Abstract
Purpose :
To identify the characteristics of Schlemm’s canal (SC) using anterior segment Fourier-domain optical coherence tomography (AS-FD-OCT) in patients with high myopia.
Methods :
Eighty-seven highly myopic eyes (axial length ≧26.5 mm) from 46 patients and 52 control eyes from 28 subjects with non-highly myopic eyes (axial length <26.5 mm) were enrolled. All subjects underwent imaging with AS-FD-OCT, and the SC length was examined in both temporal and nasal quadrants. The length of SC was measured using software provided with the device.
Results :
The average ocular axial lengths of the high myopic (HM) eyes and the non-highly myopic (NHM) eyes were 31.4 ± 3.2mm and 24.2 ± 1.1 mm, respectively. Male-female ratio was 5: 6 and 1: 3, respectively. The average age was 61.6 ± 12.0 and 66.2 ± 16.8. In the HM eyes, SC was observable in 64.4% in nasal quadrant and in 71.3% in temporal quadrant. In the NHM eyes, SC was observable in 69.0% in nasal quadrant and in 71.4% in temporal quadrant. In the HM eyes, SC length was 354.6 ± 51.5μm in nasal quadrant and 346.6 ± 50.0μm in temporal quadrant. In the NHM eyes, SC length was 289.6 ± 42.9μm in nasal quadrant and 269.3 ± 56.6μm in temporal quadrant. HM eyes had a significantly longer SC length in the both nasal and temporal quadrants than NHM eyes.
Conclusions :
The increase of the length of SC in HM eyes might result from an excessive elongation of eyeball. Furthermore, the structural change of SC in HM eyes might affect intraocular pressure and glaucoma progression.
This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.