title: Retinal microvessels reflect familial vulnerability to psychotic symptoms: A comparison of twins discordant for psychotic symptoms and controls.
abstract: Mounting evidence suggests that individuals with schizophrenia have an underlying vulnerability to cardiovascular disease, and a recent study suggested that this vulnerability might be reflected in the retinal microvasculature. The purpose of this study was to test the hypothesis that the retinal microvessels reflect familial vulnerability to psychotic symptoms. Participants were 531 adolescent and young adult twins who took part in the Brisbane Longitudinal Twin Study and the Twins Eye Study in Tasmania. The twins had photographs taken of their retina when they were adolescents or young adults (M age=20.6 years), and retinal vessel diameter was assessed using computer software. The twins completed an assessment of psychosis symptoms approximately six years later. We compared retinal venular diameters of individuals with one or more symptoms of psychosis (n=45), their unaffected co-twins (n=24), and controls (n=462). Individuals with one or more symptoms of psychosis had wider venules (standardized mean=0.29) than controls (standardized mean=-0.04; p=.03), and unaffected co-twins had venular diameters that were intermediate (standardized mean=0.13) between the two groups, suggesting that wide venules may represent a proxy marker of familial vulnerability to psychosis symptoms. Consistent with previous work, there were no differences in arteriolar diameter between individuals with and without symptoms of psychosis. Findings suggest that wide retinal venules may serve as a proxy marker of familial liability to psychosis symptoms. The pathophysiological mechanisms linking psychosis and cardiovascular disease may be operative from early in life, possibly at the level of the microvasculature.
authors.affiliation: Department of Psychology, Arizona State University, Tempe, AZ, USA. Electronic address: madeline.meier@asu.edu.
authors.forename: Madeline H
authors.initials: MH
authors.lastname: Meier
authors.affiliation: Virginia Institute for Psychiatric and Behavioral Genetics, Virginia Commonwealth University, Richmond, VA, USA; QIMR Berghofer Medical Research Institute, Brisbane, Australia.
authors.forename: Nathan A
authors.initials: NA
authors.lastname: Gillespie
authors.affiliation: QIMR Berghofer Medical Research Institute, Brisbane, Australia.
authors.forename: Narelle K
authors.initials: NK
authors.lastname: Hansell
authors.affiliation: Centre for Eye Research Australia (CERA), University of Melbourne, Royal Victorian Eye and Ear Hospital, Melbourne, Victoria, Australia; Centre for Ophthalmology and Visual Science, Lions Eye Institute, University of Western Australia, Perth, Western Australia, Australia.
authors.forename: Alex W
authors.initials: AW
authors.lastname: Hewitt
authors.affiliation: Brain and Mind Research Institute, University of Sydney, Sydney, Australia.
authors.forename: Ian B
authors.initials: IB
authors.lastname: Hickie
authors.affiliation: QIMR Berghofer Medical Research Institute, Brisbane, Australia.
authors.forename: Yi
authors.initials: Y
authors.lastname: Lu
authors.affiliation: Queensland Centre for Mental Health Research, The Park Centre for Mental Health, Wacol, Australia; Queensland Brain Institute, University of Queensland, St Lucia, Australia.
authors.forename: John
authors.initials: J
authors.lastname: McGrath
authors.affiliation: QIMR Berghofer Medical Research Institute, Brisbane, Australia.
authors.forename: Stuart
authors.initials: S
authors.lastname: MacGregor
authors.affiliation: QIMR Berghofer Medical Research Institute, Brisbane, Australia.
authors.forename: Sarah E
authors.initials: SE
authors.lastname: Medland
authors.affiliation: Environmental and Genetic Epidemiology Research, Murdoch Children's Research Institute, Parkville, Victoria, Australia; Department of Paediatrics, University of Melbourne, Parkville, Victoria, Australia.
authors.forename: Cong
authors.initials: C
authors.lastname: Sun
authors.affiliation: Singapore Eye Research Institute, Yong Loo Lin School of Medicine, National University of Singapore, Singapore; Department of Ophthalmology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore; Office of Clinical Sciences, Duke-NUS Graduate Medical School, Singapore.
authors.forename: Tien Y
authors.initials: TY
authors.lastname: Wong
authors.affiliation: QIMR Berghofer Medical Research Institute, Brisbane, Australia.
authors.forename: Margaret J
authors.initials: MJ
authors.lastname: Wright
authors.affiliation: QIMR Berghofer Medical Research Institute, Brisbane, Australia.
authors.forename: Gu
authors.initials: G
authors.lastname: Zhu
authors.affiliation: QIMR Berghofer Medical Research Institute, Brisbane, Australia.
authors.forename: Nicholas G
authors.initials: NG
authors.lastname: Martin
authors.affiliation: Centre for Eye Research Australia (CERA), University of Melbourne, Royal Victorian Eye and Ear Hospital, Melbourne, Victoria, Australia; Centre for Ophthalmology and Visual Science, Lions Eye Institute, University of Western Australia, Perth, Western Australia, Australia.
authors.forename: David A
authors.initials: DA
authors.lastname: Mackey
mesh_terms: D000293:Adolescent; D000328:Adult; D003936:Diagnosis, Computer-Assisted; D005192:Family Health; D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D011569:Psychiatric Status Rating Scales; D011618:Psychotic Disorders / Q000235:genetics / Q000473:pathology*; D012171:Retinal Vessels / Q000473:pathology*; D055815:Young Adult
keywords: Psychosis; Retinal vessel diameter; Twin