Purchase this article with an account.
Srujana Sahebjada, Paul Baird, Amirul Islam, Sanj Wickremasinghe; Comparison of macular parameters among keratoconic, myopic and non-myopic individuals using Optical Coherence Tomography. Invest. Ophthalmol. Vis. Sci. 2012;53(14):2104.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
To investigate if differences exist in macular parameters between keratoconic, myopic and non- myopic individuals, as measured by optical coherence tomography (OCT).
Keratoconus patients were recruited from private and public clinics in Melbourne, Australia. Myopic and non- myopic individuals were identified from the Genes in Myopia study. All subjects underwent clinical examination including objective refraction (NIDEX Autorefractor), biometric measurements (Zeiss IOL Master), and macular thickness measurements (Stratus OCT). Generalised Estimation Equation Model was used to estimate the means of the outcome factors adjusted for age, gender and height using SPSS software.
A total of 96 individuals comprising 56 keratoconus eyes (group 1), 43 eyes with myopia (group 2-spherical equivalent [SE] < –0.5 D to -10D) and 91 non-myopic eyes (group 3-SE ≥ –0.5 D) were analysed. The inner macular thickness of group 1 had a mean of 284.7 m (95% confidence interval (CI) 279.4, 290), which was significantly different (p=0.007) from the group 2 mean of 275.5 m (95%CI 270.2, 280.8) and group 3 mean of 272.9 m (95%CI 268.7, 277.2). Mean inner macular volume was also significantly different (p=0.006) with group 1 mean of 0.393 mm3 (95% CI 0.386, 0.401) compared to group 2 mean of 0.38 mm3 (95% CI 0.372, 0.387) and group 3 mean of 0.376 mm3 (95% CI 0.369, 0.382) .The mean axial length of group 1 was 23.9mm (95%CI 23.2, 24.6) and was statistically different (p=0.004) to the group 2 mean of 24.1mm (95%CI 23.4, 24.8) and group 3 mean of 22.7mm (95% CI 22.2, 23.3).
Keratoconus patients have thicker inner maculae and greater macular volume compared to mild/moderate myopia or non-myopia individuals. This study suggests that important differences may exist in keratoconic eyes in addition to anterior changes. In addition, mean axial length differed between keratoconus and myopia groups by only 0.08%, while the change in mean macular thickness differed by 5.3%. This finding suggests that axial elongation does not necessarily correlate with thinner maculae in keratoconus eyes.
This PDF is available to Subscribers Only