Artikel
In-vivo quantification of the lamina-cribrosa pores in healthy subjects and glaucoma patients
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Autoren
Veröffentlicht: | 22. September 2004 |
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Gliederung
Text
Objective
Scanning laser ophthalmoscopy (SLO Rodenstock Instr. Germany) allows imaging of the lamina cribrosa pores using helium neon illumination (588 nm). The ultrastructural changes of the pores were examined in patients with glaucoma and healthy controls.
Methods
By focussing through the optic nerve head excavation images of the anterior portion of the lamina cribrosa were captured and digitally processed. The visible pores were marked interactively and the area of the pores and elongation of the pores were evaluated. The measurements were correlated with visual function and optic nerve head morphology (Heidelberg Retina Tomography; HRT). In this study, 16 healthy subjects with physiological optic nerve head excavation were compared to 16 patients with either normal tension or primary open angle glaucoma.
Results
The area (glaucoma: 4147± 7889 μm2; control: 3040 ±367 μm2; p=0.0003) and the elongation (glaucoma: 1.81 ±0.36; control: 1.50 ±0.27; p=0.001) of the lamina cribrosa pores were significantly increased in patients with glaucoma. Both measurements were significantly correlated to each other (r=0.58; p=0.0004). The area of the pores increased with decreasing visual acuity (logMAR; r=0.39, p=0.02) but was not related to any of the viusal field indices. Compared to HRT measurements the area of pores correlated significantly with the cup to disk area (r=0,5;p=0.04) and cup shape measurement (r=0.6; p=0.01), whereas the elongation correlated with the maximum excavation depth (r=-0.5; p=0.04).
Conclusions
The non invasive imaging of the lamina cribrosa allows in vivo assessment of the pore area and geometry. The area and elongation of pores are significantly increased in glaucoma patients. and correlated with optic nerve head morphology. Future studies should aim if there are alterations in early manifest glaucoma and if differences among different types of glaucoma can be observed.