Characterization of retinal nerve fiber layer in nonglaucomatous eyes with tilted discs.

Comment. Previous studies that also used the Heidelberg Retina Tomograph as well as those that used other techniques have demonstrated the reversibility of cupping in adult cases of glaucoma. Those studies claimed that the compliance and position of the optic disc and lamina cribrosa were primary determinants for the cup reversal. Sigal et al proposed that elevated IOP deforms ONH tissues indirectly through its influence on the sclera rather than direct action on the internal surface of the ONH. According to them, the highest magnitude of compression occurred within the ONH neural tissues. Asymmetrical deformation of the optic disc and axial length fluctuations correlated with IOP under conditions of stable corneal curvature. This may clinically support the idea that scleral biomechanics play a critical role in the reversibility of cupping after IOP reduction. As raised by Lesk et al, younger age may contribute to the elastic scleral properties. Meanwhile, the negative correlation of rim parameters with IOP fluctuations may reflect the neural tissue strain and plasticity.