Guidelines for ultrasound examination in ophthalmology. Part III: Color Doppler ultrasonography

The effect of phacoemulsification surgery on early stage retrobulbar blood flow in patients with pseudoexfoliation syndrome

PURPOSE

Evaluation of the effect of phacoemulsification surgery on retrobulbar blood flow in cataract patients with pseudoexfoliation syndrome (PES).

METHODS

The 104 eyes of 52 cataract patients with bilateral PES were included in the study. The preoperative and the postoperative first month peak systolic velocity (PSV), end-diastolic velocity (EDV), resistive index (RI), and pulsatility index (PI) values of the central retinal artery (CRA) and ophthalmic artery (OA) of the eyes that underwent surgery and the other eyes that did not were evaluated with color Doppler ultrasonography. While the preoperative and postoperative 1st month values of the operated eye were compared, postoperative 1st month values of the operated eye were compared with the other eye that did not undergo surgery.

RESULTS

PSV and EDV values of the CRA and OA were found to be statistically significantly lower in the postoperative period compared to the preoperative period in the operated eye (p = 0.05, p = 0.017, p < 0.001, p = 0.003, respectively). When the operated and non-operated eyes were compared, the CRA PSV value was statistically significantly lower in the operated eye while no statistically significant change was observed between the groups in terms of the CRA EDV and OA PSV and EDV values (p = 0.043, p = 0.153, p = 0.091, p = 0.264, respectively). No difference was present between the groups in terms of RI and PI values of the CRA and OA (p > 0.05).

CONCLUSION

Phacoemulsification surgery causes a decrease in retrobulbar blood flow in the early postoperative period in cataract patients with PES.

Association Between Breast Arterial Calcification on Mammography and Impaired Ocular Perfusion: A Novel Study Using Color Doppler Ultrasonography

OBJECTIVES

To investigate the relationship between the mammography-detected breast arterial calcification (BAC) and orbital color Doppler ultrasonography (CDUS) results.

METHODS

Our single-center study, included female patients who applied to our hospital between January and May 2022 and underwent mammography and orbital CDUS examinations. Two radiologists evaluated the mammograms, grouped the patients as BAC (+) and BAC (-), and performed orbital CDUS. Continuous variables obtained from CDUS were compared according to the presence of BAC. Also, receiver operating characteristics (ROC) analysis was used to determine the orbital CDUS threshold values for the presence of BAC.

RESULTS

A total of 119 women were included with a median age of 62 years, 57 (47.90%) had BAC. Orbital CDUS examination was performed on both eyes of 119 patients (238 eyes in total). Peak systolic velocity (PSV) and end-diastolic velocity (EDV) values of the ophthalmic artery (OA) (P < .001) and EDV of the central retinal artery (CRA) (P < .001) were significantly lower in patients with BAC. Pulsatile index (PI) and resistive index (RI) values of OA (P < .001) and CRA (P < .001) were higher in patients with BAC. In ROC analysis, the cut-off values for the presence of BAC were calculated as OA PI ≥1.415 and OA RI ≥0.755 (P < .001); CRA PI ≥1.135 and CRA RI ≥0.655 (P < .001).

CONCLUSIONS

Orbital perfusion disorders may be observed in patients with vascular calcification detected on routine mammography. Therefore, a more detailed evaluation of patients with BAC detected on mammography with orbital CDUS may enable early detection and treatment of ocular vascular problems.

Comparing Intraocular Pressure, Ocular Blood Flow, and Retinal Nerve Fiber Layer Thickness in Early and Chronic Hypertensives With Normotensives

PURPOSE

To compare blood pressure (BP), intraocular pressure (IOP), ophthalmic artery flow (OAF) velocity, retinal nerve fiber layer (RNFL) thickness, and visual fields in newly diagnosed hypertension (HT) patients (before treatment), chronic HT (on antihypertensive medications >5 years) and normotensives.

METHODS

A prospective, cross-sectional study at a tertiary care centre in India. Three groups of 45 patients each: group 1 - early HT, group 2 - chronic HT, and Group 3 - normotensives, underwent evaluation of BP, IOP by Goldmann applanation tonometry (GAT), OAF velocity by transcranial doppler (TCD), RNFL analysis by spectral-domain optical coherence tomography (SD-OCT), and visual fields.

RESULTS

The BP was highest in early HT > chronic HT > normotensives (p < 0.001). The IOP of early HT, chronic HT, and normotensives were 15.87 ± 2.19 mmHg, 13.47 ± 1.92 mmHg, and 15.67 ± SD 1.75 mmHg (p < 0.001). The OAF velocity [peak systolic velocity (PSV), end-diastolic velocity (EDV) in cm/sec] was lowest in chronic HT (30.80 ± 7.05, 8.58 ± 1.58) < early HT (35.47 ± 5.34, 10.02 ± 1.74) < normotensives (36.29 ± 4.43, 10.44 ± 2.29), (p < 0.001). The average RNFL thickness was significantly lower in chronic HT (p = 0.022). The PSV, EDV, and MFV showed significant correlation with IOP (r = 0.247, p = 0.004; r = 0.206, p = 0.016; r = 0.266, p = 0.002) and average RNFL thickness (r = 0.309, p= <0.001; r = 0.277, p = 0.001; r = 0.341, p < 0.001).

CONCLUSIONS

Patients with chronic HT demonstrated the lowest retrobulbar flows, IOP and lower RNFL measurements. Lower ocular perfusion may be associated with lower IOP and may be a risk factor for end-organ damage (RNFL) independent of IOP.

The effect of polycythemia vera on choroidal thickness and retrobulbar blood flow

BACKGROUND

To evaluate the choroidal thickness and retrobulbar hemodynamic parameters in polycythemia vera (PV) patients in comparison with healthy individuals, and to investigate the relationship of these values with blood hematocrit levels.

METHODS

This prospective study included the 35 eyes of 35 PV patients and the 30 eyes of 30 healthy individuals. Choroidal thickness was measured at the subfoveal area and at 500 µm intervals nasal and temporal to the fovea up to a distance of 1500 µm. Color Doppler ultrasonography (CDU) was used to evaluate the retrobulbar vessels. Complete blood count values were recorded.

RESULTS

Choroidal thickness was found to be significantly lower in the PV group than in the control group at the subfoveal, nasal 500, and temporal 500 and 1000 µm measurement points (p = 0.01, p = 0.011, p = 0.04, p = 0.045, respectively). The central retinal artery (CRA) peak systolic velocity (PSV) and end diastolic velocity (EDV) values and the ophthalmic artery (OA) PSV value were significantly lower in the PV group than in the control group (p < 0.001, p < 0.001, p = 0.019, respectively). No significant difference was present between the groups in terms of CRA and OA resistive index (RI) and pulsatile index (PI) values (p = 0.388, p = 0.564, p = 0.897, p = 0.693, respectively). A negative correlation was found between the blood hematocrit levels and the subfoveal, nasal 500 µm, and temporal 500 µm choroidal thickness measurements and the CRA PSV and EDV and the OA PSV values.

CONCLUSIONS

PV may cause microvascular changes and lead to ocular vascular complications by affecting the choroidal and retrobulbar blood flow.

Monocular Painless Vision Loss in the Emergency Department: Multipurpose Utility of Point-of-Care Ultrasound

BACKGROUND

Eye-related symptoms are a common presentation in the emergency department (ED). The cases range from simple viral conjunctivitis to trauma-related eye injuries. One pathological condition that could lead to vision loss is retinal artery occlusion (RAO). Evaluating a patient with an eye symptom requires thorough eye examination and advanced imaging in certain instances. Consultation with an ophthalmologist is also necessary for cases that require treatment recommendations and further testing. In the ED, point-of-care ultrasound (POCUS) is a commonly used diagnostic tool that can be used for ocular examination.

CASE REPORT

We reported a case of a 60-year-old man who presented with painless partial right-eye vision loss. POCUS showed decreased flow in the right central retinal artery with an area of the pale retina seen on the image from the retinal camera, suggesting a possible branch RAO. Further examination with POCUS showed plaque formation at the carotid bifurcation, a potential cause of the patient's symptoms. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: Emergency physicians and other providers should be encouraged to use POCUS to diagnose eye symptoms accurately and promptly. Abnormal findings will prompt immediate specialty consult and early appropriate management. Our case and other reported cases highlight POCUS's reliability and rapid diagnostic ability.

Glaucoma Surgery and Ocular Blood Flow in Colour Doppler Imaging: Is There a Link?

Glaucoma is a common cause of blindness worldwide. This disease is characterised by increased intraocular pressure (IOP) and the concomitant disruption of ocular haemodynamic. Several studies have demonstrated that trabeculectomy is associated with changes in extraocular blood flow. In this study, we reviewed the available evidence on the use of colour Doppler imaging to evaluate and manage patients with open-angle glaucoma. We present the detailed anatomy of ocular blood flow to provide a background for the research findings. We also discuss the physiological foundations of ocular blood flow and detailed flow characteristics of specific extraocular vessels. Finally, we reviewed published studies that analysed the effects of glaucoma surgery on the blood flow parameters of the eye.

Ultrasound in ocular oncology: Technical advances, clinical applications, and limitations

Due to its accessibility and ability for real-time image acquisition of ocular structures, ultrasound has high utility in the visualization of the eye, especially in ocular oncology. In this minireview, we summarize the technical rationale and applications of ultrasound modalities, A-scan, B-scan, high-frequency ultrasound biomicroscopy (UBM), and Doppler measurement. A-scan ultrasound uses a transducer of 7-11 MHz, making it useful for determining the echogenicity of ocular tumors (7-8 MHz) and measuring the axial length of the eye (10-11 MHz). B-scan ultrasound operates at 10-20 MHz, which can be used for measuring posterior ocular tumors while UBM operates at 40-100 MHz to evaluate anterior ocular structures. Doppler ultrasonography allows for the detection of tumor vascularization. While ultrasonography has numerous clinical applications due to its favorable penetration compared with optical coherence tomography, it is still limited by its relatively lower resolution. Ultrasound also requires an experienced sonographer due to the need for accurate probe localization to areas of interest.

Early Effects of Inactivated (CoronaVac) SARS-CoV-2 Vaccine on Retrobulbar Vascular Blood Flow and Retinal Vascular Density

AIMS

We aimed to investigate the early effects of inactivated SARS-CoV-2 vaccine on retrobulbar vascular blood flow and retinal vascular density in healthy subjects.

METHODS

Thirty-four eyes of 34 healthy volunteers who received the CoronaVac (Sinovac Life Sciences, China) were included in this prospective study. Resistive index (RI), pulsatility index (PI) and peak systolic velocity (PSV) of the ophthalmic artery (OA), central retinal artery (CRA), and the temporal and nasal posterior ciliary arteries (PCA) were evaluated with color Doppler ultrasonography (CDUS) before vaccination, at the 2^nd and 4^th weeks after vaccination. Superficial capillary plexus (SCP) and deep capillary plexus (DCP) vessel density (VD), foveal avascular zone (FAZ), and choriocapillaris blood flow (CCF) measurements were made using optical coherence tomography angiography (OCTA).

RESULTS

When compared to the pre-vaccination values, there was no significant change in OA-PSV, temporal-nasal PCA-PSV, CRA-EDV, temporal-nasal PCA-EDV at 2^nd and 4^th weeks after vaccination. However statistically significant reductions were found in the OA-RI, OA-PI, CRA-RI, CRA-PI, temporal-nasal PCA-RI, temporal-nasal PCA-PI values, CRA-PSV at post-vaccination 2^nd week (p<0.05 for all). While there was sustained reduction in OA-RI, OA-PI, CRA-PSV, and nasal PCA-RI values at 4^th week after vaccination, the change in CRA-RI, CRA-PI, temporal PCA-RI, temporal-nasal PCA-PI values were not significant compared to pre-vaccination values. There was no statistically significant difference in the SCP-VD, DCP-VD, FAZ and CCF measurements.

CONCLUSIONS

Our findings demonstrating that CoronaVac vaccine did not affect retinal vascular density in the early period, but it caused alterations in the retrobulbar blood flow.

Microbubbles for human diagnosis and therapy

Microbubbles (MBs) were observed for the first time in vivo as a curious consequence of quick saline injection during ultrasound (US) imaging of the aortic root, more than 50 years ago. From this serendipitous event, MBs are now widely used as contrast enhancers for US imaging. Their intrinsic properties described in this review, allow a multitude of designs, from shell to gas composition but also from grafting targeting agents to drug payload encapsulation. Indeed, the versatile MBs are deeply studied for their dual potential in imaging and therapy. As presented in this paper, new generations of MBs now opens perspectives for targeted molecular imaging along with the development of new US imaging systems. This review also presents an overview of the different therapeutic strategies with US and MBs for cancer, cardiovascular diseases, and inflammation. The overall aim is to overlap those fields in order to find similarities in the MBs application for treatment enhancement associated with US. To conclude, this review explores the new scales of MBs technologies with nanobubbles development, and along concurrent advances in the US imaging field. This review ends by discussing perspectives for the booming future uses of MBs.

The Role of Color Doppler Imaging in the Diagnosis of Glaucoma: A Review of the Literature

Glaucoma is a progressive optic neuropathy and one of the leading causes of irreversible blindness worldwide. Elevated intraocular pressure (IOP) is the major risk factor for the onset and progression of glaucoma. In addition to elevated IOP, impaired intraocular blood flow is also considered to be involved in the pathogenesis of glaucoma. Various techniques have been used to assess ocular blood flow (OBF), including Color Doppler Imaging (CDI), a technique used in ophthalmology in recent decades. This article reviews the role of CDI in both the diagnosis and effective monitoring of glaucoma progression, presenting the protocol for imaging and its advantages, as well as the limitations of its use. Moreover, it analyzes the pathophysiology of glaucoma, focusing on vascular theory and its role in the onset and progression of the disease.

Correlation between retinal oxygen saturation and the haemodynamic parameters of the ophthalmic artery in healthy subjects

PURPOSE

The aim of the study was to obtain the values of oxygen saturation in retinal vessels and ophthalmic blood flow parameters in a healthy Caucasian population and assess whether the oximetry parameters are affected by the flow rate or the vascular resistance.

METHODS

The spectrophotometric retinal oximetry and colour Doppler imaging (CDI) of retinal vessels were successfully performed with 52 healthy subjects (average age 29.7 ± 5.6 years). The retinal oximeter simultaneously measures the wavelength difference of haemoglobin oxygen saturation in retinal arterioles and venules. The arteriolar and venular saturation in both eyes was measured. The peak systolic (PSV) end diastolic (EDV) velocities, resistive (RI) and pulsatility (PI) indices were obtained for both eyes using CDI in the ophthalmic artery. A paired t-test and two sample t-tests were used for statistical analyses. The correlation was assessed using the Pearson coefficient correlation.

RESULTS

The mean oxygen saturation level was 96.9 ± 3.0% for the retinal arterioles and 65.0 ± 5.1% for the retinal venules. The A-V difference was 31.8 ± 4.6%. The mean of the measured haemodynamic parameters was PSV 46.6 ± 9.4 cm/s, EDV 12.0 ± 3.5 cm/s, PI 1.68 ± 0.38 and RI 0.74 ± 0.05. No significant difference in oxygen saturation and haemodynamic parameters was found between the left and the right eyes or the dominant and non-dominant eye. The oximetry and ultrasound values were sex independent. The Pearson correlation coefficient demonstrated a significant yet weak negative correlation between A-V difference and RI (r = -0.321, p = 0.020).

CONCLUSIONS

A negative correlation between A-V difference and resistance index was observed, suggesting that reduced oxygen consumption may reflect the increased vascular tone of the ophthalmic vessels, which is likely determined by autoregulatory mechanisms.

Correlation of Measurements From Doppler Ultrasound and Optical Coherence Tomography in Glaucoma

OBJECTIVES

To relate the changes in ocular structure and hemodynamic response in primary open-angle glaucoma (POAG).

METHODS

Patients with POAG (n = 46) and control subjects (n = 53) were recruited. Retinal nerve fiber layer and ganglion cell complex were evaluated using optical coherence tomography (OCT). Blood flow was characterized in ophthalmic artery (OA) and central retinal artery (CRA) using color Doppler ultrasonography (CDU), and resistivity index (RI) was calculated. Measurements from CDU and OCT were statistically correlated and the degree of the association was examined. Receiver operating characteristics was produced based on RI and optimal threshold was determined.

RESULTS

In POAG patients, OCT revealed neuronal damage and CDU indicated increased resistance to arterial flow. Flow dynamics correlated negatively with the ocular tissue dimensions, sufficiently establishing an association between the ocular structure and its hemodynamic response. Based on the possibility of indirect POAG diagnosis with CDU, threshold 0.7 for RI of OA yielded 73.9% sensitivity and 77.4% specificity in distinguishing the cases of POAG from the controls. Threshold of 0.66 for RI of CRA, had higher specificity of 83%, but lower sensitivity of 52.1%.

CONCLUSIONS

Ocular flow exhibits different characteristics in individuals with POAG than normal. The changes associated with the underlying neuronal structure, suggesting the possibility of a potential new diagnostic biomarker for POAG. This justifies further studies with a larger cohort, examining the ocular flow with CDU in POAG and comparing it against OCT findings for establishing the power of CDU in differential diagnosis or glaucoma progression.

Assessment of optic nerve vascularity in healthy eyes using superb microvascular imaging: a preliminary study

BACKGROUND

Changes in optic nerve vascularity are observed in many diseases. Superb microvascular imaging (SMI) has the potential to become the method of choice for detecting microvasculature in the optic nerves.

PURPOSE

To evaluate optic nerve vascularity in healthy individuals through power Doppler sonography (PDUS) and SMI.

MATERIAL AND METHODS

Twenty-seven healthy patients with 54 eyes were prospectively evaluated. The duration of the examination for optic nerve vascularity lasted until the posterior ciliary artery blood supply was observed in PDUS and SMI. The visibility of vascularity, as well as the ratio of the vascular structures to the optic nerves (vascular index [VI]), was evaluated.

RESULTS

Fifty-four eyes were evaluated from a total of 27 patients (mean age = 49.0 ± 19.42 years). The VI value for the right optic nerve was 29.58 ± 4.00 while for the left optic nerve, it was 31.21 ± 3.52. Vascularity was clearly observed in both eyes (n = 54) in all 27 cases in the evaluation performed with the SMI technique. However, with the power Doppler examination, vascular flow was not observed in 14 right eyes and in 10 left eyes within the specified timeframe.

CONCLUSION

The results indicate that imaging of vascular structures can be done faster and better with SMI than PDUS examination. The normal VI values may provide important information about the blood supply of the optic nerve, which is of relevance in orbital pathologies and many systemic conditions.

Retrobulbar Short Posterior Ciliary Artery Hemodynamics in Patients with Pseudoexfoliation Glaucoma and Primary Open-Angle Glaucoma

Purpose

To investigate retrobulbar blood flow changes in the short posterior ciliary arteries (SPCAs) in patients with pseudoexfoliation glaucoma (PEG) and primary open-angle glaucoma (POAG).

Methods

In this prospective study, there were 22 eyes in the PEG group, 28 eyes in the POAG group, and 28 eyes with senile cataract in the control group. Peak systolic velocity (PSV), end-diastolic velocity (EDV), mean velocity (Vm), and resistivity index (RI) parameters of the temporal and nasal SPCAs were compared between the study groups.

Results

Mean temporal PSV, EDV, and Vm value were significantly lower in both the POAG group and the PEG group (P = 0.049, P = 0.004, P = 0.020), respectively. Temporal SPCA RI values were not significantly different between the groups (P = 0.115).

Conclusion

There are retrobulbar blood flow changes in glaucomatous compared to nonglaucomatous eyes. However, SPCAs blood flow characteristics are similar between PEG and POAG subtypes.

The diagnostic value of high-frequency ultrasound combined with color Doppler ultrasound versus surgical pathology in gallbladder polyps

OBJECTIVE

This study aimed to analyze the value of high-frequency ultrasound combined with color Doppler ultrasound in the diagnosis of gallbladder polyps.

METHODS

A retrospective analysis was performed on 108 patients with gallbladder polyps, all of whom were examined by high-frequency ultrasound and color Doppler ultrasound with surgical or pathological findings as the gold standard.

RESULTS

Taking surgical pathology findings as the gold standard, the diagnostic accuracy, sensitivity and specificity of high-frequency ultrasound for gallbladder polyps were 63.89%, 63.27%, and 70.00%, respectively. The diagnostic accuracy, sensitivity and specificity of color Doppler ultrasound were 74.07%, 73.47%, and 80.00%, respectively. The diagnostic accuracy, sensitivity and specificity of high-frequency ultrasound combined with color Doppler ultrasound were 91.67%, 90.82%, and 100.00%, respectively. The proportion of mulberry-like or papillary projections was 56.18% in 89 benign lesions diagnosed by high-frequency ultrasound combined with color Doppler ultrasound, the proportion of hyperechoic lesion was 47.19%, and the proportion of single lesion was 59.55%. The incidence rate of blood flow signal was 26.97% in 89 benign lesions, including 10 cases of punctiform blood flow signal, 9 cases of band-like blood flow signal and 5 cases of multiple stones in the lumen of the gallbladder.

CONCLUSION

High-frequency ultrasound combined with color Doppler ultrasound has high accuracy in the diagnosis of gallbladder polyps, and can yield better diagnostic results than either method, which can be used as an optional method for the diagnosis of gallbladder polyps.

Ocular Blood Flow in Preterm Neonates: A Preliminary Report

Purpose

Retinopathy of prematurity (ROP) is a vision-threatening complication occurring in pre-term neonates. The standard of care entails regular monitoring by dilated ophthalmoscopy examinations, which entail stress and potential morbidity. In this pilot study, we used plane-wave ultrasound (PWUS) to image, measure, and assess the association of blood-flow velocities in the retrobulbar vessels with ROP stages ranging from stage 0 (immature vessels without ROP) to stage 3.

Methods

Both eyes of 14 preterm neonates at risk for ROP were examined by 18 MHz PWUS. All but two subjects had a follow-up examination. PWUS was acquired for 1.5 seconds at 3000 compound B-scans/sec. Data were postprocessed to form color-flow images and spectrograms depicting flow velocity in the central retinal artery (CRA), central retinal vein (CRV), and the short posterior ciliary arteries (SPCA). Flow parameters derived from spectrograms were compared by ROP stage.

Results

ROP stage was found to correlate with flow velocities. Velocities were significantly elevated with respect to non-ROP eyes in all vessels at stage 3 and in the SPCAs at stage 2.

Conclusions

PWUS measurement of blood flow may provide a quantitative, clinically important, and easily tolerated means for detecting and assessing the risk of ROP in preterm neonates. We speculate that the observed increase in flow velocity results from elevated vascular endothelial growth factor (VEGF) in ROP eyes.

Translational Relevance

PWUS offers a gentle, nonmydriatic method for monitoring neonates at risk for ROP that would complement ophthalmoscopy.

Non-invasive detection of intracranial pressure related to the optic nerve

Intracranial pressure (ICP) is associated with a variety of diseases. Early diagnosis and the timely intervention of elevated ICP are effective means to clinically reduce the morbidity and mortality of some diseases. The detection and judgment of reduced ICP are beneficial to glaucoma doctor and neuro ophthalmologist to diagnose optic nerve disease earlier. It is important to evaluate and monitor ICP clinically. Although invasive ICP detection is the gold standard, it can have complications. Most non-invasive ICP tests are related to the optic nerve and surrounding tissues due to their anatomical characteristics. Ultrasound, magnetic resonance imaging, transcranial Doppler, papilledema on optical coherence tomography, visual evoked potential, ophthalmodynamometry, the assessment of spontaneous retinal venous pulsations, and eye-tracking have potential for application. Although none of these methods can completely replace invasive technology; however, its repeatable, low risk, high accuracy, gradually attracted people's attention. This review summarizes the non-invasive ICP detection methods related to the optic nerve and the role of the diagnosis and prognosis of neurological disorders and glaucoma. We discuss the advantages and challenges and predict possible areas of development in the future.

Comparison of the Doppler Indices in the Ophthalmic Artery and Central Retinal Artery in Diabetic and Nondiabetic Individuals

Objective:

Diabetes can lead to diabetic retinopathy, which damages the retina due to blood flow remodeling of occular vessels. Early stages of diabetic retinopathy may not present with patient symptoms. Doppler indices, of the ophthalmic arteries, could help in determining the effect of diabetic vascular remodeling. This research was designed to compare the Doppler indices, in the ophthalmic artery and central retinal artery, in both diabetic and nondiabetic patients.

Materials and Methods:

This was a cross-sectional observational study of 72 total patients. Sonography was performed on the ophthalmic arteries of 36 diabetics and 36 nondiabetics, to compare Doppler indices. All patients were voluntarily consented to this research that was approved by the university’s Institutional Review Board (IRB). Doppler parameters recorded were peak systolic velocity, end dystopic velocity, resistive index, and pulsatility index, which were taken in both patient groups and compared.

Results:

A significant difference was noted in the ophthalmic artery peak systolic velocity, end-diastolic velocity, pulsatility index, and resistive index for diabetic and nondiabetic individuals, with a statistically significant set at .01.

Conclusions:

There was a significant difference between diabetic and nondiabetic ophthalmic Doppler indices in this cohort of patients. This cohort demonstrated vascular remodeling of the ophthalmic arteries, caused by diabetes; therefore, blood flow resistance was increased due to diabetes.

Utility of Doppler ultrasound for the study of ocular vascular disease

Ocular vascular problems represent an emerging pathology within the activity of the internist. Ocular ultrasound is a widely used technique to evaluate a variety of eye conditions. Specifically, Doppler ultrasound of the ophthalmic vessels has become a very useful tool in diagnosing various eye diseases. Doppler ultrasound allows for examining blood flow in the eye even in the presence of eye opacities that impede viewing the posterior segment of the eye. In this review, we describe the principles and techniques of an ocular vascular Doppler ultrasound examination in clinical practice and provide a general approach to the ultrasound characteristics of the most important vascular eye disorders for internists. These include central retinal artery and vein occlusions, chronic retinal ischemic syndrome, anterior optic ischemic neuropathy, and diabetic retinopathy.