Systematic Reviews
Copyright ©The Author(s) 2024.
World J Crit Care Med. Sep 9, 2024; 13(3): 97205
Published online Sep 9, 2024. doi: 10.5492/wjccm.v13.i3.97205
Table 1 Basic characteristics of the studies on optic nerve sheath diameter in patients with non-traumatic increased intracranial pressure, n (%)
Study characteristic
Number of studies, n = 37
Year of publication
20131 (2.7)
20143 (8.1)
20155 (13.5)
20163 (8.1)
20174 (10.8)
20182 (5.4)
20194 (10.8)
20201 (2.7)
20213 (8.1)
20222 (5.4)
20237 (18.9)
20242 (5.4)
Country of origin
China8 (21.6)
India7 (18.9)
Turkey5 (13.5)
South Korea3 (8.1)
Iran2 (5.4)
Brazil2 (5.4)
Italy2 (5.4)
United States2 (5.4)
Uganda1 (2.7)
Spain1 (2.7)
Saudi Arabia1 (2.7)
Greece1 (2.7)
South Africa1 (2.7)
Germany1 (2.7)
Comparator parameter
Intraventricular ICP monitoring3 (8.1)
CSF opening pressure for lumbar puncture20 (54)
MRI/CT scans14 (37.8)
Type of study
Prospective observational study17 (45.9)
Prospective case control study12 (32.4)
Prospective cohort study4 (10.8)
Retrospective case study2 (5.4)
Case reports2 (5.4)
Table 2 Summary of studies on optic nerve sheath diameter in patients with non-traumatic raised intracranial pressure
Ref.
Country
Type of study
Number of participants
Patient characteristics
Comparator parameter and P value, r value
ONSD cut off, AUROC
Results
Limitations
Amini et al[7], 2013IranDescriptive prospective50Non-traumatic patients requiring lumbar punctureCSF pressure on LP, (P = 0.05; r = 0.88)5.5, NAThe ONSD of greater than 5.5 mm predicted an ICP of ≥ 20 cmH2O with sensitivity and specificity of 100% (95%CI: 100-100) (P = 0.001)Small sample size
Caffery et al[8], 2014United StatesProspective observational trial51Non-traumatic causes of raised ICPOpening pressure on LP, r = 0.53> 5.0 mm, 0.69Sensitivity 0.75, specificity of 0.44Use of a convenience sample could introduce bias. Sample size was small with large confidence intervals. One physician with specialized training, patients were not matched for demographic variables such as age or sex
Nabeta et al[9], 2014UgandaProspective descriptive study57HIV positive, ART naïve adults suspected with meningitisCSF opening pressure, P < 0.0015Sensitivity 86% and specificity 63% for predicting a CSF ICP > 200 mm PPV was 77% and NPV was 75%. Also, in ONSD > 5mm had a RR of 2.39 for IICP > 200 cmH2OInter-operator variability, with training being essential
Shirodkar et al[10], 2014IndiaProspective, observational case control study101, 60 study, 41 controlNon traumatic cause of increased ICPIncreased ICP on CT/MRI, P < 0.0014.71, 0.986Sensitivity of 77.8% and specificity of 100%Small size
Wang l et al[11], 2015ChinaProspective observational cohort study279Non-traumatic cause of increased ICPCSF opening pressure, P < 0.0014.1, 0.965Sensitivity of 95% and a specificity of 92%Average of 8 measurements of ONSD to decrease variability. May not be feasible practically
Du Toit et al[12], 2015South AfricaProspective observational study76MeningitisCSF opening pressure, Cohen’s kappa was 0.414.8, 0.73Sensitivity of 50% and specificity of 89.8% PPV of 54.8% and NPV of 88.3% PLR of 4.92 and NLR of 0.56The study was unable to establish inter-observer variability owing to the large number of operators and the small number of patients with increased ICP
Sangani et al[13], 2015IndiaProspective observational study25Tubercular meningitisCSF opening pressure, P < 0.001NAThose patients with TBME had a mean ONSD of 5.81 mmSmall sample size
Singleton et al[14], 2015United StatesCase report1Idiopathic ICHCSF opening and closing pressure which was 36 cm H2O and 19.5 cm H2O after removal of 19 cc of CSFNAPre-LP ONSD of left and right eye were 72 and 6.8 mm, respectively. Second study after 30 minutes left and right ONSD were 58 and 6.2 mm, respectively
Karzamni et al[15], 2015IranProspective case control study60, 30 cases and 30 controlsIntracranial SOL and ICHIncreased ICP on CT, P < 0.0014.53Sensitivity and specificity of 100%. ONSD was the most sensitive and specific parameter, followed by RI, PI and EDV. ONSD correlated significantly with GCS (r = −0.40, P = 0.003) and ventricular shift on CT images (r = 0.37, P = 0.02)Small size, lack of direct ICP measurement
Komut et al[16], 2016TurkeyProspective case control study100Nontraumatic intracranial event in EDIncreased ICP on CT, P < 0.055.3, 0.728Sensitivity 70%, specificity 74%Lack of direct ICP measurement
del Saz-Saucedo et al[17], 2016SpainProspective case control study30IIHCSF opening pressure, P = 0.0056.3 to predict CSF pressure of 25, 0.93Sensitivity 94.7%, specificity 90.9% and PLR of 10.4. After a therapeutic lumbar puncture an 87% of cases had a partial reduction of ONSD valuesSmall size
Salahudd et al[1], 2016Saudi ArabiaProspective cohort study102Non traumatic raised ICPIncreased ICP on CT, P < 0.0015.7, 0.785Sensitivity 84 % and specificity 71%. PLR = 2.89, NLR = 0.22Study did not include a detailed neurological exam or record any specific localizing neurologic signs, individual GCS
Jeon et al[18], 2017Korea
Prospective case control study62Nontraumatic cases requiring EVD placementOpening pressure on EVD insertion, P < 0.01> 5.6, 0.936Sensitivity of 93.75% and a specificity of 86.67% for identifying increased ICPTo reduce selection bias, patients with severely increased ICP which required emergency surgical decompression before ICP monitor insertion. Study reflects increased ICP due to moderate hematoma in a Korean population
Gökcen et al[19], 2017TurkeyRetrospective comparative study191Acute ischemic strokeRaised ICP on CT, P < 0.001Right ONSD 5.4, 0.941, Left ONSD 5.3, 0.922CVD subgroups were compared with the control group the highest ONSD was in TACI group and the lowest was in LACI group (P < 0.001)Unequal number of cases in the subgroups and adjustment of baseline charecteristics not mentioned
Wang et al[20], 2017ChinaProspective case control study316Nontraumatic increased ICP requiring LPCSF opening pressure, r = 0.758, P < 0.001NAXing and Wang mathematical equation for predicted ICP = −111.92 + 77.36 × ONSD (Durbin-Watson value = 1.94)Equation may underestimate the true ICP value in patients with extremely high ICP. The Bland-Altman analysis in this study suggested that any estimate might be deviate by as much as ± 80mmH2O
Liu et al[21], 2017ChinaProspective observational study110Non-traumatic increased ICP requiring LPCSF opening pressure, P < 0.0015.6, 0.861Sensitivity of 86.2% and specificity of 73.1%5%–15% of the cases were classified
Wang et al[22], 2018ChinaProspective case and control study60Nontraumatic causes of IICP requiring LPCSF opening pressure, P < 0.001. The ultrasonographic ONSD and ICP were measured on admission and follow-upNAONSD was strongly correlated with ICP (r = 0.702, P < 0.001)Small size, ONSD cut off not obtained
Canakci et al[24], 2018TurkeyProspective case control study100Non-traumatic headache presenting to ERRaised ICP on CT, P < 0.0015.5, NAONSD value in the ipsilateral side with the lesion was significantly higher than the contralateral side (P < 0.001). Discharge, clinical hospitalization, referral, ICU stay, emergency surgeryER based study including patients with nontraumatic headache not exclusively patients with clinical features of raised ICP. No AUROC calculated
Naldi et al[24], 2019ItalyProspective case control study46 cases, 40 controlsPrimary ICHIncreased ICP on CT, P < 0.015.6, 1.0Sensitivity 100%, Specificity 100%ICP was presumed to be normal in control, limited predictive value of abnormal CT findings. Second CT scan was performed not on a given day, but depending on clinical conditions
Gupta et al[25], 2019IndiaProspective observational study100Raised ICP requiring LPCSF opening pressure, P < 0.0016.3 to predict CSF pressure of > 20 cm of waterSensitivity 77.3%, specificity 92.3%, PLR = 10.05, NLR = 0.25Did not include any condition causing a mass effect, malignant infarcts, ICH or obstructive hydrocephalus
Gupta et al[26], 2019IndiaRetrospective case series study100Raised ICP requiring LPCSF opening pressure, P < 0.0014.8Sensitivity of 85% and specificity of 88%Single center, retrospective, small size
Wang et al[27], 2019ChinaCase reports2Venous sinus stenosis and venous sinus thrombosisCSF opening pressureNACase 1 A predicted ICP by ONSD was 346 mmH2O. and CSF opening pressure was 355 mmH2O. Case 2 ONSD was 5.95 mm with CSF opening pressure higher than 400 mmH2O
Zoerle et al[28], 2020ItalyProspective observational study20Aneurysmal SAH with EVDIntraventricular ICP, P > 0.05NAONSD measurements were accurate, very similar to the diameters measured by MRI (the mean difference in the Bland–Altman plot was 0.08 mm, 95% limits of agreement: −1.13; + 1.23 mm). No clear relationship was detectable between the ICP and ONSD, and a linear regression model showed an angular coefficient very close to 0 (P > 0.05). US-ONSD and ICP values were in agreement after CSF drainage and shifts in ICP in a limited number of patientsMeasured ICP in the ICU after the patients were stabilized, the aneurysm repaired, and large intracerebral hematomas surgically removed, with EVD and CSF drainage. As a consequence, the ICP values in our cohort were relatively low for the majority of cases
Sahu et al[29], 2021IndiaProspective, double blinded observational study30Nontraumatic increased ICPDirect intraventricular ICP, P = 0.015.5 to predict ICP > 20 mmHg, 0.904Sensitivity 100% and specificity 75%. The ONSD values predicting ICP at 25-, 30-, and 35-mm Hg were was 6.3 mm, 6.5 mm, and 6.7 mm, respectivelySmall number of patients having ICP > 30 mm of Hg, appropriate ONSD values could not be predicted
Yildiz et al[30], 2021TurkeyProspective, observational study82Acute ischaemic strokeIncreased ICP on CT, P < 0.05NAONSD on the 3rd day and 5th day was larger (> 5 mm) than on first day (P < 0.05). In the patients who received tPA right eye ONSD on the 5th day were significantly raised P < 0.05)ONSD only after the symptoms started, and were also not measured during the decline periods and response to treatment
Kim et al[31], 2021South KoreaProspective, observational study199Suspected raised ICPIncreased ICP on CT, P < 0.0015.3, 0.903Sensitivity of 75.4%, specificity of 90.8%, PPV of 76.8%, and NPV of 90.2%Single centre, 2 observers hence there can be variability
Qamar Akhtar et al[32], 2022IndiaProspective case control study100Non traumatic emergencies with suspected raised ICPRaised ICP on CT/MRI (P = 0.05; r = 0.88)≥ 6.3, 0.956Sensitivity of 100%, specificity of 89.2%, PPV of 83.3%, NPV of 100%, and diagnostic accuracy of 93% for detection of raised ICP by bedside USG ONSD measurement compared to CT/MRI brainCT or MRI brain scan which is an indirect indicator of raised ICP, and use of a high ONSD mean value (mm) cut-off
Oliveira et al[33], 2022BrazilProspective observational study40Malignant MCA infarct requiring decompressive craniotomyIncreased ICP on CT, P: NA5.4 mm, ROC for, Right eye: 0.82, Left eye: 0.77Post craniectomy, there was a decrease in the mean value of 1.04mm in the right eye 086 mm in left. (P = 0.003)Small size, CT unreliable for increased ICP. DC individualized is routinely adopted at this center, the neurosurgical team was allowed to perform surgery using individual interpretations of criteria, with controversial decisions on some patients
Roemer et al[34], 2022GermanyProspective observational study23Increased ICHCSF opening pressure, P = 0.9NANo correlation between CSF opening pressure and ONSD was foundSmall size, results could be biased by the ongoing treatment of the patients
Bhide et al[35], 2023IndiaProspective observational study114Non-traumatic causes of raised ICPIncreased ICP on CT/MRI, P < 0.0015.75, 0.844Sensitivity and specificity of 77.55% and 89.06%. PLR and NLR of 7.09 and 0.25Comparator used was CT or MRI brain scan which is an indirect indicator of raised ICP, and use of a high ONSD mean value (mm) cut-off
Yu et al[36], 2023ChinaProspective observational study107Non traumatic increased ICP requiring LPCSF opening pressure, P < 0.0016.3 mm73% sensitivity and 83% specificity, ODH with ONSD showed the highest value under the receiver operating characteristic curve of 0.965 with a sensitivity of 93% and a specificity of 92%Single lumbar puncture
Batur et al[37],
2023
TurkeyProspective case control study105Acute ischemic strokeFeatures of raised ICP on MRI (P < 0.001)5.05, 0.978Sensitivity 96.8%, specificity 95.6%. The cut-off for need for treatment 4.95 mm with AUC of 0.807 (sensitivity = 71.4%, specificity = 79.6%)Single-centered study. Although 30-day mortality rates were recorded, a detailed information about the outcome could be given by monitoring the neurological healing rate and time of the patients
Li et al[38], 2023ChinaProspective observational study56Suspected encephalitisCSF pressure, r = 0.769, P < 0.01NABoth ODH and ONSD had the ability to predict ICP (P < 0.05), but with time factors, ONSD displayed a stronger ability to predict ICP than ODHSingle-center design and small sample size. Cut-off value with AUROC not calculated
de Moraes et al[39], 2023BrazilProspective observation study18Acute stroke (ischemic and hemorrhagic)A 5-point visual scale for n raised ICP on CT and two parameters (time-to-peak and P2/P1 ratio) of a noninvasive ICP wave morphology monitor (r = 0.29)5.2, 0.69Sensitivity was 71.4%, the specificity was 70.4%, the PPV was 43.5%, and the NPV was 88.6%Small size, assessment intervals varied, Non blinded, correlation modest to moderate strengths
Cheng et al[40], 2023ChinaProspective cohort study223Non-traumatic causes of raised ICP requiring LPCSF opening pressure, P < 0.0015.47, 0.933ICP values were strongly correlated with ONSD, ONSD, and ONSD/ETD. ONSD and OND combined model predicted ICP = 139.394 × ONSD-112.428 × OND267.461 prediction accuracy was the highest. (ICC = 0.88)Underestimated the ICP in very high cases, the maximum limit of our ICP values was 330 mmH2O, and values greater than 330 mmH2O were counted as 330 mmH2O
Bakola et al[41], 2024GreeceProspective center case-control study31 case and 34 controlsIdiopathic ICHCSF opening pressure on LP, (r = 0.716, P < 0.001)5.15, 0.914Sensitivity and specificity of TOS for diagnosis of IIH were 85% (95%CI: 66%-95%) and 90% (95%CI: 76%-98%), respectively. PPV 83% (95%CI: 74%-96%), NPV 94% (95%CI: 83-98%)Subsequent measurements to estimate the potential treatment response using TOS were not part of our study protocol.
Kim et al[42], 2024KoreaRetrospective analysis of prospectively gathered data ONSD measurements were conducted using a handheld ultrasonography device during the course of endovascular treatment126Aneurysmal SAHCSF opening pressure on LP, (P < 0.001), the association between ONSD and ICP was validated through the application of a linear regression machine learning model. The correlation between ICP and various factors was explored through the modeling5.45, 0.90, SHAP 5.58Sensitivity 92.50, specificity 78.00, PPV 82.70 NPV 90.20Small size, single center
Table 3 Pertinent concerns regarding optic nerve sheath diameter measurement in medical intensive care unit

Related issues
How to measure ONSD?
(1)A scan or B scan? What is blooming effect?
(2)CLOSED protocol?
(3)Transverse or horizontal?
(4)How many values before obtaining a mean?
(5)ONSD or OND or ratio?
What is the body of evidence in various subset of patients?
(1)Acute ischemic stroke and CVST
(2)Acute hemorrhagic stroke
(3)Hydrocephalus
(4)Idiopathic intracranial hemorrhage
(5)Meningitis
(6)Septic metabolic encephalopathy
Can ONSD be used as a management tool?
Can ONSD be a reliable outcome measure?
(1)Post cardiac arrest
(2)Dysnatremia
Table 4 Differences between A scan and B scan on ultrasonography
A scan
B scan
Amplitude modulation scanBrightness modulation scan
8 mHertz frequency with small non focused probe10 mHertz with a larger focused probe
One-dimensional image of spikes of varying amplitudes along a baselineTwo-dimensional image
Provides quantitative information: Ex length of eyeball before surgery.Provides topographical information
Basis of ocular biometryEvaluation of ocular pathology
No blooming effectBlooming effect while measuring ONSD
Not available as bedside equipmentPart of point-of-care ultrasonography, easily available