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In order to investigate the immune mechanisms involved in regression of canine cutaneous histicytoma (CCH), major histocompatibility complex (MHC) class-II immuno-expression and the number of T- and B-lymphocytes and macrophages were analyzed in 93 cases of CCH. MHC class-II was also studied in 16 cases of CCH by immunoelectron microscopy. All tumors expressed MHC class-II, and two major staining patterns were identified: focal juxtanuclear cytoplasmic staining and rim-like staining along the cell periphery. The MHC class-II labelling pattern and T- and B-lymphocyte infiltrates were associated with tumor regression. In regressing lesions, MHC class-II molecules shift to the cell surface and an increase of both T- and B-lymphocytes were noted. The increasing expression of MHC class-II molecules on the cell surface could be a significant factor for the onset and progression of tumour regression.

Purpose: To evaluate the efficacy and safety of standard photodynamic therapy with verteporfin at 48 months in patients with chronic central serous chorioretinopathy., Methods: A retrospective, multicenter, interventional case series analysis in patients with chronic central serous chorioretinopathy, treated with standard photodynamic therapy, and with ≥4 years of follow-up. Evaluations were performed every 3 months in the first year, every 6 months in the second year, and thereafter annually. Optical coherence tomography was performed in all visits. Fluorescein angiography and indocyanine green angiography were performed at baseline and thereafter as necessary. Retinal thickness on optical coherence tomography was measured manually, evaluating central macular thickness and neural retina thickness. Main outcomes included the evolution of best-corrected visual acuity, the resolution of subretinal fluid, documented with optical coherence tomography, the number of treatments, and the evaluation of neural retina thickness during the 48 months of follow-up., Results: The study included 46 eyes of 42 patients, 38 men (90.4%) and 4 women (9.5%), with mean age of 49.19 ± 9.9 years (range, 32-70 years), and the minimal follow-up period was 48 months (mean, 56.8 ±10.3 months). Subretinal fluid was observed in all the included eyes at baseline, and 10 eyes (21.7%) had intraretinal diffuse or cystoid fluid. Concerning the mean best-corrected visual acuity, a statistically significant improvement (P < 0.01, Student t-test) was registered from 58.8 ± 18.3 letters at baseline to 66.9 ± 18.6 letters at 48th month. A complete resolution of subretinal fluid was achieved in 93.4%, and resolution of intraretinal fluid occurred in all 10 cases at 48 months. Neural retina thickness remained stable during the 48 months of follow-up (163.8 ± 47 μm at baseline and 163.8 ± 46 μm at 48 months). The mean number of treatments was 1.08 ± 0.3. No systemic or ocular side effects were registered., Conclusion: Standard photodynamic therapy with verteporfin was effective and safe in chronic central serous chorioretinopathy treatment with a significant improvement in the long term, both anatomic and visual, without inducing additional retinal atrophy or systemic adverse effects.

Investigation of the mechanisms behind the regulation of cellular motility and adhesion is key to understanding metastasis and the biology of tumor spreading. There are many technologies available for these studies, but the majority of them are either dependent on the use of labels or limited to endpoint analysis. The xCELLigence RTCA (real-time cell analysis) provides a platform for label free and operator independent investigation of the migration, invasion and adhesion proprieties of cells in physiologically relevant conditions. The real-time kinetic data acquisition also allows for a more accurate characterization of short-lived cellular events. In this chapter we describe the use of the xCELLigence Real-Time Cell Analyzer to investigate changes in cellular adhesion and motility in real time.

To evaluate macular thickness in eyes with mild nonproliferative diabetic retinopathy (NPDR), patients with diabetes type 2, NPDR level 20 or 35, and without evidence of clinical macular edema underwent best-corrected visual acuity assessment, color fundus photography and Stratus optical coherence tomography. Mean center point thickness (CPT) and mean central subfield (CSF) thickness were compared with those of a healthy control population. 410 eyes/patients aged 61.2 ± 8.3 years, and with glycosylated hemoglobin of 7.9 ± 1.5% were included. Mean CPT and CSF were 186.6 ± 28.4 and 215.2 ± 25 µm, respectively, significantly increased compared to healthy subjects (p < 0.001). CSF thickness was abnormally increased in 17.6% of the patients, with values within the normal range in 79.5%, and abnormally decreased in 2.9%. CPT and CSF thickness were significantly thicker in men. No systemic factors showed a significant association. A significant increase in the macular thickness was found in eyes/patients with mild NPDR without clinical macular edema; however, only 17.6% of the eyes/patients had abnormally increased values and less than 3% abnormally decreased values., (Copyright © 2013 S. Karger AG, Basel.)

Objective: To examine the relationship between subclinical diabetic macular edema (DME) and the development of clinically significant macular edema (CSME) in nonproliferative diabetic retinopathy (NPDR) in patients with type 2 diabetes., Methods: A prospective, monocenter, observational study was designed to follow patients/eyes with type 2 diabetes and NPDR (Early Treatment Diabetic Retinopathy Study levels 20 and 35) with no prior laser treatment for 2 years or until development of CSME. Ophthalmologic examinations, including best-corrected visual acuity, fundus photography and optical coherence tomography (OCT), were performed at baseline, 6 months and a final visit., Results: A total of 348 patients completed study follow-up; 26 eyes developed CSME. Six out of 32 eyes/patients presenting subclinical DME at baseline developed CSME (18.7%), while 20 out of 316 eyes without subclinical DME developed CSME (6.3%). Eyes/patients with subclinical DME presented a risk for DME progression 3.686 times higher than that of eyes/patients without subclinical DME (95% confidence interval 1.221-7.988)., Conclusions: Subclinical DME in eyes with NPDR identified by center point thickness measured on a Stratus OCT is a good predictor of CSME development., (© 2013 S. Karger AG, Basel.)

Purpose: To evaluate the 36-month efficacy of intravitreal ranibizumab injections for choroidal neovascularization secondary to age-related macular degeneration (AMD) in real world clinical practice., Methods: Retrospective study involving 84 eyes of 77 patients; 52 eyes completed 3 years of follow-up. Subjects were observed initially on a monthly basis and with extended follow-up intervals if signs of quiescence were detected, according to an established protocol. A comprehensive ophthalmologic examination was performed, including best-corrected visual acuity (BCVA) determined with Early Treatment Diabetic Retinopathy Study charts, stereoscopic macular biomicroscopy and optical coherence tomography (OCT) with fluorescein angiography and indocyanine green angiography if considered necessary. Treatment was given if signs of active lesions were present., Results: The mean baseline BCVA was 49.33 and 49.52 letters at the 36-month visit. The average of treatments was 8.6 at 3 years. At this time point, 77% of treated eyes stabilized or improved their vision (VA loss ≤ 5 letters). A predictive value for better VA was found for younger age, better baseline VA, good response on OCT and more frequent treatments., Conclusion: At 3 years, intravitreal ranibizumab is able to maintain baseline VA in exudative AMD patients, with a reduced number of injections, but not to show VA improvement, in clinical practice., (Copyright © 2013 S. Karger AG, Basel.)

Mast cell tumours (MCTs) are among the most common cutaneous neoplasms in dogs and have a highly variable clinical behaviour. Cyclooxygenase (Cox) catalyzes the rate-limiting step in prostanoid biosynthesis and has recently gained attention as a prognostic factor and therapeutic target in human and animal oncology. In order to evaluate the potential value of non-steroidal anti-inflammatory drugs (NSAIDs) in the treatment of canine MCTs, expression of Cox-2 was determined in 49 such tumours (14 of grade I, nine of grade II and 22 of grade III). Cox-2 was expressed by 86% of the tumours studied. The percentage of labelled cells ranged from isolated positive cells throughout the tumour (n=8) to localized foci of labelled cells (n=3) or diffuse labelling of >50% of the cells (n=31). The intensity of Cox-2 labelling ranged from weak (n=4) to moderate (n=16) and strong (n=22) and was greatest at the advancing margin of the tumour. The intensity of Cox-2 labelling was significantly different between the three histological groups (P=0.018). However, no significant differences were noted for the percentage of Cox-2 positive cells (P=0.122) and for the immunoreactivity score (P=0.348) between the histological grades. The results of this study suggest that NSAIDs, particularly Cox-2 inhibitors, may be of value in the treatment of canine MCTs., (Copyright © 2011 Elsevier Ltd. All rights reserved.)

We describe the case of a 14-year-old Domestic Short Hair male cat that presented with a single mammary tumour one centimetre in diameter, classified as invasive micropapillary carcinoma. Histology and immunohistochemistry revealed a high mitotic index, a KI-67 index of 10%, a lack of reactivity to myoepithelial markers, and a dense infiltration with T and B lymphocytes at the periphery of the tumour. Micrometastases were detected in the regional lymph node at the time of surgery. Overall survival time was 10 months with a disease-free interval of 7.5 months. Distant metastases in the sublumbar lymph nodes confirmed the aggressiveness of this tumour, which has recently been subtyped in female cats. This is the first case reported in male cats with a complete follow-up, highlighting the importance of prompt and aggressive treatment in the presence of mammary tumours in male cats.

Background and Purpose: For patients diagnosed with advanced renal cell carcinoma (RCC), there are few therapeutic options. Radiation therapy is predominantly used to treat metastasis and has not proven effective in the adjuvant setting for renal cancer. Furthermore, RCC is resistant to standard cytotoxic chemotherapies. Targeted anti-angiogenics are the standard of care for RCC but are not curative. Newer agents, such as mTOR inhibitors and others that induce autophagy, have shown great promise for treating RCC. Here, we investigate the potential use of the small molecule STF-62247 to modulate radiation., Materials and Methods: Using RCC cell lines, we evaluate sensitivity to radiation in addition to agents that induce autophagic cell death by clonogenic survival assays. Furthermore, these were also tested under physiological oxygen levels., Results: STF-62247 specifically induces autophagic cell death in cells that have lost VHL, an essential mutation in the development of RCC. Treatment with STF-62247 did not alter cell cycle progression but when combined with radiation increased cell killing under oxic and hypoxic/physiological conditions., Conclusions: This study highlights the possibility of combining targeted therapeutics such as STF-62247 or temsirolimus with radiation to reduce the reliance on partial or full nephrectomy and improve patient prognosis., (Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.)

Melanocytic tumors occur as much in humans as in dogs and are frequently associated with receptor tyrosine kinase dysregulation. The transmembrane c-kit protein is a receptor tyrosine kinase that is crucial in melanocytic homeostasis and, when mutated, is associated with tumor development in those cells. In human studies, its expression is generally detected in melanocytomas and primary malignant melanomas, being lost with tumor progression and metastasis. In this study, we aimed to analyze c-kit expression in canine cutaneous melanocytic tumors and its association with tumor behavior, in order to investigate the dog's potential in comparative pathology and c-kit's potential in the diagnosis of these tumors. The expression of c-kit was evaluated immunohistochemically in 39 canine cutaneous melanocytic tumors and scored in terms of the labeling location, extension, and intensity. The labeling location was essentially cytoplasmic, and the labeling extension and intensity were generally higher in melanocytomas (83.3% diffuse-labeled cells) than those in malignant melanomas (22.2% negative-labeled cells). The differences found in the labeling extension were statistically significant (P < 0.001). There was no association between c-kit immunoexpression in malignant melanomas and the clinicopathological criteria, except between the labeling intensity and the degree of intralesional pigmentation (P = 0.048). Our results for labeling extension are in agreement with similar human studies, reinforcing the dog's potential as a model organism for investigation in this type of cancer. In addition, the loss of c-kit expression in malignant melanomas might be a criterion of tumor aggressiveness, indicating that this receptor may be useful in the diagnosis of these tumors.

Purpose: To evaluate the long-term safety and efficacy of intravitreal ranibizumab in the treatment of myopic choroidal neovascularization (CNV)., Methods: Three-year retrospective, nonrandomized, interventional case series. Forty eyes of 39 patients with myopic CNV were included; 15 with previous photodynamic therapy, and 25 naïve eyes. Best-corrected visual acuity (BCVA) changes, central foveal thickness (CFT), and number of treatments were assessed, from baseline to month 36., Results: Mean visual acuity improved from 55.4 Early Treatment Diabetic Retinopathy Study (ETDRS) letters at baseline to 59.7 letters at 12 months (p = 0.07), 61.8 letters at 24 months (p = 0.008) and 63.4 letters at 36 months (p = 0.039). Twenty-five percent of the patients gained ≥15 letters (3 lines) at 12 months, 30% at 24 months and 35% at 36 months. There was a mean reduction of 80 μm in CFT (p < 0.001). A mean of 4.1 injections were performed in the first year, 2.4 in the second year and 1.1 in the third year. Fifty-three percent of the eyes had no need for treatment during the third year of follow-up., Conclusions: Intravitreal ranibizumab seems to be an effective and safe therapeutic procedure to treat CNV in highly myopic eyes, with a high proportion of patients gaining or stabilizing BCVA at a 3-year follow-up., (Copyright © 2011 S. Karger AG, Basel.)

In recent years, considerable progress has been made in understanding the role of the immune system in tumour progression. However, in canine mammary tumours (CMT), the prognostic value of T-lymphocytes is not established. The aims of the present study were to characterize T-lymphocytic infiltrate in 57 canine mammary tumours (21 benign and 36 malign), by immunohistochemical detection of CD3 antigen, and to determine its association with several clinicopathological parameters and overall survival. CD3+ positive cells were counted in 10 high-power fields within the tumour (i.e. The tumour-infiltrating T-lymphocytes, TIL), in the peripheral area of the tumour and in the adnexal non-tumoural mammary gland. CD3(+) TILs were significantly more frequent in benign than in malignant tumours (p<0.001). Conversely, peripheral CD3(+) TILs were significantly more frequent in malignant than in benign neoplasias (p<0.001). For CD3(+) T-lymphocytes in the adnexal non-tumoural mammary gland, there was no statistical difference in their frequency between benign and malignant tumours. On survival analysis, there was a tendency towards an association of a higher number of CD3(+) TILs and a shorter overall survival (p=0.08). Interestingly for CD3(+) T-lymphocytes in the adnexal non-tumoural mammary gland, a statistically significant relationship was observed, with a higher number of lymphocytes conferring a reduced overall survival (p=0.045). Further studies will be required to better understand the biological implications of the current findings.

This study was designed to investigate the possible roles of cyclooxygenase-2 (COX-2) and vascular endothelial growth factor (VEGF) in canine mammary cancer angiogenesis. Immunohistochemistry was performed on 70 tumours (28 benign and 42 malignant) in order to detect COX-2 and VEGF expression. Microvessel density (MVD) was determined by CD31 immunolabelling to assess tumour angiogenesis. There was a significantly higher expression of COX-2 (P<0.001), VEGF (P<0.001) and MVD (P<0.001) in malignant compared to benign tumours. In the malignant group, the MVD of COX-2 positive tumours was significantly higher than that of COX-2 negative tumours (P=0.026). A similar association was observed for VEGF (P<0.001) positive tumours. The results from this study suggested that over-expression of COX-2 and VEGF may contribute to increased angiogenesis and aggression in malignant tumours., (Copyright © 2010 Elsevier Ltd. All rights reserved.)

Clinical and molecular similarities between canine mammary tumours and human breast cancer have been described in recent decades. Clinically, the similarities are very strong: spontaneous tumours, hormonal aetiology, age of onset and an identical course of the disease. The clinical characteristics that have an impact on the clinical outcome are also identical: tumour size, lymph node invasiveness and clinical stage. Nowadays, as far as human medicine is concerned, the goal is to identify prognostic factors, mainly at the molecular level, such as those involved in metastasis, which could be used as therapeutic targets to support a better outcome. Moreover, in this area, canine mammary tumours seem to mimic human breast cancer, as a range of similarities are found at the molecular level concerning the overexpression of steroid receptors, proliferation markers, epidermal growth factor, p53 supressor gene mutations, metalloproteinases, cyclooxygenases, among many others. Clinical and molecular data that support canine mammary tumours as a model to study human breast cancer are analysed in this review. Additionally, it is shown that some recent molecular targets in canine mammary tumours may be seen as indicators for similar research to be performed in the corresponding human disease.

Acute and chronic hypoxia exists within the three-dimensional microenvironment of solid tumors and drives therapy resistance, genetic instability, and metastasis. Replicating cells exposed to either severe acute hypoxia (16 hours with 0.02% O(2)) followed by reoxygenation or moderate chronic hypoxia (72 hours with 0.2% O(2)) treatments have decreased homologous recombination (HR) protein expression and function. As HR defects are synthetically lethal with poly(ADP-ribose) polymerase 1 (PARP1) inhibition, we evaluated the sensitivity of repair-defective hypoxic cells to PARP inhibition. Although PARP inhibition itself did not affect HR expression or function, we observed increased clonogenic killing in HR-deficient hypoxic cells following chemical inhibition of PARP1. This effect was partially reversible by RAD51 overexpression. PARP1(-/-) murine embryonic fibroblasts (MEF) showed a proliferative disadvantage under hypoxic gassing when compared with PARP1(+/+) MEFs. PARP-inhibited hypoxic cells accumulated γH2AX and 53BP1 foci as a consequence of altered DNA replication firing during S phase-specific cell killing. In support of this proposed mode of action, PARP inhibitor-treated xenografts displayed increased γH2AX and cleaved caspase-3 expression in RAD51-deficient hypoxic subregions in vivo, which was associated with decreased ex vivo clonogenic survival following experimental radiotherapy. This is the first report of selective cell killing of HR-defective hypoxic cells in vivo as a consequence of microenvironment-mediated "contextual synthetic lethality." As all solid tumors contain aggressive hypoxic cells, this may broaden the clinical utility of PARP and DNA repair inhibition, either alone or in combination with radiotherapy and chemotherapy, even in tumor cells lacking synthetically lethal, genetic mutations., (©2010 AACR.)

Purpose: The purpose of this study was to evaluate the efficacy of verteporfin photodynamic therapy on the treatment of polypoidal choroidal vasculopathy., Methods: A prospective, nonrandomized institutional study was conducted involving 42 eyes of 38 patients with newly diagnosed symptomatic polypoidal choroidal vasculopathy treated exclusively with photodynamic therapy. Twenty-seven eyes completed 3 years of follow-up. Subjects were observed every 3 months with evaluation of best-corrected visual acuity (BCVA), retinography, and fluorescein and indocyanine green angiography. Treatment was given whenever the patient exhibited subfoveal exudation on fluorescein angiography., Results: Mean BCVA was 0.91 +/- 0.33 logarithm of the minimum angle of resolution on the initial visit and 0.93 +/- 0.39 on the 36-month visit. Patients were submitted to an average of 3.19 treatment sessions. On the final evaluation at 36 months, 14.8% of the treated eyes improved their BCVA by at least 0.3 logarithm of the minimum angle of resolution, 74.1% had no significant loss of BCVA, and 25.9% lost >or=0.3 logarithm of the minimum angle of resolution. Recurrences were frequent (59.3% of the eyes at 3 years of follow-up), responded well to retreatment, and were not associated with additional BCVA loss., Conclusion: Photodynamic therapy remains a good option for management of polypoidal choroidal vasculopathy. After 3 years, approximately three fourths of the treated eyes had no significant loss of vision, and 14.8% showed significant improvement in visual acuity.

Severe hypoxia has been demonstrated to induce a replication arrest which is associated with decreased levels of nucleotides. Chk1 is rapidly phosphorylated in response to severe hypoxia and in turn deactivates TLK1 through phosphorylation. Loss of Chk1 has been shown to sensitize cells to hypoxia/reoxygenation. After short (acute) exposure to hypoxia this is due to an increased rate of reoxygenation-induced replication restart and subsequent p53-dependent apoptosis. After longer (chronic) exposure to hypoxia S phase cells do not undergo reoxygenation-induced replication restart. Cells exposed to these levels of hypoxia however are sensitive to loss of Chk1. This suggests a new role for Chk1 in the cell cycle response to reoxygenation., (© 2010 Landes Bioscience)

Immunohistochemical detection of Cyclooxygenase (Cox)-1 and -2 enzymes in canine mammary tumours (CMT) has recently been described. However, the prognostic value of their expression needs to be established. The aim of this study was to investigate Cox (-1 and -2) prognostic value in malignant CMT by evaluating its correlation with clinicopathological parameters (tumour size, histological type, necrosis, lymph node metastasis) and with Disease Free Survival (DFS) and Overall Survival (OS). Twenty seven female dogs with malignant tumours were included. Cox-2 expression was associated with lymph node metastasis at surgery time, development of distant metastasis during follow-up (p=0.038), DFS (p=0.03) and OS (p=0.04). Multivariate survival analysis showed that Cox-2 did not retain its significance as an independent prognostic factor. For Cox-1 expression, no statistically significant association was observed. Present study suggests the usefulness of testing Cox-2 specific inhibitors as part of an adjuvant therapy in female dogs with malignant mammary neoplasias., (Copyright 2009 Elsevier Ltd. All rights reserved.)

Questions exist concerning the effects of acute versus chronic hypoxic conditions on DNA replication and genomic stability that may influence tumorigenesis. Severe hypoxia causes replication arrest independent of S-phase checkpoint, DNA damage response, or transformation status. Arrests occur during both the initiation and elongation phases of DNA replication, correlated with a rapid decrease in available deoxynucleotide triphosphates. With fluctuating oxygen tensions in tumors, arrested hypoxic cells may undergo rapid reperfusion and reoxygenation that leads to reoxygenation-induced DNA damage. In cells subjected to chronic hypoxia, we found that replicative restart was inhibited along with numerous replication factors, including MCM6 and RPA, the latter of which limits the hypoxia-induced DNA damage response. In contrast, in cells where replicative restart occurred, it was accompanied by extensive reoxygenation-induced DNA damage and compromised DNA repair. We found that cells reoxygenated after acute hypoxia underwent rapid p53-dependent apoptosis. Our findings suggest that cells lacking functional p53 are more susceptible to genomic instability and potentially tumorigenesis if they experience reoxygenation after acute exposure to hypoxia.

Epithelioid hemangiosarcoma is a specific variant of hemangiosarcoma that has recently been recognized in domestic animals. These malignant vascular neoplasms histologically resemble, and may be mistaken for, carcinomas. Four epithelioid hemangiosarcomas in the urinary bladders of 4 cows with severe enzootic hematuria are described in the current study. Grossly, the vesicular mucosa of the urinary bladder of each cow contained a single red elevated nodule. Histologically, each neoplasm was composed of short strands, cords, or nests of epithelioid, round, or slightly spindle-shaped endothelial cells that formed small vascular structures. Neoplastic cells were immunohistochemically positive for factor VIII-related antigen and vimentin, and were negative for cytokeratin and desmin. Ultrastructurally, the neoplastic cells often contained cytoplasmic intermediate filaments, a prominent granular endoplasmic reticulum, a Golgi complex, mitochondria, marked pinocytotic activity, and rare Weibel-Palade bodies. These neoplasms were diagnosed as epithelioid hemangiosarcomas based on their histologic, immunohistochemical, and ultrastructural features. The present report widens the spectrum of mesenchymal tumors of the bovine urinary bladder and aids in the characterization of these vascular neoplasms.

Background: Canine cutaneous histiocytoma (CCH) is an epidermotropic tumour of Langerhans cells, most frequent in young dogs, which undergoes spontaneous regression., Materials and Methods: E-cadherin immunoexpression was analysed in ninety-three CCH, categorized according to Cockerell and Slauson (1976) criteria into four histological groups, representing different stages of tumour regression., Results: All tumours expressed membranous E-cadherin both in keratinocytes, and in tumoural cells and no differences were noted among the histological groups analysed. However, the intensity of the E-cadherin immunolabeling decreased in the presence of lymphoid infiltration and varied significantly among the groups considered (p<0.0001)., Conclusion: This study strongly suggests a down-regulation of E-cadherin expression in CCH pathogenesis and progression. The loss of E-cadherin expression might represent an activation/ maturation process of the tumoural cells constituting a switch for CCH regression.

Background: To identify alterations of retinal capillary blood flow in the papillomacular area in preclinical diabetic retinopathy using the Heidelberg scanning laser Doppler flowmeter., Methods: Ten eyes from ten patients with type 2 diabetes and no lesions visible on fundus photography (level 10 of Wisconsin grading) and ten eyes from ten healthy subjects of similar age range were examined with the HRF. Intravisit reproducibility of retinal capillary blood flow measurements was assessed in normal subjects and in type 2 diabetic patients, comparing different measurement areas and different analysis procedures: (a) 10x10 pixel box with original software, (b) 10x10 pixel box with SLDF software, and (c) whole-scan analysis with SLDF software (automatic full-field perfusion image analysis)., Results: Intravisit reproducibility for the whole-scan analysis in the papillomacular area was 3.52%, 4.81% and 4.60% for volume (VOL), flow (FLW) and velocity (VEL) respectively. Using this method, mean and SD values for retinal capillary blood-flow are 13.25+/-2.87, 214.58+/-55.30 and 0.74+/-0.17, for VOL, FLW and VEL for healthy eyes, comparing with 19.85+/-6.22, 360.87+/-158.70 and 1.20+/-0.48 in eyes with preclinical diabetic retinopathy (P<0.010, P<0.019 and P<0.015 respectively)., Conclusions: The HRF shows acceptable reproducibility when using whole-scan analysis in the papillomacular area. Retinal capillary blood VOL, FLW and VEL were particularly increased in five of the ten diabetic eyes examined, with values over the mean + 2SD of the control population, suggesting that eyes showing increased retinal capillary blood flow may indicate risk of progression.

Objective: To compare measurements of retinal thickness in eyes with mild nonproliferative retinopathy in patients with type 2 diabetes mellitus using 2 different techniques: the retinal thickness analyzer (RTA) and optical coherence tomography (OCT)., Methods: Twenty-eight eyes from 28 patients with type 2 diabetes mellitus and mild nonproliferative retinopathy were classified according to the Wisconsin grading system by 7-field stereoscopic fundus photography. Ten eyes were classified as level 10 (absence of visible lesions) and 18 as level 20 or 35 (minimal retinopathy). All eyes were examined by the RTA and OCT. Healthy populations were used to establish reference maps for the RTA (n = 14; mean age, 48 years; age range, 42-55 years) and OCT (n = 10; mean age, 56 years; age range, 43-68 years). Reference maps were computed using the means + 2 SDs of the values obtained for each location. Increases in thickness were computed as a percentage of increase over these reference maps., Results: The RTA detected increases in thickness in 1 or more locations in 24 of the 28 diabetic eyes examined, whereas OCT detected increases in only 3 eyes. The percentages of increase detected by the RTA ranged from 0.3% to 73.5%, whereas OCT detected percentages of increase of 0.3% to 4.8%., Conclusion: Optical coherence tomography is less sensitive than the RTA in detecting localized increases in retinal thickness in the initial stages of diabetic retinal disease.