caused by amyloid deposits in the small and mid-sized vessels (Yamada 2015). Cerebral amyloid angiopathy mainly affects the brain, and only few cases describing vascular changes in the retina in patients with CAA have been reported and are predominantly hereditary cases (Kojima et al. 2003; Kawaji et al. 2005; Cheung et al. 2010). Here, we describe a rare case of severe retinal ischaemia in a patient with sporadic ‘probable CAA’ according to the Boston criteria for diagnosis of CAA-related haemorrhage (Knudsen et al. 2001). A 57-year-old man complained of vision loss in the right eye. He had previously been diagnosed with CAA visualized by MRI scan of the cerebrum by neurologists. He was originally admitted due to a spontaneous aneurysm in the basal ganglia causing right-sided hemiparesis and aphasia. The patient was known with hypertension and hypercholesterolaemia. Moreover, the patient presented with a family history of hypertension (sister and mother), Alzheimer's disease (father diagnosed at the age of 66) and stroke (paternal uncle at the age of 52 and paternal grandfather at the age of 58). Due to pain in the right eye, the patient was referred to a general ophthalmologist. An intraocular pressure (IOP) above 50 mmHg was measured with air tonometry. Best-corrected visual acuities were <0.1 (right eye) and <0.6 (left eye; Snellen eye chart). Immediate IOP-lowering treatment was initiated, and the patient was referred to the hospital for further care. At first hospital examination, best-corrected visual acuity (BCVA) had decreased to 0.02 on the right eye. The patient no longer had pain. The IOP was 20 mmHg, measured with Goldman tonometry. On the right eye, the anterior segment examination and gonioscopy revealed neovascularization of the iris (rubeosis) and in the angle. The BCVA, IOP, anterior segment and gonioscopy of the left eye were normal. Funduscopic examination of the right eye revealed a pale optic nerve head and thin arterials white ‘ghost vessels’ (Fig. 1A and C). The retina of the left eye showed micro haemorrhages and alterations in vessel calibre (Fig. 1B and D). Fluorescein angiography displayed perfusion of a cilioretinal artery on the right retina. In addition, severe ischaemia with reduced filling of the vessels characterized the posterior pole. On the left eye, a general delayed vessel filling was observed (Fig. 1E–H). To further investigate the retinal blood flow, a Doppler flow ultrasound was performed. The examinations obstructed retinal artery flow of the right eye and impaired vessel filling on the left eye (Fig. 1I–L). As expected, ocular coherence tomography (OCT) revealed severe thinning of the retinal nerve fibre layer of the right eye and moderate thinning of the left eye. Visual field examinations exposed severe visual field loss on right eye with maintained tunnel vision. In spite of panretinal laser treatment and maximal IOP-lowering medications, the IOP remained unacceptable above 40 mmHg on the right eye. Thus, filtration surgery (trabeculectomy) was performed. Hereafter, the IOP became acceptable (8 mmHg) and the BCVA stabilized to 0.05. Due to the suspicious family history, the patient was referred to genetic testing including a dementia panel with APP. No pathogenic variants were detected. Thus, the patient most likely represents a sporadic case of CAA but a genetic predisposition to CAA cannot be ruled out. Overall, this is an inexpedient story of a patient with diagnosed CAA who lost sight due to neovascular glaucoma in response to retinal ischaemia. We recommend that patients which meet the MRI-supported Boston criteria for diagnosis of CAA should be referred to an ophthalmologist and propose that such recommendation can potentially save sight.