Morphology of the optic nerve head and factors affecting it in the Northern Finland birth cohort.

PURPOSE: To assess topographic characteristics of the optic nerve head (ONH) and retinal nerve fibre layer (RNFL) and study the effect of ocular and physiological factors on them in a middle-aged population. METHODS: A 1552-person randomised sample from Northern Finland population aged 45-49 was examined. Laser scanning tomography and optical coherency tomography were performed to obtain measurements for ONH and RNFL morphology. Measurements of the RNFL included global thickness and the six zones used in automated structure-function analysis (S-F analysis). Influence of central corneal thickness (CCT), refractive correction, intraocular pressure (IOP), anterior chamber angle, gender, blood pressure, height, weight and body mass index (BMI) on tomographic data was analysed. RESULTS: The optic disc area had a strong correlation with all other parameters of ONH morphology (R = 0.261 to 0.706) as did spherical equivalent (R = -0.280 to 0.280). The correlations between ONH and RNFL measurements were weaker (R = 0.057 to 0.180). Gender, CCT, anterior chamber angle, blood pressure, height and BMI had statistically significant, yet feeble, correlations with a number of ONH parameters. CONCLUSION: Other than spherical equivalent, the studied anatomical and physiological attributes had little predictive value on the ONH morphology. The optic disc area itself had a significant effect on other measurements of ONH tomography and should be taken into consideration when the thresholds for normal ONH morphology are calculated.

Antenatal and neonatal factors and morphology of the optic nerve head in the Northern Finland birth cohort.

PURPOSE: The optic nerve head (ONH) is a part of the brain that can be evaluated through the transparent medium of the eye. The purpose of this study was to explore the possible correlations among the properties of the optic nerve head, maternal factors during pregnancy and neonatal parameters in a randomized sample of a birth cohort. METHODS: The Northern Finland 1966 Birth Cohort has been prospectively monitored since their antenatal period. Data on pregnancy and neonatal period were collected during gestation and right after birth in 1966. A randomized sample of 3070 subjects underwent an ophthalmic assessment at the age of 46-48 years. The examination protocol included scanning laser ophthalmoscopy with the Heidelberg Retina Tomograph. The ophthalmological parameters assessed were the disc area and the neuroretinal rim volume of the ONH. RESULTS: We found that chronic pulmonary disease of the mother (p = 0.007), the number of gestational weeks (p = 0.030) and the mother's highest measured systolic blood pressure (p = 0.035) during pregnancy had a statistically significant effect on the disc area. Smaller disc size was associated with pulmonary disease and early gestation. There was a significant difference in rim volume between genders (p < 0.001). Women had larger neuroretinal rim volumes compared to men. CONCLUSION: In this population-based study, the vast majority of antenatal and neonatal factors showed no correlation with optic disc area or rim volume. Furthermore, even the factors with statistically significant correlation with ONH morphology had limited predictive value.

Optic Nerve Parameters and Cognitive Function in the Northern Finland Birth Cohort Eye Study.

PURPOSE: The optic nerve head (ONH) is a part of the brain that can be easily studied through the transparent medium of the eye. We explored the relationship between the properties of the optic nerve head, the retinal nerve fiber layer (RNFL) and cognitive function. METHODS: Participants of the Northern Finland Birth Cohort (NFBC) 1966 underwent an ophthalmic and cognitive assessment after randomization at age 46. The ophthalmological parameters obtained were the disc area and the neuroretinal rim volume of the ONH and the average RNFL thickness. The surrogates used for cognitive function were the paired associates learning test (PAL), level of education, grade point average (GPA) and Humphrey 24-2 perimetric test time (HFA). We did exploratory research between the ophthalmological parameters and the surrogates for cognition and the correlations between the surrogates for cognition. RESULTS: We found that a larger disc area was associated with a higher level of education, faster accomplishment of the HFA (R = -0.065) but a lower GPA (R = -0.084). An increase in neuroretinal rim volume was associated with fewer errors in the PAL test (R = -0.056), higher level of education, higher GPA (R = 0.072) and faster accomplishment of the HFA (R = -0.047). A thicker RNFL was associated with faster accomplishment of the HFA (R = -0.047). CONCLUSION: We were able to find statistically significant associations between the parameters of the optic nerve head, the RNFL and cognition in the NFBC Eye study. However, the correlations were negligible at best and of limited predictive value.