Prevalence of diplopia among giant cell arteritis patients: a systematic review and meta-analysis.

Diplopia is an infrequent manifestation of GCA, but may precede other visual disturbances such as transient or permanent vision loss. The literature-pooled prevalence of diplopia in GCA patients stratified by cranial nerve (CN) involvement was assessed. The protocol was registered prospectively (PROSPERO: CRD420251071956). MEDLINE, Embase, and Cochrane CENTRAL databases were searched from inception to April 17, 2025. Studies were included if they reported on the proportion of diplopia events in patients with GCA. Literature screening, data extraction, and risk of bias (ROB) assessments were performed independently and in duplicate. A non-pairwise, random-effects meta-analysis was performed. 50 studies were included, encompassing 21,680 patients with GCA and 664 diplopia events. Overall, the pooled prevalence of diplopia in GCA patients was 7.15% (95% CI = 5.52-9.22%). The pooled prevalence of diplopia in GCA patients with CN III involvement was 0.96% (95% CI = 0.35-2.60%). The pooled prevalence of diplopia in GCA patients with CN IV involvement was 0.30% (95% CI = 0.07-1.26%). The pooled prevalence of diplopia in GCA patients with CN VI involvement was 1.41% (95% CI = 0.54-3.62%). Excluding studies with high risk of ROB, the pooled prevalence of diplopia in GCA patients was 7.14% (95% CI = 5.44-9.33%). Overall, 7.15% of patients with GCA experience diplopia, more frequently reported due to abducens nerve palsy compared to oculomotor and trochlear nerve palsies. Accordingly, new-onset binocular diplopia in adults may warrant consideration of GCA and further investigation. Future prospective studies should aim to better characterise underlying aetiologies and assess whether early recognition of diplopia translates to improved visual prognosis.