Evaluation of the optic nerve and scleral-choroidal-retinal layer with ultrasound elastography in glaucoma and physiological optic nerve head cupping.

Aim: To evaluate the strain ratio of the optic nerve and retina-choroid-sclera (RCS) layers in individuals with physiological optic disc cupping (PC) and glaucoma patients using strain elastography.

Material And Methods: We evaluated 56 eyes of 56 subjects (20 eyes with glaucoma, 19 eyes with PC, and 17 normal eyes). The strain ratio of orbital fat to optic nerve (SROFON) was calculated as the ratio of the optic nerve to intraconal fat tissue and the strain ratio of orbital fat to retina-choroid-sclera (SROFRCS) was calculated as the ratio of RCS layers to intraconal fat tissue.

Results: SROFON was 0.92 in the control group, 1.07 in the PC group and 1.6 in the glaucoma group and a statistically significant difference was present between the three groups (p<0.05). SROFRCS had no statistically significant difference between the three groups.

Conclusions:  SROFON values could contribute to the differentiation of the patients with glaucoma and PC.