Purchase this article with an account.
Alfredo R. Castillejos, Andrea X. Arata, Saman Kiumehr, Syril K. Dorairaj, Carlos G. De Moraes, Jeffrey M. Liebmann, Robert Ritch; Sequential Imaging of Schlemm’s Canal and the Collector Channels in Normal and POAG Eyes. Invest. Ophthalmol. Vis. Sci. 2011;52(14):3959.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
To quantitatively and qualitatively evaluate the morphology of Schlemm’s canal (SC) and the collector channels (CC) in normal and POAG eyes through sequential imaging using anterior segment Fourier-domain OCT (ASFDOCT)
15 normal subjects with no ocular pathology (N group) and 15 POAG patients (G group, no intraocular surgeries, abnormal 24-2 perimetry, untreated IOP >21mmHg, CDR >0.6) were imaged on the right temporal limbus. The initial set consisted of 15 radial and 5 longitudinal scans. When a collector channel was identified, additional sequential scans were performed in order to follow its course and composite images were created. SC cross-sectional area, minimum and maximum width, index of variability, ostium diameter, and mean diameter of the CC were compared using a T test. Correlations between the morphometry of SC/CC and the maximum and treated IOP, CDR and visual field PSD were evaluated using Spearman’s correlation coefficient.
The groups were comparable in age (N=64.5 G=65.5 years p=0.77). SC area (N=1530±640 G=1150±376 µm² p=0.06) reached marginal significance. SC length (p=0.003), minimum longitudinal width (p=0.002) and the index of variability (p=0.04) were reduced in the G group. No differences were observed in CC morphometry. A significant negative correlation was observed between SC length (r=-0.38), minimum longitudinal width (r=-0.51) and the maximum IOP. Qualitatively, SC and CC dimensions appeared reduced in both groups. In the G group, SC appeared more tortuous and less intense, suggesting decreased aqueous flow. SC appeared widest at the area of junction with CC, suggesting that circumferential flow is lost before vertical flow.
SC and CC can be evaluated in vivo using ASFDOCT. Sequential imaging of SC and CC provided a better assessment of the overall condition of SC and CC. Modifications of SC in eyes with POAG may be better explained as a change in configuration rather than a simple loss of lumen.
This PDF is available to Subscribers Only