Ratio of optic nerve sheath diameter to eye ball transverse diameter in patients with raised ICP by ultrasonography: a correlational study

Measurement of ONSD has emerged as a popular tool for indirect assessment of intra cranial pressure. It has gained popularity as USG measurement of ONSD is a non- invasive, risk free, reproducible as well as point of care service. There has been multiple study with different value of ONSD suggested as cut off for increased ICP but there is no consensus among different studies. Recently a study was carried out to see, what are the different anthropometric and other variables which correlates best with ONSD in general population with no risk of increased ICP. This study correlated ONSD with sex, height, weight (head circumference and Eyeball Transverse Diameter (ETD). In their study they found that it is size of Eyeball Transverse Diameter (ETD) which correlated best with ONSD. They suggested in their final opinion that ONSD/ETD ratio might be more reliable than absolute value ONSD of as marker of raised ICP. So in this study we are planning to evaluate the correlation between ONSD/ETD ratio and direct ICP in patients coming for VP shunt surgeries.