Protective role of glutathione peroxidase 4 in laser-induced choroidal neovascularization in mice.

PURPOSE: To evaluate the influence of glutathione peroxidase 4 (GPx4) expression in retinal pigment epithelium (RPE)/choroid tissue using a mouse model of laser-induced choroidal neovascularization (CNV). METHODS: In this study, GPx4+/-, GPx4+/+, and GPx4-overexpressing transgenic mice were created for comparison. The mRNA and protein expression of vascular endothelial growth factor (VEGF)-A in RPE/choroid tissue were evaluated before and after CNV induction by laser. Moreover, we investigated the changes in the VEGF-A mRNA level in RPE/choroid tissue in the CNV model that have not been clearly shown previously. Lipid peroxidation in RPE/choroid tissue was evaluated by immunohistochemistry using antibody against 4-hydroxy-2-nonenal. To investigate the protective role of GPx4, the size of laser-induced CNV was compared on day 7 among the mice expressing different levels of GPx4. RESULTS: In the laser-induced CNV mouse model, laser treatment reduced the VEGF-A mRNA level in RPE/choroid tissue, while it increased the VEGF-A protein level. Evaluation of VEGF-A expression in RPE/choroid tissue of the GPx4+/-, GPx4+/+, and GPx4 transgenic mice revealed that GPx4 increased the VEGF-A protein level under physiological conditions (i.e., without laser treatment), while GPx4 suppressed the increase in the VEGF-A protein level under pathological conditions (i.e., after CNV induction by laser). In addition, GPx4 reduced the CNV size in a dose-dependent manner in vivo. CONCLUSIONS: GPx4 suppresses the increase in the VEGF-A protein level, which occurs during the development of pathological CNV, thus partly explaining the protective effect of GPx4 against CNV.

Impact of robotic assistance on precision of vitreoretinal surgical procedures.

PURPOSE: To elucidate the merits of robotic application for vitreoretinal maneuver in comparison to conventional manual performance using an in-vitro eye model constructed for the present study. METHODS: Capability to accurately approach the target on the fundus, to stabilize the manipulator tip just above the fundus, and to perceive the contact of the manipulator tip with the fundus were tested. The accuracies were compared between the robotic and manual control, as well as between ophthalmologists and engineering students. RESULTS: In case of manual control, ophthalmologists were superior to engineering students in all the 3 test procedures. Robotic assistance significantly improved accuracy of all the test procedures performed by engineering students. For the ophthalmologists including a specialist of vitreoretinal surgery, robotic assistance enhanced the accuracy in the stabilization of manipulator tip (from 90.9 µm to 14.9 µm, P = 0.0006) and the perception of contact with the fundus (from 20.0 mN to 7.84 mN, P = 0.046), while robotic assistance did not improve pointing accuracy. CONCLUSIONS: It was confirmed that telerobotic assistance has a potential to significantly improve precision in vitreoretinal procedures in both experienced and inexperienced hands.

[Use of fibrin glue in ocular surgery]. / Utilização de adesivo de fibrina em cirurgias oftalmológicas.

PURPOSE: To evaluate the use of fibrin glue and its complications in different ophthalmic surgeries. METHODS: A retrospective and non-comparative case series study. 161 eyes were evaluated. The mean age was 51.8 years. Fibrin glue (Beriplast--Aventis Behring, Germany) was used in all patients for tissue adherence or incisional closure. RESULTS: Main preoperatives diseases were pterygium (76 patients), superior limbic keratoconjunctivitis (4 patients), limbal tumor (4 patients), conjunctivochalasis (21 patients), bullous keratopathy (31 patients), limbal stem cell deficiency (7 patients), alkali injury (6 patients), Stevens-Johnson syndrome (2 patients), cataract (5 patients) and glaucoma (5 patients). Complications occurred in 28 patients (17.4%). Detachment of the fixed tissue and granulomatous foreign body reaction were the main complications. Detachment occurred in 10 cases (5.6%) (7 in amniotic membrane transplantation in bullous keratopathy, 2 in autologous conjunctival grafting for pterygium surgery, 1 in autologous limbal transplantation in a Stevens-Johnson syndrome). Granulomatous foreign body reaction was described in 9 patients (5.6%) (5 in amniotic membrane transplantation due to acute alkali injury, 1 in autologous limbal graft due to chronic burn injury, and 3 in autologous conjunctival transplant due to pterygium surgery). All the complications described occurred in the first week after surgery. CONCLUSION: Despite the limitations related to the retrospective and non-comparative setting, this study suggests that the use of fibrin glue seems to be safe and effective for tissue fixation or incisional closure presenting low rates of complications in ocular surface and anterior segment surgeries.

Utilização de adesivo de fibrina em cirurgias oftalmológicas / Use of fibrin glue in ocular surgery

OBJETIVO: Avaliar as diferentes técnicas cirúrgicas oftalmológicas nas quais se pode utilizar a cola biológica e possíveis complicações relacionadas ao seu uso. MÉTODOS: Estudo de série de casos retrospectivo, não-comparativo. Foram avaliados 161 olhos de pacientes com idade média de 51,8 anos em que foi utilizada cola biológica (Beriplast P® - Aventis Behring, Alemanha) para fixação de tecido ou fechamento incisional. RESULTADOS: Foram avaliados 76 pacientes com pterígio, 4 com ceratoconjuntivite límbica superior, 4 com tumor limbar, 21 com conjuntivocálase, 31 com ceratopatia bolhosa, 7 com deficiência límbica, 6 com queimadura alcalina, 2 com Stevens-Johnson, 5 com catarata e 5 com glaucoma. Complicações foram relatas em 28 casos (17,4 por cento). Descolamento do tecido fixado e granuloma foram as complicações mais frequentes. Descolamento ocorreu em 10 casos (5,6 por cento) (7 em transplante de membrana amniótica em ceratopatia bolhosa, 2 em transplante de conjuntiva autólogo após exérese de pterígio, 1 após transplante de limbo autólogo por Stevens-Johnson). Granuloma ocorreu em 9 casos (5,6 por cento) (5 em pacientes com queimadura alcalina aguda tratados com transplante de membrana amniótica, 1 em paciente com sequela de queimadura tratado com transplante de limbo autólogo e 3 em pacientes após exérese de pterígio tratados com transplante de conjuntiva autólogo). Todas as complicações ocorreram dentro da primeira semana de pós-operatório. CONCLUSÃO: Embora o presente seja retrospectivo e não-comparativo, podemos observar que a utilização do adesivo de fibrina parece ser segura e efetiva, além de apresentar baixas taxas de complicações nas cirurgias de superfície ocular e de segmento anterior.

PURPOSE: To evaluate the use of fibrin glue and its complications in different ophthalmic surgeries. METHODS: A retrospective and non-comparative case series study. 161 eyes were evaluated. The mean age was 51.8 years. Fibrin glue (BeriplastTM - Aventis Behring, Germany) was used in all patients for tissue adherence or incisional closure. RESULTS: Main preoperatives diseases were pterygium (76 patients), superior limbic keratoconjunctivitis (4 patients), limbal tumor (4 patients), conjunctivochalasis (21 patients), bullous keratopathy (31 patients), limbal stem cell deficiency (7 patients), alkali injury (6 patients), Stevens-Johnson syndrome (2 patients), cataract (5 patients) and glaucoma (5 patients). Complications occurred in 28 patients (17.4 percent). Detachment of the fixed tissue and granulomatous foreign body reaction were the main complications. Detachment occurred in 10 cases (5.6 percent) (7 in amniotic membrane transplantation in bullous keratopathy, 2 in autologus conjunctival grafting for pterygium surgery, 1 in autologus limbal transplantation in a Stevens-Johnson syndrome). Granulomatous foreign body reaction was described in 9 patients (5.6 percent) (5 in amniotic membrane transplantation due to acute alkali injury, 1 in autologus limbal graft due to chronic burn injury, and 3 in autologus conjunctival transplant due to pterygium surgery). All the complications described occurred in the first week after surgery. CONCLUSION: Despite the limitations related to the retrospective and non-comparative setting, this study suggests that the use of fibrin glue seems to be safe and effective for tissue fixation or incisional closure presenting low rates of complications in ocular surface and anterior segment surgeries.

Cataract and type 1 diabetes mellitus.

AIMS: To evaluate the prevalence of cataract and the possible factors associated with cataract in young type 1 diabetes mellitus (DM). METHODS: 293 patients were evaluated. The association of cataract with diabetic retinopathy (DR), retinal laser treatment, hypertension, body mass index, peripheral neuropathy, lipid profile, glycemic control, serum creatinine and albuminuria was evaluated. RESULTS: Cataract was present in 19.8% (n=58) of the sample. Patients with cataracts were older, had a higher frequency of history of retina photocoagulation treatment, higher serum creatinine values and higher prevalence of arterial hypertension. There was a progressive increase in cataract frequency according to the number of risk factors, starting to rise with two or more. In logistic regression model cataract was associated with mild/moderate DR (odd ratio (OR) 4.28 95% CI 1.63-11.29), severe DR (OR 4.07 95% CI 1.63-10.23) and macroalbuminuria (OR 2.34 95% CI 1.06-5.16). CONCLUSION: These data indicate a high prevalence of cataract in subjects with type 1 DM attending a general hospital in Southern Brazil and suggest that the more severe the disease process the greater is the risk of having this diabetic complication. Cataract should be suspected in young patients with two or more risk factors.

[Cataract and type 1 diabetes mellitus]. / Catarata e diabetes mellitus tipo 1.

PURPOSE: To evaluate the prevalence of cataract and associated risk factors in a diabetic type 1 population. METHODS: 181 patients (362 eyes) were evaluated in a case-control study. Cases were classified when cataract was present at the time of the examination. The studied outcomes were the presence of diabetic retinopathy, retinal panphotocoagulation, high blood pressure, peripheral neuropathy, total cholesterol levels, triglyceride levels, HDL, LDL, body mass index, creatinine levels, albuminuria, glycosylated hemoglobin and glycemia levels. RESULTS: Cataract was present in 19.9% of the studied patients. The association of the presence of cataract and diabetic retinopathy, peripheral neuropathy, elevated levels of creatinine, panphotocoagulation and high blood pressure were statistically significant (univariate analysis). After the logistic regression analysis the presence of cataract was significantly associated with the presence of diabetic retinopathy. CONCLUSION: The prevalence of cataract was 19.9% and the presence and severity of the diabetic retinopathy were the main risk factors for its development.

Catarata e diabetes mellitus tipo 1 / Cataract and type 1 diabetes mellitus

OBJETIVO: Avaliar a prevalência de catarata e seus fatores de risco em uma população portadora de diabetes mellitus tipo 1 (DM1). MÉTODOS: Estudo de casos e controles de um banco de dados de 181 pacientes (362 olhos) com diagnóstico de diabetes mellitus tipo 1. Os pacientes foram classificados como casos quando apresentavam diagnóstico de catarata. As variáveis estudadas foram a presença ou não de retinopatia diabética, tratamento com panfotocoagulação, presença de hipertensão arterial sistêmica e neuropatia periférica, colesterol total, triglicerídios séricos, HDL, LDL, índice de massa corporal, creatinina sérica, albuminúria, hemoglobina glicosilada e glicemia de jejum. RESULTADOS: A prevalência de catarata foi de 19,9 por cento. Na análise univariada foi encontrada associação estatisticamente significativa (p<0,005) entre a presença de catarata e retinopatia diabética, neuropatia periférica, creatinina sérica elevada, panfotocoagulação e hipertensão arterial. Após a análise de regressão logística a variável que permaneceu com associação estatisticamente significativa foi a presença de retinopatia diabética. CONCLUSÃO: A prevalência de catarata foi de 19,9 por cento, sendo a presença e a gravidade da retinopatia diabética os principais fatores de risco para desenvolvimento desta.

PURPOSE: To evaluate the prevalence of cataract and associated risk factors in a diabetic type 1 population. METHODS: 181 patients (362 eyes) were evaluated in a case-control study. Cases were classified when cataract was present at the time of the examination. The studied outcomes were the presence of diabetic retinopathy, retinal panphotocoagulation, high blood pressure, peripheral neuropathy, total cholesterol levels, triglyceride levels, HDL, LDL, body mass index, creatinine levels, albuminuria, glycosylated hemoglobin and glycemia levels. RESULTS: Cataract was present in 19.9 percent of the studied patients. The association of the presence of cataract and diabetic retinopathy, peripheral neuropathy, elevated levels of creatinine, panphotocoagulation and high blood pressure were statistically significant (univariate analysis). After the logistic regression analysis the presence of cataract was significantly associated with the presence of diabetic retinopathy. CONCLUSION: The prevalence of cataract was 19.9 percent and the presence and severity of the diabetic retinopathy were the main risk factors for its development.