Three-dimensional Microarchitecture of Lamina Cribrosa Pores in High and Normal-tension Glaucoma using Optical Coherence Tomography.

Abstract

The lamina cribrosa pores of high-tension glaucoma subjects appear to take a more tortuous pathway than the LC pores of non-glaucomatous subjects. To compare the lamina cribrosa pore microarchitecture in high-tension glaucoma (HTG), normal-tension glaucoma (NTG) and in non-glaucomatous (NG) subjects, by reconstructions of the lamina cribrosa made from tomographic images. SD-OCT images of 52 eyes (18 NG, 18 HTG, 16 NTG) of 29 patients were analyzed. Pores were traced using segmentation software. Pore length, tortuosity and verticality were the three quantitative parameters compared between the three groups. Correlation analyses were performed to determine the effects of covariates on the three quantitative parameters. Pore tortuosity in HTG (1.419 +/- 0.093) was significantly higher (P=0.011) than in NG (1,347 +/- 0,034) but did not differ from that of NTG eyes (P=0.251). In addition, NTG had significantly shorter pores (P=0.005) than NG. No difference in pore tortuosity or verticality was found between NG and NTG (P=0.587 and P=0.120 respectively). Pore verticality and length in HTG eyes did not significantly differ from that of NG eyes (P=0.049 and P=0.033 respectively) and NTG eyes (P=0.827 and P=0.968 respectively). All of the quantitative parameters measured were not correlated with age, but were associated with glaucoma severity (VFI, MD, RNFL, GCC), except for pore verticality which was not correlated with RNFL. The LC pores of HTG subjects appear to be more tortuous than the pores of NG subjects and the pores of NTG patients are shorter than those of NG subjects. Changes in pore parameters appear to be associated with severity of the glaucomatous optic neuropathy.