54. Binocular sight loss: uncommon, yet a devastating complication of GCA
Authors: Borukhson Liubov , Kayani Abdul , Dasgupta Bhaskar 
Published: September 2019

Abstract

Introduction
GCA (giant cell arteritis) affects cranial branches of the arteries from aortic arch, especially the superficial temporal artery and vessels supplying the eye. Ophthalmic manifestations of GCA are characterised by the vasculitis of the ophthalmic artery and its branches. We present a case of a patient who developed the binocular sequential permanent vision loss secondary to GCA due to the delayed diagnosis.

Case description
A seventy-six year-old lady with a background of type two diabetes mellitus, hypertension and dyslipidemia and hemicolectomy for appendix tumour two years ago (no recurrence) was admitted with blurring of vision in the eye. She did not complain about other symptoms, however, on direct questioning she admitted six weeks history of weight loss (2.5 stones), severe tiredness and occasional night sweats, mild left sided temporal headache. She was initiated on 60mg of prednisolone. One week prior to admission she had right eye CRAO diagnosed by the ophthalmology team with preceding three weeks history of right eye blurring of vision. CRP at that time was 12 g/L and GCA was not considered likely. Following her permanent right sided vision loss, she was referred to stroke team for further management and was given aspirin. Her CT and MRI brain scans were unremarkable, USS carotid arteries revealing diffuse intimal thickening in all the arteries of the neck.
On assessment in the rheumatology fast track clinic she denied any associated jaw/tongue/arms claudication and no proceeding or historical PMR symptoms. She had mild left sided temporal artery tenderness and decreased temporal artery pulses bilaterally, no vision in the right eye along with the blurring in the left eye. There were no audible bruits in carotid, axillary, femoral arteries. Her acute phase maker (CRP) was mild but persistently elevated with a maximum level of 12 g/L for one week prior the admission. USS showed features consistent with GCA with extensive non-compressible halo signs in temporal arteries and its branches bilaterally. An urgent ophthalmology review revealed AION changes in the left eye, her vision deteriorated over the next forty-eight hours despite the initiation of high dose intravenous methylprednisolone. The patient was also started on tocilizumab infusion in an attempt to reverse the sight loss.

Discussion
The ophthalmic manifestations of GCA range from AION (anterior ischaemic optic neuropathy), CRAO (anterior central retinal artery occlusion), cilioretinal artery occlusion to occipital lobe infarcts, transient monocular vision loss, photopsias or diplopia. Ophthalmic GCA is an emergency and requires urgent ophthalmological evaluations and initiation of treatment with high dose of steroids to avoid permanent loss of vision. The reported incidence of visual symptoms in GCA ranges widely from 12% to 70% of cases. GCA is often associated with constitutional symptoms such as weight loss, night sweats, fevers, systemic inflammatory response with elevated inflammatory markers. However, it had been reported that this can be very mild in ischaemic GCA.
The diagnosis of GCA in this particular case was delayed for approximately six weeks due to the atypical initial presentation with mainly constitutional symptoms and unilateral vision blurring as well as mildly elevated inflammatory markers. A collaboration of three teams (namely ophthalmology, stroke and rheumatology) proved necessary to initiate high dose steroid treatment and tocilizumab. However, patient still suffered from permanent binocular vision loss. She was registered blind and will in future require extensive physical and psychological support.

Key learning points
Despite the recent advances and increased awareness with good availability of fast track GCA services, cases of bilateral blindness are still observed. This is due to a lack of awareness of atypical non-cranial symptoms that frequently accompany a GCA ischaemic presentation. Inflammatory markers are often only mildly elevated in such cases. We suggest a heightened public and professional awareness program to mitigate this irreversible disastrous complication.

Conflicts of interest
The authors have declared no conflicts of interest.