Abstract
Purpose:
Lamina cribrosa (LC) of the optic nerve head has been considered as primary site for glaucoma pathogenesis. LC thickness determined by optical coherence tomography (OCT) was decreased in glaucomatous eyes, so it can be a potential marker for glaucoma diagnosis. Thus, we intended to evaluate the characteristics of LC related parameters in normal and glaucomatous eyes with wide range of axial length (AXL) and the baseline LC thickness measurement can predict future progression of glaucoma.
Methods:
LC and prelamina thickness were determined by Spectralis OCT enhanced depth imaging mode. Eyes were divided into three groups according to AXL, longer (26mm>), mid-level (23-26mm), and shorter (23mm) groups in each normal and glaucomatous eyes. Glaucoma diagnostic capability of LC related parameters was evaluated by area under the receiver operating characteristic curve (AUC). Glaucomatous subjects followed longer than 2 years from baseline LC measurement were also analyzed. Cox proportional hazard model was used to find putative factors associated with glaucoma progression.
Results:
Total 410 subjects (glaucoma; 240, normal; 170) were included. Overall, LC was significantly thinner in eyes with longer AXL than those with shorter AXL. In eye with mid-level AXL, glaucomatous eye showed significantly lower LC thickness than normal group (p<0.002), but no difference between normal and glaucomatous eyes in both eyes with longer and shorter AXL (p=0753, 0.212, respectively). Thus, AUCs for discrimination between normal and glaucomatous eyes were generally lower in eyes with longer and shorter AXL groups (0.533-0.678). Among 120 subjects who were followed more than 2 years after baseline LC measurement, 35 eyes showed glaucoma progression. Average retinal nerve fiber layer, LC and prelamina thicknesses were significantly associated with glaucoma progression (Hazard ratio; 0.973, 0.979, and 0.993, p=0.008, 0.011, and 0.035, respectively).
Conclusions:
LC thickness determined by OCT showed possibility of glaucoma progression prediction. In the mean time, eyes with longer and shorter AXL, LC thickness did not show good diagnostic capability for glaucoma. Thus, when using LC related parameters for glaucoma diagnosis, the result should be interpreted with caution considering AXL. Our result also suggests that glaucomatous LC change may be differently manifested in eyes with different AXL.
Keywords: 550 imaging/image analysis: clinical •
577 lamina cribrosa •
629 optic nerve