Correlation of Ductoscopic and Histopathological Findings and Their Relevance as Predictors for Malignancy: A German Multicenter Study

BACKGROUND/AIM

The study aimed at investigating the correlation between ductoscopic and histopathological findings and clarify whether the former allow for accurate prediction of malignancy.

PATIENTS AND METHODS

The prospective national multi-center study covered a sample of 224 patients with pathologic nipple discharge. A total of 214 patients underwent ductoscopy with subsequent extirpation of the mammary duct. The ductoscopic findings were categorized according to shape, number, color and surface structure of lesions and vascularity and compared to the histological results and analyses.

RESULTS

Ductoscopy revealed lesions in 134 of 214 patients (62.2%). The criteria "multiple versus solitary lesion" differed significantly between malignant and benign lesions. All other criteria were not statistically significant. Malignant tumors were more frequently presented as multiple lesions, benign lesions or masses as solitary lesions (80% vs. 24.8%; p=0.018).

CONCLUSION

The ductoscopic criterion "solitary vs. multiple lesion" appears to have a low diagnostic prediction of malignancy or benignity.

Nipple discharge: role of ductoscopy in comparison with standard diagnostic tests

BACKGROUND

This study aims to assess the role of ductoscopy for detecting intraductal anomalies in patients with nipple discharge in comparison to conventional tests and to find an effective combination of both approaches.

MATERIALS AND METHODS

Prior to duct excision, ductoscopy was performed in 97 women. Histologic and all other diagnostic results were compared. Sensitivity, specificity, and efficiency were calculated for all methods. These parameters were also calculated for all possible test combinations in 12 patients who had completed all tests.

RESULTS

Breast sonography reached the highest sensitivity (64.1%) and efficiency (64%); mammography had the highest specificity (100%). The sensitivity of ductoscopy was 53.2%, its specificity 60%, and its efficiency 55.1%. Among combinations of all methods, the combination ductoscopy + galactography was the most sensitive (80%). Mammography, magnetic resonance imaging, and ductoscopy were each 100% specific. Ductoscopy was the most efficient (75%) single method.

CONCLUSION

Ductoscopy is a valuable test for diagnosing intraductal lesions in patients with nipple discharge. It is more efficient than conventional tests in patients undergoing all tests.

Breast lesion sizing by B-mode imaging and sonoelastography in comparison to histopathological sizing--a prospective study

PURPOSE

This prospective study evaluates whether sonoelastography can improve B-mode ultrasonographic sizing of breast tumors. Precise measuring is important for effective therapy planning for breast cancer patients.

MATERIALS AND METHODS

The size of 100 surgically excised breast lesions (92 patients: 77 malignant, 23 benign) was compared to preoperative measurements. Lesions were imaged with both ultrasonographic techniques in identical planes. The largest sizes measured with each modality were compared to the largest histopathological measurements. The interobserver variability was also computed from measurements made by two examiners assessing identical planes.

RESULTS

Both ultrasonographic measuring techniques underestimate lesion size. The sonoelastography measurements were within ± 5 mm of the histological size in 70.1 % of malignant lesions, and the B-mode measurements in 57.1 % of cases. Sonoelastography leads to more accurate measurements of 13.0 % of cases (statistically not significant). A total of 22 lesions were also imaged by a second examiner. Sonoelastography had 27.3 % less interobserver variability (examiners agreed in 36.4 % of sonoelastography and in 9.1 % of B-mode results).

CONCLUSION

In this study there is no significant advantage of sonoelastography, although a tendency is apparent. The low interobserver variability also favors sonoelastography for preoperative diagnostics, since it may be less dependent on the observer than conventional B-mode imaging. The results of this prospective study require validation in a prospective multicenter study with larger case numbers.

Sonoelastography in the diagnosis of malignant and benign breast lesions: initial clinical experiences

PURPOSE

This prospective study aimed to compare sonoelastography, B-mode ultrasonography, and mammography in terms of their ability to distinguish benign from malignant breast lesions. We also assessed how the diagnostic value of sonoelastography differs between palpable and clinically occult lesions.

MATERIALS AND METHODS

Evaluation revealed a total of 97 lesions (66 benign; 31 malignant) without histological confirmation at the time of the initial examination. The sensitivity, specificity, positive (PPV) and negative predictive value (NPV) as well as efficiency were calculated. These parameters were separately assessed for palpable lesions and for non-palpable lesions. We subsequently compared these results.

RESULTS

Sonography had a sensitivity of 97% and a specificity of 82% (PPV: 71 %, NPV: 98%, efficiency: 87%). For mammography, the respective figures were 84% and 89% (PPV: 79%, NPV: 92%, efficiency: 88%). Sonoelastography had a sensitivity of 71% and a specificity of 48% (PPV: 39%, NPV: 78%, efficiency: 56%). The combination of sonography and sonoelastography yielded a sensitivity of 100% and a specificity of 38% (PPV: 43%, NPV: 100%, efficiency: 58%). The sensitivity and specificity were not statistically different between the groups of palpable and non-palpable lesions.

CONCLUSION

Sonoelastography is easily performed and not very time-consuming. Used by itself, the method is not more efficacious than alternative techniques. When used in conjunction with B-mode ultrasonography, the latter's sensitivity was increased, albeit at the expense of specificity.

Ductoscopy-based descriptors of intraductal lesions and their histopathologic correlates

BACKGROUND

In order to elucidate criteria for distinguishing benign from malignant lesions, this study correlated the ductoscopy-based macroscopic description of intraductal lesions with histopathologic results.

MATERIALS AND METHODS

Aiming to use diagnostic criteria consistent with previous publications, we analyzed the literature and established a uniform set of diagnostic descriptors. Based on these criteria, we subsequently analyzed and catalogued video and photographic material from 68 patients with nipple discharge, who had undergone ductoscopy followed by open surgery. For all breast lesions, the factors lesion type, number of lesions, lesion color, surface characteristics, and presence of blood or atypical vessels were reported. Based on the frequency distribution and the odds ratio, we were able to evaluate the differential diagnostic value of ductoscopic criteria in comparison with the respective histopathologic results.

RESULTS

Among the ductoscopic criteria, a fissured surface, hemorrhage or atypical vessels, and a polypoid appearance were important predictors for malignant lesions. In contrast, a smooth surface, the absence of hemorrhage and atypical vessels and a level appearance of the lesions predicted benign lesions.

CONCLUSIONS

For predicting the benign versus malignant character of ductoscopic lesions, the following criteria should be used: presence or absence of blood and atypical vessels, surface type, and level versus polypoid appearance.

Tree-based modeling of complex interactions of phosphorus loadings and environmental factors

Phosphorus (P) enrichment has been observed in the historic oligotrophic Greater Everglades in Florida mainly due to P influx from upstream, agriculturally dominated, low relief drainage basins of the Everglades Agricultural Area (EAA). Our specific objectives were to: (1) investigate relationships between various environmental factors and P loads in 10 farm basins within the EAA, (2) identify those environmental factors that impart major effects on P loads using three different tree-based modeling approaches, and (3) evaluate predictive models to assess P loads. We assembled thirteen environmental variable sets for all 10 sub-basins characterizing water level management, cropping practices, soils, hydrology, and farm-specific properties. Drainage flow and P concentrations were measured at each sub-basin outlet from 1992-2002 and aggregated to derive monthly P loads. We used three different tree-based models including single regression trees (ST), committee trees in Bagging (CTb) and ARCing (CTa) modes and ten-fold cross-validation to test prediction performances. The monthly P loads (MPL) during the monitoring period showed a maximum of 2528 kg (mean: 103 kg) and maximum monthly unit area P loads (UAL) of 4.88 kg P ha(-1) (mean: 0.16 kg P ha(-1)). Our results suggest that hydrologic/water management properties are the major controlling variables to predict MPL and UAL in the EAA. Tree-based modeling was successful in identifying relationships between P loads and environmental predictor variables on 10 farms in the EAA indicated by high R(2) (>0.80) and low prediction errors. Committee trees in ARCing mode generated the best performing models to predict P loads and P loads per unit area. Tree-based models had the ability to analyze complex, non-linear relationships between P loads and multiple variables describing hydrologic/water management, cropping practices, soil and farm-specific properties within the EAA.

Ultrasound and mammography guided wire marking of non-palpable breast lesions: analysis of 741 cases

PURPOSE

Aim of the study were to evaluate the success of ultrasound and mammography guided wire marking of non-palpable breast lesions and the results of specimen mammography/ultrasonography, completeness of resection, and number of secondary resections (during the initial surgical session and as a separate intervention) were analysed.

MATERIALS AND METHODS

Between May 1994 and December 2004, 668 women with 741 non-palpable breast lesions underwent surgery at the Greifswald University Department of Gynaecology and Obstetrics. Ultrasound directed wire marking was used in 418, mammography directed marking in 284 cases. In 39 lesions, both techniques were combined.

RESULTS

Out of all lesions approached with ultrasound directed wire marking, 88 (21.1 %) were malignant. Among lesions marked during mammography, 52 (19.3 %) were malignant. Specimen ultrasonography indicated that 90.9 % of lesions were resected completely. Specimen mammography demonstrated complete resection in 89.1 %. On histological examination, 19.5 % of the malignant lesions marked with sonographic guiding and 36.5 % of the malignant lesions marked with mammographic guiding did not have clear margins. Secondary resections (during the first procedure) for incomplete specimens were needed in 10 patients in whom sonographic localisation had been used, and in 25 patients in whom mammographic localisation had been employed. A second surgical session for secondary resection was required in 5.5 % of lesions marked with ultrasound and in 12.3 % of lesions marked with mammography guidance.

CONCLUSION

Sonography directed wire localisation appears to be superior to the respective mammographic method. Ultrasound guided wire marking should be considered the preferred method for all mammographic lesions with an ultrasonographic equivalent and no micro-calcifications.

Significance of laboratory studies for ruling out metastases in primary endometrial carcinoma

BACKGROUND

At the time of initial diagnosis of endometrial cancer, therapeutic decisions depend on the recognition of remote metastases. Tumor markers and hepatic enzymes are frequently used to screen for metastases. This study aimed to assess the clinical value of serum concentrations of tumor markers and liver enzymes.

PATIENTS AND METHODS

Laboratory test results from all patients with the initial diagnosis of endometrial cancer treated in our department between 1990 and 2000 were retrospectively reviewed. Hepatic enzyme levels and tumor markers relevant for endometrial cancer were recorded. Analysis of variance and post hoc tests were used to rule out or to confirm systematic differences. Significances were examined by the Mann-Whitney test.

RESULTS

A total of 336 women were included in the analysis. Recorded data included serum concentrations of alanine aminotranspherase (ALT) (n = 228), aspartate aminotranspherase (AST) (n = 289), gamma-glutamyltranspherase (Gamma-GT) (n = 176) and alkaline phosphatase (AP) (n = 86). The following tumor markers were analysed: carcinoembryonic antigen (CEA) (n = 182), squamous cell carcinoma antigen (SCC) (n = 40), cancer-associated serum antigen (CASA) (n = 10), CA 15-3 (n = 5), CA 19-9 (n = 21), and CA 125 (n = 28). Only CEA serum levels differed significantly between patients with endometrial cancer and hepatic and pulmonary metastases at the time of initial diagnosis and patients without metastases.

CONCLUSION

Our data show that neither the level of the tumor markers CEA, SCC, CA 15-3, CA 125, CA 19-9, CA 72-4 and CASA nor the hepatic enzymes AST, ALT, Gamma-GT and AP in routine evaluation accurately predict the presence of remote metastases.

Diagnostic value of ductoscopy in the diagnosis of nipple discharge and intraductal proliferations in comparison to standard methods

BACKGROUND

Ductoscopy is gaining increased importance in the diagnosis of nipple discharge of unclear origin and intraductal proliferation. For this reason we compared its diagnostic value and feasibility to standard diagnostic methods.

MATERIAL AND METHODS

Ductoscopy was compared to mammography, galactography, sonography, magnetic resonance imaging (MRI), nipple smear, fine needle aspiration cytology (FNAC), and high-speed core biopsy; feasibility, sensitivity, and specificity were investigated for each method.

RESULTS

71 ductoscopies were evaluated, which were followed up by open biopsies. Here, 3 invasive and 8 ductal carcinomas in situ were found, as well as 3 atypical ductal hyperplasias, 44 papillomas/papillomatoses, and 13 benign findings. Feasibility of ductoscopy was in this series 100%. Duct sonography showed the highest sensitivity (67.3%), followed by MRI (65.2%), galactography (56.3%), ductoscopy (55.2%), and FNAC (51.9%). The highest specificity was shown by FNAC, core biopsy, and galactography (each 100.0%), followed by mammography (92.3%), nipple smear (77.8%), ductoscopy, and duct sonography (each 61.5%); the lowest specificity was displayed by MRI (25.0%).

CONCLUSION

The results confirm that ductoscopy can be performed within the same range of sensitivity and specificity as other techniques. In order to make conclusive statements about ductoscopy, especially in order to precisely define the indications for this method, a prospective multicenter study was initiated.

Radial scar/complex sclerosing lesion of the breast--value of ultrasound

PURPOSE

Although benign, radial scar/complex sclerosing adenosis is a lesion which histopathologically resembles tubular carcinoma. On physical examination, it is difficult to distinguish radial scar from a malignant tumour. Mammography cannot differentiate radial scar from malignancy. This clinical study aims to delineate the role of preoperative ultrasonography with emphasis on the question whether ultrasonography could lower the number of false-positive readings and therefore the number of open biopsies required.

MATERIALS AND METHODS

In this examination, we present the clinical, mammographic, ultrasonographic, and histopathological features of 6 cases of radial scars.

RESULTS

Although most authors describe radial scars as non-palpable, 2 of 6 lesions were indeed palpable. On mammograms, radial scars have a spiculated appearance, a feature observed in all of our cases. Numerous ultrasonographic characteristics are listed in the literature, but ultrasonography is not reported to have clear-cut advantages.

CONCLUSION

Although this study did not elucidate any unique ultrasonographic features to characterise these lesions, the analysis of all ultrasonographic results made us recognise a set of "nearly specific ultrasonographic features" of radial scars. Current B-mode imaging does not appear to lead to the desirable reduction of the rate of unnecessary open biopsies.

Mammary ductoscopy for the evaluation of nipple discharge and comparison with standard diagnostic techniques

STUDY OBJECTIVE

To describe performance of breast duct endoscopy and compare the method with conventional diagnostic techniques.

DESIGN

Canadian Task Force classification III.

SETTING

Interdisciplinary Breast Unit of a university hospital.

PATIENTS

Consecutive and unselected series of 15 female patients including 20 breasts with nipple discharge.

INTERVENTIONS

Prospective data assessment on all patients with ductoscopy for nipple discharge between April 2003 to April 2004. All preoperative (mammography, ultrasonography, nipple smear) and minimally invasive (galactography, fine needle aspiration cytologic study) diagnostics were evaluated and compared with ductoscopy.

MEASUREMENTS AND MAIN RESULTS

Mammography on 20 breasts showed BI-RADS-I (5%), BI-RADS-II (50%), and BI-RADS-III (45%). Breast ultrasound scanning showed abnormalities, classified as BI-RADS-III equivalent lesions in all cases. Nipple smear showed in 69.2% a normal cytology and in most cases revealed a papilloma later (n=8/9). Unilateral galactography was performed in 46.7% who had spontaneous nipple discharge. Two galactography results were unremarkable, and open biopsy demonstrated 1 atypical ductal hyperplasia and papilloma. On 20 breasts of 15 women, 19 ductoscopies were successfully performed (95%). In 17 cases open biopsy followed ductoscopy, and 1 ductal carcinoma in situ (DCIS), 3 atypical ductal hyperplasia (ADH), 1 ductal hyperplasia without atypias, and 12 ductal papillomas were found.

CONCLUSION

Compared to nipple smear, the diagnostic value of ductoscopy in this study is superior but marginally inferior to galactography and highly specialized breast ultrasound scanning. Therefore ductoscopy needs to be evaluated on a larger scale, preferably in multicenter trials to further determine its potential and indications.

Non-palpable breast lesions in asymptomatic women: diagnostic value of initial ultrasonography and comparison with mammography

AIM

This prospective double-blind study was designed to assess (i) if primary breast screening by ultrasonography is capable of detecting breast cancer independent of tissue density and (ii) if the rate of unnecessary biopsies remains acceptable when diagnostics are based on ultrasonography.

PATIENTS AND METHODS

Bilateral breast ultrasonography was performed in 448 asymptomatic women as the initial diagnostic method. Sonograms were interpreted using a set of standardized diagnostic criteria. Subsequently, mammograms were obtained. The radiologists reading the mammograms were blinded to the sonographic results.

RESULTS

Overall, 3 non-palpable breast cancers were detected by ultrasound and mammography. All 3 ultrasonographically detected breast cancers were smaller than 1 cm (0.7, 0.7, 0.6 cm). All 3 carcinomas were correctly detected by both methods. For ultrasonography, the false positive rate was 1.1% (n=5) and for mammography 0.6% (n=3). When both methods were combined, the rate of unnecessary open biopsies was 1.6% (n=7). The ratio of benign to malignant lesions was 3.7/1.

CONCLUSION

Without prior mammography, primary high-resolution breast ultrasonography is capable of detecting non-palpable breast carcinomas in asymptomatic women at an early stage. The rate of unnecessary open biopsies is low and the ratio of benign to malignant biopsies acceptable.

Real-time elastography--an advanced method of ultrasound: First results in 108 patients with breast lesions

OBJECTIVES

To evaluate whether real-time elastography, a new, non-invasive method for the diagnosis of breast cancer, improves the differentiation and characterization of benign and malignant breast lesions.

METHODS

Real-time elastography was carried out in 108 potential breast tumor patients with cytologically or histologically confirmed focal breast lesions (59 benign, 49 malignant; median age, 53.9 years; range, 16-84 years). Tumor and healthy tissue were differentiated by measurement of elasticity based on the correlation between tissue properties and elasticity modulus. Evaluation was performed using the three-dimensional (3D) finite element method, in which the information is color-coded and superimposed on the B-mode ultrasound image. A second observer evaluated the elastography images, in order to improve the objectivity of the method. The results of B-mode scan and elastography were compared with those of histology and previous sonographic findings. Sensitivities and specificities were calculated, taking histology as the gold standard.

RESULTS

B-mode ultrasound had a sensitivity of 91.8% and a specificity of 78%, compared with sensitivities of 77.6% and 79.6% and specificities of 91.5% and 84.7%, respectively, for the two observers evaluating elastography. Agreement between B-mode ultrasound and elastography was good, yielding a weighted kappa of 0.67.

CONCLUSIONS

Our initial clinical results suggest that real-time elastography improves the specificity of breast lesion diagnosis and is a promising new approach for the diagnosis of breast cancer. Elastography provides additional information for differentiating malignant BI-RADS (breast imaging reporting and data system) category IV lesions.

Assessment of the spatial distribution of soil properties in a northern Everglades marsh

Florida Everglades restoration plans are aimed at maintaining and restoring characteristic landscape features such as soil, vegetation, and hydrologic patterns. This study presents the results from an exhaustive spatial sampling of key soil properties in Water Conservation Area 1 (WCA 1), which is part of the northern Everglades. Three soil strata were sampled: floc, upper 0- to 10-cm soil layer, and 10- to 20-cm soil layer. A variety of properties were measured including bulk density (BD), loss on ignition (LOI), total phosphorus (TP), total inorganic phosphorus (TIP), total nitrogen (TN), total carbon (TC), total iron (TFe), total magnesium (TMg), total aluminum (TAl), and total calcium (TCa). Interpolated maps and model prediction uncertainties of properties were generated using geostatistical methods. We found that the uncertainty associated with spatial predictions of floc, particularly floc BD, was highest, whereas spatial predictions of soil chemical properties such as soil Ca were more accurate. The resultant spatial patterns for these soil properties identified three predominant features in WCA 1: (i) a north to south gradient in soil properties associated with the predominant hydrological gradient, (ii) areas of considerable soil nutrient enrichment along the western canal of WCA 1, and (iii) areas of considerable Fe enrichment along the eastern canal. By using geostatistical techniques we were able to describe the spatial dynamics of soil variables and express these predictions with an acceptable level of uncertainty.

Parenchymal leiomyoma of the breast--clinical, sonographic, mammographic and histological features

BACKGROUND

Intraparenchymal leiomyomas of the breast are quite rare. Areolar lesions are distinguished from intraparenchymal leiomyomas, which are less frequent. Clinically, leiomyomas appear as nodules; mammographically, they show up as round lesions. Reports on sonographic criteria are rare, and the criteria are nonspecific. Based on our case of an intraparenchymal leiomyoma, we describe additional sonographic features. The clinical, mammographic and sonographic characteristics of an intraparenchymal leiomyoma of the breast were evaluated. After surgery, the diagnosis was confirmed histologically.

RESULTS

The clinical presentation of our patient with deep-seated leiomyoma of the breast included skin dimpling and a reduction in tissue mobility, differing from more commonly reported characteristics. Mammographically, the lesion was dense and only partly demarcated clearly, corresponding to other reports. On breast ultrasonography, the leiomyoma appeared as a hypodense, well demarcated, inhomogeneous lesion with posterior acoustic shadowing. A central tumour vessel was visible on Doppler imaging, and Cooper's ligaments were discontinuous. Acoustic shadowing, the hypodense character, hyperechoic border and the central tumour vessel are therefore additional ultrasonographic characteristics of an intraparenchymal leiomyoma of the breast. This type of lesion is usually described as isodense to hyperdense and homogeneous, possibly containing semicystic components. Previous reports have only described posterior acoustic enhancement, but not acoustic shadowing.

CONCLUSION

On breast ultrasonography, an intraparenchymal leiomyoma of the breast can present with posterior acoustic shadowing, hypodense echogenicity, a hyperechoic border and a central tumour vessel. Neither imaging studies nor palpation allow distinction between benign and malignant lesions.

Spatial patterns of labile forms of phosphorus in a subtropical wetland

Phosphorus (P) has been identified as the key constituent defining wetland productivity, structure, and function. Our goal was to investigate the spatial patterns of total P and three labile forms of P (labile organic, inorganic, and microbial biomass P) across a subtropical wetland located in east-central Florida, the Blue Cypress Marsh Conservation Area (BCMCA), and link spatial patterns to ecosystem processes. The wetland received a continual input of nutrients primarily from the south and intermittently from the west and east, respectively, which ceased in the mid-1990s. Since then the marsh system has been undergoing natural succession. We used (i) ordinary kriging to characterize the spatial patterns of total P and labile P forms across the wetland, (ii) local, moving spatial correlations to investigate relationships between total P and labile P forms, and (iii) a clustering technique to link the identified spatial patterns to biogeochemical processes. The spatially explicit analyses revealed patterns of total P and labile P forms as well as changing relationships between variables across the marsh. We were able to distinguish P-enriched areas from unaffected ("natural") areas and intermediate zones that are currently undergoing change as P is mobilized and translocated. We also identified areas that are at risk, showing a shift toward a more P-enriched status. Our results improve our understanding of P and its labile components within a spatially explicit context.

Primäres intrazystisches Plattenepithelkarzinom der Brust

We report on a 45-year-old patient who presented with a 7 cm palpable right breast mass which had been classified as a cyst by ultrasonography. Multiple aspiration cytologies revealed no evidence of malignancy. Repeat sonography in our institution showed a lesion at 1 o'clock, 1 cm deep, and 3-8 cm from the nipple. The lesion contained a solitary cystic component measuring 3.9 x 4.1 x 4.4 cm. A 3.1 x 2.6 x 2.5 cm solid, inhomogeneous mass with irregular margins was found at the lateral border of the cyst. This mass raised suspicion of an intracystic carcinoma. Histopathologic analysis of 5 high-speed biopsy tissue cores demonstrated an invasive large-cell ductal carcinoma (G2-3). Final histopathologic assessment subsequent to breast-preserving resection and axillary node dissection confirmed the initial diagnosis: keratinizing intracystic squamous cell carcinoma (G2-3, pT2, pN0 (0/15)). The search for a remote primary squamous cell carcinoma included a chest X-ray, cystoscopy, colposcopy and PAP smear, esophago-gastroscopy, ENT consultation (laryngoscopy), and did not reveal any extramammary cancer. The postoperative management consisted of a total of 6 cycles of chemotherapy (Cisplatinum 75 mg/m (2) BSA and Paclitaxel 175 mg/m (2) BSA every 21 days) and subsequent percutaneous radiotherapy. In accordance with published reports, the diagnostic and therapeutic management was analogous to that of adenocarcinoma of the breast. However, some authors recommend the same chemotherapy as used for squamous cell carcinomas of other organs. It remains difficult to make any statements regarding the adjuvant therapy and prognosis, since this type of tumor is so infrequent, especially as an intracystic lesion.

Strict control of glycaemia: effects on blood flow in the large retinal vessels and in the macular microcirculation

AIMS

The purpose of this study was to investigate the effect of instituting strict diabetic glycaemic control on the retinal macular microcirculation and to compare this effect with that observed in the main retinal veins.

METHODS

In 28 insulin dependent diabetic patients with poor glycaemic control a regimen of strict diabetic control, consisting of four daily insulin injections was instituted and maintained for 6 months. Retinal haemodynamics were investigated in the macular microcirculation by the blue field simulation technique and in the major retinal veins by a combination of bidirectional laser Doppler velocimetry and monochromatic fundus photography. Progression of diabetic retinopathy was assessed from fundus photographs taken at baseline and at the end of the study.

RESULTS

Institution of strict diabetic control resulted in a significant increase in leucocyte velocity in the macular circulation (p = 0.013). No significant difference in this increase was observed between eyes that showed progression (n = 8) and no progression (n = 20) of retinopathy during the study. Significant correlations were found between relative changes over time of blood flow measured in the main retinal veins and relative changes of leucocyte velocity determined in the macular microcirculation at 2 months (p = 0.008) and 6 months (p = 0.001) but not at 5 days (p = 0.49). In the eight eyes that showed progression of retinopathy, the product of leucocyte velocity and density at baseline was significantly higher than normal (p < 0.05). During the length of this study, this product was also significantly higher in the eight eyes that showed retinopathy progression than in the 20 eyes that did not show progression (p = 0.005).

CONCLUSION

Our results suggest that increased flow in the macular microcirculation may be associated with progression of retinopathy, thus supporting the hypothesis that increased blood flow may play a role in the development of diabetic microangiopathy. Although there are correlations between the changes detected in the macular microcirculation and those measured in the main retinal vessels, there are also differences which need to be further investigated in order to better understand pathogenetic mechanisms.