Evaluation of unilateral corneal collagen cross-linking on fellow untreated eyes of patients with keratoconus / A avaliação da reticulação unilateral do colágeno corneano em olhos não tratados de pacientes com ceratocone

ABSTRACT Purpose: This study aimed to examine the effects of unilateral corneal collagen cross-linking treatment on visual acuity and the topographic findings of the fellow untreated eye of patients who had bilateral progressive keratoconus. Methods: Patients with progressive keratoconus who underwent cross-linking treatment were screened retrospectively. A total of 188 untreated eyes of 188 patients whose eyes were treated unilaterally with either standard or accelerated cross-linking and refused cross-linking procedure for the fellow eye were included. Visual acuity and topographic findings of the fellow untreated eyes were obtained preoperatively and postoperatively at the 1st, 3rd, 6th, 12th, 24th, 30th, and 36th months. Results: The change over time of variables examined was similar in the untreated eyes of patients who received standard and accelerated cross-linking methods (p>0.05). At the 12th month, 136 (95.8%) untreated eyes were stable according to progression criteria. Only 4 (8%) eyes were progressive at the 24th month. No progression was observed in any of the 16 patients with a 36-month follow up. Conclusions: The results showed that the fellow untreated eyes of patients with bilateral progressive keratoconus did not have significant progression rates after unilateral cross-linking treatment.

RESUMO Objetivo: Examinar os efeitos do tratamento de reticulação unilateral do colágeno corneano na acuidade visual e os achados topográficos em olhos não tratados de pacientes com ceratocone progressivo bilateral. Métodos: Foram rastreados retrospectivamente pacientes com ceratocone progressivo submetidos a tratamento de reticulação. Foram incluídos no estudo 188 olhos não tratados de 188 pacientes tratado unilateralmente com reticulação padrão ou acelerada e que recusaram o procedimento de reticulação no outro olho. A acuidade visual e os achados topográficos dos olhos não tratados foram obtidos no pré- e pós-operatório no 1º, 3º, 6º, 12º, 24º, 30º e 36º mês. Resultados: As alterações ao longo do tempo foram semelhantes para as variáveis examinadas nos olhos não tratados de pacientes tratados com métodos de reticulação padrão e acelerado (p>0,05). No 12º mês, 136 olhos não tratados (95,8%) estavam estáveis, de acordo com os critérios de progressão. Apenas quatro olhos (8%) mostraram progressão no 24º mês. Nenhuma progressão foi observada nos 16 pacientes que tiveram um acompanhamento de 36 meses. Conclusões: O estudo mostrou que os olhos não tratados de pacientes com ceratocone progressivo bilateral não apresentaram taxas de progressão significativas após o tratamento unilateral com reticulação.

Application of proanthocyanidin in the treatment and repair of deep caries / 口腔疾病防治

@#Proanthocyanidin (PA), as a kind of natural plant polyphenol, have a variety of biological functions, such as promoting remineralization, inducing collagen cross-linking, inhibiting protease activity and inhibiting bacteria. Therefore, PA could be broadly used in the clinical application of treatment and repair of deep caries in the future; for example, PA could promote dentin remineralization, improve resin-dentin bonding durability and improve the dentin acid erosion effect. This application potential of PA arises from several features, firstly, PA can not only promote dentin remineralization on its own or with other remineralizers but also exhibits antibacterial effects, which can inhibit acid production while reducing the formation of cariogenic pathogens and their biofilms. Based on the above features, PA can reduce the incidence of caries disease; thus, PA improves deep caries and long-term effects after treatment. In addition, PA added to adhesives or etch agents can improve the etching and bonding effect of dentin by inducing collagen cross-linking and inhibiting protease activity, thus achieving the ultimate goal of improving the bonding performance of deep caries. This paper summarizes recent progress of research on PA for the treatment and repair of deep caries, including the promotion of dentin remineralization and antibacterial activity as well as the improvement in dentin bonding and acid etching effect, to provide a more comprehensive reference for treating and restoring deep caries in clinical practice.

Corneal crosslinking efficacy in patients with keratoconus under 18 years of age / Eficácia do crosslinking corneano em portadores de ceratocone com idade inferior a 18 anos

ABSTRACT Purpose: Keratoconus presents certain specificities in pediatric patients compared with adults. The greatest challenge is because the disease is typically more severe and progresses faster in children. This retrospective study aimed to report crosslinking procedure in patients under 18 years of age and their follow-up for at least 24 months after the procedure. Methods: Overall, 12 eyes from 10 patients were studied and data, such as visual acuity with and without correction, maximum keratometry, corneal thickness, foveal thickness, and endothelial microscopy, were assessed at both preoperative and postoperative visits. Corneal crosslinking was performed in all patients. Results: A tendency toward reduced Kmax and improved Corrected Distance Visual Acuity at all postoperative moments. Only one of the 12 eyes exhibited increased Kmax of more than 1 D during a time frame longer than 12 months. Regarding pachymetry, a tendency for corneal thinning was observed in the first four months after surgery. Conclusion: Encouraging results were obtained regarding the stabilization of the disease, progression, and procedural safety, corroborating to other authors' findings. The significance of early diagnosis and short-term follow-up were highlighted.

RESUMO Objetivo: O ceratocone na população pediátrica apresenta algumas particularidades em relação à população adulta. O maior desafio é devido à doença ser geralmente mais severa e rapidamente progressiva em crianças. Métodos: Este artigo utiliza uma análise retrospectiva para relatar o uso do crosslinking em jovens menores de 18 anos e sua evolução pelo menos 24 meses após o procedimento. Foram estudados 12 olhos de 10 pacientes, e dados como acuidade visual com e sem correção, ceratometria máxima, espessura corneana, espessura foveal e microscopia endotelial avaliados no pré e pós-operatórios. O crosslinking corneano foi realizado em todos os pacientes pelo mesmo cirurgião. Resultados: Observou-se uma tendência de redução do valor do Kmax e melhora da acuidade visual corrigida em todos os momentos de pós operatório. Com relação à paquimetria, observou-se afinamento corneano do ponto mais fino, nos primeiros quatro meses de pós-operatório. Conclusão: Resultados encorajadores foram obtidos com relação à estabilização da doença, progressão e segurança do procedimento, corroborando com as conclusões de outros autores. A importância do diagnóstico precoce e do acompanhamento a curto prazo do paciente deve ser destacada.

Accelerated corneal cross-linking with hypo-osmolar riboflavin in thin keratoconic corneas: 2-year follow-up / Cross-linking corneano acelerado com riboflavina hiposmolar em córneas ceratocônicas finas: 2 anos de acompanhamento

ABSTRACT Purpose: This study was performed to evaluate the outcomes of accelerated corneal cross-linking in keratoconic corneas with thinnest pachymetry values of <400 µm. Methods: The study included 28 eyes of 24 patients. The uncorrected and best-corrected visual acuities (logMAR), flattest and steepest keratometric readings, central corneal thickness at the thinnest point, corneal higher-order aberrations, and contrast sensitivity were assessed before and at 1, 3, 6, 12, and 24 months after corneal cross-linking. Result: The mean best-corrected visual acuity and contrast sensitivity increased (p=0.02, p=0.03, respectively), whereas the mean uncorrected visual acuity did not significantly differ (p>0.05) at 24 months after corneal cross-linking, compared with measurements before corneal cross-linking. Although the mean flattest keratometric reading showed no significant change (p=0.58), the mean steepest keratometric reading was reduced when compared with its value before corneal cross-linking (p=0.001). No change was observed in the mean central corneal thickness at the thinnest point at 24 months after corneal cross-linking, compared with its value before corneal cross-linking (p=0.12). Conclusion: Accelerated corneal cross-linking in keratoconic eyes with thin corneas could halt the progression of keratoconus in corneas thinner than 400 µm at 24 months after treatment.

RESUMO Objetivo: Este estudo foi realizado para avaliar os resultados do cross-linking corneano acelerado em córneas ceratocônicas com os valores mais baixos de paquimetria <400 µm. Métodos: O estudo incluiu 28 olhos de 24 pacientes. As acuidades visuais não corrigidas e melhor corrigidas (logMAR), leituras ceratométricas mais planas e íngremes, espessura corneana central no ponto mais fino, aberrações corneanas de mais alta ordem e a sensibilidade ao contraste foram avaliadas antes e em 1, 3, 6, 12 e 24 meses após a realização do do cross-linking. Resultados: A média da acuidade visual melhor corrigida e a sensibilidade ao contraste aumentaram (p=0,02, p=0,03, respectivamente), enquanto a média da acuidade visual não corrigida não diferiu significativamente (p>0,05) aos 24 meses após o cross-linking, comparada com medidas antes do procedimento. Embora a leitura da média da ceratometria mais plana não tenha apresentado alteração significativa (p=0,58), a leitura ceratométrica mais íngreme diminuiu quando comparada ao seu valor antes do cross-linking (p=0,001). Não foi observada alteração na média da espessura corneana central no ponto mais fino aos 24 meses após o cross-linking em comparação com seu valor antes do procedimento (p=0,12). Conclusão: O cross-linking corneano acelerado nos olhos ceratocônicos com córneas finas pode interromper a progressão do ceratocone nas córneas mais finas que 400 µm 24 meses após o tratamento.

Accelerated collagen cross-linking in the management of advanced Acanthamoeba keratitis / Cross-linking acelerado de colágeno no controle da ceratite por Acanthamoeba avançada

ABSTRACT Purpose: To report our initial experience in the treatment of Acanthamoeba keratitis with accelerated corneal collagen cross-linking. Methods: Retrospective chart review of patients diagnosed with Acanthamoeba keratitis with progressive corneal melting who were treated with accelerated collagen cross-linking. Results: A total of 6 eyes (5 patients) were reviewed. All the patients received adjuvant therapy with moxifloxacin and chlorhexidine. In 4 cases, the ulcer healed with a mean interval to epithelialization of 108.8 days (range 59-217). In 2 eyes, there was a persistent neurotrophic ulcer. The melting was not progressive in any case, nor did any eye required emergency penetrating keratoplasy. Conclusion: This study suggests a beneficial effect of accelerated collagen cross-linking in cases of Acanthamoeba keratitis with corneal melting. Thus, collagen cross-linking may be considered as adjuvant treatment for Acanthamoeba keratitis.

RESUMO Objetivo: Relatar nossa experiência inicial no tra tamento da ceratite por Acanthamoeba com reticulação acelerada de colágeno corneano. Métodos: Revisão retrospectiva de prontuários de pacientes diagnosticados com ceratite por Acanthamoeba, com deformação progressiva da córnea, tratados com reticulação acelerada de colágeno. Resultados: Seis olhos (5 pacientes) foram incluídos. Todos os pacientes receberam terapia adjuvante com moxifloxacina e clorexidina. Em 4 casos, a úlcera cicatrizou com uma média de epitelização de 108,8 dias (amplitude de 59-217 dias). Em dois pacientes, a úlcera apresentou um comportamento neurotrófico. A deformação não foi progressiva em nenhum dos pacientes e nenhum dos olhos exigiu ceratoplastia penetrante de emergência. Conclusão: Este estudo sugeriu um efeito benéfico da reticulação acelerada de colágeno em casos de ceratite por Acanthamoeba infecciosa com deformação corneal. A reticulação de colágeno parece ser uma alternativa coadjuvante possível para casos de ceratite por Acanthamoeba.

Effect of the bioprotectant agent trehalose on corneal epithelial healing after corneal cross-linking for keratoconus / Efeito do agente bioprotetor trealose na cicatrização epitelial da córnea após reticulação corneana para ceratocone

ABSTRACT Purpose: This study aimed to compare the effectiveness of eye drops containing a combination of sodium hyaluronate and trehalose and sodium hyaluronate for the treatment of corneal cross-linking and epithelial healing. Methods: This study included 46 eyes of 23 keratoconus patients who underwent corneal cross-linking on both eyes. Unpreserved trehalose 30 mg/mL and sodium hyaluronate 1.5 mg/mL (Thealoz Duo®; Thea, France) were applied six times a day on one eye of each patient and unpreserved sodium hyaluronate 0.15% (Eye Still®; Teka, Inc., Istanbul) was applied on the other eye. Patients were examined daily until complete re-epithelialization. Postoperative examinations to assess the measured size of epithelial defect were performed using slit-lamp biomicroscopy. Results: The study included 23 patients (13 females and 10 males) with a mean age of 20.9 ± 10.3 years. Corneal epithelial healing time after cross-linking was 2.3 ± 1.2 days for the trehalose and sodium hyaluronate group and 3.8 ± 2.9 days for the sodium hyaluronate group (p=0.03). Conclusion: The application of eye drops containing the combination of trehalose and sodium hyaluronate resulted in faster corneal re-epithelialization following corneal cross-linking than that of eye drops containing sodium hyaluronate alone.

RESUMO Objetivo: Este estudo teve como objetivo comparar a eficácia de colírios contendo uma combinação de hialurônico de sódio e hialuronato de sódio e trealose para o tratamento da cicatrização epitelial em pacientes com cross-linking corneano. Métodos: Este estudo inclui 46 olhos de 23 pacientes com ceratocone, que foram operados com cross-linking corneano em ambos os olhos. Trealose não preservada 30 mg/mL e hialuronato de sódio 1,5 mg/mL (Thealoz Duo®; Thea, França) foram aplicados seis vezes por dia em um olho de cada paciente e hialuronato de sódio não conservado, 0,15% (Eye Still®; Teka, Inc., Istambul) foi aplicada no outro olho. Os pacientes foram examinados diariamente até a completa reepitelização. Exames pós-operatórios para avaliar o tamanho medido do defeito epitelial foram realizados usando biomicroscopia com lâmpada de fenda. Resultados: O estudo incluiu 23 pacientes (13 mulheres e 10 homens) com idade média de 20,9 ± 10,3. O tempo de cicatrização epitelial da córnea após o cross-linking foi de 2,3 ± 1,2 dias para o grupo trealose e hialuronato de sódio e 3,8 ± 2,9 dias para o grupo hialurônico de sódio (p=0,03). Conclusão: A aplicação de gotas para os olhos contendo combinação de trealose e hialuronato de sódio resultou em uma re-epitelização da córnea mais rápida após o cross-linking corneano do que a de gotas contendo hialurônico de sódio apenas.

PACK-CXL:corneal collagen cross-linking for infectious keratitis / 中华实验眼科杂志

Infectious keratitis is one of the leading causes of irreversible vision loss.With the emergence of multidrug-resistant pathogen,despite appropriate diagnosis and antimicrobial treatment,infectious keratitis can still result in corneal opacity and even melting and perforation.Therefore,it is imperative to develop novel treatment for infectious keratitis.More recently,several articles have demonstrated the effectiveness of collagen cross-linking (CXL) in treating infectious keratitis via direct antimicrobial activity and inhibition of corneal enzymatic degradation.In order to highlight the use of CXL tor infectious keratitis treatment,a new term was proposed at the 9th CXL congress to rename its use in infections as photoactivated chromophore for infectious keratitis-CXL (PACK-CXL).Based on the current literature,PACK-CXL appears to be effective for bacterial keratitis,especially on inhibiting corneal perforation.The effect was limited for fungal and amoebic keratitis,and maybe aggravative on viral keratitis.In this article,we will review the basic profile,technical operation,prevention of complication of CXL,the principle mechanism of PACK-CXL and its clinical application for bacterial,fungal keratitis,amoebic and viral keratitis.

Biophysical characteristics of genipin-crosslinked amniotic membrane bio-scaffold / 中华实验眼科杂志

Objective To investigate the characteristics and feasibility of genipin-crosslinked amniotic membrane(AM) as bio-scaffold.Methods Human umbilical cord mesenchymal stem cells (hUCMSCs) were isolated from fresh umbilical cord and cultured by adherent method.The expressions of PE-CD34,PE-CD45,PE-CD90,FITC-105 and FITC-Oct-4,the markers of hUCMSCs,were detected by flow cytometry.Alizarin red and oil red O staining were performed to identify the cells after adipogenesis and osteogenesis induction on the third-generation cells.Human AMs were treated at 37 ℃ and 45 ℃ by 0.5％ and 1％ genipin solution for 24,36 and 48 hours respectively,and the mechanical properties of AM in each group were measured and compared.The hUCMSCs were divided into only hUCMSCs culture group,fresh AM group,crosslinked AM group,gelatin group and crosslinked AM+gelatin group,and the cells were cultured in the corresponding medium.The content of hydroxyproline among the groups was detected with hydroxyproline kit,and proliferation of the cells (absorbance) was assayed by MTT method to evaluate the biological compatibility of crosslinked AM.Results The maximum tensile displacement of the crosslinked-AM by 0.5％ and 1％ genipin was (8.31±0.43)mm and (4.49±0.37)mm respectively,and those after crosslinked with 0.5％ genipin under the 37 ℃ and 45 ℃ for 24 hours was (9.89±1.09)mm and (5.39±0.59)mm,respectively,showing a significant difference between them (t =6.389,P＜0.05).The maximum tensile displacement of the crosslinked-AM was gradually decreased as the lapse of crosslinking time,and an insignificant difference was found among 24,36 and 48 hours after 0.5％ genipin treatment under the 37 ℃ (P＞0.05).The loading force of the crosslinked-AM was significantly higher in the 1％ genipin treated group than that in the 0.5％ genipin treated group (P＜0.05),and the loading force of the AM was significantly increased in 45 ℃,0.5％ genipin,24 hours crosslinked group compared with the 37 ℃,0.5％ genipin,24 hours crosslinked group (t =5.528,P＜0.05).The content of hydroxyproline in the AM was (1.28±0.36),(2.03 ±0.49) and (2.11 ±0.10) mg/g in the 1％ genipin crosslinked AM group,0.5％ genipin crosslinked AM group and fresh AM group,respectively,and the content of hydroxyproline in the AM in the 1％ genipin group was significantly lower than that in the 0.5％ genipin group in the fresh AM group (both at P＜0.05).The proliferative values of the hUCMSCs were significantly lower in the only hUCMSCs culture group,fresh AM group and gelatin group were significantly reduced in comparison with the crosslinked AM group and crosslinked AM+gelatin group (all at P＜0.05).There was no significant difference in the proliferative values of the hUCMSCs between crosslinked AM group and crosslinked AM+gelatin group (P＞0.05).Conclusions Different crosslinked temprature,crosslinking period and concentration of genipin impact the mechanical properties of AM.Crosslinked AM with genipin is feasible as a carrier scaffold of artificial cornea because of less tissue toxicity and better plasticity.

Cross-linking da cornea: protocolo padrão / Corneal Crosslinking: The Standard Protocol

RESUMO O objetivo desta revisão é de determinar as indicações e eficácia da cirurgia que promove novas ligações covalentes entre as fibras de colágeno da córnea, conhecida como Cross-Linking (CXL), assim como esclarecer seus objetivos. O ceratocone é uma doença ectasica da córnea, bilateral, assimétrica, que, principalmente, cursa com encurvamento e afinamentos progressivo, e se inicia em geral na segunda década de vida. O uso primário do CXL tem sido na interrupção da progressão do Ceratocone. Apesar do conhecido encurvamento no estroma da córnea ocorrer nesses pacientes, a fisiopatologia por trás do ceratocone ainda é desconhecida e parece ser multifatorial. Pela evidencia literária disponível até o momento, o CXL da córnea esta, portanto indicado nos pacientes com doença em progressão. Concluímos que existe evidencia suficiente para afirmar que o CXL da córnea é eficaz na estabilização da doença ectásica da cornea.

ABSTRACT The purpose of this review is to determine the indications and efficacy of the surgery that promotes new covalent bonds between the collagen fibers of the cornea, known as Cross-Linking (CXL), as well as to clarify its objectives. Keratoconus is a bilateral, asymmetric ectasic disease of the cornea that mainly courses with steepening and progressive thinning, and usually begins in the second decade of life. The primary use of CXL has been in discontinuing the progression of keratoconus. Although known corneal stromal remodeling occurs in these patients, the pathophysiology behind keratoconus is still unknown and appears to be multifactorial. By the literary evidence available to date, the CXL of the cornea is safely indicated in patients with progressing disease. We conclude that there is sufficient evidence to affirm that cornea CXL is effective in stabilizing corneal ectasic disease.

Six-month outcomes of corneal crosslinking with dextran-free isotonic riboflavin solution / Resultados após seis meses de crosslinking de córnea com solução isotônica de riboflavina sem dextrano

ABSTRACT Purpose: To analyze the short-term clinical and topographic outcomes in patients with keratoconus after corneal collagen cross-linking treatment (CXL) with dextran-free isotonic riboflavin solution. Methods: In this retrospective case series, 26 eyes from 26 patients with keratoconus were studied. The best corrected visual acuity (BCVA) and refractive and topographic findings were analyzed at a 6-month follow-up. Results: The mean BCVA (Snellen lines) values before and 1, 3, and 6 months after CXL were 0.51 ± 0.2, 0.48 ± 0.2, 0.57 ± 0.2, and 0.64 ± 0.2, respectively, and the difference between the preoperative and 6-month values was statistically significant (p=0.006). The mean spherical equivalent refraction decreased from -5.6 ± 2.4 diopters (D) preoperatively to -5.0 ± 2.1 D, and mean simulated keratometry decreased from 48.5 ± 2.5 D to 47.8 ± 2.6 D at 6 months. (p=0.145 and p=0.001, respectively). In addition, the maximum keratometry decreased progressively and significantly from the preoperative value during follow-up (p=0.003). The central and minimal corneal thicknesses, including those of the epithelium, also decreased from 442.8 ± 25.6 µm and 430.5 ± 23.9 µm preoperatively to 420.7 ± 31.8 µm and 409.3 ± 28.7 µm at the most recent follow-up (p<0.001), respectively. No intraoperative or postoperative complications were observed. Conclusions: CXL with dextran-free isotonic riboflavin solution appears to be a safe treatment alternative for keratoconus and yields sustained short-term improvements in visual acuity, keratometric readings, and corneal thickness. However, long-term results are needed to confirm these outcomes.

RESUMO Objetivo: Analisar os resultados clínicos e topográficos curto prazo após crosslinking (CXL) de córnea com solução isotônica de riboflavina sem dextrano, em pacientes com ceratocone. Método: Estudamos 26 olhos de 26 pacientes com ceratocone, nesta série retrospectiva de casos. Melhor acuidade visual corrigida (BCVA), refração e achados topográficos foram analisados aos 6 meses de acompanhamento. Resultados: BCVA pré-operatória (linhas de Snellen) foi de 0,51 ± 0,2. BCVA após CXL foram de 0,48 ± 0,2, 0,57 ± 0,2 e 0,64 ± 0,2 no 1º, 3º e 6º meses, respectivamente. A diferença entre a BCVA pré-operatória e mais recente foi estatisticamente significativa (p=0,006). O equivalente esférico médio diminuiu de -5,6 ± 2,4 dioptrias (D) no pré-operatório para -5.0 ± 2.1 D e a média da ceratometria simulada diminuiu de 48,5 ± 2,5 D para 47, 8± 2,6 D aos 6 meses. (p=0,145 e p=0,001, respectivamente). A ceratometria máxima diminuiu progressivamente durante o acompanhamento com as mudanças sendo significativamente diferentes do valor pré-operatório (p=0,003). As espessuras corneanas central e mínima, diminuiram de 442,8 ± 25,6 µm e 430,5 ± 23,9 µm para 420,7 ± 31,8 µm e 409,3 ± 28,7 µm, respectivamente, na visita mais recente (p<0,001). Não foram observadas complicações intraoperatórias e pós-operatórias. Conclusões: CXL com solução de riboflavina isotônica sem dextrano parece ser uma opção segura de tratamento para o ceratocone com melhora mantida na acuidade visual, ceratometria e espessura corneana, no curto prazo. Resultados a longo prazo são necessários para confirmar estes resultados.

Factors affecting visual acuity after accelerated crosslinking in patients with progressive keratoconus / Fatores que afetam a acuidade visual após crosslinking acelerado entre pacientes com ceratocone progressivo

ABSTRACT Purpose: The present study aimed to report the outcomes of patients with progressive keratoconus who were treated via accelerated crosslinking (CXL) 6 months earlier and to determine the factors that promoted improved visual acuity after treatment. Methods: This retrospective study included 35 eyes of 34 patients with progressive keratoconus who underwent CXL. Topographical measurements were obtained preoperatively and in the first, third, and sixth months postoperatively using a rotating Scheimpflug camera. The uncorrected visual acuity (UCVA), best-corrected visual acuity (BCVA), flat keratometry (K) value (K1), steep K value (K2), average K value (avgK), topographic cylindrical value (Cyl), apical keratoscopy front (AKf), apical keratoscopy back (AKb), symmetry index front (SIf), symmetry index back (SIb), and thinnest point of the cornea (ThkMin) were recorded. Results: At the 6-month follow-up, the mean UCVA and BCVA values were improved, and the K values remained stable. Statistically significant decreases in AKf (p=0.04) and the thinnest point of the cornea (p=0.001) and a statistically significant increase in AKb (p=0.01) were observed. A correlation analysis revealed that the preoperative BCVA, UCVA, K1, K2, avgK, AKf, and AKb values significantly affected visual acuity at the 6-month follow-up. Conclusions: Accelerated CXL is an effective treatment for the prevention or even reversal of keratoconus progression. The preoperative K values and apexes of the anterior and posterior cornea were found to affect visual acuity at 6 months after accelerated CXL. Both AKb steepening and AKf flattening appear to be important factors in the stabilization of keratometric values and improvement of visual outcomes.

RESUMO Objetivo: O objetivo do estudo é relatar os resultados do sexto mês após o tratamento de crosslinking acelerado (CXL) em pacientes com ceratocone progressivo e determinar os fatores que afetam a melhora da acuidade após o tratamento. Métodos: Neste estudo retrospectivo, foram incluídos 35 olhos de 34 pacientes com ceratocone progressivo que se submeteram CXL. Acuidade visual não corrigida (UCVA) e melhor acuidade visual corrigida (BCVA) foram registradas. Medidas topográficas foram obtidas utilizando uma câmara Scheimpflug rotativa no pré-operatório e no 1º, 3º e 6º meses após a cirurgia. Os valores de ceratometria (K) mais plana (K1), K mais curva (K2), médio de K (avgK), astigmatismo topográfico (Cyl), ápice anterior da ceratoscopia (AKf), ápice posterior da ceratoscopia (AKb), índice anterior de simetria (SIf), índice posterior de simetria (SIb) e ponto mais fino da córnea (ThkMin) foram avaliados. Resultados: A média UCVA e BCVA melhoraram, enquanto valores de K ficaram estáveis 6º mês. Houve uma diminuição estatisticamente significativa na AKf e um aumento estatisticamente significativo na AKb (p=0,04, p=0,01, respectivamente). O ponto mais fino da córnea diminuiu significativamente (p=0,001). Na análise de correlações, além da UCVA e BCVA pré-operatórias; valores K1, K2, avgK, AKf e AKb pré-operatórios influenciaram significativamente a acuidade visual no 6º mês de acompanhamento. Conclusões: CXL acelerado é uma forma eficaz de tratamento na prevenção ou no mesmo inversão da progressão do ceratocone. A acuidade visual no 6º mês após CXL acelerado foi afetada a partir dos valores de K e dos ápice anterior e posterior da córnea. Encurvamento do AKb e aplanamento do AKf parecem ser fatores importantes na estabilização dos valores ceratométricos e na melhora da acuidade visual.

Corneal collagen cross-linking for progressive keratoconus in patients aged 9 to 14 / Cross-linking corneano para ceratocone progressivo em pacientes de 9 a 14 anos de idade

RESUMO Objetivo: Determinar a segurança e eficácia do cross-linking corneano (CXL) em pacientes de 9 a 14 anos de idade com ceratocone progressivo. Métodos: Dezesseis olhos de onze pacientes (8 homens e 3 mulheres) com ceratocone progressivo foram submetidos ao CXL, de acordo com o protocolo padrão de Dresden. A média do tempo de seguimento foi de 26 meses (variando de 12 a 60 meses). Os exames pré e pós-operatórios incluíram: acuidade visual sem correção (AVSC), melhor acuidade visual com correção (AVCC), topografia corneana, tonometria, refração, paquimetria corneana, e contagem de células endoteliais. Resultados: Na última visita de acompanhamento ambulatorial, a AVCC melhorou pelo menos uma linha na tabela de Snellen em 6 olhos (37,5%) e permaneceu estável em 9 olhos (56,25%). Dois olhos (12,5%) de pacientes que coçam os olhos com frequência, exigiram retratamento devido à progressão do ceratocone, 15 e 28 meses após o primeiro CXL. A refração e contagem de células endoteliais mantiveram-se estáveis. Os resultados topográficos mostraram melhora estatisticamente significativa nos valores do K máximo até dois anos após o CXL. No entanto, houve perda de significância ao longo do tempo. Nenhuma complicação peroperatória foi observada. Dois olhos (12,5%) apresentaram haze grau I, que regrediu após um mês de terapia com esteróide tópico. Conclusão: Neste estudo com pacientes selecionados, de 9 a 14 anos de idade, o CXL mostrou ser uma opção segura e eficaz para o tratamento do ceratocone progressivo. No entanto, o efeito pode não ser duradouro, podendo ser necessário um novo tratamento. Maior amostragem e maior seguimento são necessários para verificar esta tendência.

ABSTRACT Purpose: To determine the safety and efficacy of corneal collagen cross-linking (CXL) for progressive keratoconus in patients aged between 9 and 14 years old. Methods: Sixteen eyes of 11 patients (8 male and 3 female) with progressive keratoconus underwent epithelium-off CXL according to the standard Dresden protocol. Mean follow-up was 26 months (range, 12 to 60 months). Pre- and postoperative examinations included: uncorrected visual acuity (UCVA), best spectacle-corrected visual acuity (BSCVA), corneal topography, tonometry, refraction, corneal pachymetry, and endothelium cell count. Results: At the last follow-up visit, BSCVA improved by at least one Snellen line in six eyes (37.5%) and remained stable in nine eyes (56.25%). Two eyes (12.5%) in habitual eye rubbers required a re-treatment due to keratoconus progression, at 15 and 28 months after first CXL. Manifest refraction and endothelium cell count remained stable. Topographic results showed statistically significant improvement in maximum K readings up to two years after CXL. However, this lost significance over time. No intraoperative complications were observed. Two eyes (12.5%) presented grade one haze, which regressed after a month of topical steroid therapy. Conclusion: In this study of selected patients aged 9 to 14, CXL was a safe and effective option for the treatment of progressive keratoconus. However, the effect in stemming the disease may not be long lasting and may require retreatment. A larger sample size and longer follow-up time are needed to verify this trend.

Early clinical outcomes of laser in situ keratomileusis concurrent with accelerated corneal collagen crosslinking for myopia and astigmatism with thin cornea / 中华实验眼科杂志

Background Keratectasia after laser in situ keratomileusis (LASIK) is a rare but severe complication,which threatens the visual acuity and corneal strength.Corneal collagen crosslinking (CXL) is a new therapy that increases the security and decreases the risk of complication.However,the effectiveness and safety of LASIK-CXL is still need to be concerned.Objective This study was to evaluate the safety of LASIK-CXL for myopia and astigmatism with thin cornea.Methods A prospective cohort study was designed.A total of 128 eyes of 64 patients with thin corneal and myopic astigmatism enrolled in Beijing Tongren Eye Center from January 2014 to January 2015.The patients were assigned to LASIK group (74 eyes of 37 patients) and LASIK-CXL group (54 eyes of 27 patients).Refractive surgery was performed by Visumax femtosecond lasrer and VISX S4 excimer laser.Eyes of LASIK-CXL group applied accelerated CXL immediately after LASIK.The follow-up was 6 months.Manifest refraction,uncorrected (UDVA) and corrected distance visual acuity (CDVA),average keratometry values (AveK),anterior segment OCT (AS-OCT),corneal hysteresis (CH) and corneal resistance factor (CRF) were examined before and after operation.This research passed through Ethics Committee of Beijing Tongren Hospital.Results The spherical equivalent (SE) of the LASIK group and LASIK-CXL group were (-6.49 ±2.41)D and (-6.97 ±2.41) D before operation and decreased to (-0.68 ±0.88) D and (-0.75 ±0.94) D 6 months after operation.The UDVA (LogMAR) was 1.18±0.28 and 1.05±0.38 before operation and elevated to-0.06±0.09 and-0.03±0.186 months after operation in the LASIK group and LASIK-CXL group.The preoperative AveK values were (44.37 ±1.46) D and (44.47± 1.50)D in the LASIK group and LASIK-CXL group and reduced to postoperative (39.30±2.06) D and (38.66± 1.80) D.The preoperative SRI of LASIK group and LASIK-CXL group were 0.25 ±0.21 and 0.24±0.22,which increased to 0.29±0.24 and 0.28±0.24.The SAI values were 0.36±0.16 and 0.39±0.15 before operation,which increased to 0.57 ±0.31 and 0.75 ±0.376 months after operation,and the SAI value of the LASIK-CXL group was significantly higher than that of LASIK (F =10.220,P--0.002).CRF values of LASIK and LASIK-CXL were (8.44±1.44)mmHg and (8.63±1.35) mmHg in preoperation,which decreased to (5.74±1.31) mmHg and (6.25± 1.24) mmHg in postoperation.The result of LASIK-CXL was higher than that of LASIK (F=8.650,P =0.040).CH values were 8.78 ± 1.51 and 8.69 ± 1.62 in preoperation,which decreased to (7.23 ± 1.08) mmHg and (6.50±1.32)mmHg.The value of LASIK-CXL was lower than that of LASIK (F =5.860,P =0.017).The mean depth of demarcation line was (228.45±28.24) μm (range 165 to 310 μm) on OCT,which was presented in 45 eyes (81.82％) at 1 month in postoperation.Conclusions Accelerated CXL with FS-LASIK is effective and safe in improving visual acuity in myopic astigmatism patients with thin cornea,which also can increase the rigidity of the cornea.

Influence of carbodiimide-ethanol solution surface treatment on dentin microtensile bond strength / 北京大学学报(医学版)

Objective:To evaluate the microtensile bond strength changes and patterns of fractures of the bonding interface after dentine surface treatment with carbodiimide-ethanol solution .Methods:1-eth-yl-3-(3-dimethylaminopropyl) carbodiimide (EDC) dissolved in ethanol was diluted into different con-centrations of 2, 1, 0.3, 0.1 and 0.01 mol/L EDC-ethanol solutions.Twenty-eight caries-free extracted human third molars were ground metallurgically to prepare flat occlusal mid-coronal dentin surfaces and etched with 35%( mass fraction) phosphoric acid gel .Then they were treated with EDC-ethanol solution for 60 s before the bonding procedure and randomly divided into five experimental groups corresponding to the tested EDC-ethanol concentrations .The ethanol treated and no pre-treated surfaces were used as con-trols.Single Bond 2 adhesive was applied and resin composite disk was stacked on the treated dentine surface .The teeth with resin composite disks were stored in water at room temperature for 24 h and then sectioned longitudinally to produce stick specimens for microtensile bond strength test .Fracture patterns were observed with a stereomicroscope .Results:The dentin surfaces pre-treated with 2 mol/L [ (22.17 ± 13.31) MPa] and 1 mol/L [(45.31 ±17.80) MPa] EDC-ethanol solutions resulted in statistically sig-nificant lower bond strength value ( P0.05).Conclusion:No significant difference of immediate bond strengths was found in the 0.3, 0.1, 0 .01 mol/L groups compared with the control group .EDC-ethanol solution surface treatment with con-centrations of 2 mol/L and 1 mol/L resulted in decreasing of the bonding strength .

Induction of corneal collagen cross-linking in experimental corneal alkali burns in rabbits / Indução de ligações covalentes de colágeno em queimaduras corneanas experimentais por álcali em coelhos

Objective: To evaluate the effect of riboflavin-ultraviolet-A-induced cross-linking (CXL) following corneal alkali burns in rabbits. Methods: The right corneas and limbi of ten rabbits were burned using a 1N solution of NaOH and the animals were then divided into two groups: a control group submitted to clinical treatment alone and an experimental group that was treated 1 h after injury with CXL, followed by the same clinical treatment as administered to the controls. Clinical parameters were evaluated post-injury at 1, 7, 15, and 30 days by two independent observers. Following this evaluation, the corneas were excised and examined histologically. Results: There were no statistically significant differences in clinical parameters, such as hyperemia, corneal edema, ciliary injection, limbal ischemia, secretion, corneal neovascularization, symblepharon, or blepharospasm, at any of the time-points evaluated. However, the size of the epithelial defect was significantly smaller in the CXL group (p<0.05) (day 15: p=0.008 and day 30: p=0.008) and the extent of the corneal injury (opacity lesion) was also smaller (day 30: p=0.021). Histopathology showed the presence of collagen bridges linking the collagen fibers in only the CXL group. Conclusions: These results suggest that the use of CXL may improve the prognosis of acute corneal alkali burns. .

Objetivo: Avaliar o efeito de ligações covalentes de colágeno (cross-linking [CXL]) induzidas pelo tratamento com riboflavina e radiação ultravioleta A após queimaduras por álcali em córneas de coelhos. Métodos: Dez coelhos foram submetidos a queimadura ocular direita abrangendo estruturas da córnea e limbo usando uma solução de NaOH a 1N. A seguir, os animais foram divididos em dois grupos: um grupo controle submetido a tratamento clínico pós dano corneano e um grupo experimental que foi tratado com CXL uma hora após o dano, seguido pelo mesmo tratamento clínico administrado aos controles. Os parâmetros clínicos foram avaliados 1, 7, 15 e 30 dias após a lesão, por dois observadores independentes. Na etapa seguinte, foi realizada a excisão e o exame histológico das córneas. Resultados: Não houve diferenças estatisticamente significantes nos parâmetros clínicos de hiperemia, edema da córnea, injeção ciliar, isquemia límbica, secreção, neovascularização da córnea, simbléfaro ou blefaroespasmo, em qualquer dos momentos da avaliação. Entretanto, o grupo CXL apresentou um defeito epitelial menor (p<0,05) (dia 15: p=0,008 e dia 30: p=0,008) e menor extensão da lesão na córnea (lesão opaca) (dia 30: p=0,021). O exame histopatológico revelou a presença de pontes de colágeno conectando as fibras de colágeno somente no grupo CXL. Conclusões: Estes resultados sugerem que o uso de CXL pode melhorar o prognóstico de queimaduras agudas da córnea causadas por alcáli. .

Changes in corneal sensitivity following cross-linking for progressive early-stage keratoconus / Alterações da sensibilidade corneana após cross-linking para ceratocone progressivo em estágio inicial

Purpose: To evaluate changes in corneal sensitivity following corneal cross-linking (CXL) in patients with progressive earlier stage keratoconus. Methods: Thirty-eight eyes of 19 patients (11 women, 8 men) were included in a prospective, nonrandomized clinical study. The mean patient age was 22 years (range, 18-26 years). Inclusion criteria were early stage bilateral progressive keratoconus, a transparent cornea, and a thickness of ≥440 µm in the thinnest area of the cornea. Using the Cochet-Bonnet esthesiometer, central corneal sensitivity was measured before surgery, 7 days after surgery, and once a month thereafter until recovery of baseline preoperative levels. Central corneal sensitivity >40 mm was considered normal. Results: Corneal sensitivity gradually returned to preoperative levels in all treated eyes. The mean central corneal sensitivity was 52.2, 24.0, 38.2, 42.5, 50.0, and 52.5 mm before surgery, 7 days after surgery, and at 1, 2, 3, and 4 months after surgery, respectively. Normal levels of corneal sensation, but not baseline (preoperative) levels, were observed 2 months after surgery. The preoperative levels were observed 3 months after surgery. Conclusions: Our results suggest that central corneal sensitivity can be decreased for as long as 3 months after CXL for progressive earlier stage keratoconus. .

Objetivo: Avaliar as alterações da sensibilidade corneana após cross-linking (CXL) da córnea em pacientes com ceratocone progressivo em estágio inicial. Métodos: Trinta e oito olhos de 19 pacientes (11 mulheres, 8 homens) foram incluídos em um estudo clínico prospectivo, não randomizado. A média de idade dos pacientes era de 22 anos (variação, 18-26 anos). Os critérios de inclusão foram ceratocone progressivo bilateral em estágio inicial, córnea transparente e espessura da córnea ≥440 µm usando o estesiômetro de Cochet-Bonnet, mediu-se a sensibilidade da córnea no pré-operatório, após 7 dias, e uma vez por mês até a recuperação dos níveis pré-operatórios. Foram considerados normais, valores de sensibilidade corneana superiores a 40 mm. Resultados: A sensibilidade da córnea retornou gradualmente aos níveis pré-operatórios em todos os olhos tratados. A média de sensibilidade corneana central foi de 52,2, 24,0, 38,2, 42,5, 50,0 e 52,5 mm, antes da cirurgia, aos 7 dias, e em 1, 2, 3 e 4 meses após a cirurgia, respectivamente. Níveis normais de sensibilidade, mas não os níveis pré-operatórios basais, foram observados dois meses após a cirurgia. Níveis pré-operatórios foram observados três meses após a cirurgia. Conclusão: Nossos resultados sugerem que após CXL para ceratocone progressivo em estágio inicial, a sensibilidade corneana permanece diminuída por até 3 meses. .

Construction of tissue-engineered cartilage with cross-linked sodium hyaluronate as scaffold materials in vitro / 中国组织工程研究

BACKGROUND:Tissue engineering provides new ideas and approaches for repair of cartilage defects. OBJECTIVE:To develop a complete set of solutions for construction of tissue engineered cartilagein vitro, with chondrocytes as seed cels and cross-linked sodium hyaluronate as scaffold materials. METHODS: New Zealand rabbit articular chondrocytes were isolated, counted, and then cultured and passaged to prepare cellsuspension. Toluidine blue staining, RT-PCR and immunocytochemistry were exerted to evaluate the cultured cels. Chondrocytes were seeded and co-cultured with cross-linked sodium hyaluronate scaffold for 21 days. Then, RNA was isolated for RT-PCR, and frozen sections were prepared for morphological observation and immunohistochemistry study. RESULTS AND CONCLUSION:The chondrocytes could adhere to the cross-linked sodium hyaluronate scaffold and aggregate, growing between fibers or adhering to the scaffold in a monolayer manner. The transcripts of cartilage specific aggrecan gene and colagen type II alpha 1 gene and cartilage specific protein colagen type II were expressed in cel-scaffold complexes to maintain the phenotype of chondrocytes. Cel-scaffold complexes co-cultured in vitro can form cartilage extracelular matrix, by which tissue engineered cartilage is expected to be obtained.

Biocompatibility of Genipin cross-linked type I collagen with human adipose-derived stem cells in vitro / 中国组织工程研究

BACKGROUND:Low toxicity of Genipin has certain species and cellspecificity. Biocompatibility of Genipin cross-linked type I colagen with human adipose-derived stem cels is essential for construction of tissue-engineered adipose. OBJECTIVE:To investigate the bbiocompatibility of Genipin cross-linked type I colagen with human adipose-derived stem cels. METHODS:Human adipose-derived stem cels were isolated and cultured to the third generation, and the cels were seeded on Genipin cross-linked type I colagen scaffold. MTT assay was used to evaluate the adhesion and proliferation of cels on the scaffold, and the toxic effects of Genipin cross-linked type I colagen on human adipose-derived stem cels. Optical microscopy and scanning electron microscopy were utilized to observe the adhesion and growth process of human adipose-derived stem cels on the scaffold as wel as the morphological changes of cels. RESULTS AND CONCLUSION:Human adipose-derived stem cels could adhere to the scaffold immediately after seeded and increase gradualy on the scaffold, with the average adhesion rate of 86.5%. Optical microscopy and scanning electron microscopy showed that human adipose-derived stem cels adhered wel on the scaffold. The cels increased gradualy over time, and could migrate into the scaffold, and distribute evenly with the passage of time when observed with optical microscopy. The result showed Genipin possesses very low cytotoxicity to the cels, and the outstanding biocompatibility is found between the cels and scaffoldin vitro after cross-linked with Genipin.

Corneal thickness changes during corneal collagen cross-linking with UV-A irradiation and hypo-osmolar riboflavin in thin corneas / Alterações na espessura da córnea durante "cross-linking" do colágeno com irradiação UV-A e riboflavina hipo-osmolar em córneas finas

PURPOSE: To evaluate the thinnest corneal thickness changes during and after corneal collagen cross-linking treatment with ultraviolet-A irradiation, using hypo-osmolar riboflavin solution in thin corneas. METHODS: Eighteen eyes of 18 patients were included in this study. After epithelium removal, iso-osmolar 0.1% riboflavin solution was instilled to the cornea every 3 minutes for 30 minutes. Hypo-osmolar 0.1% riboflavin solution was then applied every 20 seconds for 5 minutes or until the thinnest corneal thickness reached 400 µm. Ultraviolet-A irradiation was performed for 30 minutes. During irradiation, iso-osmolar 0.1% riboflavin drops were applied every 5 minutes. Ultrasound pachymetry was performed at approximately the thinnest point of the cornea preoperatively, after epithelial removal, after iso-osmolar riboflavin instillation, after hypo-osmolar riboflavin instillation, after ultraviolet-A irradiation, and at 1, 6 and 12 months after treatment. RESULTS: Mean preoperative thinnest corneal thickness was 380 ± 11 µm. After epithelial removal it decreased to 341 ± 11 µm, and after 30 minutes of iso-osmolar 0.1% riboflavin drops, to 330 ± 7.6 µm. After hypo-osmolar 0.1% riboflavin drops, mean thinnest corneal thickness increased to 418 ± 11 µm. After UVA irradiation, it was 384 ± 10 µm. At 1, 6 and 12 months after treatment, it was 372 ± 10 µm, 381 ± 12.7, and 379 ± 15 µm, respectively. No intraoperative, early postoperative, or late postoperative complications were noted. CONCLUSIONS: Hypo-osmolar 0.1% riboflavin solution seems to be effective for swelling thin corneas. The swelling effect is transient and short acting. Corneal thickness should be monitored throughout the procedure. Larger sample sizes and longer follow-up are required in order to make meaningful conclusions regarding safety.

OBJETIVO: Avaliar as alterações da espessura mínima da córnea durante e após o cross-linking do colágeno corneano com radiação ultravioleta A e solução hipo-osmolar de riboflavina em córneas finas. MÉTODOS: Dezoito olhos de 18 pacientes foram incluídos neste estudo. Após a remoção do epitélio, solução iso-osmolar de riboflavina 0,1% foi instilada a cada 3 minutos por 30 minutos. Solução hipo-osmolar de riboflavina 0,1% foi então aplicada a cada 20 segundos por 5 minutos ou até que a espessura mínima da córnea atingisse 400 µm. Irradiação UVA foi feita durante 30 minutos. Durante a irradiação, riboflavina iso-osmolar 0,1% foi aplicada a cada 5 minutos. Paquimetria ultrassônica foi realizada no ponto mais fino da córnea antes da cirurgia, após a remoção do epitélio, após a instilação de riboflavina iso-osmolar, após a instilação de riboflavina hipo-osmolar, após a irradiação com UVA e após 1, 6 e 12 meses do tratamento. RESULTADOS: Antes da cirurgia, a espessura mínima da córnea era de 380 ± 11 µm. Após a remoção do epitélio, este valor foi reduzido para 341 ± 11 µm e após 30 minutos de riboflavina iso-osmolar, caiu para 330 ± 7,6 µm. Após a riboflavina hipo-osmolar, a espessura mínima da córnea aumentou para 418 ± 11 µm. Após a irradiação com UVA, era de 384 ± 10 µm. Após 1, 6 e 12 meses do tratamento este valor era de 372 ± 10, 381 ± 12,7 e 379 ± 15 µm, respectivamente. Não foram observadas complicações no intra ou no pós-operatório precoce ou tardio. CONCLUSÕES: A solução de riboflavina hipo-osmolar 0,1% parece ser eficaz para edemaciar córnea finas. Este efeito é transitório e de curta duração. A espessura da córnea deveria ser monitorada durante todo o procedimento. Maior número de casos e seguimento prolongado são necessários para tirarmos conclusões quanto à segurança.

Antimicrobial susceptibility of photodynamic therapy (UVA/riboflavin) against Staphylococcus aureus / Suscetibilidade antimicrobiana da terapia fotodinâmica (UVA/riboflavina) contra Staphylococcus aureus

PURPOSE: To assess S. aureus in vitro viability after the exposure to ultraviolet light A (UVA) and riboflavin (B2). METHODS: Samples of S. aureus in 96 well plates (in triplicate) were exposed to riboflavin (B2) and ultraviolet light A (365 nm wavelength) at a power density of 3 mW/cm², 8 mm spot diameter, for 30 minutes. Control groups were prepared as well in triplicate: blank control, ultraviolet light A only, riboflavin only and dead bacteria Control. The bacterial viability was measured using fluorescent microscopy. In order to investigate the occurrence of "viable but non-culturable" microorganisms after treatment, the cell viability was also investigated by plate culture procedure onto a broth medium. Statistical analysis was performed using the triplicate values from each experimental condition. RESULTS: No difference was observed among the treatment group and the control samples (p=1). CONCLUSION: The combination of riboflavin 0.1% and ultraviolet light A at 365 nm did not exhibit antimicrobial activity against oxacillin susceptible S. aureus.

OBJETIVO: Avaliar a viabilidade celular de S. aureus in vitro após a exposição de riboflavina (B2) e luz ultravioleta A (UVA). MÉTODOS: Amostras de S. aureus colocadas em uma placa de 96 poços (em triplicata) foram expostas a riboflavina 0,1% (B2) e luz ultravioleta (comprimento de onda de 365 nm) poder de 3 mW/cm², 8 mm de diâmetro, por 30 minutos. Grupos controles foram também preparados em triplicata: controle branco, somente luz ultravioleta A, somente riboflavina e controle morto. A viabilidade bacteriana foi analisada usando microscópio de fluorescência. Para investigar a ocorrência de micro-organismos "viáveis porem não cultiváveis" a viabilidade celular foi avaliada utilizando-se placas de meio de cultivo bacteriano. Analise estatística foi realizada utilizando-se os valores obtidos em triplicata de cada grupo experimental. RESULTADOS: Nenhuma diferença foi observada entre o grupo tratamento e os grupos controle (p=1). CONCLUSÃO: A combinação riboflavina 0,1% e luz ultravioleta 365 nm de comprimento de onda não demonstrou atividade antimicrobiana contra S. aureus oxacilina sensível.