Abstract
Abstract: :
Purpose: To evaluate the relationship between optic disk parameters and age, gender, refractive status, and IOP in a random sample of the population. Methods: In 94% of 263 consecutive subjects (248 subjects) over 60 years of age in the Thessaloniki Eye Study, we obtained three HRT measurements of the optic disk. Three subjects (6 eyes) were excluded from analysis because there were no images of good quality. Thirteen subjects (26 eyes) were excluded from analysis because of a diagnosis for glaucoma. One eye per subject was randomly selected. A total of 193 eyes with mean images (83.2%) and 39 eyes with single images (16.8%) were included in the analysis. Mean images of three measurements were used when the quality assessment indication was less than 30µm in the HRT software (328 eyes) and the best single image was used when the indication was over than 30µm (134 eyes). Mean values, standard deviation, range for the main HRT parameters as well as correlations among the HRT parameters were evaluated. Linear regression models for each HRT parameter were adjusted for the following covariates: age, gender, refractive status, IOP and type of image. Results: Increasing age was associated with decreasing mean RNFL thickness (r=-0.18, p=0.01) and RNFL cross-sectional areas (r=-0.17, p=0.01) in the unadjusted results. None of the topographic parameters was associated significantly with changes in age in the adjusted models. Female discs had greater rim volume, mean RNFL thickness and RNFL cross-sectional areas compared to male discs (t-test, p=0.03, p=0.02, and p=0.04, respectively). Increased IOP was associated with increased maximum cup depth in the adjusted model (estimated slope=0.01, p=0.04). All HRT parameters but mean RNFL thickness were positively correlated with disk size. Conclusion: In the adjusted models, age does not appear to affect HRT parameters in subjects over 60 years of age. Interesting, female discs have increased rim volume, mean RNFL thickness and RNFL cross-sectional areas compared to male discs even though there is no difference in disc size.
Keywords: 432 imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound) • 498 optic disc • 430 imaging/image analysis: clinical