Abstract
Abstract: :
Purpose: To characterize the optic disc in healthy Latinos and explore the relationship of various optic disc parameters with age, gender, and refractive error. Methods: LALES is a population-based study of eye disease in Latinos aged 40 years and older. Simultaneous stereoscopic optic disc images were obtained on all participants. The optic disc margin was identified by the operator. The cup margin was defined as 150 microns below the surface of the disc margin. Data were corrected for differences in magnification using the Littmann equation. The relationship between the optic disc parameters and age, gender, and refractive error was determined using an ANOVA, t-tests, and linear regression analyses. Results: Of the 388 individuals, 360 were analyzed with an image analyzer. Twenty-eight individuals were excluded owing to the absence of good quality images from either eye or the presence of glaucoma, ocular hypertension, or optic neuropathy. In the right eyes, the mean values + SD for the measurements were: disc area 2.33 + 0.48 mm2, cup area 0.67 + 0.35 mm2, neural rim area 1.66 + 0.36 mm2, neural rim area-to-disc area ratio 0.72 + 0.11, vertical cup-to-disc ratio 0.53 + 0.13, horizontal cup-to-disc ratio 0.45 + 0.13, and cup volume 0.21 + 0.17 mm3. On average, males had larger disc areas (males 2.43 mm2, females 2.26 mm2, p=0.0024) and larger neural rim areas (males 1.73 mm2, females 1.62 mm2, p=0.0067) when compared to females. There were no age-related differences in optic disc measurements. Disc area (p=0.05) and neural rim area (p=0.047) were greater in eyes with myopia compared to those with hyperopia. Conclusion: Gender- and refractive error-related differences in disc area and neural rim area in the normal optic disc are present in Latinos. These differences should be considered when evaluating glaucoma and other optic neuropathies. In comparison with Blacks and Whites in the Baltimore Eye Survey, Latinos had smaller disc areas, smaller cup areas, and smaller neural rim areas.
Keywords: 498 optic disc • 430 imaging/image analysis: clinical • 355 clinical (human) or epidemiologic studies: risk factor assessment