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Dive into the research topics where Sergio Kwitko is active.

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Featured researches published by Sergio Kwitko.


Brazilian Journal of Microbiology | 2003

CONJUNCTIVAL ENDOGENOUS MICROBIOTA IN PATIENTS SUBMITTED TO CATARACT SURGERY

Claudete Inês Locatelli; Sergio Kwitko; Amauri Braga Simonetti

Bacterial isolation, identification and antimicrobial susceptibility tests were carried out in ocular material collected with swab and polimethylmethacrylate (PMMA) or silicone intraocular lenses (IOL) from forty six patients submitted to cataract surgery. Seventy six isolates and seven different microorganisms were identified. Coagulase-negative staphylococci (CNS) were the predominant microorganisms isolated from swabs (71.4% of cases), PMMA lenses (81.3%) and silicon lenses (77.8%). Coagulase-negative staphylococci isolates revealed high resistance to penicillin G followed by tetracycline, chloramphenicol and aminoglicosides. However, these isolates displayed great susceptibility to vancomycin, cephalothin and ofloxacin. Except for penicillin G, Staphylococcus aureus was very sensitive to the antimicrobial agents including oxacillin. Among Gram-negatives, Proteus mirabilis was prevalent and presented high resistance to tetracycline and chloramphenicol. Enterococcus isolates were vancomycin sensitive.


Graefes Archive for Clinical and Experimental Ophthalmology | 2012

Orbscan II and double-K method for IOL calculation after refractive surgery

Sergio Kwitko; Diane Ruschel Marinho; Samuel Rymer; Nórton Souto Severo; Carlos G. Arce

BackgroundPrecise IOL calculation in post-refractive surgery patients is still a challenge for the cataract surgeon. The purpose of this study is to test whether adding Orbscan II values into the double-K method improves IOL calculation in this group of patients.MethodsA prospective study with 43 eyes previously submitted to refractive surgery that underwent cataract extraction. IOL calculation was performed with double-K method. Post-K value was derived from Orbscan total-mean power map. The average corneal curvature of the general population (43.8D) was used as the pre-K value. Refraction results 30 days after surgery were compared with refraction that would be obtained if we used: (1) post-K values from keratometry, (2) post-K values from topography, and (3) pre-K values from Orbscan total-mean power. Anterior chamber depth measures obtained with the IOL Master and Orbscan II were compared.ResultsMean postoperative spherical equivalent (SE) was −0.25 ± 1.10 D in eyes submitted to radial keratotomy , –1.04 ± 1.42 D in eyes previously submitted to myopic Lasik, and +0.05 ± 1.76 D in those submitted to hyperopic surgeries. Had we inputted post-K values derived from keratometer and from topography, we would have obtained significantly higher postoperative refractive errors in eyes previously submitted to myopic refractive surgery (p < 0.05). Refractions using pre-K derived from the central 8 mm Orbscan instead of 43.8 D were similar in all studied groups (p > 0.05). Anterior chamber depth measured with IOL Master or Orbscan were similar.ConclusionsOrbscan measurements used as the post-K values into the double-K method provide a precise IOL calculation, especially in post myopic refractive surgery patients.


Journal of Cataract and Refractive Surgery | 1991

Light and electron microscopic analysis of intraocular 2% hydroxypropylmethylcellulose

Sergio Kwitko; Rubens Belfort

ABSTRACT Twenty samples of 2% hydroxypropylmethylcellulose for intraocular surgery, obtained from two Brazilian laboratories, were studied to determine the presence and type of impurities in the solutions. These were compared with ten samples of balanced salt solution (control group). Using light and scanning electron microscopy, five types of particles were identified: cellulose fibers, vegetable flakes, crystals, glass fragments, and other impurities. At least one of these contaminants was present in each sample of 2% hydroxypropylmethylcellulose. The vegetable matter was also seen in a sample of the raw material from which the clinical material had been prepared. Control solutions (i.e., balanced salt solution) were free of vegetable matter and of crystals, but glass fragments and other impurities were present. The average number of foreign particles in the solutions of hydroxypropylmethyl cellulose (91.2 and 96.7 particles per milliliter for each of the two groups) was statistically greater than in the balanced salt solutions (13.7 particles per milliliter).


Expert Review of Ophthalmology | 2011

Iris-claw (Artisan®/Artiflex®) phakic intraocular lenses for high myopia and high hyperopia

Sergio Kwitko; Andressa Prestes Stolz

Artisan®/Artiflex® phakic intraocular lenses (pIOLs) demonstrate reversibility, high optical quality with better best spectacle-corrected visual acuity, refractive predictability, and stability compared with keratorefractive surgeries, in addition to the potential gain in visual acuity in myopic patients due to retinal magnification. With proper anatomical conditions, this lens also shows good results in hyperopic patients. Combined with corneal refractive surgery as an additional procedure, this pIOL shows the most predictable optical result. The main complications of iris-fixated anterior chamber pIOLs are chronic subclinical inflammation, corneal endothelial cell loss, cataract formation, secondary glaucoma, iris atrophy and dislocation. Comprehensive preoperative evaluation and long-term postoperative follow-up examinations are needed to monitor for and prevent serious complications. This article is a review of iris-claw pIOLs, and addresses the results and their complications.


Arquivos Brasileiros De Oftalmologia | 2002

Transplante autólogo de limbo conjuntival e de limbo córneo-conjuntival no tratamento das queimaduras químicas oculares em coelhos

Samuel Rymer; Miguel N. Burnier; Diane Ruschel Marinho; Sergio Kwitko; Rubens Belfort; Daniela Rohe

Purpose: To compare corneal recovery after ocular chemical burn in rabbit eyes treated with conjunctival limbus or keratoconjunctival limbus autografts. Methods: Thirty-five rabbits underwent a unilateral ocular chemical burn, including the cornea and the limbus, applying a NaOH 1 mol -1 solution. After 30 days, a conjunctival limbus autograft from the contralateral eye was performed in Group 2 (12 eyes); a keratoconjunctival limbus autograft from the contralateral eye was performed in Group 3 (11 eyes) and no surgeries were carried out in the control group (Group 1). Statistical analysis regarding induction and regression of corneal neovascularization, time for corneal re-epithelialization, rate of corneal transparency was performed. The corneal surface phenotype was also analyzed by monoclonal antibodies (AE-5). Results: After 90 days of follow-up, improvement of corneal transparency, decreased corneal neovascularization and corneal re-ephitelialization were significantly associated with limbal transplantation, carried out in Groups 2 and 3. The control group (Group 1) showed epithelial necrosis in all cases. Corneal surfaces of the operated eyes (Groups 2 and 3) showed a gradual decrease of goblet cells, a gradual increase of corneal epithelial cells, and postoperative stabilization after 30 days. Conclusions: Conjunctival limbus and keratoconjunctival limbus autografts produced the same clinical and epithelial phenotype results in an experimental model of chemical burns in rabbit eyes.


Ocular Immunology and Inflammation | 1994

Endogenous endophthalmitis due to Listeria monocytogenes.

J Melamed; Sergio Kwitko; Simone Barcaro; Jose M Verri; Victor F Petrillo

The authors report a case of Listeria monocytogenes endophthalmitis in a patient who had undergone cardiac revascularization surgery and was receiving systemic corticosteroids. The organism was isolated both in the aqueous humor and in blood culture. The infection was successfully treated with intravenous crystalline penicillin, but the patient developed a bullous keratopathy and secondary glaucoma, resulting in poor visual acuity (counting fingers at 0.5 m). The visual acuity recovered to 20/30 after a penetrating keratoplasty and the glaucoma was controlled with a Molteno implant and a trabeculectomy combined with administration of mitomycin. Listeria monocytogenes endogenous endophthalmitis should be suspected in any immunosuppressed patient with severe anterior uveitis, especially when a brown hypopyon, high intraocular pressure and corneal edema are present.


Arquivos Brasileiros De Oftalmologia | 2012

Optical coherence tomography image in gelatinous drop-like corneal dystrophy: case report

Otávio de Azevedo Magalhães; Samuel Rymer; Diane Ruschel Marinho; Sergio Kwitko; Isabel Habeyche Cardoso; Lucia Maria Kliemann

Gelatinous drop-like corneal dystrophy is a rare disorder with few cases described in the present literature. The following report will show how difficult it is to diagnose this disease in early stages. Modern image exams, such as optical coherence tomography helps to diagnose and can be crucial to establish the best treatment. We will present the histopathological changes and clinical features in this unusual dystrophy.


Arquivos Brasileiros De Oftalmologia | 2008

Experiência inicial com a ceratoprótese de Dohlman-Doane: relato de casos

Andressa Prestes Stolz; Sergio Kwitko; Melissa Manfroi Dal Pizzol; Diane Ruschel Marinho; Samuel Rymer

PURPOSE To describe 9 eyes in 8 patients who received Dohlman-Doane type 1 keratoprosthesis (KPro) with a mean follow-up of 11.2 months (2 to 25 months). METHODS A retrospective, non-comparative interventional case series. Previous corneal disease was alcaline burn in 4 eyes, multiple graft failure in 3 eyes, Stevens-Johnson syndrome in 1 eye and thermal injury in 1 eye. Best corrected visual acuity (BCVA) was hand motions or worse in all patients. Glaucoma was present preoperatively in 3 eyes and received Ahmed valve implantation. RESULTS 88,9% eyes achieved BCVA of better than or equal to 20/100, and 44,4% better than or equal to 20/40. In the postoperative period, 3 eyes developed posterior capsule opacity treated with YAG laser capsulotomy; 3 retroprosthetic membrane treated with tPA injection or steroids; 2 glaucoma in clinical treatment; 1 corneal melting, treated with donor cornea bottom exchange; and 1 fungic endophthalmitis, treated with corneal transplant, anterior vitrectomy, KPro and intraocular lens explantation, and specific intravitreal and endovenous treatment. CONCLUSION Dohlman-Doane K-Pro seems to be a good option for cases of corneal blindness with poor prognosis for traditional penetrating keratoplasty. Its main advantage is not requesting systemic immunossuppression. Best results were achieved in non-immune diseases.


Arquivos Brasileiros De Oftalmologia | 2008

Contaminação de halos doadores córneo-esclerais em ceratoplastia penetrante no Hospital de Clínicas de Porto Alegre

Cláudia Martins Borowsky; Anelise Dutra Wallau; Aline Reetz; Sergio Kwitko; Samuel Rymer; Claudete Inês Locatelli

PURPOSE: To determine the incidence of positive corneoscleral rim cultures preserved in Optisol GS medium, to identify pathogens involved and possible recipient eye infection. METHODS: A hundred sixty-three corneoscleral rim cultures penetrating keratoplasties performed from January 2001 to January 2003 in the Hospital de Clinicas de Porto Alegre were reviewed. Enucleations and corneal storage were done as aseptic as possible and gentamicin 0.3% was instilled. Corneoscleral rim was divided into two segments, half was inoculated into Sabouraud broth and the other half into thioglycolate broth; inoculation into blood agar, chocolate agar and MacConkey agar was done later if necessary for pathogen identification. The receivers eye data were reviewed. RESULTS: There were eleven positive cultures (6.7%) out of 163 evaluated corneoscleral rim cultures. Of these, four were Staphylococcus epidermidis, one was Staphylococcus aureus, one was Serratia sp., one was Pseudomonas aeruginosa and the other four were different subtypes of Candida (two Candida sp., one Candida albicans and one Candida parapapilosis). All pathogens were resistant to gentamicin. None of the eleven cases of positive corneoscleral rim cultures resulted in ocular infection at the receivers eyes (six months follow-up). CONCLUSIONS: We found low rates of positive corneoscleral rim cultures after penetrating keratoplasty at the Porto Alegre Clinical Hospital. The most frequent involved pathogens were Staphylococcus sp and Candida sp. Although we did not identify any postoperative infection at the receivers eyes, we recommend corneoscleral rim culture for guidance of postoperative infection, a rare but possible devastating ocular event.


Revista Brasileira De Oftalmologia | 2012

Ceratoprótese de Boston

Sergio Kwitko; Andressa Prestes Stolz

A short review of type 1 Dohlman-DoaneKeratoprosthesis (KPro) addresses results and complications. Dohlman-DoaneKPro is today a good option for cases of corneal blindness with poor prognosis for traditional penetrating keratoplasty. KPro design and surgical improvements along with proper preoperative ocular surface condition allows good results in non-immune diseases. Main complications of this KPro areinflammatory retroprosthetic membrane, glaucoma, corneal melting,vitreitis, and infection (keratitis and endophthalmitis). Comprehensive long-term postoperative follow-up examinationsare needed to monitor for and prevent serious complications.

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Samuel Rymer

Universidade Federal do Rio Grande do Sul

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Diane Ruschel Marinho

Universidade Federal do Rio Grande do Sul

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Rubens Belfort

Federal University of São Paulo

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Claudete Inês Locatelli

Universidade Federal do Rio Grande do Sul

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Aline Reetz

Universidade de Passo Fundo

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Amauri Braga Simonetti

Universidade Federal do Rio Grande do Sul

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Anelise Dutra Wallau

Federal University of São Paulo

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Carla Putz

Universidade Federal do Rio Grande do Sul

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Carlos G. Arce

Federal University of São Paulo

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Cláudia Martins Borowsky

Universidade Federal do Rio Grande do Sul

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