title: Retinal ganglion cell neuronal damage in diabetes and diabetic retinopathy.
abstract: BACKGROUND
  To examine the association of diabetes and diabetic retinopathy (DR) with retinal ganglion cell (RGC) loss.
  
  
  METHODS
  Observational case-control study.
  
  
  METHODS
  Type 2 diabetes cases and age-gender matched controls without diabetes.
  
  
  METHODS
  Spectral-domain optical coherence tomography (OCT) parameters of RGCs were calculated after automated segmentation of macular scans. DR severity was graded on fundus photographs using the modified Airlie House Classification system. Generalized estimating equation was used to compare OCT parameters between cases and controls, adjusted for covariates.
  
  
  METHODS
  Average ganglion cell-inner plexiform layer (GC-IPL) and average retinal nerve fibre layer (RNFL) thicknesses.
  
  
  RESULTS
  We analyzed 227 cases and 227 controls. The mean age (years) of cases was 58.3 and controls was 58.1 (P = 0.13). Among cases, 101 had none, 25 had mild and 101 had moderate or severe DR. Compared with controls, GC-IPL and RNFL were thinner in all cases [mean difference (95% confidence interval [CI]): GC-IPL -4.49 µm (-2.92; -6.06), RNFL -0.93 µm (-0.09; -1.85)], including cases with no DR [mean difference (95% CI), GC-IPL -4.37 µm (-2.72; -6.02), RNFL -1.06 µm (-0.10; -2.02)]. Cases with any DR had thinner GC-IPL than controls [mean difference (95% CI): GC-IPL -4.81 µm (-2.12; -7.50)]. Among cases, subjects with moderate or severe DR had thinner GC-IPL than subjects with no DR [mean difference (95% CI): GC-IPL -2.07 µm (-0.08; -4.07)].
  
  
  CONCLUSIONS
  RGC loss is present in subjects with diabetes and no DR, and is progressive in moderate or severe DR. RGC neuronal damage in diabetes and DR can be clinically detected using OCT.
authors.affiliation: Singapore Eye Research Institute, Singapore National Eye Centre, Singapore.|Department of Ophthalmology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore.
authors.forename: Dorothy Sk
authors.initials: DS
authors.lastname: Ng
authors.affiliation: Singapore Eye Research Institute, Singapore National Eye Centre, Singapore.
authors.forename: Peggy Pc
authors.initials: PP
authors.lastname: Chiang
authors.affiliation: Singapore Eye Research Institute, Singapore National Eye Centre, Singapore.|Duke-NUS Graduate Medical School, National University of Singapore, Singapore.
authors.forename: Gavin
authors.initials: G
authors.lastname: Tan
authors.affiliation: Singapore Eye Research Institute, Singapore National Eye Centre, Singapore.|Duke-NUS Graduate Medical School, National University of Singapore, Singapore.
authors.forename: Cm Gemmy
authors.initials: CG
authors.lastname: Cheung
authors.affiliation: Singapore Eye Research Institute, Singapore National Eye Centre, Singapore.|Duke-NUS Graduate Medical School, National University of Singapore, Singapore.|Department of Ophthalmology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore.
authors.forename: Ching-Yu
authors.initials: CY
authors.lastname: Cheng
authors.affiliation: Singapore Eye Research Institute, Singapore National Eye Centre, Singapore.|Duke-NUS Graduate Medical School, National University of Singapore, Singapore.
authors.forename: Carol Y
authors.initials: CY
authors.lastname: Cheung
authors.affiliation: Singapore Eye Research Institute, Singapore National Eye Centre, Singapore.|Duke-NUS Graduate Medical School, National University of Singapore, Singapore.|Department of Ophthalmology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore.
authors.forename: Tien Y
authors.initials: TY
authors.lastname: Wong
authors.affiliation: Singapore Eye Research Institute, Singapore National Eye Centre, Singapore.|Duke-NUS Graduate Medical School, National University of Singapore, Singapore.|Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, University of Melbourne, Melbourne, Victoria, Australia.
authors.forename: Ecosse L
authors.initials: EL
authors.lastname: Lamoureux
authors.affiliation: Singapore Eye Research Institute, Singapore National Eye Centre, Singapore.|Duke-NUS Graduate Medical School, National University of Singapore, Singapore.|Memory Aging and Cognition Centre, National University Health System, Singapore.
authors.forename: Mohammad K
authors.initials: MK
authors.lastname: Ikram
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D058452:Axial Length, Eye / Q000473:pathology; D001794:Blood Pressure; D016022:Case-Control Studies; D003924:Diabetes Mellitus, Type 2 / Q000150:complications*; D003930:Diabetic Retinopathy / Q000150:complications*; D005260:Female; D006442:Glycated Hemoglobin / Q000378:metabolism; D006801:Humans; D008297:Male; D008875:Middle Aged; D009412:Nerve Fibers / Q000473:pathology*; D012165:Retinal Ganglion Cells / Q000473:pathology*; D041623:Tomography, Optical Coherence
chemical_list: D006442:Glycated Hemoglobin; C517652:hemoglobin A1c protein, human
keywords: diabetes; diabetic retinopathy; neuronal damage; optical coherence tomography; retinal ganglion cell