Diagnosis of infection in the foot of patients with diabetes: A systematic review

BACKGROUND

Securing an early accurate diagnosis of diabetic foot infections and assessment of their severity are of paramount importance since these infections can cause great morbidity and potential mortality and present formidable challenges in surgical and antimicrobial treatment.

METHODS

In June 2022, we searched the literature using PubMed and EMBASE for published studies on the diagnosis of diabetic foot infection (DFI). On the basis of pre-determined criteria, we reviewed prospective controlled, as well as non-controlled, studies in English. We then developed evidence statements based on the included papers.

RESULTS

We selected a total of 64 papers that met our inclusion criteria. The certainty of the majority of the evidence statements was low because of the weak methodology of nearly all of the studies. The available data suggest that diagnosing diabetic foot infections on the basis of clinical signs and symptoms and classified according to the International Working Group of the Diabetic Foot/Infectious Diseases Society of America scheme correlates with the patient's likelihood of the need for hospitalisation, lower extremity amputation, and risk of death. Elevated levels of selected serum inflammatory markers such as erythrocyte sedimentation rate (ESR), C-reactive protein and procalcitonin are supportive, but not diagnostic, of soft tissue infection. Culturing tissue samples of soft tissues or bone, when care is taken to avoid contamination, provides more accurate microbiological information than culturing superficial (swab) samples. Although non-culture techniques, especially next-generation sequencing, are likely to identify more bacteria from tissue samples including bone than standard cultures, no studies have established a significant impact on the management of patients with DFIs. In patients with suspected diabetic foot osteomyelitis, the combination of a positive probe-to-bone test and elevated ESR supports this diagnosis. Plain X-ray remains the first-line imaging examination when there is suspicion of diabetic foot osteomyelitis (DFO), but advanced imaging methods including magnetic resonance imaging (MRI) and nuclear imaging when MRI is not feasible help in cases when either the diagnosis or the localisation of infection is uncertain. Intra-operative or non-per-wound percutaneous biopsy is the best method to accurately identify bone pathogens in case of a suspicion of a DFO. Bedside percutaneous biopsies are effective and safe and are an option to obtain bone culture data when conventional (i.e. surgical or radiological) procedures are not feasible.

CONCLUSIONS

The results of this systematic review of the diagnosis of diabetic foot infections provide some guidance for clinicians, but there is still a need for more prospective controlled studies of high quality.

IWGDF/IDSA guidelines on the diagnosis and treatment of diabetes-related foot infections (IWGDF/IDSA 2023)

The International Working Group on the Diabetic Foot (IWGDF) has published evidence-based guidelines on the management and prevention of diabetes-related foot diseases since 1999. The present guideline is an update of the 2019 IWGDF guideline on the diagnosis and management of foot infections in persons with diabetes mellitus. The Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) framework was used for the development of this guideline. This was structured around identifying clinically relevant questions in the P(A)ICO format, determining patient-important outcomes, systematically reviewing the evidence, assessing the certainty of the evidence, and finally moving from evidence to the recommendation. This guideline was developed for healthcare professionals involved in diabetes-related foot care to inform clinical care around patient-important outcomes. Two systematic reviews from 2019 were updated to inform this guideline, and a total of 149 studies (62 new) meeting inclusion criteria were identified from the updated search and incorporated in this guideline. Updated recommendations are derived from these systematic reviews, and best practice statements made where evidence was not available. Evidence was weighed in light of benefits and harms to arrive at a recommendation. The certainty of the evidence for some recommendations was modified in this update with a more refined application of the GRADE framework centred around patient important outcomes. This is highlighted in the rationale section of this update. A note is also made where the newly identified evidence did not alter the strength or certainty of evidence for previous recommendations. The recommendations presented here continue to cover various aspects of diagnosing soft tissue and bone infections, including the classification scheme for diagnosing infection and its severity. Guidance on how to collect microbiological samples, and how to process them to identify causative pathogens, is also outlined. Finally, we present the approach to treating foot infections in persons with diabetes, including selecting appropriate empiric and definitive antimicrobial therapy for soft tissue and bone infections; when and how to approach surgical treatment; and which adjunctive treatments may or may not affect the infectious outcomes of diabetes-related foot problems. We believe that following these recommendations will help healthcare professionals provide better care for persons with diabetes and foot infections, prevent the number of foot and limb amputations, and reduce the patient and healthcare burden of diabetes-related foot disease.

Interventions in the management of diabetes-related foot infections: A systematic review

The optimal approaches to managing diabetic foot infections remain a challenge for clinicians. Despite an exponential rise in publications investigating different treatment strategies, the various agents studied generally produce comparable results, and high-quality data are scarce. In this systematic review, we searched the medical literature using the PubMed and Embase databases for published studies on the treatment of diabetic foot infections from 30 June 2018 to 30 June 2022. We combined this search with our previous literature search of a systematic review performed in 2020, in which the infection committee of the International Working Group on the Diabetic Foot searched the literature until June 2018. We defined the context of the literature by formulating clinical questions of interest, then developing structured clinical questions (Patients-Intervention-Control-Outcomes) to address these. We only included data from controlled studies of an intervention to prevent or cure a diabetic foot infection. Two independent reviewers selected articles for inclusion and then assessed their relevant outcomes and methodological quality. Our literature search identified a total of 5,418 articles, of which we selected 32 for full-text review. Overall, the newly available studies we identified since 2018 do not significantly modify the body of the 2020 statements for the interventions in the management of diabetes-related foot infections. The recent data confirm that outcomes in patients treated with the different antibiotic regimens for both skin and soft tissue infection and osteomyelitis of the diabetes-related foot are broadly equivalent across studies, with a few exceptions (tigecycline not non-inferior to ertapenem [±vancomycin]). The newly available data suggest that antibiotic therapy following surgical debridement for moderate or severe infections could be reduced to 10 days and to 3 weeks for osteomyelitis following surgical debridement of bone. Similar outcomes were reported in studies comparing primarily surgical and predominantly antibiotic treatment strategies in selected patients with diabetic foot osteomyelitis. There is insufficient high-quality evidence to assess the effect of various recent adjunctive therapies, such as cold plasma for infected foot ulcers and bioactive glass for osteomyelitis. Our updated systematic review confirms a trend to a better quality of the most recent trials and the need for further well-designed trials to produce higher quality evidence to underpin our recommendations.

Rationale and design of the RAPID-WATER-FLOW trial: Radiolabeled perfusion to identify coronary artery disease using water to evaluate responses of myocardial FLOW

OBJECTIVES

The objective of this study was to determine the diagnostic performance of 15O-water positron emission tomography (PET) myocardial perfusion imaging to detect coronary artery disease (CAD) using the truth-standard of invasive coronary angiography (ICA) with fractional flow reserve (FFR) or instantaneous wave-Free Ratio (iFR) or coronary computed tomography angiogram (CCTA).

BACKGROUND

15O-water has a very high first-pass extraction that allows accurate quantification of myocardial blood flow and detection of flow-limiting CAD. However, the need for an on-site cyclotron and lack of automated production at the point of care and relatively complex image analysis protocol has limited its clinical use to date.

METHODS

The RAPID WATER FLOW study is an open-label, multicenter, prospective investigation of the accuracy of 15O-water PET to detect obstructive angiographic and physiologically significant stenosis in patients with suspected CAD. The study will include the use of an automated system for producing, dosing, and injecting 15O-water and enrolling approximately 215 individuals with suspected CAD at approximately 10 study sites in North America and Europe. The primary endpoint of the study is the diagnostic sensitivity and specificity of the 15O-water PET study using the truth-standard of ICA with FFR or iFR to determine flow-limiting stenosis, or CCTA to rule out CAD and incorporating a quantitative analytic platform developed for the 15O-water PET acquisitions. Sensitivity and specificity are to be considered positive if the lower bound of the 95% confidence interval is superior to the threshold of 60% for both, consistent with prior registration studies. Subgroup analyses include assessments of diagnostic sensitivity, specificity, and accuracy in female, obese, and diabetic individuals, as well as in those with multivessel disease. All enrolled individuals will be followed for adverse and serious adverse events for up to 32 hours after the index PET scan. The study will have >90% power (one-sided test, α = 0.025) to test the hypothesis that sensitivity and specificity of 15O-water PET are both >60%.

CONCLUSIONS

The RAPID WATER FLOW study is a prospective, multicenter study to determine the diagnostic sensitivity and specificity of 15O-water PET as compared to ICA with FFR/iFR or CCTA. This study will introduce several novel aspects to imaging registration studies, including a more relevant truth standard incorporating invasive physiologic indexes, coronary CTA to qualify normal individuals for eligibility, and a more quantitative approach to image analysis than has been done in prior pivotal studies.

CLINICAL TRIAL REGISTRATION INFORMATION

Clinical-Trials.gov (#NCT05134012).

IWGDF/IDSA Guidelines on the Diagnosis and Treatment of Diabetes-related Foot Infections (IWGDF/IDSA 2023)

The International Working Group on the Diabetic Foot (IWGDF) has published evidence-based guidelines on the management and prevention of diabetes-related foot diseases since 1999. The present guideline is an update of the 2019 IWGDF guideline on the diagnosis and management of foot infections in persons with diabetes mellitus. The Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) framework was used for the development of this guideline. This was structured around identifying clinically relevant questions in the P(A)ICO format, determining patient-important outcomes, systematically reviewing the evidence, assessing the certainty of the evidence, and finally moving from evidence to the recommendation. This guideline was developed for healthcare professionals involved in diabetes-related foot care to inform clinical care around patient-important outcomes. Two systematic reviews from 2019 were updated to inform this guideline, and a total of 149 studies (62 new) meeting inclusion criteria were identified from the updated search and incorporated in this guideline. Updated recommendations are derived from these systematic reviews, and best practice statements made where evidence was not available. Evidence was weighed in light of benefits and harms to arrive at a recommendation. The certainty of the evidence for some recommendations was modified in this update with a more refined application of the GRADE framework centred around patient important outcomes. This is highlighted in the rationale section of this update. A note is also made where the newly identified evidence did not alter the strength or certainty of evidence for previous recommendations. The recommendations presented here continue to cover various aspects of diagnosing soft tissue and bone infections, including the classification scheme for diagnosing infection and its severity. Guidance on how to collect microbiological samples, and how to process them to identify causative pathogens, is also outlined. Finally, we present the approach to treating foot infections in persons with diabetes, including selecting appropriate empiric and definitive antimicrobial therapy for soft tissue and bone infections; when and how to approach surgical treatment; and which adjunctive treatments may or may not affect the infectious outcomes of diabetes-related foot problems. We believe that following these recommendations will help healthcare professionals provide better care for persons with diabetes and foot infections, prevent the number of foot and limb amputations, and reduce the patient and healthcare burden of diabetes-related foot disease.

Pooled study-level analysis of randomized controlled trials analyzing the effect of negative pressure wound therapy with irrigation vs traditional negative pressure wound therapy on diabetic foot outcomes

INTRODUCTION

The benefits of NPWT-T for the diabetic foot have been established. The addition of regular periodic irrigation with broad-spectrum antiseptic solution has been shown to reduce bioburden and total bacterial colonies; however, debate remains as to the clinical effect on diabetic foot outcomes.

OBJECTIVE

This study investigated the differences between NPWT-T and NPWT-I for treatment of the diabetic foot and the associated clinical outcomes.

METHODS

PubMed, Medline/Embase, the Cochrane Library, and Web of Science were searched for relevant literature published between January 1, 2002, and March 1, 2022. Keywords included "Negative Pressure Wound Therapy" AND "Instillation" OR "Irrigation." Three studies with a total of 421 patients (NPWT-T [n = 223], NPWT-I [n = 198]) were included in the meta-analysis.

RESULTS

No significant differences were observed between NPWT-T and NPWT-I for BWC (OR, 1.049; 95% CI, 0.709-1.552; P =.810), time to wound closure (SMD, -0.039; 95% CI, -0.233-0.154; P =.691), LOS (SMD, 0.065; 95% CI, -0.128-0.259; P =.508), or AEs (OR, 1.092; 95% CI, 0.714-1.670; P =.69).

CONCLUSION

Results of this systematic review and meta-analysis indicate that further RCTs are required to assess the role of NPWT-I in the management of DFU and DFI.

Abstract 2478: Development of a novel HIF2a PET tracer: From proof of concept to a clinical trial

Normally induced by hypoxia, hypoxia-inducible factor 2 alpha (HIF2a) is arguably the most important driver of kidney cancer. HIF2a is constitutively activated following von Hippel-Lindau (VHL) gene inactivation, which is the signature event of the most common type of kidney cancer, clear cell renal cell carcinoma (ccRCC). HIF2a functions as a heterodimeric transcription factor in partnership with the constitutive HIF1b subunit and regulates a program of gene expression that promotes cell proliferation, stemness, and angiogenesis. While as a transcription factor HIF2a had escaped drug targeting, structural studies revealed an unusual cavity, which became the foundation for the development of small molecule inhibitors such as PT2385 (a first-in-class drug), or the related PT2399 tool compound and the recently FDA-approved PT2977 (also called belzutifan). PT drugs bind a small pocket in the PAS-B domain of HIF2a inducing a conformational change that triggers dissociation from its obligatory partner HIF1b. PT drugs are highly specific - they do not bind the close paralog HIF1a and do not induce changes in gene expression in cells devoid of HIF2a. Using an extensive library of patient-derived xenografts (PDXs), we previously showed that PT drugs have activity against 50% of ccRCCs implanted in mice, and similar observations were made in the clinic. Perhaps unsurprisingly, sensitive tumors showed higher HIF2a levels. Here, we leverage the specificity of PT2385 to develop a HIF2a tracer for positron emission tomography (PET). By substituting a native fluorine atom for 18F, we generated [18F]PT2385. [18F]PT2385 was able to discriminate HIF2a-expressing ccRCCs from tumors that did not express HIF2a in mice simultaneously implanted with both. These data set the foundation for an investigator new drug (IND) approval from the FDA, and a clinical trial that is currently accruing patients (NCT04989959). [18F]PT2385 PET may have applications in identifying kidney cancer patients most likely to respond to HIF2a-targeted therapies, the identification of other tumors relying on HIF2a, and beyond oncology. Reporting on a hypoxia sensor, a HIF2a radiotracer may be a useful ischemia probe. In summary, we report the development of a novel radiotracer with extensive potential applications currently being evaluated in humans.

Citation Format: Sashi Debnath, Christina Stevens, Olivia Brandenburg, Justin Sovich, Paulina Gonzalez, Qian (Janie) Qin, Sydney Haldeman, Vanina Toffessi Tcheuyap, Alana Christie, Pawan Thapa, Ning Zhou, Aditi Mulgaonkar, Guiyang Hao, Jeffrey Miyata, Deyssy Carrillo, Jeffrey Cadeddu, Payal Kapur, Jon Anderson, Ivan Pedrosa, Marianna Dakanali, Orhan Oz, Xiankai Sun, James Brugarolas. Development of a novel HIF2a PET tracer: From proof of concept to a clinical trial [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 2478.

Abstract 1234: PD-L1 PET: A potential biomarker of checkpoint inhibitor sensitivity in renal cancer

Immune checkpoint inhibitors (ICIs) have revolutionized cancer therapy. Program death-ligand 1 (PD-L1) and its corresponding receptor (PD-1) are the target of most FDA-approved ICIs. Perhaps unsurprisingly, PD-L1 levels are predictive of response to targeting drugs in lung and other cancers. However, PD-L1 is not predictive in other tumor types including renal cell carcinoma (RCC). PD-L1 is typically measured on tumor biopsies or archival tissues and we hypothesized that the lack of PD-L1 predictive power is due to tumor heterogeneity and tumor evolution. To test this notion, we embarked upon the generation of a PD-L1 probe that would enable real time assessment of PD-L1 across sites of disease using molecular imaging. We leveraged atezolizumab, a highly specific PD-L1 therapeutic antibody with a mutant Fc. Atezolizumab (ATZ) was labeled with 89Zr after conjugation with a bifunctional chelator and evaluated by positron emission tomography (PET). In extensive preclinical studies using multiple patient-derived xenografts (PDXs) with variable PD-L1 levels, we show that 89Zr-ATZ PET is able to distinguish RCC with variable PD-L1 expression. These data set the foundation for an investigator new drug (IND) approval from the FDA and an ongoing clinical trial in RCC patients (NCT04006522). Consistent with our hypothesis, 89Zr-ATZ PET shows substantial PD-L1 heterogeneity not only across but also within patients at different sites of disease. Furthermore, preliminary data suggest that PD-L1 levels may be predictive of response to ICI. By assessing PD-L1 expression in real time, 89Zr-ATZ PET may enable: (1) the identification of patients most likely to respond to PD-L1/PD-1 targeted therapies; (2) tailored management of the disease across different sites; (3) the evaluation of interventions that modulate PD-L1 levels; (4) insights into toxicities; and (5) probing resistance.

Citation Format: Aditi Mulgaonkar, Layton Woolford, Roy Elias, Kien Nham, Bing Guan, Guiyang Hao, Christina Stevens, Vanina Toffessi Tcheuyap, Sydney Haldeman, Jeffrey Miyata, Deyssy Carrillo, Qian (Janie) Qin, Nirmish Singla, Isaac Bowman, Jeffrey Cadeddu, Vitaly Margulis, Alana Christie, Payal Kapur, Ivan Pedrosa, Marianna Dakanali, Orhan Oz, Xiankai Sun, James Brugarolas. PD-L1 PET: A potential biomarker of checkpoint inhibitor sensitivity in renal cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 1234.

Are Surrogate Markers for Diabetic Foot Osteomyelitis Remission Reliable?

BACKGROUND

We aimed to evaluate surrogate markers commonly used in the literature for diabetic foot osteomyelitis remission after initial treatment for diabetic foot infections (DFIs).

METHODS

Thirty-five patients with DFIs were prospectively enrolled and followed for 12 months. Osteomyelitis was determined from bone culture and histologic analysis initially and for recurrence. Fisher exact and χ2 tests were used for dichotomous variables and Student t and Mann-Whitney U tests for continuous variables (α = .05).

RESULTS

Twenty-four patients were diagnosed as having osteomyelitis and 11 as having soft-tissue infections. Four patients (16.7%) with osteomyelitis had reinfection based on bone biopsy. The success of osteomyelitis treatment varied based on the surrogate marker used to define remission: osteomyelitis infection (16.7%), failed wound healing (8.3%), reulceration (20.8%), readmission (16.7%), amputation (12.5%). There was no difference in outcomes among patients who were initially diagnosed as having osteomyelitis versus soft-tissue infections. There were no differences in osteomyelitis reinfection (16.7% versus 45.5%; P = .07), wounds that failed to heal (8.3% versus 9.1%; P = .94), reulceration (20.8% versus 27.3%; P = .67), readmission for DFIs at the same site (16.7% versus 36.4%; P = .20), amputation at the same site after discharge (12.5% versus 36.4%; P = .10). Osteomyelitis at the index site based on bone biopsy indicated that failed therapy was 16.7%. Indirect markers demonstrated a failure rate of 8.3% to 20.8%.

CONCLUSIONS

Most osteomyelitis markers were similar to markers in soft-tissue infection. Commonly reported surrogate markers were not shown to be specific to identify patients who failed osteomyelitis treatment compared with patients with soft-tissue infections. Given this, these surrogate markers are not reliable for use in practice to identify osteomyelitis treatment failure.

SAT-024 Adipose Specific Inactivation of Aromatase is Sufficient to Cause Adiposity and Impaired Glucose Tolerance in Mice

Aromatase synthesizes estrogens from androgens. While the gonads are major sites of aromatase expression, it is expressed in multiple other organs including adipose tissue, brain and bone. In global aromatase knockouts in mice, studied by us, or man aromatase deficiency there are phenotypes of adiposity and low bone mass as well as varying degrees of insulin resistance. Breast cancer patients treated with aromatase inhibitors (AIs) also develop adiposity and low bone mass. Thus, it remains unclear the role of site specific aromatase activity in the phenotypes observed in chemically or genetically induced aromatase deficiency. To begin to understand the relative contributions of tissue specific aromatase activity and develop a model that will be useful for understanding and developing therapeutic strategies for ailments in aromatase inhibitor therapy, we have developed mouse models with tissue specific aromatase inactivation. Embryonic stem cells were purchased from EUCOMM. Using standard methods and appropriate breeding strategies we generated C57Bl6 mice with Lox P sites flanking Exon 2 in the aromatase gene (Arom fl/fl). Mice with adipose specific inactivation of aromatase were generated by interbreeding Arom fl/fl mice with mice expressing Cre recombinase driven by the adiponectin promoter (AdipoCre). We measured body composition by dual energy x-ray absorptiometry (Lunar PIXIMus 2). As a first step in examining glucose homeostasis we performed oral glucose tolerance tests. All mice were fed normal chow and the study was approved by the local IACUC. Female mice aged 4-6 months were studied with at least 4 animals in each group. Arom fl/fl mice were compared as controls for the AdipoCre+; Arom fl/fl mice. Mean body weight was higher in fat specific aromatase knockout female mice (33.6 vs 21.6, p<0.05). On DEXA Mean %Body fat was higher in female AdipoCre+;Arom fl/fl mice (29.3% vs. 17.3%, p<0.05). Following a 16h fast female mice with adipose specific aromatase inactivation had higher fasting blood glucose levels (93.3+/-10.3 vs 74.5+/-10, p=0.03). For the glucose tolerance test, a bolus of glucose (2 g/kg) was delivered into the stomach by a gavage needleand blood was sampled at 0, 5, 10, 20, 30, 60, 90, 120, and 180 min for plasma glucose analyses. On OGTT peak glucose levels were higher and did not return to baseline. Insulin tolerance tests will be performed to further understand the mechanism of impaired glucose homeostasis. Male mice with fat specific aromatase inactivation showed similar patterns in higher body weight, percent body fat and glucose levels but the phenotype was more variable. In summary, fat specific aromatase inactivation is sufficient to cause adiposity and impaired glucose homeostasis. The observed phenotype in females is more robust than we have observed in the global knockout.

Choroidal Neovascularization after Laser in Situ Keratomileusis in a Patient with Presumed Ocular Histoplasmosis Syndrome

Purpose

A 44-year-old patient with presumed ocular histoplasmosis syndrome (POHS) who developed a choroidal neovascularmembrane (CNV) after laser in situ keratomileusis (LASIK) surgery is presented.

METHODS

A 44-year-old male patient with moderate myopia and POHS who underwent LASIK surgery complained of distorted vision after the procedure. He had a quiet POHS lesion prior to refractive surgery. Fundus examination and fluorescein angiography revealed subfoveal CNV after the LASIK surgery. He underwent 2 sessions of photodynamic therapy (PDT).

Results

Subfoveal CNV involuted after PDT and his vision improved from 20/300 to 20/25 at 13 months follow-up.

CONCLUSIONS

CNV can be triggered by LASIK surgery in patients with POHS. Those patients should be made aware of and closely followed up postoperatively for this complication.

A Short Duration Transient Ischemia Induces Apoptosis in Retinal Layers: An Experimental Study in Rabbits

Purpose

To investigate retinal cell apoptosis in an experimental transient, short duration ocular ischemia model.

Methods

An experimental ischemia model, which simulates creating temporary high intraocular pressure to control intraocular bleeding during pars plana vitrectomy, was set up. Rabbits were randomly divided into three groups. Group 1 was the control group. In Group 2, intraocular pressure was increased to 97 mmHg for 5 minutes. In Group 3, intraocular pressure was increased to 97 mmHg for 10 minutes. After 24 hours, terminal deoxyribonucleotidyl transferase-mediated dUTP-digoxigenin nick-end labeling assay was used to detect retinal apoptosis in rabbit eyes. Only nuclear staining in retinal cells was counted.

Results

Groups with 5 minutes and 10 minutes of ischemia showed significantly higher amount of ganglion cell layer apoptosis when compared with the control group (p<0.05). Light microscopy and standard hematoxylin-eosin did not show any significant damage in the retina cells.

Conclusions

Apoptotic cell death in the retinal cell layers occurs in temporary ischemia-reperfusion as early as 5 and 10 minutes duration.

Multicenter study of pars plana vitrectomy for optic disc pit maculopathy: MACPIT study

PurposeTo evaluate surgical intervention with pars plana vitrectomy (PPV) for correction of optic disc pit maculopathy (ODP-M).Patients and methodsRetrospective chart review from 13 centres of 51 eyes of 50 patients with ODP-M who underwent PPV between 2002-2014. Anatomic and final best-corrected visual acuity (BCVA) outcomes were evaluated for all cases with different adjuvant techniques.ResultsThere were 23 males and 27 females with median age 25.5 (6-68) years. Preoperative median foveal thickness was 694.5 (331-1384) μm and improved to 252.5 (153-1405) μm. Median BCVA improved from 20/200 (20/20000 to 20/40) to 20/40 (20/2000 to 20/20) with 20/40 or better in 31 eyes. Complete retinal reattachment was achieved in 44 eyes (86.3%) at 7.1 (5.9) months. The good surgical outcomes were achieved in different adjuvant groups. Median follow-up was 24 (6 to 120) months.ConclusionsThese results confirm the long-term effectiveness of PPV for ODP-M. Prospective studies are needed to determine the effectiveness of any adjuvant technique in improving the success of PPV for ODP-M.

Relationship between oxidative stress and chronic daily headache in children

The aim of this study was to investigate the relationship between oxidative stress and chronic daily headache (CDH) in children. Although there are reports that oxidative injury may play a role in the pathophysiology of some neurologic disorders, such as migraine and epilepsy, by disrupting or destroying cell membranes through the formation of free radical and reactive oxygen species, the pathophysiology of headache is not clearly established. A total of 38 children (16 boys and 22 girls) with CDH, aged between 7 and 15 years, were enrolled in the study. The control group consisted of 39 healthy children (17 boys and 22 girls), aged between 7 and 14 years. The mean age was 10.9 ± 2.2 years for both the groups. Activities of erythrocyte superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx) as well as malondialdehyde (MDA) levels in all the children of both the groups were measured. Mean activities of erythrocyte SOD, CAT, and GPx as well as MDA levels were significantly higher in the study group than in the control group (p < 0.001). The findings of this study suggest that oxidative stress may play a causal or consequential role in children with CDH.

Cutaneous silent period changes in Type 2 diabetes mellitus patients with small fiber neuropathy

OBJECTIVE

Small myelinated (A-delta) and unmyelinated (C) somatic sensory fibers are initially affected and may be the earliest exhibited sign of neuropathy in glucose dysmetabolism. Cutaneous silent period (CSP) is an inhibitory spinal reflex and its afferents consist of A-delta nerve fibers. The aim of this study was to evaluate CSP changes in Type 2 diabetic patients with small fiber neuropathy.

METHODS

Forty-three patients and 41 healthy volunteers were included. CSP latency and duration, as well as CSP latency difference of the upper and lower extremities, were examined.

RESULTS

Nerve conduction studies were within normal limits in both groups. Lower extremity CSP latency was longer (122.1+/-15.5 vs. 96.4+/-6.4 ms; p<0.001), CSP duration was shorter (29.5+/-8.9 vs. 43.1+/-5.0 ms; p<0.001), and latency difference was longer (48.1+/-12.6 vs. 22.7+/-3.7; p<0.001) in patients than controls. The difference was more significant in patients with neuropathic pain. No significant difference existed in upper extremity on CSP evaluation.

CONCLUSION

The CSP evaluation together with nerve conduction study, has been demonstrated to be beneficial and performance of latency difference in addition to CSP latency and duration may be a valuable parameter in electrophysiological assessment of diabetic patients with small fiber neuropathy.

SIGNIFICANCE

An additional CSP evaluation may be considered in cases which nerve conduction studies do not provide sufficient information.

Cyclooxygenase-2 expression in primary and recurrent pterygium

PURPOSE

Pterygium is a proliferative, inflammatory, and invasive ocular surface disease associated with excessive ultraviolet radiation exposure and has several tumor-like characteristics. Cyclooxygenase-2 (COX-2) is an inducible enzyme and recently increased expression of the enzyme was found in many cancers and premalign lesions. This study was conducted to identify the COX-2 expression in pterygium tissues.

METHODS

Immunohistochemical staining using a primary antibody for COX-2 was performed on 30 specimens with primary pterygium (20 pterygium without recurrence and 10 pterygium which recurred during a 12-month follow-up), 11 specimens with recurrent pterygium, and 8 specimens of conjunctival tumor. As a control we used 10 specimens of normal conjunctiva. Extent and intensity of cytoplasmic and membranous staining in epithelial cells were evaluated.

RESULTS

Higher expression of COX-2 was detected in conjunctival tumor (87.5%) specimens and recurrent pterygium specimens (72.7%) compared to the both normal conjunctiva (30%) and primary pterygium without recurrence (30%). COX-2 expression in primary pterygium tissues with recurrence (60%) was not different from primary pterygium without recurrence (p=0.114) and recurrent pterygium (p=0.537). However, recurrent pterygium tissues were found to express higher COX-2 than primary pterygium without recurrence (p=0.022).

CONCLUSIONS

COX-2 expression is increased in recurrent pterygium tissues and COX-2 expression may be a marker for the prediction of recurrence.

Glutathione s-transferase m1, t1, and p1 gene polymorphism in exudative age-related macular degeneration: a preliminary report

PURPOSE

To elucidate whether the gene polymorphisms of glutathione S-transferase (GST) M1, T1, and P1 are associated with the development of exudative age-related macular degeneration.

METHODS

The authors genotyped 35 white patients with exudative age-related macular degeneration and 159 healthy controls. Genomic DNA from peripheral blood was examined using polymerase chain reaction and defined for the genetic polymorphisms of GST.

RESULTS

No association was observed between GSTM1, GSTT1, and GSTP1 polymorphisms and age-related macular degeneration risk (p>0.05). The frequencies of the combination of the GSTM1 (null) and GSTP1 (mutant), GSTM1 (null), and GSTT1 (null) genotype polymorphisms in patients with exudative age-related macular degeneration differed greatly from those of the control group (p=0.001 OR [95% CI]: 7.70 [2.28-25.98] and p=0.007 OR [95% CI]: 3.88 [1.51-10.02], respectively).

CONCLUSIONS

The present study suggests that the GSTM1 (null) and GSTT1 (null), GSTM1 (null), and GSTP1 (mutant) combinations may be a genetic risk factor for the development of exudative age-related macular degeneration. However, the potential role of GST polymorphisms as a marker of susceptibility to age-related macular degeneration needs further studies in a larger number of patients. (Eur J Ophthalmol 2006; 16: 105-10).

Glutathione S-transferase M1, T1, and P1 gene polymorphism in exudative age-related macular degeneration: a preliminary report

PURPOSE

To elucidate whether the gene polymorphisms of glutathione S-transferase (GST) M1, T1, and P1 are associated with the development of exudative age-related macular degeneration.

METHODS

The authors genotyped 35 white patients with exudative age-related macular degeneration and 159 healthy controls. Genomic DNA from peripheral blood was examined using polymerase chain reaction and defined for the genetic polymorphisms of GST.

RESULTS

No association was observed between GSTM1, GSTT1, and GSTP1 polymorphisms and age-related macular degeneration risk (p>0.05). The frequencies of the combination of the GSTM1 (null) and GSTP1 (mutant), GSTM1 (null), and GSTT1 (null) genotype polymorphisms in patients with exudative age-related macular degeneration differed greatly from those of the control group (p=0.001 OR [95% CI]: 7.70 [2.28-25.98] and p=0.007 OR [95% CI]: 3.88 [1.51-10.02], respectively).

CONCLUSIONS

The present study suggests that the GSTM1 (null) and GSTT1 (null), GSTM1 (null), and GSTP1 (mutant) combinations may be a genetic risk factor for the development of exudative age-related macular degeneration. However, the potential role of GST polymorphisms as a marker of susceptibility to age-related macular degeneration needs further studies in a larger number of patients.

Mucociliary clearance after external dacryocystorhinostomy

We investigated the nasal mucociliary clearance time in 17 patients who underwent a primary unilateral external dacryocystorhinostomy operation. Mucociliary clearance function in both nasal cavities was assessed with the saccharin test. The results were compared with each other using paired samples t-test. We found significantly worse mucociliary clearance time on the operated side (mean: 6.3 min) than on the non-operated side (mean: 5.5 min) (P = 0.004). External dacryocystorhinostomy negatively affected the mucociliary clearance function in this study.

Choroidal neovascularization after laser in situ keratomileusis in a patient with presumed ocular histoplasmosis syndrome

PURPOSE

A 44-year-old patient with presumed ocular histoplasmosis syndrome (POHS) who developed a choroidal neovascular membrane (CNV) after laser in situ keratomileusis (LASIK) surgery is presented.

METHODS

A 44-year-old male patient with moderate myopia and POHS who underwent LASIK surgery complained of distorted vision after the procedure. He had a quiet POHS lesion prior to refractive surgery. Fundus examination and fluorescein angiography revealed subfoveal CNV after the LASIK surgery. He underwent 2 sessions of photodynamic therapy (PDT).

RESULTS

Subfoveal CNV involuted after PDT and his vision improved from 20/300 to 20/25 at 13 months follow-up.

CONCLUSIONS

CNV can be triggered by LASIK surgery in patients with POHS. Those patients should be made aware of and closely followed up postoperatively for this complication.

Successful surgical repair and good visual outcome of a recurrent macular hole of seven years duration

PURPOSE

To report anatomical closure and visual improvement in a patient with seven-year history of recurrent macular hole.

METHODS

A 68-year-old woman underwent vitrectomy and silicone oil tamponade for a seven-year old recurrent macular hole.

RESULTS

Macular hole closed and visual acuity improved form 20/400 to 20/60 at 12 months follow-up.

CONCLUSIONS

The eyes with very-long standing macular holes may be considered for surgery. Predictors of successful visual outcome after surgery in very-long standing macular holes should be studied in larger series.

Uveitis associated with granuloma annulare

PURPOSE

To report a case of uveitis associated with granuloma annulare (GA). GA is a benign, usually self-limited dermatosis of unknown origin, causing necrobiotic dermal and subcutaneous papules. So far, ocular involvement has not been reported in GA.

METHODS

We describe a case of uveitis with GA. Ocular examination findings were consistent with uveitis. Histopathologic studies on lower extremity lesions revealed features consistent with GA.

RESULTS

The patient was successfully treated with systemic and topical corticosteroids. After two months, however, the skin and eye lesions relapsed. When the same treatment was restarted, her lesions regressed within four weeks.

CONCLUSIONS

This case provides an example of concomitant uveitis and GA. To our knowledge, this is the first report of this combination.

A case of lichen planus-lupus erythematosus overlap syndrome with eyelid involvement

PURPOSE

To report a case of lichen planus-lupus erythematosus overlap syndrome with eyelid involvement. Lichen planus and lupus erythematosus infrequently coexist in the same patients. Ocular involvement has rarely been reported for both diseases.

CASE REPORT

We describe a case of lichen planus-lupus erythematosus overlap syndrome with eyelid involvement. Histopathologic and immunofluorescent studies were done on buccal, lip, left conjunctival, malar, auricular and scalp lesions. The immunopathologic features of the conjunctiva, buccal mucosa and lip were consistent with lichen planus, while those of the malar, auricular and scalp lesions favoured lupus erythematosus.

RESULTS

The patient was successfully treated with hydroxychloroquine 200 mg/day and all lesions responded to therapy within weeks.

CONCLUSIONS

This is a rare example of two coexisting autoimmune disease entities: lichen planus of the oral mucosa, lip, eyelid and discoid lupus erythematosus of the skin. To our knowledge, this is the first reported case of lichen planus-lupus erythematosus overlap syndrome with eyelid involvement.

Factors influencing treatment results in pseudophakic endophthalmitis

PURPOSE

To evaluate risk factors, therapeutic approaches and factors associated with the poor visual outcome in pseudophakic endophthalmitis.

METHODS

Data related to 28 cases with the diagnosis of endophthalmitis after cataract surgery and IOL implantation were gathered retrospectively.

RESULTS

Preceding surgery was extracapsular cataract extraction (ECCE) in 18, phacoemulsification in 8 and scleral fixated intraocular lens implantation in two cases. Posterior capsule rupture and diabetes mellitus were considered to contribute to the development of endophthalmitis because of their high incidences (50% and 25%) in the study group. Microbiological studies from aqueous and vitreous humour were done in 85% of the cases and 58% were positive. S. Epidermidis was the most common organism, accounting for 50% of the isolates. All cases were given topical and systemic antibiotics. Inflammation was controlled by addition of subconjunctival antibiotics to this regimen in two, intravitreal antibiotic injection in 14, pars plana vitrectomy, total capsular and lens extraction and intravitreal antibiotic injection in three, lens exchange, intracapsular and intravitreal antibiotic injection in three cases. Six (21%) cases eventually needed evisceration. Visual acuity of 20/40 or better was achieved in 25%, and 20/100 or better in 64%.

CONCLUSIONS

Treatment delay (p=0.039), capsular rupture complicating cataract surgery, especially with extracapsular cataract extraction (p=0.015), and initial visual acuity worse than hand motion (p=0.003) were strong predictors of poor visual outcome. The risk of endophthalmitis was not different forplanned ECCCE (0.26%) andphacoemulsification (0.27%) but the prognosis was better with the latter.

Nonlinear dynamics applied to blood pressure control

Hypertension is a very frequent disease, known to trigger a range of severe cardiovascular problems. The elucidation of its pathophysiology requires investigation of the mechanisms responsible for the maintenance of blood pressure in the normal system, and their possible failure in hypertension. Some of these control mechanisms display nonlinear features, indicating that the blood pressure signal might be characterized by nonlinear dynamics. Our aim was thus to investigate the nonlinear properties of the blood pressure signal under normal conditions, and in a cardiovascular system prone to hypertension. Blood pressure was investigated in young spontaneously hypertensive rats (SHR), versus their age-matched normotensive progenitors (WKY). The correlation dimension was computed as quantification of blood pressure control complexity. The parameters required for the calculation procedure of the correlation dimension were carefully determined. The results were tested with surrogate data statistics. assuming linear autocorrelated Gaussian noise as the null hypothesis. Non-integer correlation dimension values were found in both strains, with lower values for SHR than for WKY, in particular following alpha-blockade. In all cases, a statistically significant difference was found between the real and surrogate data. These results show that the nonlinear dynamics parameter D, can be used to detect differences in BP control between prehypertensive SHR and WKY rats as early as 6-7 weeks after birth.

Correlation dimension estimation: can this nonlinear description contribute to the characterization of blood pressure control in rats?

The application of correlation dimension estimation to the study of cardiovascular control, via the blood pressure (BP) time series was investigated. We chose to calculate the Grassberger-Procaccia (GP) correlation dimension. In order to obtain a reliable estimate of the correlation dimension, we studied impact of various parameters such as the appropriate sampling rate, the time delays, the embedding dimension, the minimal trace length required, and the number of points needed as reference points. We developed a recipe for the reliable treatment of the continuous BP signal in rats, our animal model, and discussed the possible pitfalls which demand special attention. Next, we applied the surrogate data method to a BP time series, looking for the existence of nonlinear components, in order to test whether the nonlinear modeling is necessary for accurately describing the system. We found that, indeed, the correlation dimension does reveal information which cannot be unveiled by the commonly used power spectral technique, thus, making the nonlinear modeling an important approach, providing additional insight into the cardiovascular control system.

Nonmalignant renal disease in pediatric patients with Beckwith-Wiedemann syndrome

OBJECTIVE

The objective of this retrospective review was to determine the incidence and spectrum of nonmalignant renal disease in patients with Beckwith-Wiedemann syndrome.

MATERIALS AND METHODS

Patient records were obtained from the Beckwith-Wiedemann Registry of the National Cancer Institute. Imaging findings and medical records of 152 neonates, infants, children, and adults with Beckwith-Wiedemann syndrome (age range, 1 day to 30 years old; median age, 1 year 3 months old) were retrospectively reviewed by three radiologists. Available pathologic material also was reviewed.

RESULTS

Thirty-eight (25%) of 152 patients with Beckwith-Wiedemann syndrome had 45 nonmalignant renal abnormalities, including medullary renal cysts (n = 19, 13%), caliceal diverticula (n = 2, 1%), hydronephrosis (n = 18, 12%), and nephrolithiasis (n = 6, 4%). Thirty-three (87%) of the 38 patients with nonmalignant renal disease were asymptomatic. Clinical manifestations of the remaining five patients included urinary tract infections (n = 4) and flank pain due to obstructive stone disease (n = 1). Nonmalignant renal disease was mistaken for Wilms' tumor in two patients, resulting in unnecessary nephrectomies. Seven children (18%) had Wilms' tumor and nonmalignant renal disease.

CONCLUSION

Nonmalignant renal abnormalities occur in approximately 25% of patients with Beckwith-Wiedemann syndrome but are generally asymptomatic. Nonmalignant renal abnormalities should be considered in the differential diagnosis of a mass revealed during screening sonography of a patient with Beckwith-Wiedemann syndrome to avoid unnecessary surgery.

Beat-to-beat fluctuations in the BP related signals in rats: can it contribute to the understanding of the development of hypertension?

The goal of this study was to investigate the alterations in blood pressure control in young spontaneously hypertensive rats (SHR), as reflected in the power distribution of blood pressure fluctuations. We studied six SHR preceding the onset of overt hypertension, compared to six age matched control rats, the normotensive Wistar-Kyoto rats (WKY), and analyzed the power density distribution of several blood pressure related signals, namely: arterial blood pressure (ABP), systolic blood pressure (SBP), diastolic blood pressure (DBP), pulse pressure (PP) and heart rate (HR). ABP fluctuations exhibited a basic difference in the power distribution pattern between the strains: at low frequencies (< 0.15 Hz) more power was observed in WKY than in SHR, while in the (0.35-1.00 Hz) range, more power was observed in SHR. These significant differences in patterns which existed at baseline, were abolished by prazosin (2.5 mg/kg). Observing the power distribution in the BP related signals, the patterns were different from that found in the ABP itself. At baseline, in SBP and DBP, the most dominant power was located at low frequencies < 0.04 Hz, like in ABP. However, unlike ABP, the remainder of the power was located in the high frequency region (HF: 1.5-3.0 Hz), mainly in SHR. Prazosin had a marked effect on PP power spectra; it shifted the power to the HF region in both strains. In PP, power spectra differences observed between the strains at baseline in HF were eliminated by prazosin. This seems to indicate that, in SHR compared to WKY, respiratory fluctuations which are low at baseline in PP, are a mechanical reflection of the higher sympathetic tone in SHR before alpha1 sympathetic blockade. This study supports previous findings in which differences in cardiovascular control occur in SHR already at the prehypertensive stage. The above results suggest that alpha1 sympathetic control is altered in the SHR strain, and therefore, when this limb is blocked, some of the differences between the strains disappear. Furthermore, the analysis of the BP related signals enable us to identify alterations existing in the control mechanisms in SHR, which involve adjunct control mechanisms enhanced under alpha1 sympathetic blockade. Finally, an important result is, that for all BP related signals under study, excluding HR, the response to alpha1-blockade reduces the power density in the 0.07-0.15 Hz region indicating that this region is directly associated with the activity of alpha control.

Autonomic response to change of posture among normal and mild-hypertensive adults: investigation by time-dependent spectral analysis

In this study, we applied the time-dependent spectral analysis approach (SDA) to investigate the autonomic changes occurring during a transition from supine to standing position (CP), in normal and unmedicated mild hypertensive subjects. The SDA method enables an accurate follow-up of the instantaneous changes in autonomic activity, even during the unsteady phase of the transition, where sudden changes in heart rate (HR) and arterial blood pressure (ABP) are observed. We were able to quantify the vagal withdrawal (reflected in the high frequency component of the time-dependent spectrum of HR fluctuations) in the immediate response to CP and the more slowly following sympathetic increase (reflected in the low frequency component of ABP). This general pattern was observed in both groups. In addition, our results identified an altered sympathetic response to CP in mild-hypertensives, as compared to normal adults. Their basal sympathetic activity is enhanced (higher mean HR and increased low frequency fluctuations in ABP) and their response to CP is reduced, as reflected only in the LF content of ABP fluctuations, relative to normals. No difference was observed in HR fluctuations, showing that there is no parasympathetically mediated alteration of the baroreflex control of HR in mild-hypertension.

The diastolic decay constant in spontaneously hypertensive rats versus WKY rats as an indicator for vasomotor control

This research uses the diastolic decay constant (tau) to investigate the short term mechanism responsible for vasomotor control, mainly the alpha-sympathetic control system. Previous studies have shown that vasomotor control is altered in spontaneously hypertensive rats (SHR) preceding the phase of overt hypertension. The diastolic decay, according to the two element Windkessel model, displays an exponential shape with a decay constant, tau, depending on both the vascular resistance and the compliance. In our experiments, we used tau to characterize vasomotor activity and its control in the normotensive rats as well as in the spontaneously hypertensive rats (SHR) prone to hypertension. The beat to beat value of tau was evaluated from a continuous arterial blood pressure (ABP) signal, measured in the tail artery of the conscious, unrestrained rat. Four months old prehypertensive SHR were compared to their age matched normotensive controls (WKY). To study vasomotor regulation, we computed gains and delay times by investigating the compensatory response in tau to changes in mean ABP (MBP). These parameters are expected in the short term to be neurally controlled by the sympathetic system, mainly alpha-sympathetic. Our set of experiments consisted of changing MBP by performing successive injections in bolus of increasing doses of the vasoconstrictor angiotensin II. This procedure was repeated under double cardiac autonomic blockade of the vagal and beta 1 = sympathetic limbs. Our results show that, under baseline conditions, the absolute gain and delay times of tau are reduced in SHR compared to WKY. Double cardiac blockade decreases the absolute gain in both strains, while abolishing the baseline strain differences. These results reinforce our assumption that, in SHR, the alpha-sympathetic system is in a basic state of excitation even prior to the onset of overt hypertension and therefore reacting with reduced sensitivity (lower gain) to changes in MBP.

Nonlinear analysis of BP signal. Can it detect malfunctions in BP control?

In the present study, our aim was to evaluate the applicability of the nonlinear technique to the investigation of cardiovascular control. We applied an approach known as the "surrogate data method" to test for nonlinear components in the blood pressure (BP) signal. Our results strongly indicate that there are nonlinear components in the BP time series taken from a Wistar-Kyoto rat (WKY), suggesting that the use of nonlinear methods may provide new information about the BP control system. We developed a procedure appropriate for the stable and reliable calculation of the Grassberger-Procaccia correlation dimension (D) of the arterial BP signal. The saturation value D was 5.48 +/- 0.30 for the WKY group and 5.92 +/- 0.26 for the spontaneously hypertensive rat (SHR) group, with P < 0.001. We also found that in the WKY group D displays a significant response to complete alpha 1 blockade and bleeding, whereas no response is observed in the SHR group. These results imply that differences in the control mechanisms may be detected by the nonlinear dynamics approach both under baseline conditions and when interfering with cardiovascular control.