Human Tears Reveal Insights into Corneal Neovascularization

Corneal neovascularization results from the encroachment of blood vessels from the surrounding conjunctiva onto the normally avascular cornea. The aim of this study is to identify factors in human tears that are involved in development and/or maintenance of corneal neovascularization in humans. This could allow development of diagnostic tools for monitoring corneal neovascularization and combination monoclonal antibody therapies for its treatment. In an observational case-control study we enrolled a total of 12 patients with corneal neovascularization and 10 healthy volunteers. Basal tears along with reflex tears from the inferior fornix, superior fornix and using a corneal bath were collected along with blood serum samples. From all patients, ocular surface photographs were taken. Concentrations of the pro-angiogenic cytokines interleukin (IL)-6, IL-8, Vascular Endothelial Growth Factor (VEGF), Monocyte Chemoattractant Protein 1 (MCP-1) and Fas Ligand (FasL) were determined in blood and tear samples using a flow cytometric multiplex assay. Our results show that the concentration of pro-angiogenic cytokines in human tears are significantly higher compared to their concentrations in serum, with highest levels found in basal tears. Interestingly, we could detect a significantly higher concentration of IL- 6, IL-8 and VEGF in localized corneal tears of patients with neovascularized corneas when compared to the control group. This is the first study of its kind demonstrating a significant difference of defined factors in tears from patients with neovascularized corneas as compared to healthy controls. These results provide the basis for future research using animal models to further substantiate the role of these cytokines in the establishment and maintenance of corneal neovascularization

Desperdício de exames complementares na avaliação pré-operatória em cirurgias de catarata Waste of medical tests in preoperative evaluation for cataract surgery

O objetivo deste experimento clínico foi determinar a freqüência dos exames considerados dispensáveis numa rotina pré-operatória de facectomias e avaliar os gastos com eles. Se o paciente foi sorteado para testes-seletivos, solicitou-se que nenhum teste fosse executado, a menos que o paciente apresentasse um novo problema médico, ou piora de uma doença preexistente, a qual requeresse os testes independentemente da realização da cirurgia. Para pacientes sorteados para testes-rotineiros, foram solicitados: eletrocardiograma, dosagem de hemoglobina e glicemia de jejum. Foram calculados os gastos com exames considerados desnecessários. A amostra de 1.025 pacientes incluiu 513 sorteados para testes seletivos e 512 para testes rotineiros. A freqüência de eventos adversos intra-operatórios foi semelhante nos dois grupos (p = 0,923). O grupo de testes seletivos realizou de 60,7% menos exames que o de testes rotineiros. Os resultados sugerem que a requisição seletiva de exames pré-operatórios em facectomias, além de não prejudicar o paciente do ponto de vista de complicações clínicas intra-operatórias, possibilita expressiva economia de recursos quando comparada à atual rotina.<br>The objective of this clinical trial was to determine the frequency of medical tests considered unnecessary in routine preoperative evaluation for cataract surgery. Unnecessary costs with these tests were also evaluated. For patients assigned to the selective testing group, it was requested that no preoperative testing be performed unless the patient presented a new or worsening medical problem warranting medical evaluation with testing. For patients assigned to the routine testing group, three tests were requested: a 12-lead electrocardiogram, complete blood count, and serum glucose level. The costs of tests considered unnecessary were calculated. The sample of 1,025 patients consisted of 512 assigned to the routine testing group and 513 to the selective testing group. Cumulative rate of medical events was similar in the two groups (p = 0.923). The selective group underwent 60.7% fewer tests. The results suggest that selective preoperative testing in cataract surgery does not harm patients in terms of peri-operative clinical complications and also represents a significant cost reduction compared to routine testing