Quantitative evaluation of experimental choroidal neovascularization by confocal scanning laser ophthalmoscopy: fluorescein angiogram parallels heparan sulfate proteoglycan expression

The objective of the present study was to develop a quantitative method to evaluate laser-induced choroidal neovascularization (CNV) in a rat model using Heidelberg Retina Angiograph 2 (HRA2) imaging. The expression of two heparan sulfate proteoglycans (HSPG) related to inflammation and angiogenesis was also investigated. CNV lesions were induced with argon laser in 21 heterozygous Zucker rats and after three weeks a fluorescein angiogram and autofluorescence exams were performed using HRA2. The area and greatest linear dimension were measured by two observers not aware of the protocol. Bland-Altman plots showed agreement between the observers, suggesting that the technique was reproducible. After fluorescein angiogram, HSPG (perlecan and syndecan-4) were analyzed by real-time RT-PCR and immunohistochemistry. There was a significant increase in the expression of perlecan and syndecan-4 (P < 0.0001) in retinas bearing CNV lesions compared to control retinas. The expression of these two HSPG increased with increasing CNV area. Immunohistochemistry demonstrated that the rat retina damaged with laser shots presented increased expression of perlecan and syndecan-4. Moreover, we observed that the overexpression occurred in the outer layer of the retina, which is related to choroidal damage. It was possible to develop a standardized quantitative method to evaluate CNV in a rat model using HRA2. In addition, we presented data indicating that the expression of HSPG parallels the area of CNV lesion. The understanding of these events offers opportunities for studies of new therapeutic interventions targeting these HSPG.

Alterações oculares de doenças sistêmicas: retinopatia diabética e oftalmopatia de Graves / Systemic diseases with ocular involvement: diabetic retinopathy, Grave's disease

Das doenças sistêmicas com alterações oculares, destacam-se a retinopatia diabética e a oftalmopatia de Graves que têm em comum vários aspectos: são alterações endócrinas e metabólicas, auto-imunes e o acometimento ocular pode ser grave, levando à perda da função visual. A orientação correta do médico generalista pode modificar o prognóstico visual dos portadores destas doenças, pois dá oportunidade para que o oftalmologista intervenha no momento adequado.No diabetes a principal alteração ocular ocorre na retina, com o desenvolvimento da retinopatia diabética que se manifesta em 30% dos casos.Na oftalmopatia de Graves é importante o esclarecimento de que nem sempre as alterações oculares estão relacionadas a alterações hormonais que possam sinalizar a atividade da doença. A doença ocular pode ocorrer no hipertireoidismo, bem como no hipotireoidismo; em pacientes sem alterações hormonais afeta principalmente os tecidos adiposo e muscular da órbita e do olho. Descreve-se neste artigo o tratamento atual da retinopatia diabética e da oftalmopatia de Graves para que os pacientes possam ser orientados e esclarecidos sobre as condutas a serem adotadas pelo oftalmologista.