Background/AimThe aim of this study was to evaluate the effect of prediabetes and diabetes on macular thickness and retinal vascular calibres in our population-based cohort (Northern Finland Birth Cohort).MethodsThe population of 2005 individuals was divided into diabetes (n=57), prediabetes (n=1638) and normal glucose metabolism (NGM) groups (n=310). Total thickness of the macula was measured using Cirrus HD-OCT 4000. Central retinal arteriolar equivalent (CRAE) and central retinal venular equivalent (CRVE) calibres were measured from the fundus images. The diagnosis of diabetes and prediabetes was made according to WHO 2006 diagnostic standards.ResultsSignificant macular thinning was observed in subjects with prediabetes (−2.69 μm (95% CI −4.29 to −1.09), p<0.05 and −0.10 mm3 (95% CI −0.16 to −0.04), p<0.05 for macular cube average thickness and cube volume, respectively) and it was greatest in the pericentral area. Macular cube average thickness and macular cube volume decreased significantly by worsening glucose metabolism. Furthermore, CRAE was decreased by increases in 2-hour post-load glucose, glucose area under the curve and increase in Matsuda index (p<0.001, 0.019 and <0.001, respectively). In mediation analysis, macular thickness had significant average causal mediation effect (ACME) on CRVE and CRAE in subjects with prediabetes.ConclusionWe detected significant thinning of the macula in subjects with prediabetes. The diameters of retinal arteries were decreased by impaired glucose metabolism. This study provides a new perspective since it revealed that the early and subtle changes caused by prediabetes as macular thinning had significant ACME on retinal vessels, therefore supporting the neurodegenerative theory of diabetes-induced changes in the retina.

AimTo assess the applicability of a structure–function (S-F) analysis combining spectral-domain optical coherence tomography (SD-OCT) and standard automated perimetry (SAP) in glaucoma screening in a middle-aged population.MethodsA randomised sample of 3001 Caucasian participants aged 45–49 years of the Northern Finland Birth Cohort Eye Study was examined. We performed an eye examination, including 24–2 SAP, optic nerve head (ONH) and retinal nerve fibre layer (RNFL) photography and SD-OCT of the peripapillary RNFL. The S-F report was generated by Forum Glaucoma Workplace software. OCT, SAP and the S-F analysis were evaluated against clinical glaucoma diagnosis, that is, the positive ‘2 out of 3’ rule based on the clinician’s evaluation of ONH and RNFL photographs and visual fields (VFs).ResultsAt a specificity of 97.5%, the sensitivity for glaucomatous damage was 26% for abnormal OCT, 35% for SAP and 44% for S-F analysis. Estimated areas under the curve were 0.74, 0.85 and 0.76, and the corresponding positive predictive values were 8 %, 10% and 12%, respectively. By applying a classification tree approach combining OCT, SAP and defect localisation data, a sensitivity of 77% was achieved at 90% specificity. In a localisation analysis of glaucomatous structural and functional defects, the correlation with glaucoma increased significantly if the abnormal VF test points were located on borderline or abnormal OCT zones.ConclusionSAP performs slightly better than OCT in glaucoma screening of middle-aged population. However, the diagnostic capability can be improved by S-F analysis.

AimsStudying the relationship between retinal vessel diameter (RVD) with (1) macular thickness and volume, (2) retinal nerve fibre layer (RNFL), (3) ganglion cell-inner plexiform layer (GC-IPL) and (4) optic nerve head (ONH) in a population cohort of middle-aged Caucasians.MethodsWe collected data from 3070 individuals. We used a semiautomated computer-assisted programme to measure central retinal arteriolar equivalent and central retinal venular equivalent. Macular and ONH parameters were assessed by optical coherence tomography.ResultsData from 2155 persons were analysed. A larger RVD was associated with a thicker macula and increased macular volume; each SD increase in average macular thickness and volume was associated with a 3.28 µm and a 3.19 µm increase in arteriolar diameter and a 5.10 µm and a 5.08 µm increase in venular diameter, respectively (p<0.001 for all). A larger rim area, greater GC-IPL and RNFL thicknesses were associated with larger RVD; each SD increase in rim area, GC-IPL thickness and RNFL thickness was associated with a 1.21 µm, 2.68 µm and a 3.29 µm increase in arteriolar diameter and a 2.13 µm, 4.02 µm and 5.04 µm increase in venular diameter, respectively (p<0.001 for all).ConclusionsIncreased macular thickness, macular volume, GC-IPL thickness, RNFL thickness and optic nerve rim area were associated with larger RVDs in all subjects. This study clarified the anatomical correlations between both macular and ONH parameters with RVD for middle-aged Caucasians; these can represent a basis for further studies investigating the vascular aetiology of eye diseases.