Retinal nerve fiber layer changes in migraine: a systematic review and meta-analysis

Background Migraine is one of the most common disabling diseases in the world. Its recurrent attacks may lead to abnormalities in the structure of the brain and retina. An increasing number of studies have investigated retinal nerve fiber layer (RNFL) thickness alterations in migraine by the optical coherence tomography (OCT); however, no consensus has yet reached. Method We searched Pubmed, Embase, and Web of Science databases to identify studies that investigated RNFL thickness in migraine by OCT measurement and performed a meta-analysis of eligible studies. Results Twenty-six studies were included in the meta-analysis, comprising 1530 migraine patients and 1105 healthy controls. The mean RNFL thickness was thinner in the migraine group compared to the control group (SMD =− 0.53). In the subgroup analyses, RNFL thickness were decreased most significantly in the superior (SMD = − 0.71) and inferior (SMD = − 0.63) quadrants among all quadrants. Migraine with aura (SMD = − 0.91) showed a greater effect size of RNFL thickness reduction than migraine without aura (SMD =− 0.47). Spectral-domain OCT (SMD = − 0.55) seems more sensitive to detect RNFL thickness reduction than time-domain OCT (SMD = − 0.44). In addition, age, sex, disease duration, attack frequency, and intraocular pressure were not significantly associated with RNFL thickness. Conclusions The findings from our comprehensive meta-analysis with large datasets strengthen the clinical evidence of the RNFL thickness reduction in migraine. RNFL thickness via spectral-domain OCT measurement demonstrates the potential role in differentiating patients with migraine, especially migraine with aura, from healthy controls.