title: Determinants of peripapillary retinal nerve fiber layer thickness regarding ocular and systemic parameters - the MIPH Eye&Health Study.
abstract: BACKGROUND
  Optical coherence tomography (OCT) allows quantitative image analysis of retinal tissue in vivo. Peripapillary retinal nerve fiber layer (pRNFL) thickness is widely used for evaluation of retinal nerve fiber rarefaction in several optic neuropathies. This study evaluates associations of pRNFL thickness in healthy adult subjects in order to evaluate influencing factors.
  
  
  METHODS
  A cross-sectional study was performed in a working-age population. Only eyes without detectable ocular pathologies were included in the analysis. Among analyzed systemic cardiovascular parameters were age, gender, body-mass index, mean arterial blood pressure, HbA1c, high- and low-density-lipoproteins, and triglycerides. A comprehensive ophthalmological examination including refraction, tonometry, keratometry, and central corneal thickness measurmentwas performed. In addition, pRNFL thickness was imaged by spectral-domain OCT. Univariable and multivariable associations of pRNFL thickness in all four quadrants and on average with systemic and ocular parameters were calculated using a generalized estimating equation model.
  
  
  RESULTS
  Three hundred and six subjects were included. pRNFL thickness measurements showed a significant association with spherical equivalent: pRNFL thickness decreased with increasing myopia in all quadrants (multivariable regression coefficients Beta: superior: 1.16, 95 % CI [0.62;1.71], p < 0.001; temporal: 0.87, [0.33;1.41], p = 0.001; inferior: 1.80, [1.18;2.42], p < 0.001; nasal: 2.60, [2.01;3.20], p < 0.001) and on average (1.51, [1.20;1.82], p < 0.001). A thicker central cornea thickness was related to lower pRNFL in the superior (-0.05, [-0.10; -0.01], p = 0.01), the inferior quadrant (-0.05, [-0.10;0.00], p = 0.03) and on average (-0.04, [-0.07; -0.01], p = 0.02). All other parameters were not  associated.
  
  
  CONCLUSIONS
  Our findings highlight the importance of refraction when evaluating pRNFL thickness and its independence from other systemic parameters.
authors.affiliation: Mannheim Institute of Public Health, Social and Preventive Medicine, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany.
authors.forename: Alexander Karl-Georg
authors.initials: AK
authors.lastname: Schuster
authors.affiliation: Mannheim Institute of Public Health, Social and Preventive Medicine, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany.
authors.forename: Joachim Ernst
authors.initials: JE
authors.lastname: Fischer
authors.affiliation: Private practice, Charlottenstrasse, Stuttgart, Germany.
authors.forename: Christine
authors.initials: C
authors.lastname: Vossmerbaeumer
authors.affiliation: Mannheim Institute of Public Health, Social and Preventive Medicine, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany. urs.vossmerbaeumer@gmx.de.|Department of Ophthalmology, Mainz University Medical Center, Langenbeckstr. 1, 55131, Mainz, Germany. urs.vossmerbaeumer@gmx.de.
authors.forename: Urs
authors.initials: U
authors.lastname: Vossmerbaeumer
mesh_terms: D000293:Adolescent; D000328:Adult; D001794:Blood Pressure / Q000502:physiology; D001824:Body Constitution / Q000502:physiology; D003430:Cross-Sectional Studies; D005260:Female; D064368:Healthy Volunteers; D006801:Humans; D007429:Intraocular Pressure; D008055:Lipids / Q000097:blood; D008297:Male; D008875:Middle Aged; D009412:Nerve Fibers; D009898:Optic Disk / Q000033:anatomy & histology* / Q000000981:diagnostic imaging; D012029:Refraction, Ocular; D012165:Retinal Ganglion Cells / Q000166:cytology*; D041623:Tomography, Optical Coherence
chemical_list: D008055:Lipids
keywords: Cardiovascular parameter; Keratometry; RNFL thickness; Refraction; Spectral-domain OCT