Doppler ultrasonography imaging of hemodynamic alteration of retrobulbar circulation in type 1 diabetic children and adolescents without retinopathy

AIM

We aimed to investigate the retrobulbar blood circulation using Colour Doppler Imaging (CDI) in type 1 diabetic children and adolescents who had no diabetic retinopathy and to compare the results with their healthy peers.

METHODS

Forty-nine patients with type 1 diabetes mellitus with no retinopathy on fundoscopic examination were included in the study. Forty-nine healthy children were defined as the control group. Central retinal artery (CRA), ophthalmic artery (OA) and posterior ciliary artery (PCA) were examined with Doppler US bilaterally. Peak systolic velocity (PSV), end diastolic velocity (EDV) and resistive indices (RI) for each artery were recorded.

RESULTS

Blood flow velocity of the OA was significantly different in diabetic patients (p<0.05). EDV of the OA was significantly higher (p=0.011) and RI was significantly lower (p=0.027) in patients with diabetes duration of longer than 5 years. RI of the CRA was significantly higher in patients who had higher microalbuminuria levels (p=0.016).

CONCLUSION

EDV of the OA increases and RI of the OA decreases in diabetes duration longer 5 years. Raised AER increases RI of the CRA. These findings may be the initial changes in the arterial circulation before vascular rigidity develops.

Assessment of the spontaneous pulsations of the central retinal vein in daily ophthalmic practice

The purpose of this study is to assess the frequency of eyes with a spontaneous pulsation of the central retinal vein in the setting of a busy daily ophthalmic practice. The clinical observational case-series study included 690 eyes (345 subjects). The optic disc was ophthalmoscopically assessed using a non-contact ophthalmoscopic lens at the slit lamp. Out of the study population, 526 eyes (76.2%) of 265 (76.8%) subjects showed a detected spontaneous pulsation of the central retinal vein (prevalence rate: 76.2 +/- 1.6% [mean +/- standard error] per eye, and 76.8 +/- 2.3% per subject). In univariate analysis, the presence of a detected spontaneous central retinal vein pulsations was statistically associated with systolic systemic blood pressure (P = 0.04) and with the ocular perfusion pressure (P = 0.03). The results suggest that as examined in the setting of a busy daily ophthalmic practice, the central retinal vein was found to show a spontaneous pulsation in about 80% of the subjects.

Biomechanical Assessment of Radial Optic Neurotomy

PURPOSE

A biomechanical model was constructed to simulate the potential therapeutic effect that the surgical procedure radial optic neurotomy (RON) would have on an eye with a central retinal vein occlusion.

DESIGN

Experimental study.

CONTROLS

Model eyes undergoing RON were compared to control eyes under the same baseline conditions.

INTERVENTION

Radial optic neurotomy. We modeled the optic nerve, lamina cribrosa, and the sclera separately and then reassembled the components. Material properties of the sclera and lamina cribrosa were extracted from the literature and both stiff and more elastic values were used for the optic nerve. Intraocular and arterial pressures were varied across a wide range in the analysis.

MAIN OUTCOME MEASURE

Change in central retinal vein lumen size.

RESULTS

Over a clinically relevant range of boundary conditions, the increase in the lumen area of the central retinal vein lumen after RON remained trivial, ranging from 1% to a maximum of 5%.

CONCLUSIONS

The biomechanical effect of RON is negligible, and is unlikely to be a procedure that could mechanically ameliorate the clinical sequelae of a central vein occlusion.

The relationship of retinal vascular calibre to diabetes and retinopathy: the Australian Diabetes, Obesity and Lifestyle (AusDiab) study

AIMS/HYPOTHESIS

The aim of the study was to examine the relationship of retinal vascular calibre with glucose intolerance, diabetes and retinopathy in a population-based cohort.

METHODS

The Australian Diabetes, Obesity and Lifestyle study recruited adults aged > or =25 years old from across Australia. Participants were classified using an oral glucose tolerance test as having normal glucose tolerance (NGT), impaired glucose tolerance (IGT), impaired fasting glucose (IFG), known diabetes or newly diagnosed diabetes. Digital retinal photographs were taken of all participants with diabetes, IGT and IFG, and a sample of those with NGT, and graded for the presence of retinopathy. Retinal vascular calibre was measured from photographs by a computer-assisted method.

RESULTS

Of the 1,998 participants with gradable retinal images, 16% had known diabetes, 17% newly diagnosed diabetes, 42% IGT, 6% IFG and 19% NGT. After multivariable adjustment, retinal arteriolar calibre was significantly larger in people with known diabetes (178.9 microm) compared with participants with NGT (174.6 microm, p = 0.02), IGT/IFG (175.5 microm, p = 0.02) or newly diagnosed diabetes (175.6 microm, p = 0.047). One SD increase in mean arteriolar calibre was associated with higher odds of diabetes compared with NGT (odds ratio [OR] = 1.28, 95%CI = 1.06-1.55). After multivariable adjustment, each SD increase in venular calibre was associated with higher odds of having retinopathy in persons with IGT/IFG (OR = 1.78, 95%CI = 1.36-2.34) or in persons with diabetes (OR = 1.68, 95%CI = 1.23-2.29).

CONCLUSIONS/INTERPRETATION

Diabetes is associated with larger retinal arteriolar calibre and retinopathy with larger retinal venular calibre. The contrasting associations may reflect different underlying pathophysiological processes in the natural history of diabetes.

Functional and anatomical investigations in racemose haemangioma

PURPOSE

To determine the vascular morphology of racemose haemangioma and related functional alterations in arteriovenous (AV) malformation type 3.

METHODS

A 17-year-old patient with unilateral racemose haemangioma received a full ophthalmic examination including Snellen visual acuity (VA) and Goldmann visual field. The central vision was investigated by scanning laser ophthalmoscope (SLO) and multifocal electroretinogram (mfERG). The ocular haemodynamics were examined by fluorescence angiography and Doppler ultrasound. The tomographic contour of the vascular architecture was visualized using B-scan ultrasound, Stratus optical coherence tomography (OCT) and three-dimensional Heidelberg retina tomograph (3D-HRT II).

RESULTS

The VA of the patient's right eye was reduced to 20/400 and her visual field was constricted concentrically. Microperimetry revealed a small central field with good central fixation. The mfERG demonstrated reduced amplitudes of the central retina. On fluorescein angiography, there was a fast filling of the retinal branches related to the racemose vessels. Doppler ultrasound confirmed a significantly changed haemodynamic flow in the racemose vessels. Ultrasound, OCT and HRT demonstrated a prominent optic nerve head.

CONCLUSION

The racemose haemangioma led to a marked visual field defect. Racemose haemangiomas are associated with severe changes in the haemodynamics of the retinal vasculature.

Diagnostic accuracy of retinal abnormalities in predicting disease activity in MS

OBJECTIVES

To assess the association between the thickness of the retinal nerve fiber layer (RNFL), assessed by optical coherence tomography (OCT), retinal periphlebitis (RP), and multiple sclerosis (MS) disease activity.

METHODS

We studied a prospective cohort of 61 patients and 29 matched controls for 2 years, performing a neurologic assessment every 3 months and an ophthalmologic evaluation, including OCT scans, every 6 months. Baseline MRI studies were also carried out from which brain volume and lesion load were assessed.

RESULTS

We found that the RNFL thickness in patients with MS was thinner than in controls, particularly in the temporal quadrant (p = 0.004). Although RNFL atrophy was greater in patients who also had optic neuritis (p = 0.002), it also augmented in MS patients who did not have optic neuritis compared with controls (p = 0.014). RNFL atrophy was correlated with greater disability (r = -0.348, p = 0.001) and longer disease duration (r = -0.301, p = 0.003). Furthermore, baseline temporal quadrant RNFL atrophy was associated with the presence of new relapses and changes in the Expanded Disability Status Scale by the end of the study (p < 0.05 in all cases). Indeed, RNFL thickness was correlated with white matter volume (r = 0.291, p = 0.005) and gray matter volume (r = 0.239, p = 0.021). The presence of RP was a risk factor for having new relapses in the next 2 years (odds ratio = 1.52, p = 0.02), and patients with RP had larger gadolinium-enhancing lesions volume (p = 0.003).

CONCLUSION

Retinal nerve fiber layer atrophy and the presence of retinal periphlebitis are associated with disease activity, suggesting that retinal evaluation can be used as biomarkers of multiple sclerosis activity.

Long-term effects of radial optic neurotomy for central retinal vein occlusion consecutive interventional case series

PURPOSE

To investigate the long-term (minimum 24 months follow-up) clinical results of radial optic neurotomy (RON) following a pars plana vitrectomy (PPV) with internal limiting membrane peeling as treatment for central retinal vein occlusion (CRVO).

METHODS

Interventional case series of 14 consecutive patients (14 eyes) with CRVO who were treated with a PPV combined with RON within 1 year of diagnosis.

RESULTS

Median baseline visual acuity (VA) was 1.05 logMAR (approximately 0.09 Snellen) in the affected eye. The follow-up period ranged from 24 to 48 months postoperatively, median 30 months. At the 24-month follow-up examination, median VA was 1.005 logMAR in the affected eye-a significant improvement (p = 0.013). Six patients (43%) gained 1 or more lines of VA (mean VA gain = 1.7 lines), while the VA of four patients (29%) improved by 3 or more lines. The eyes with nonischemic CRVO demonstrated a significantly higher improvement in VA (p = 0.0007) than the eyes with ischemic CRVO.

CONCLUSION

With RON clinically relevant improvements on a long-term basis seem achievable. Patients with nonischemic CRVO may respond more favorably than patients with ischemic CRVO.

Retinal vein pulsation predicts increasing optic disc excavation

Spontaneous retinal vein pulsation in glaucoma

Altered Retrobulbar Hemodynamics in Patients Who Have Transient Monocular Blindness Without Carotid Stenosis

Background and Purpose— This study was to evaluate the retrobulbar hemodynamics in patients who have transient monocular blindness (TMB) without carotid stenosis.

Methods— Fifty-nine patients who have TMB without carotid stenosis were studied along with 59 age- and sex-matched controls. Color Doppler–imaging was used to study the retrobulbar hemodynamic by measuring the flow velocities (peak-systolic velocity, and end-diastolic velocity), vascular resistance indices (pulsatility index, and resistance index) in central retinal arteries, short posterior ciliary arteries, and ophthalmic arteries. The patients were divided into 2 groups according to the attack frequency: group 1 (occasional TMB, 2 or fewer attacks, 26 patients) and group 2 (frequent TMB, 3 or more attacks, 33 patients).

Results— The risk factors for atherosclerosis were similar between the cases and controls. The means of end-diastolic velocity were significantly lower in central retinal arteries and ophthalmic arteries, and the pulsatility index and resistance index were significantly higher in all the 3 retrobulbar vessels in TMB patients than for the controls. The differences between patients and controls were greater for the group-2 patients.

Conclusion— Patients who have TMB without carotid stenosis had altered retrobulbar hemodynamics with a generalized increase in vascular resistance in the retrobulbar arteries. The role of venous hypertension as an etiology needs further study.

Central retinal artery and vein collapse pressure in giant cell arteritis versus nonarteritic anterior ischaemic optic neuropathy

Arteritic anterior ischaemic optic neuropathy and nonarteritic anterior ischaemic optic neuropathy are acute optic neuropathies, which have to be differentiated from each other. It was the purpose of this study to assess whether ophthalmodynamometry with an assessment of the collapse pressure of the central retinal artery (CRA) and vein (CRV) is helpful for that. Using a Goldmann contact lens-associated ophthalmodynamometer, the diastolic collapse pressure of the CRA and CRV were measured in six patients (eight eyes) with giant cell arteritis-induced anterior ischaemic optic neuropathy (GC-AION) and in 10 patients (12 eyes) with acute non-arteritic anterior ischaemic optic neuropathy (NAION). CRA collapse pressure was significantly (P=0.001; 95% confidence interval (CI): -68.7, -20.0) lower in the GC-AION group (52.7+/-24.6 arbitrary units) than in the NAION group (97.0+/-25.8 arbitrary units). CRV collapse pressure did not vary significantly (P=0.47). As measured by ophthalmodynamometry, CRA pressure is significantly lower in GC-AION than in NAION. CRV pressure does not vary markedly. These finding may be helpful for the clinical differentiation between GC-AION and NAION, and may give hints for the pathogenesis.

Orbital color Doppler imaging in Behçet's disease with or without ocular involvement

PURPOSE

To investigate the value of color Doppler imaging (CDI) of orbital vasculature in the assessment of ocular involvement in patients with Behçet's disease (BD) without clinical ophthalmologic abnormalities.

METHODS

CDI of the orbital vessels were performed on 26 eyes of 13 patients who were diagnosed as having BD with ocular involvement (group 1), 65 eyes of 33 patients who had BD without ocular involvement (group 2) and 40 eyes of 20 healthy volunteers (group 3). Peak systolic (PSV) and end-diastolic (EDV) blood flow velocities and resistivity index (RI) measurements were obtained for the ophthalmic artery (OA) and central retinal artery (CRA). The mean velocity of the central retinal vein (CRV) was also measured.

RESULTS

For the OA, PSV and EDVs were significantly lower and RIs were significantly higher in group 2 than in control subjects. In group 1, only the EDVs of OA were significantly lower than in healthy subjects. For the CRA, PSV and EDVs were significantly lower, and RIs were significantly higher in both BD groups than those in group 3. When group 1 and group 2 were compared, the differences between PSV, EDV and RI measurements for the CRA and OA were statistically insignificant. There was no significant difference in blood flow velocity of the CRV between the three groups.

CONCLUSION

Major hemodynamic changes were observed in the ophthalmic vasculature of Behçet's patients with or without ocular involvement by CDI. CDI may detect ocular blood flow alterations before initial clinical manifestations.

[Transient increased retinal hemorrhage and the retinal venous blood flow change in the course of non-ischemic central retinal vein occlusion treated with an anticoagulant]

PURPOSE

To investigate transient increased retinal hemorrhage during anticoagulant therapy and changes in the retinal venous blood flow in the course of non-ischemic central retinal vein occlusion (CRVO).

METHODS

Seventeen patients(eighteen eyes) with non-ischemic CRVO were studied. The retinal vein diameter, blood velocity, and blood flow were determined by the laser Doppler method in seven patients.

RESULTS

The retinal hemorrhage increased in nine eyes (50%); however, the retinal hemorrhage was transient and it finally decreased without vision loss in seven of the eyes. The retinal hemorrhage increased in the other two eyes and they became ischemic. The vessel diameter decreased and both velocity and blood flow increased in six of the seven patients two weeks after the treatment. There was no significant change in blood flow in cases which showed a transient increase in retinal hemorrhage, and they did not show a decrease in vision; however, only one eye which became ischemic showed a decrease in blood flow.

CONCLUSION

We can judge whether an increase in retinal hemorrhage is transient or the clinical condition is getting worse in an early stage by measuring the retinal vein blood flow quantitatively by laser Doppler flowmetry.

MRI findings in isolated spontaneous thrombosis of the superior ophthalmic vein

We report the case of a 40-year-old woman with systemic lupus erythematosus who presented with spontaneous thrombosis of the superior ophthalmic vein resulting in permanent vision loss. The diagnosis was established by noncontrast CT scanning, gadolinium-enhanced MRI, and conventional catheter angiography.

Correlation between higher blood flow velocity in the central retinal vein than in the central retinal artery and severity of nonproliferative diabetic retinopathy

PURPOSE

To assess the correlation between a higher blood flow velocity in the central retinal vein (CRV) than in the central retinal artery (CRA) and the severity of nonproliferative diabetic retinopathy (non-PDR).

METHODS

We evaluated both eyes of 20 non-PDR patients with higher peak systolic velocity (PSV) in the CRV than in the CRA unilaterally as determined by color Doppler imaging (CDI). The eyes with higher PSV in the CRV were placed in group D2-H, and the fellow eyes were placed in group D2-L. The stage of non-PDR was determined by the guidelines of the Early Treatment Diabetic Retinopathy Study. Normal subjects and non-PDR patients without higher PSV in the CRV were evaluated as CDI controls.

RESULTS

Advanced non-PDR (P=0.001) and cystoid macular edema (P=0.02) were statistically more frequent in group D2-H. The velocities in the ophthalmic artery and the short posterior ciliary artery were not statistically different among all groups. The velocities in the CRA were similar in all non-PDR groups and significantly lower than in the normal subjects (P<0.05). The velocities in the CRV were significantly higher only in group D2-H (P<0.001).

CONCLUSION

Higher PSV in the CRV than in the CRA was significantly correlated with the severity of non-PDR, especially in the presence of cystoid macular edema.

[Pathogenesis and treatment of myopic foveoschisis]

Myopic foveoschisis (MF) can now be recognized as the result of recent progress in imaging diagnostic technology such as optical coherence tomography (OCT). MF predominantly occurs in highly myopic eyes with posterior staphyloma, and often induces visual loss and/or metamorphopsia. In order to better understand the detailed pathogenesis of MF, we observed 21 myopic eyes after vitrectomy using OCT. Retinal microfolds along the retinal vessels were observed in over 60% of the patients 6 months after surgery. Relative inflexibility of retinal arterioles/venules may be one of the causes for MF. We performed a pilot study (6 eyes of 5 patients) to treat MF by vitrectomy including vitreous cortex removal, internal limiting membrane peeling, and gas tamponade. In all 6 eyes the fovea was reattached and vision improved by more than two lines. This pilot study indicates that vitrectomy is an effective and safe treatment for MF.

Value of retinal vein pulsation characteristics in predicting increased optic disc excavation

BACKGROUND

Retinal vein pulsation is often absent in glaucoma, but can be induced by applying a graded ophthalmodynamometric force (ODF) to the eye, which is elevated in glaucoma.

AIM

To assess whether ODF has a predictive value in determining glaucoma progression.

METHODS

75 patients with glaucoma and suspected glaucoma were examined prospectively in 1996, and then re-examined at a mean of 82 months later. All subjects had intraocular pressure, visual fields, stereo optic disc photography and ODF measured on their initial visit. When venous pulsation was spontaneous, the ODF was said to be 0 g. At re-examination, central corneal thickness and blood pressure were also measured. Initial and subsequent optic disc photographs were compared and graded into those that had increased excavation and those that had remained stable. The relationship between increased excavation (recorded as a binary response) and the measured variables was modelled using a multiple mixed effects logistic regression.

RESULTS

ODF at the initial visit was strongly predictive of increased excavation (p = 0.004, odds ratio 1.16/g, range 0-60 g), with greater predictive value in women than in men (p = 0.004). Visual field mean deviation was predictive of increased excavation (p = 0.044), as was optic nerve haemorrhage in association with older age (p = 0.038). Central corneal thickness was not significantly predictive of increased excavation (p = 0.074) after having adjusted for other variables.

CONCLUSION

ODF measurement seems to be strongly predictive of the patient's risk for increased optic disc excavation. This suggests that ODF measurement may have predictive value in assessing the likelihood of glaucoma progression.

A "throttle" mechanism in the central retinal vein in the region of the lamina cribrosa

AIMS

To demonstrate a constriction in the central retinal vein in the region of the lamina cribrosa.

METHODS

A prospective comparative interventional study of 13 controls and 19 patients with central retinal vein occlusion (CRVO) using colour Doppler imaging of the central retinal artery and vein in the region of the lamina cribrosa and optic nerve posterior to the globe.

RESULTS

In controls peak velocities in the vein were higher in the region of the lamina cribrosa than the optic nerve, mean 175 mm/second (mm/s) and 49 mm/s respectively, p<0.0001. The velocities in the artery were also higher in the region of the lamina cribrosa, mean 122 mm/s and 92 mm/s, p = 0.007. The variability of the velocities in the region of the lamina cribrosa was 7.4% in the artery and 15.2% in the vein. The mean ratio of the velocities in the vein (4.2 (SD 2.1)) was significantly higher than the mean ratio in the artery (1.4 (SD 0.4), p<0.0001). In CRVO, the mean ratio in the vein was lower in the affected eyes (2.2 (SD 1.9), p<0.01) and fellow unaffected eyes (2.2 (SD 1.0), p = 0.003) than controls. The values were stable in eight after radial optic neurotomy.

CONCLUSION

The presence of a constriction of the vein in the region of the lamina cribrosa can be inferred from the presence of higher blood velocities at this site than further back in the optic nerve. In CRVO there may be a more uniform narrowing of the vein along its course in the nerve. Neurotomy did not affect the measurements.

Return of vision after transarterial coiling of a carotid cavernous sinus fistula: case report

BACKGROUND

Carotid cavernous sinus fistulae are abnormal communications between the carotid circulation and cavernous sinus that may arise spontaneously or develop after craniocerebral trauma. They may present with a constellation of signs and symptoms characteristic of raised cavernous sinus pressure, including orbital or retro-orbital pain, pulsatile proptosis, chemosis, ocular or cranial bruit, deterioration of visual acuity, or ophthalmoplegia. Visual loss is likely the result of multiple insults to the visual system, including reversal of venous drainage from the fistula, arterial flow into the superior ophthalmic vein, increased intraocular venous pressure, venous stasis retinopathy, and eventually ischemic optic neuropathy [Brodsky MC, Hoyt WF, Halbach VV, et al. Recovery from total monocular blindness after balloon embolization of carotid-cavernous fistula. Am J Ophthalmol 1987;104:86-87; Sanders MD, Hoyt WF. Hypoxic ocular sequelae of carotid-cavernous fistulae: study of the causes of visual failure before and after neurosurgical treatment in a series of 25 cases. Br J Ophthalmol 1969;53:82-97].

CASE DESCRIPTION

With few exceptions, the literature is replete with evidence of persistent blindness despite successful treatment of the CCF [Albuquerque FC, Heinz GW, McDougall CG. Reversal of blindness after transvenous embolization of a carotid-cavernous fistula: case report. Neurosurgery 2003;52:233-237; Brodsky MC, Hoyt WF, Halbach VV, et al. Recovery from total monocular blindness after balloon embolization of carotid-cavernous fistula. Am J Ophthalmol 1987;104:86-87; Weinstein JM, Rufenacht DA, Partington CR, et al. Delayed visual loss due to trauma of the internal carotid artery. Arch Neurol. 1991;48:490-497]. Here, we report a patient who experienced recovery of vision after endovascular obliteration of the offending CCF.

DISCUSSION

To our knowledge, this is the second reported case of recovery of visual function in a patient presenting with loss of light perception after treatment of a direct CCF.

Retrobulbar haemodynamics and morphometric optic disc analysis in primary open-angle glaucoma

BACKGROUND

Previous studies confirmed reduced retrobulbar haemodynamics in primary open-angle glaucoma (POAG).

AIM

To investigate a correlation between retrobulbar haemodynamics and morphometric neuroretinal rim analysis in patients with POAG.

METHODS

51 patients with POAG (mean (standard deviation (SD)) age 65 (11) years) were included in this clinical study. Blood flow velocities (peak systolic velocity (PSV) and end-diastolic velocity (EDV)) of the ophthalmic artery, central retinal artery (CRA), posterior ciliary arteries (PCA) and central retinal vein were measured using colour Doppler imaging (Siemens Sonoline Sienna, Erlangen, Germany). Optic disc morphometry was carried out using scanning laser tomography (Heidelberg Retinal Tomograph II Heidelberg Egineering Heidelberg, Germany). The stereometric parameters of the neuroretinal rim (rim area, rim volume, cup shape measure and retinal nerve fibre layer (RNFL) cross-sectional area) were used for analysis.

RESULTS

The PSV of the CRA was significantly (p<0.001) correlated with rim area (r = 0.50) and rim volume (r = 0.51). The minimum velocities of the central retinal vein were significantly (p<0.001) correlated with rim volume (r = 0.56) and RNFL cross-sectional area (r = 0.49). No correlations were found for the flow velocities of the ophthalmic artery and PCAs.

CONCLUSION

Retrobulbar haemodynamics of the central retinal artery and vein are correlated with the neuroretinal rim damage in POAG.

Regression of Alterations in Retinal Microcirculation Following Treatment for Arterial Hypertension

Evaluation of early hypertension-related alterations in retinal microcirculation has been subjective and poorly reproducible. The authors recently described a semiautomatic computerized system for evaluation of the calibre of retinal blood vessels that has shown very good reproducibility. In the study, this system was used to measure the calibres of retinal arterioles and veins, and their ratio, in a group of 51 hypertensive outpatients before and after 6 months of treatment with losartan or, if required for satisfactory blood pressure control, losartan plus hydrochlorothiazide. Mean retinal arteriole diameter increased from 0.0842 +/- 0.003 mm to 0.0847 +/- 0.003 mm (p = 0.001). Arteriovenous ratio increased from 0.753 +/- 0.03 to 0.756 +/- 0.03 (p = 0.005). This observation suggests regression of early hypertension-related alterations in retinal microcirculation after 6 months of antihypertensive treatment.

Early increase of retinal arterial and venous blood flow velocities at color Doppler imaging in brittle type 1 diabetes after islet transplant alone

Little information is currently available about the role of islet transplantation alone (ITA) on the retinal microcirculation. Our purpose was to investigate with color-Doppler-imaging the effect of ITA after one year on the blood flow velocities of central retinal artery and vein. Central retinal arteries and veins of both eyes of 10 ITA patients were evaluated with color-Doppler-imaging before and one year after transplant. Peak systolic velocity (psv), end diastolic velocity (edv) for arteries and maximum velocity (maxv), minimum velocity (minv) for veins were recorded and compared with a control group of type 1 diabetic patients. At one year, a statistically significant increase of blood flow velocities of central retinal arteries (psv: 6.09+/-0.46 vs. 10.12+/-1.20 cm/s, P=0.01) and veins (maxv: 3.12+/-0.28 vs. 6.12+/-1.00 cm/s, P=0.01) was found only in the ITA patients. An early, significant increase of arterial and venous retinal blood flow velocities was found after ITA.