Effect of Axial Length of the Globe on Retinal Nerve Fibre Thickness

the goal of this obsrevational study is to learn about retinal nerve fibres and if their numbers changed with axial length of the globe or not. the main question to answer is there is effect of long axial length on the thickness of the retinal nerve fibers participants will be asked to:measure the axial length with ultrasoundmeasure the thickness of retinal nerve fibers with optical coherence tomography

Inclusion Criteria:Healthy volunteers attending the outpatient clinic for surface ocular diseases.patients who are cooperative with optical coherence tomography (OCT) device.Exclusion Criteria:Glaucoma patients.Media opacity (corneal, lens or vitreous opacity)Previous ocular surgery.Diabetic patients.Retinal diseases.