Biomedical subjects

Rubens Belfort

Publications and source records attributed to Rubens Belfort.

At least 19 recordsLinked to original sources

PubMed2006

Visual performance of AcrySof ReSTOR apodized diffractive IOL: a prospective comparative trial.

PURPOSE: Evaluate the visual performance of the AcrySof ReSTOR intraocular lens (IOL) and compare it with the monofocal SA60AT IOL. DESIGN: Prospective, nonrandomized, clinical trial. METHODS: Forty patients (80 eyes) from the Federal University of São Paulo were enrolled in two groups. Twenty-five patients were assigned to the ReSTOR group and 15 patients to the monofocal group. Inclusion criteria were corneal astigmatism <1.0 diopter, potential acuity meter >0.2 logMAR units, and no associated ocular diseases. Parameters analyzed included distance uncorrected and best-corrected visual acuity, near uncorrected and distance corrected visual acuity, intermediate visual acuity, contrast sensitivity (Pelli-Robson chart), stereopsis (Titmus test), reading speed, wavefront measurement (LADARWave aberrometer), and a quality-of-life questionnaire. main outcome measure: Distance and near uncorrected and best distance corrected visual acuity, contrast sensitivity, and reading speed. RESULTS: Distance uncorrected and best-corrected visual acuity in the ReSTOR group were not statistically different from the monofocal group (P = .66). Near uncorrected and distance corrected visual acuity were statistically better in the ReSTOR group than the monofocal group (0.16 +/- 0.13 vs 0.62 +/- 0.09, P < .001, and 0.14 +/- 0.12 vs 0.62 +/- 0.07, P < .001, respectively). The ReSTOR group demonstrated less spherical aberrations compared with the monofocal group (P < .001). Monocular photopic contrast sensitivity was statistically lower in the ReSTOR group (P < .001). Stereopsis and reading speed were not statistically different between the groups. CONCLUSION: The AcrySof ReSTOR IOL provides a satisfactory full range of vision and achieves a more satisfactory quality of life when compared with the monofocal SA60AT IOL, but with lower contrast sensitivity.

Acrylic Resins↗

PubMed2006

[Comparison between self-reported quality of vision and visual acuity in a low-income elderly population in the city of São Paulo].

PURPOSE: Self-reported visual function questionnaires are becoming more common in clinical research. The purpose of this study is to evaluate and correlate self-reported visual function assessed by a visual function questionnaire with visual acuity. METHODS: 806 patients aged 60 years and older, who were included in an epidemiological eye study, were interviewed and present visual acuity for near and distance was taken; they also answered a visual function questionnaire. RESULTS: Weak correlations were found between self-reported visual function assessed by a visual function questionnaire and visual acuities for both distance and near. CONCLUSION: Self-reported visual function assessed by a visual function questionnaire did not correspond to visual acuity, nevertheless it can provide important information to the ophthalmologist.

Aged↗

PubMed2006

Haplogroup effects and recombination of mitochondrial DNA: novel clues from the analysis of Leber hereditary optic neuropathy pedigrees.

The mitochondrial DNA (mtDNA) of 87 index cases with Leber hereditary optic neuropathy (LHON) sequentially diagnosed in Italy, including an extremely large Brazilian family of Italian maternal ancestry, was evaluated in detail. Only seven pairs and three triplets of identical haplotypes were observed, attesting that the large majority of the LHON mutations were due to independent mutational events. Assignment of the mutational events into haplogroups confirmed that J1 and J2 play a role in LHON expression but narrowed the association to the subclades J1c and J2b, thus suggesting that two specific combinations of amino acid changes in the cytochrome b are the cause of the mtDNA background effect and that this may occur at the level of the supercomplex formed by respiratory-chain complexes I and III. The families with identical haplotypes were genealogically reinvestigated, which led to the reconnection into extended pedigrees of three pairs of families, including the Brazilian family with its Italian counterpart. The sequencing of entire mtDNA samples from the reconnected families confirmed the genealogical reconstruction but showed that the Brazilian family was heteroplasmic at two control-region positions. The survey of the two sites in 12 of the Brazilian subjects revealed triplasmy in most cases, but there was no evidence of the tetraplasmy that would be expected in the case of mtDNA recombination.

DNA, Mitochondrial↗

PubMed2006

Ultrasound energy and endothelial cell loss with stop-and-chop and nuclear preslice phacoemulsification.

PURPOSE: To evaluate ultrasound (US) energy and endothelial cell loss in cataract surgery using the stop-and-chop and nuclear preslice techniques. SETTING: Vision Institute, Federal University of São Paulo, São Paulo, Brazil. METHODS: This prospective clinical trial comprised 43 patients (50 eyes) with senile nuclear cataract who were randomly assigned to 1 of 2 groups: stop-and-chop (n=26) or nuclear preslice (n=24). The groups were divided according to nuclear density (NO(3) NC(3) and NO(4) NC(4)) using the Lens Opacity Classification System III. A full ophthalmic examination including biometry, specular microscopy, and pachymetry was performed preoperatively and postoperatively. The following parameters were evaluated: age, anterior chamber depth, lens thickness, axial length, phaco time and power, effective phaco time (EPT), infusion volume, ocular inflammation, endothelial cell loss, and best corrected visual acuity (BCVA). RESULTS: Phacoemulsification time, power, and EPT were significantly higher in the stop-and-chop group. Infusion volumes did not vary significantly between the groups. A significant decrease in endothelial cell density occurred postoperatively and was similar with both techniques (stop-and-chop, 8.70%; nuclear preslice, 8.72%). The BCVA improved significantly in both groups. No significant correlations were found between endothelial cell loss and either technique. CONCLUSIONS: Ultrasound energy consumption was lower with the nuclear preslice technique. Both techniques had similar results including endothelial cell loss.

Aged↗

PubMed2006

Recently acquired Toxoplasma gondii infection, Brazil.

The city of Erechim, Brazil, has a 17% prevalence of ocular toxoplasmosis, and type 1 Toxoplasma gondii predominates. To examine risk factors for acute T. gondii infection in this area, we administered a questionnaire to recently infected persons (n = 131) and seronegative controls (n = 110). Eating undercooked meat; having a garden; working in the garden or yard more than once per week; eating rare meat; eating cured, dried, or smoked meat; eating frozen lamb; and being male increased risk for T. gondii infection in univariate analysis. Risk factors independently associated with acute T. gondii infection in multivariate analysis were working in the garden (odds ratio [OR] 2.35, 95% confidence interval [CI] 1.27-4.33) and eating frozen lamb (OR 2.06, 95% CI 1.15-3.67). Among women (n = 86), having had children markedly increased the risk for T. gondii infection (OR 14.94, 95% CI 3.68-60.73).

Adolescent↗

PubMed2006

Genetic divergence of Toxoplasma gondii strains associated with ocular toxoplasmosis, Brazil.

Previous studies have shown a high prevalence of toxoplasmosis and the frequent occurrence of ocular disease in Brazil. To identify the genotypes of parasite strains associated with ocular disease, we compared 25 clinical and animal isolates of Toxoplasma gondii from Brazil to previously characterized clonal lineages from North America and Europe. Multilocus nested polymerase chain reaction analysis was combined with direct sequencing of a polymorphic intron to classify strains by phylogenetic methods. The genotypes of T. gondii strains isolated from Brazil were highly divergent when compared to the previously described clonal lineages. Several new predominant genotypes were identified from different regions of Brazil, including 2 small outbreaks attributable to foodborne or waterborne infection. These findings show that the genetic makeup of T. gondii is more complex than previously recognized and suggest that unique or divergent genotypes may contribute to different clinical outcomes of toxoplasmosis in different localities.

Animals↗

PubMed2006

Visual acuity, contrast sensitivity, reading speed, and wavefront analysis: pseudophakic eye with multifocal IOL (ReSTOR) versus fellow phakic eye in non-presbyopic patients.

PURPOSE: To compare the visual performance in the pseudophakic eye and the phakic eye in four patients who underwent unilateral intraocular lens (IOL) implantation. METHODS: Four patients presenting with unilateral cataract underwent ReSTOR (Alcon Laboratories, Ft Worth, Tex) IOL implantation in their nondominant eye, targeting emmetropia. RESULTS: Uncorrected near visual acuity was >20/32 in all operated eyes and best spectacle-corrected distance visual acuity was 20/16 for two eyes, 20/25 for one eye, and 20/32 for one eye. Reading speed was similar between the eyes, but not for critical print size. Contrast sensitivity was lower in the pseudophakic eyes. Wavefront analysis showed no considerable difference in total high order aberrations, coma, and spherical aberration between eyes for all patients. CONCLUSIONS: In young patients with unilateral cataract surgery, unilateral multifocal IOL implantation provides satisfactory visual acuity and may be considered an alternative treatment option in this patient population.

Adult↗

PubMed2005

[Contrast sensitivity and stereopsis in pseudophakic patients with multifocal intraocular lens].

PURPOSE: To evaluate the contrast sensitivity and stereopsis tests in patients who underwent bilateral implantation of multifocal intraocular lens. METHODS: Tests of contrast sensitivity using the Pelli-Robson chart and stereopsis evaluation with the Titmus Stereo Test were performed in 20 patients 30-60 days after the bilateral implantation of Acrysof Restor multifocal intraocular lens. RESULTS: The binocular contrast sensitivity test demonstrated that 6 patients (30%) presented 1.80 log units, 13 (65%) 1.65 and in only 1 (5%) the sensitivity was 1.50 log units. By the other hand, the monocular test in right eye showed 17 patients (85%) with 1.65 log units and 3 (15%) with 1.50. In the left eye, the test presented 16 patients (80%) with 1.65 log units and 4 (20%) with 1.50 log units. The average and the standard deviation of the contrast sensitivity were 1.63 (+/-0.05) for right eye, 1.62 (+/-0.06) for left eye and 1.69 (+/-0.08) for binocular test. Stereopsis test disclosed 12 patients (60%) presenting 40", 6 (30%) 50" and only 2 (10%) 60" (average: 45" and standard deviation: 6.88"). CONCLUSIONS: The Acrysof Restor intraocular lens provided results of contrast sensitivity and stereopsis in accordance with the criteria of normality established previously in other studies for phakic and pseudophakic patients. Therefore, this intraocular lens does not decrease visual functionality.

Aged↗

PubMed2005

[Teleophthalmology as an auxiliary approach for the diagnosis of infectious and inflammatory ocular diseases: evaluation of an asynchronous method of consultation].

PURPOSE: The purpose of this study was to evaluate the efficacy of teleophthalmology as an auxiliary approach for diagnosis of infectious and inflammatory ocular diseases and to study the main problems associated with the conclusion reached by consultation. METHODS: Two hundred and thirty three 35 mm slides (retinography or biomicroscopy photos) were digitalized and stored in a Compact Disc to be later analyzed in a computer monitor by two consultants, specialists in uveitis. The consultants filled out a form and a questionnaire, indicating the diagnosis and probable treatment for the analyzed cases also the main difficulties found to reach a conclusion of the consultation. The Kappa statistic, an assessment of the change-corrected agreement (reproducibility) among consultants, was calculated. Kappa values of > 0.7 indicated excellent agreement; values between 0.4 and 0.7 indicated fair to good agreement and values of < 0.4 indicated poor agreement. RESULTS: Agreement between the consultants and the final diagnosis was of 73.5%. Treatment suggestion or management was not possible in 8% of the cases for consultant A and in 10.4% for consultant B. The higher agreement rate among consultants, relating to the reasons that rendered diagnosis difficult, was found in relation to "lack of clinical data" and "low quality of images". CONCLUSION: Teleophthalmology, through the asynchronous method, was an efficient means for diagnosis of patients with infectious and inflammatory ocular diseases. The main problems affecting the teleophthalmology consultation were lack of detailed clinical data and low quality of the images.

Diagnostic Techniques, Ophthalmological↗

PubMed2005

The role of c-kit and imatinib mesylate in uveal melanoma.

BACKGROUND: Uveal melanoma (UM) is the most common primary intraocular tumor in adults, leading to metastasis in 40% of the cases and ultimately to death in 10 years, despite local and/or systemic treatment. The c-kit protein (CD117) is a membrane-bound tyrosine kinase receptor and its overexpression has been observed in several neoplasms. Imatinib mesylate is a FDA approved compound that inhibits tyrosine quinase receptors, as well as c-kit. Imatinib mesylate controls tumor growth in up to 85% of advanced gastrointestinal stromal tumors, a neoplasia resistant to conventional therapy. METHODS: Fifty-five specimens of primary UM selected from the archives of the Ocular Pathology Laboratory, McGill University, Montreal, Canada, were immunostained for c-kit. All cells displaying distinct immunoreactivity were considered positive. Four human UM cell lines and 1 human uveal transformed melanocyte cell line were tested for in vitro proliferation Assays (TOX-6) and invasion assay with imatinib mesylate (concentration of 10 microM). RESULTS: The c-kit expression was positive in 78.2% of the UM. There was a statistical significant decrease in the proliferation and invasion rates of all 5 cell lines. CONCLUSION: The majority of UM expressed c-kit, and imatinib mesylate does decrease the proliferation and invasion rates of human UM cell lines. These results justify the need for a clinical trial to investigate in vivo the response of UM to imatinib mesylate.

Journal Article↗

PubMed2005

Pseudohypopyon immediately after intravitreal injection of triamcinolone acetonide--case reports.

Report on the development of pseudohypopyon immediately after intravitreal injection of triamcinolone acetonide (TAAC). Two phakic patients presenting with a transient pseudohypopyon after having been treated with intravitreal triamcinolone. One had a clinically significant macular edema with cystoid component (CSME with CMS) and the other, active Vogt-Koyanagi-Harada (VKH) with serous retinal detachment of the macula. One eye from each patient developed a pseudohypopyon with crystal deposits adherent to the corneal endothelium. In one case it appeared right after the injection and disappeared spontaneously in 24 hours. In the other patient it appeared on day 3 and disappeared also spontaneously within 2 days. The pseudohypopyon is an important sign that can be observed after intravitreal injection of TAAC, in phakic patients, with spontaneous resolution and without complication. The pseudohypopyon caused by the deposition of TAAC in the anterior chamber immediately after its injection into the vitreous should be differentiated from other forms of hypopyon associated with this type of treatment.

Adult↗

PubMed2005

Concentration of hyaluronic acid in primary open-angle glaucoma aqueous humor.

We compared the concentration of hyaluronic acid in the aqueous humor of primary open-angle glaucoma (POAG) patients and non-glaucomatous patients. Aqueous humor samples were obtained from 22 patients just before trabeculectomy for clinically uncontrolled POAG (POAG group). Aqueous humor (0.1 mL) was aspirated by inserting a 26-gauge needle into the anterior chamber. The same procedure was performed for 22 non-glaucomatous patients just before cataract surgery (control group). Immediately after collection, the aqueous humor was stored at -20 degrees C. The concentration of hyaluronic acid was determined by a sensitive, noncompetitive and nonisotopic fluoroassay. The median (range) concentrations of hyaluronic acid of the POAG and control groups were 298.4 microg L(-1) (99.0-743.7 microg L(-1)) and 545.1 microg L(-1) (145.0-2366.0 microg L(-1)), respectively. The difference in concentrations of hyaluronic acid between the groups was statistically significant (P<0.001). In conclusion, the concentration of hyaluronic acid in the aqueous humor in POAG patients is lower than in non-glaucomatous patients. Further studies are necessary to determine the role of hyaluronic acid in the pathophysiology of POAG.

Adult↗

PubMed2005

The involvement of autoimmunity against retinal antigens in determining disease severity in toxoplasmosis.

PURPOSE: Ocular lesions are frequent in various individuals infected with Toxoplasma gondii. Disease intensity in ocular toxoplasmosis varies greatly between patients. Autoimmunity has been suggested as a possible component to retinal destruction. METHODS: Immunologic parameters in the response to retina antigens were evaluated in infected persons with and without ocular lesions and in non-infected controls. Subjects were divided into groups on the basis of titers of serum antibodies to T. gondii, presence and severity of ocular lesions, and clinical history. RESULTS: Peripheral blood mononuclear cells from patients with mild disease responded to one or more retinal antigens with a significantly higher frequency than patients without disease or with severe disease. Interestingly, the cytokines produced by the proliferating mononuclear cells did not follow any specific patterns, except for the fact that IL-4 and IL-5 were seldom detected. CONCLUSIONS: Our results suggest that although the presence of an immune response towards autoantigens is not protective against the development of ocular lesions by the T. gondii, it may protect against the development of severe disease.

Antigens↗

PubMed2005

The genotype of Toxoplasma gondii strains causing ocular toxoplasmosis in humans in Brazil.

PURPOSE: To determine Toxoplasma gondii genotype in scars of retinochoroiditis in humans. DESIGN: Immunopathology analysis. METHODS: DNA was isolated from retinochoroidal specimens taken from the borders of the scars from eye bank eyes as well as enucleated eyes from uveitis patients with retinochoroidal toxoplasmic scars. The SAG2 region was amplified by polymerase chain reaction and analyzed by restriction fragment length polymorphism. RESULTS: Of the 92 eyes studied, 9 had toxoplasmic scars. All of them, as well as the 2 enucleated eyes, disclosed the presence of type I parasites by the gel electrophoresis analysis of the restriction fragment length polymorphism from SAG2. CONCLUSION: These results suggest that type I strain seems to be responsible for the ocular infections in the population studied.

Animals↗

PubMed2005

Cystoid macular edema in gyrate atrophy of the choroid and retina: a fluorescein angiography and optical coherence tomography evaluation.

PURPOSE: To analyze the importance f optical coherence tomography (OCT) to diagnose the cystoid macular edema in a case of gyrate atrophy. DESIGN: Observational case report. METHODS: A 12-year-old boy presenting with gyrate atrophy of the choroid and retina underwent ophthalmologic, clinical, and laboratory tests. RESULTS: Plasma ornithine level was 735 mumol/l. Fluorescein angiography showed bilateral hyperfluorescence involving the central region of the macula. Optical coherence tomography (OCT) disclosed bilateral intraretinal cysts areas of low reflectivity with occasional high-signal elements bridging the retinal layers and intraretinal thickening. CONCLUSIONS: Both fluorescein angiography and OCT were helpful to confirm the diagnosis of macular involvement as a complication of gyrate atrophy of the choroid and retina in a patient who presented without any clinical evidence of cystoid macular edema, except a decrease in visual acuity.

Child↗

PubMed2005

Survival analysis of conjunctival limbal grafts and amniotic membrane transplantation in eyes with total limbal stem cell deficiency.

PURPOSE: To evaluate the survival of conjunctival limbal grafts and amniotic membrane transplantation (AMT) for total limbal stem cell deficiency (LSCD) and the influence of several parameters as cause of LSCD, dry eye, keratinization, eyelid abnormalities, HLA compatibility, systemic immunosuppression, and keratoplasty (PKP) on surgical outcome. DESIGN: Prospective, noncomparative, interventional case series. METHODS: Thirty-three eyes of 31 patients with total LSCD that underwent conjunctival limbal grafts and AMT at the Department of Ophthalmology, Federal University of São Paulo were included in this study. Cumulative graft survival as well as the influence of several variables on surgical outcome was analyzed. RESULTS: Ten eyes (30%) underwent conjunctival limbal autograft and 23 (70%) underwent conjunctival limbal allograft from living HLA-matched donor. Graft survival was seen in 13 eyes (40%) at 1 year and in 11 eyes (33.3%) at 2 years, with a cumulative survival of 33% after a mean follow-up time of 33 months. Increase in postoperative visual acuity was observed in 20 eyes (60.6%) during this period. Marked impact on graft survival was observed for patients with Stevens-Johnson syndrome, dry eye, keratinization, eyelid abnormalities, and allogeneic conjunctival limbal transplantation (independently of HLA compatibility) (P < .05). Preoperative dry eye was the most important prognostic parameter for surgical outcome (P < .001). CONCLUSIONS: Conjunctival limbal grafts associated with AMT are useful for restoring corneal epithelium phenotype in eyes with total LSCD. However, the cumulative survival declines substantially over a 2-year period. Considering all investigated variables, dry eye was the most important prognostic parameter.

Adult↗

PubMed2005

Comparison of intravitreal versus posterior sub-Tenon's capsule injection of triamcinolone acetonide for diffuse diabetic macular edema.

PURPOSE: To compare the safety and efficacy of intravitreal versus posterior Sub-Tenon's capsule injection of triamcinolone acetonide for diffuse diabetic macular edema. DESIGN: Prospective, double-masked, randomized controlled trial. PARTICIPANTS: Twelve patients (24 eyes) with bilateral diffuse diabetic macular edema. INTERVENTION: One eye of each patient was randomly assigned to receive a single 4-mg triamcinolone acetonide intravitreal injection and the fellow eye to receive a 40-mg triamcinolone acetonide posterior Sub-Tenon's capsule injection. MAIN OUTCOME MEASURES: Changes in visual acuity and central macular thickness obtained using optical coherence tomography were measured during a 6-month follow-up. Potential treatment complications were monitored, including increases in intraocular pressure (IOP) and cataract progression. RESULTS: Both intravitreal and Sub-Tenon's capsule injections of triamcinolone acetonide resulted in significant but transient improvements in central macular thickness. The mean (+/-standard deviation [SD]) central macular thickness in eyes with intravitreal injection was significantly thinner than in the Sub-Tenon's capsule-injected eyes at 1 month (226.8+/-41.7 microm and 431.5+/-165.8 microm, respectively; P = 0.002) and 3 months (242.3 +/- 93.9 microm and 364.7+/-78.2 microm, respectively; P = 0.005) after triamcinolone acetonide injection. The mean visual acuity (logarithm of the minimum angle of resolution) in the intravitreally injected eyes was significantly better than in the Sub-Tenon's capsule-injected eyes at 3 months post injection (0.832+/-0.293 and 1.107+/-0.339, respectively; P = 0.004). Intraocular pressure did not show any significant difference between the 2 forms of triamcinolone acetonide delivery at any follow-up visit, and no eyes had IOPs >25 mmHg. CONCLUSIONS: The findings from our study neither advocate nor support the use of corticosteroids for the treatment of diabetic macular edema, but do imply that both intravitreal and Sub-Tenon's capsule injections of triamcinolone acetonide may be equally tolerated, with short-term performance clearly favoring the intravitreal (4 mg) more than the SBT capsule (40 mg) route for the anatomic and functional aspects of improvement tested in this investigation.

Adult↗

PubMed2005

Extranodal B-cell lymphoma of the uvea: a case report.

CASE REPORT: Ocular involvement by non-Hodgkin's lymphoma is a rare condition that can result from a primary intraocular lymphoma of the retina or an intraocular manifestation of systemic lymphoma. Uveal involvement is seldom the initial manifestation of extranodal lymphoma. We describe an 80-year-old patient with a blind and painful left eye and a history of recurrent uveitis. After ultrasound evaluation, the eye was enucleated and histopathologic examination revealed a malignant B-cell lymphoma of the uveal tract. The patient has been followed for 8 years after surgery, but she has had no further systemic manifestations of lymphoma and has not required subsequent treatment. COMMENTS: Primary extranodal lymphoma can be easily mistaken for recurrent uveitis or primary intraocular lymphoma of the retina and central nervous system; it is a differential diagnosis to be considered in cases of recurrent uveitis-like symptoms evolving to blind painful eye.

Aged, 80 and over↗