In Vivo Evaluation of the Biomechanical Properties of Optic Nerve and Peripapillary Structures by Ultrasonic Shear Wave Elastography in Glaucoma

Abstract

BackgroundPrimary open-angle glaucoma is a multifactorial serious disease characterized by progressive retinal ganglion cell death and loss of visual field.ObjectivesThe purposes of this study were to investigate shear wave elastography (SWE) use in the evaluation of the optic nerve (ON) and peripapillary structures, and to compare the findings between glaucomatous and control eyes.Patients and MethodsA case-controlled study, including 21 patients with primary open-angle glaucoma and 21 age-matched control subjects, was carried out. All of the participants had comprehensive ophthalmological exams that included corneal biomechanical measurements with ocular response analyzer. In vivo evaluation of the biomechanical properties of the ON and peripapillary structures were performed with SWE in all participants. The Kolmogorov–Smirnov test was used to analyze the normal distribution of data. Differences of parameters in ophthalmologic data and stiffness values of patients with and without glaucoma were evaluated using the Mann-Whitney U test.ResultsThere were no statistically significant differences between the glaucoma and control groups in terms of age (P > 0.05) and gender (P > 0.05). Corneal hysteresis was lower in the glaucoma group (P < 0.05). Corneal compensated intraocular pressure and Goldmann correlated intraocular pressure were higher in the glaucoma group (P < 0.0001 for both). The mean stiffness of the ON and peripapillary structures were significantly higher in glaucoma patients for each measured region (P < 0.05).ConclusionThe study evaluated the biomechanical properties of the ON and peripapillary structures in vivo with SWE in glaucoma. We observed stiffer ON and peripapillary tissue in glaucomatous eyes, indicating that SWE claims new perspectives in the evaluation of ON and peripapillary structures in glaucoma disease.

Evaluation of the Optic Nerve by Strain and Shear Wave Elastography in Patients With Migraine

“…In addition, in a living rat model, Zha et al assessed the safety and feasibility of acoustic radiation force impulse elastography at a fixed high US pressure (MI of 1.6) and reported that it could be safely applied in human eyes. Recently, in the literature, elastographic studies have been performed for ocular and periocular tissues in human eyes, and there have been reported side effects . There were no changes in visual function before and after an SWE examination in the participants involved in the study.…”

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

“…However, we found only 3 studies in which elastography was used for the study of the optic nerve in glaucoma patients but none of these studies included subjects with PC [12,15,18]. Agladioglu et al compared the SROFRCS and optic disk/ optic nerve SR values obtained in glaucoma patients with a control group but found no statistically significant difference [18].…”

“…Agladioglu et al compared the SROFRCS and optic disk/ optic nerve SR values obtained in glaucoma patients with a control group but found no statistically significant difference [18]. Dikici et al detected higher elasticity values in the glaucoma group [12] and Unal et al found higher optic nerve elasticity values in the glaucoma group than the control group (in these two studies the Shear Wave Elastography [SWE] technique was used) [15]. We obtained similar results regarding the elasticity of the optic nerve in glaucomatous patients.…”

“…The basic limitation of this technique is the wide variability of the image and elasticity values as the pressure applied with the probe is examiner-dependent and not standard [11]. The sensitivity of SE vary between 57% and 92% [12,13].…”

“…The main problems in the SE evaluation of ocular structures are the possible influence of the small dimension and ocular fluid content. The semiquantitative nature of SE also creates difficulties [12,15]. Various studies have evaluated the ON using elastographic techniques in glaucoma, optic neuritis, and multiple sclerosis [12,[15][16][17][18].…”