ABSTRACT
ABSTRACT The burden of corneal blindness and visual deficiency can be felt worldwide. Its association with several endemic diseases such as childhood blindness, trauma, infectious keratitis (including variants caused by herpes, hanseniasis, and fungi), vitamin A deficiency, diabetes mellitus, and other dry eye syndromes reflects its poorly understood underlying mechanisms and suggests that the actual frequency of the disease is underestimated. The low effectiveness of preventive and therapeutic strategies against corneal scarring or deformity predicts a high frequency of patients with corneal blindness in the future. Corneal blindness is associated with environmental factors and socioeconomic limitations that restrain health assistance and maintain a modest efficiency of the current therapeutic strategies for resolving corneal diseases in large-scale programs. We present here a critical review of the concepts associated with corneal blindness that need to be considered when planning strategies to prevent and treat corneal blindness worldwide (to be able to leave Plato's cave, where corneal blindness is encaged.
RESUMO O problema da deficiência visual e da cegueira corneal abrange o mundo todo e corresponde à quarta causa de cegueira e deficiência visual, com acometimento estimado de mais de 16 milhões de pessoas. A associação com várias doenças endêmicas, como cegueira infantil, trauma, ceratites infecciosas (incluindo herpes, hanseníase e fungos), hipovitaminose A, diabetes mellitus e outras causas de síndromes de olho seco, indicam que a verdadeira frequência é subestimada e que os diferentes mecanismos são pouco conhecidos. A baixa eficácia na prevenção e tratamento da cicatriz e deformidade da córnea permite antecipar que a prevalência da cegueira corneal irá crescer no futuro. As razões para o aumento da cegueira corneal envolvem fatores ambientais, limitações socioeconômicas para ampliar a assistência à saúde e a modesta eficiência das estratégias terapêuticas para resolver o problema em grande escala. O presente trabalho traz uma revisão crítica dos conceitos associados à cegueira corneal. Essa análise é uma etapa necessária para preparar o caminho com o objetivo de deixar a caverna que encarcera a cegueira corneal, em analogia ao mito de Platão, e melhorar as estratégias para prevenir e tratar a cegueira corneal em escala mundial.
Subject(s)
Humans , Blindness , Corneal Opacity , Blindness/prevention & control , Blindness/therapy , Blindness/epidemiologyABSTRACT
Objective To evaluate short term effects of a single photodynamic therapy (PDT) treatment with visudyne (CIBA Vision Corp.) for choroidal neovascularization (CNV) in age ralated macular degeneration (AMD). Methods Thirty cases (35 eyes) diagnosed as AMD patients with classic CNV were treated with PDT. The data of visual acuity testing, fluorescein angiography (FFA), indocyanine green angiography (ICGA) and optic coherence tomography (OCT) were used to evaluate the effects of a single treatment of PDT before and 1 week, 1 ,3 month after treatment. Results The visual acuity of 34 eyes were stable or improved in 3 months follow up;and the visual acuity of 1 eye was decreased. Decrease or dispearance of fluorescein leakage from CNV was noted in 19 eyes. No serious complication occurred. Conclusion Single treatment of PDT for CNV in AMD can achieve short term decrease or cessation of fluorescein leakage from CNV without loss of visual acuity.
ABSTRACT
Objective To study the clinical results and safty of photodynamic therapy (PDT) after single and multi treatments of patients with subfoveal choroidal neovascularization (CNV) caused by wet age related macular degeneration (AMD). Methods From July, 2000 to July, 2001, 20 wet AMD patients (31 eyes) 47 88 years old (mean 68.2 years old) with best corrected visual acuity from FC/10 cm to 0.6 diagnosed through optic coherence tomography (OCT), fluorescein angiography (FFA) and indocyanine green angiography (ICGA) were treated with PDT. All cases were assigned to benzoporphyrin derivative mono acid (BPD) (6 mg per square meter of body surface area), administered via intravenous infusion of 30 ml over 10 minutes. Fifteen minutes after the start of the infusion, a laser light at 689 nm (Zeiss company, German) delivered 50 J/cm 2 at an intensity of 600 mW/cm 2 over 83 seconds on CNV. Visual acuity, photochrome of ocular fundus, OCT, FFA, ICGA were used to evaluate the effects of photodynamic therapy with BPD. Follow up of these patients was planned 1 2 week and every 3 month after PDT. Once the lesion area progressed, PDT was applied again. Tweenty cases (31 eyes) were followed up from 3 to 18 months (average 12 month).In 1 affected eye, PDT was applied fow 4 times, 4 eye for 2 times, and the other 26 eyes for 1 time. Results The visual acuity in 13 (41 9%) eyes was improved ( increase≥2 lines) after PDT. Stabilized (?1 line) in 17 (54 8%) eyes and decreased 2 lines (attributed to the recur of CNV ) in 1 (3 2%) eye. After PDT, the fundus haemorrhage and fluid leakage reduced. FFA and ICGA showed. cessation and obvious reduction of fluorescein leakage from CNV in all patients 2 weeks after photodynamic therapy, and retreatment decreased the leakage step by step. Fluorescein leakage from at least a portion of the CNV reappeared by 1 3 month after treatment in some cases. OCT also showed the reduction of the size of CNV, moreover, the edema of surrounding retina and choriodal and serous neural epithelial detachment recovered obviously. No side affect during and after PDT was noticed. Conclusions PDT with BPD can achieve short term effect on part or total cessation of fluorescein leakage from CNV without loss of vision or growth of classic CNV in patients with age related macular degeneration, retreatment of PDT was also effective.