To characterize the in vivo morphology of human lamina cribrosa pores in healthy and
glaucoma eyes.
Patients and methods
In this cross-sectional, observational study, a flood-illumination adaptive optics fundus (FIAO) camera was used to perform in vivo, high-resolution, noninvasive imaging of the optic disc and lamina cribrosa in 30 patients diagnosed with primary open-angle glaucoma (POAG), in 15 healthy controls and in 14 healthy subjects with at least one direct relative with POAG. Two masked graders measured each visible lamina cribrosa pore along the major and minor axes in order to categorize pores as oval (minor/major axis ratio < 0.75) or round. We used these same measurements to calculate pore surface area as a best-fit oval.
Results
Lamina cribrosa pores were visible in 95.2% of the subjects. In 52% of controls, the pores were visualized under the neuroretinal rim. In POAG patients, 78% of visible pores had an oval shape versus 19.4% in controls (P < 0.01). Average pore surface area was significantly different (1561 px2 versus 724 px2; P < 0.01). In healthy subjects with at least one direct relative with POAG, 21% had pores with an appearance comparable to that of subjects in the glaucoma group.
Conclusion
On average, lamina cribrosa pores are elongated in POAG eyes and also in healthy eyes of POAG relatives. In vivo characterization of lamina cribrosa pore morphology by FIAO imaging may enhance our understanding of glaucoma, and offer new means for its early detection.
