Background Endoscopic ultrasound-guided fine-needle aspiration and biopsy (EUS-FNA/FNB) has been traditionally used for making a tissue diagnosis. Several newer techniques are emerging as a viable alternative to EUS-FNA/FNB, including mucosal incision-assisted biopsy (MIAB), with a view to increasing the diagnostic yield for upper gastrointestinal (GI) subepithelial tumors (SETs). We conducted a systematic review and meta-analysis to describe the overall diagnostic yield of MIAB for upper GI SETs. Methods Multiple electronic databases (MEDLINE, EMBASE and Google Scholar) and conference abstracts were comprehensively searched. The primary outcome of our meta-analysis was the overall diagnostic yield of the MIAB. The secondary outcome was to study complications in terms of perforation and clinically significant bleeding. The meta-analysis was performed using a DerSimonian and Laird random-effect model. Results Seven studies were included in the final meta-analysis, reporting a total of 159 patients (male 86, female 73) with a mean age of 58 years. The overall pooled diagnostic yield of MIAB was 89% (95% confidence interval [CI] 82.65-93.51, I2=0.00). Histologically, GI stromal tumor was the reported diagnosis in 38.62% (95%CI 22.29-56.24, I2=77.51%) of tumors, followed by leiomyoma 25% (95%CI 18.02-32.62, I2=4.42%). The overall rate of clinically significant bleeding following the procedure was 5.03% (95%CI 0.36-12.86, I2=57.43%) and no perforations were reported. Conclusions MIAB is a safe and effective technique for the diagnosis of upper GI SETs and can be considered as a viable alternative to EUS-FNA/FNB. MIAB can be performed during routine endoscopy and no advanced equipment is required.

京都大学 / 0048 / 新制・論文博士 / 博士(医学) / 乙第13029号 / 論医博第2111号 / 新制||医||1016(附属図書館) / 32987 / (主査)教授 大森 孝一, 教授 別所 和久, 教授 坂井 義治 / 学位規則第4条第2項該当 / Doctor of Medical Science / Kyoto University / DFAM

As diferentes técnicas cirúrgicas propostas para tratamento das recessões mostram resultados variáveis, especialmente em áreas de recessão profunda. O objetivo deste estudo é avaliar a efetividade da técnica de enxerto ósseo em neoformação (EONF) como uma alternativa de tratamento em recessões classe I ou II de Miller. Para tanto, foram selecionados indivíduos de ambos os sexos com idade entre 18 e 45 anos apresentando pelo menos um sítio com recessão >4mm e que apresentassem ao menos um dente condenado ou rebordo desdentado que possibilitasse confecção de alvéolo cirúrgico, (grupo teste). Os pacientes foram divididos em dois grupos, de acordo com o tratamento: teste (n=35)- técnica de EONF e controle (n=30)- enxerto de tecido conjuntivo subepitelial (ETCS). O exame clínico foi realizado por examinador único na visita inicial e 1, 3, 6 e 9 meses pós-operatórios, de acordo com as medidas de profundidade de sondagem (PS), nível de inserção clínica (NIC), recessão da margem gengival (R), sangramento à sondagem (SS), índice de placa (IPl) e quantidade de gengiva ceratinizada (GC). Os resultados obtidos demonstraram que as duas técnicas cirúrgicas são igualmente efetivas, segundo o teste t, na diminuição da recessão (-2,77±0,16 x -3,20±0,24; p=0,14). O EONF foi mais efetivo na redução da PS (-0,85±0,10 x 0,24±0,12; p<0,0001), SS (-0,65±0,21 x 0,00±0,13; p=0,01), IPl (-1,57±0,25 x 0,43±0,31; p<0,0001) e no ganho de inserção clínica (-3,74±0,26 x -2,95±0,19; p=0,024), mas menos efetivo no aumento da faixa de gengiva ceratinizada (0,48±0,13 x 1,43±0,17, p<0,0001). A análise intra-grupo mostrou que houve melhora significativa de todos os parâmetros clínicos (p<0,05; ANOVA) nos grupos teste e controle, com exceção do IPI (p=0,577), SS (p=2,19) e PS (p=1,05) no grupo controle. Esses resultados sugerem que a técnica de granulação óssea é efetiva para o tratamento de recessões gengivais profundas, possibilitando redução da recessão e, possivelmente, regeneração dos tecidos periodontais. / Different surgical techniques have been proposed for root coverage, showing varying results, especially in areas of extense recessions. The aim of this study is to evaluate the effectiveness of the newly forming bone technique (NFB) as an alternative treatment of Millers class I or II recessions. Both gender patients aged 18-45 years presenting at least one site with recession >4 mm and one condemned tooth or edentulous ridge allowing the surgical creation of an alveolus (test group) were selected. The sample was divided into two groups, according to the root coverage procedure: test (n=35) - NFB and control (n=30)- subepithelial connective tissue graft (SCTG). Clinical examinations were performed by a single trained examiner at baseline and 1, 3, 6 and 9 months after surgery according to probing depth (PD), clinical attachment level (CAL), recession (R), bleeding on probing (BOP), plaque index (PI) and keratinized gingiva width (KG). The analysis by t test have shown that both techniques are effective in the reduction of recession (-2,77±0,16 x - 3,20±0,24; p=0,14). The NFB technique was more effective in the reduction of PD (-0,85±0,10 x 0,24±0,12; p<0,0001), BOP (-0,65±0,21 x 0,00±0,13; p=0,01), PI (-1,57±0,25 x 0,43±0,31; p<0,0001) and gain of CAL (-3,74±0,26 x - 2,95±0,19; p=0,024), but less effective in the increase of KG width (0,48±0,13 x 1,43±0,17, p<0,0001). Intra-group analysis showed a significant improvement of all clinical parameters (p<0,05; ANOVA) for both groups, except for PI (p=0,4267), BOP (p=2,19) and PD (p=1,05) in control group. These results suggest that the NFB technique is effective to the treatment of large recession defects, allowing the reduction of recession and, possibly, regeneration of periodontal tissues.

As diferentes técnicas cirúrgicas propostas para tratamento das recessões mostram resultados variáveis, especialmente em áreas de recessão profunda. O objetivo deste estudo é avaliar a efetividade da técnica de enxerto ósseo em neoformação (EONF) como uma alternativa de tratamento em recessões classe I ou II de Miller. Para tanto, foram selecionados indivíduos de ambos os sexos com idade entre 18 e 45 anos apresentando pelo menos um sítio com recessão >4mm e que apresentassem ao menos um dente condenado ou rebordo desdentado que possibilitasse confecção de alvéolo cirúrgico, (grupo teste). Os pacientes foram divididos em dois grupos, de acordo com o tratamento: teste (n=35)- técnica de EONF e controle (n=30)- enxerto de tecido conjuntivo subepitelial (ETCS). O exame clínico foi realizado por examinador único na visita inicial e 1, 3, 6 e 9 meses pós-operatórios, de acordo com as medidas de profundidade de sondagem (PS), nível de inserção clínica (NIC), recessão da margem gengival (R), sangramento à sondagem (SS), índice de placa (IPl) e quantidade de gengiva ceratinizada (GC). Os resultados obtidos demonstraram que as duas técnicas cirúrgicas são igualmente efetivas, segundo o teste t, na diminuição da recessão (-2,77±0,16 x -3,20±0,24; p=0,14). O EONF foi mais efetivo na redução da PS (-0,85±0,10 x 0,24±0,12; p<0,0001), SS (-0,65±0,21 x 0,00±0,13; p=0,01), IPl (-1,57±0,25 x 0,43±0,31; p<0,0001) e no ganho de inserção clínica (-3,74±0,26 x -2,95±0,19; p=0,024), mas menos efetivo no aumento da faixa de gengiva ceratinizada (0,48±0,13 x 1,43±0,17, p<0,0001). A análise intra-grupo mostrou que houve melhora significativa de todos os parâmetros clínicos (p<0,05; ANOVA) nos grupos teste e controle, com exceção do IPI (p=0,577), SS (p=2,19) e PS (p=1,05) no grupo controle. Esses resultados sugerem que a técnica de granulação óssea é efetiva para o tratamento de recessões gengivais profundas, possibilitando redução da recessão e, possivelmente, regeneração dos tecidos periodontais. / Different surgical techniques have been proposed for root coverage, showing varying results, especially in areas of extense recessions. The aim of this study is to evaluate the effectiveness of the newly forming bone technique (NFB) as an alternative treatment of Millers class I or II recessions. Both gender patients aged 18-45 years presenting at least one site with recession >4 mm and one condemned tooth or edentulous ridge allowing the surgical creation of an alveolus (test group) were selected. The sample was divided into two groups, according to the root coverage procedure: test (n=35) - NFB and control (n=30)- subepithelial connective tissue graft (SCTG). Clinical examinations were performed by a single trained examiner at baseline and 1, 3, 6 and 9 months after surgery according to probing depth (PD), clinical attachment level (CAL), recession (R), bleeding on probing (BOP), plaque index (PI) and keratinized gingiva width (KG). The analysis by t test have shown that both techniques are effective in the reduction of recession (-2,77±0,16 x - 3,20±0,24; p=0,14). The NFB technique was more effective in the reduction of PD (-0,85±0,10 x 0,24±0,12; p<0,0001), BOP (-0,65±0,21 x 0,00±0,13; p=0,01), PI (-1,57±0,25 x 0,43±0,31; p<0,0001) and gain of CAL (-3,74±0,26 x - 2,95±0,19; p=0,024), but less effective in the increase of KG width (0,48±0,13 x 1,43±0,17, p<0,0001). Intra-group analysis showed a significant improvement of all clinical parameters (p<0,05; ANOVA) for both groups, except for PI (p=0,4267), BOP (p=2,19) and PD (p=1,05) in control group. These results suggest that the NFB technique is effective to the treatment of large recession defects, allowing the reduction of recession and, possibly, regeneration of periodontal tissues.

Insulin-like growth factor-1 (IGF-1), a known secretory product of intestinal subepithelial myofibroblasts (ISEMF), is essential for the intestinotrophic effects of glucagon-like peptide-2(GLP-2). I hypothesized that GLP-2 increases the production of IGF-1 by primary murine ISEMF in culture. Immunocytochemistry showed that the ISEMF stained appropriately for α smooth muscle actin and vimentin but not for desmin. The ISEMF also expressed GLP-2 receptor and IGF-1 mRNA transcripts. ISEMF treated with GLP-2 revealed a maximal increase in IGF-1 mRNA transcript levels at 10-8 M GLP-2 and 2hr. Interestingly, immunoblotting revealed an increase in P-AKT/T-AKT with GLP-2, but no changes in cAMP, P-ERK/T-ERK or calcium were detected. PI3K inhibition and kinase-dead AKT over-expression abrogated GLP-2-induction of IGF-1 mRNA, and ISEMF from GLP-2R null mice demonstrated reductions in IGF-1 mRNA and cellular IGF-1, but not in media IGF-1, vs. wild-type ISEMF. These findings suggest a possible mechanism by which GLP-2 increases intestinal growth in-vivo.

Insulin-like growth factor-1 (IGF-1), a known secretory product of intestinal subepithelial myofibroblasts (ISEMF), is essential for the intestinotrophic effects of glucagon-like peptide-2(GLP-2). I hypothesized that GLP-2 increases the production of IGF-1 by primary murine ISEMF in culture. Immunocytochemistry showed that the ISEMF stained appropriately for α smooth muscle actin and vimentin but not for desmin. The ISEMF also expressed GLP-2 receptor and IGF-1 mRNA transcripts. ISEMF treated with GLP-2 revealed a maximal increase in IGF-1 mRNA transcript levels at 10-8 M GLP-2 and 2hr. Interestingly, immunoblotting revealed an increase in P-AKT/T-AKT with GLP-2, but no changes in cAMP, P-ERK/T-ERK or calcium were detected. PI3K inhibition and kinase-dead AKT over-expression abrogated GLP-2-induction of IGF-1 mRNA, and ISEMF from GLP-2R null mice demonstrated reductions in IGF-1 mRNA and cellular IGF-1, but not in media IGF-1, vs. wild-type ISEMF. These findings suggest a possible mechanism by which GLP-2 increases intestinal growth in-vivo.

Chez les patients asthmatiques, on retrouve un remodelage de la matrice extracellulaire des poumons, caractérisé par une augmentation du collagène ou fibrose de la couche sous-épithéliale des voies respiratoires. Le souffle, maladie inflammatoire chronique des voies respiratoires inférieures des chevaux matures, présente des similarités physiopathologiques avec l’asthme humain, incluant le remodelage. Ceci nous conduit à l’hypothèse que la fibrose de la couche sous-épithéliale pourrait être une composante des lésions pulmonaires chez les chevaux affectés, ce que notre étude avait pour objectif d’évaluer. Des biopsies pulmonaires périphériques réalisées par voie thoracoscopique ont été obtenues chez 5 chevaux témoins et 6 chevaux atteints du souffle, avant (T0) et après une stimulation antigénique de 30 jours avec du foin moisi et de la paille. Avant le début de l’étude, les sujets étaient en rémission clinique et ne démontraient aucun signe clinique de maladie. Un examen microscopique des échantillons prélevés a été réalisé après traitement au picrosirius-rouge, colorant spécifique des fibres de collagène. La surface du collagène de la couche sous-épithéliale a été mesurée et corrigée en fonction de la taille de la voie respiratoire en utilisant des techniques morphométriques standards. Les chevaux atteints de souffle ont une surface de collagène plus grande dans la couche sous-épithéliale (p<0.1) en comparaison avec les chevaux témoins. La fibrose de la couche sous-épithéliale demeure inchangée chez les chevaux malades après la stimulation antigénique de 30 jours. À T0, la fibrose de la couche sous-épithéliale est associée positivement aux variations maximales de pression pleurale et à la résistance pulmonaire chez les chevaux atteints de souffle. Les résultats de cette étude suggèrent qu’une fibrose de la couche sous-épithéliale est présente dans les voies respiratoires périphériques des chevaux atteints de souffle et contribue au déficit de fonction résiduel pulmonaire observé lors de rémission clinique. / Extracellular matrix remodelling is present in the human asthmatic lung, and is characterized by increased collagen or fibrosis of the subepithelial area of the airway. Heaves, a naturally occurring chronic lower airway inflammatory condition in horses shares aspects of pathophysiology with asthma, including features of airway remodelling. We thus hypothesize that airway fibrosis is a characteristic of remodelling in heaves. The aim of this study was to evaluate the presence of fibrosis in the subepithelial area of the peripheral airways of heaves-affected horses. Peripheral lung biopsies acquired under thoracoscopic guidance were obtained from 5 control and 6 heaves-affected horses, both before (T0) and after a 30 day antigenic challenge with mouldy hay and straw. Prior to the study, diseased horses were in clinical remission and exhibited no clinical signs of disease. Obtained samples were microscopically examined using picrosirius-red, a collagen specific histological staining technique. Collagen area in the subepithelial layer, e.g. the region between the airway smooth muscle and the epithelial layer was measured, and corrected for airway size using standard morphometric techniques. In comparison with controls, heaves-affected horses had an increased collagen content in the airway subepithelial area (p<0.1). No change in fibrosis of the subepithelial area was observed in diseased horses after the 30 day antigenic challenge. Peripheral airway subepithelial collagen at baseline was positively associated with maximal changes in transpulmonary pressure and pulmonary resistance in horses with heaves but not in controls. Results of this study indicate that fibrosis of the subepithelial area is present in the peripheral airways of heaves-affected horses, and may play a role in residual lung function deficits observed in diseased horses even while in clinical remission.

OBJETIVO: Avaliar comparativamente os resultados de duas técnicas de cirurgia refrativa de superfície com excimer laser, ceratectomia fotorrefrativa (PRK) e ceratectomia subepitelial borboleta assistida à laser (LASEKb). LOCAL: Hospital de Olhos Sadalla Amin Ghanem, Joinville, Santa Catarina, Brasil. MÉTODOS: Realizou-se um estudo prospectivo, randomizado e duplo-cego envolvendo 102 olhos de 51 pacientes. Cada paciente teve aleatoriamente um dos olhos operado com a técnica do PRK e o outro com LASEKb. Os pacientes foram acompanhados por 1 ano. RESULTADOS: Não houveram diferenças significativas entre os dois grupos na acuidade visual (AV) para longe, sem correção, (P = 0,5593). No 12o mês pós-operatório (PO), 98,04% dos olhos no grupo do PRK e 96,08% no grupo do LASEKb atingiram AV sem correção de 20/20. A previsibilidade, eficácia, segurança e estabilidade não apresentaram diferença estatisticamente significativa entre os grupos. O índice de segurança foi de 1 no PRK e 0,996 no LASEKb. Um olho do grupo do LASEKb perdeu uma linha de visão. A porcentagem de olhos que apresentou EE aos 12 meses na faixa de ±0,50 D foi de 94,1% no grupo do PRK e de 86,3% no grupo do LASEKb (P = 0,1883). Enquanto que na faixa de ±1,0 D foi de 100% no grupo do PRK e 98% no grupo do LASEKb (P = 0,3125). Não houve necessidade de reoperações. O tempo médio de cirurgia na técnica PRK foi de 304,86 + 58,77 segundos (aproximadamente 5 minutos) e na técnica LASEKb de 608,35 + 76,88 segundos (aproximadamente 10 minutos) (P < 0,001). O tempo médio de reepitelização no grupo do PRK foi de 4,35 ± 0,48 dias (variação, 4 a 5 dias) e no grupo do BLASEK foi de 4,75 ± 0,72 dias (variação, 4 a 6 dias) (P < 0,002). Os níveis de dor e o desconforto ocular PO não foram estatisticamente diferentes entre os grupos, entretanto houve uma tendência para menor dor no PRK (3,31 ± 4,09 vs 4,43 ± 4,27; P = 0,18). Houve uma redução estatisticamente significativa nos valores do teste de Schirmer em todas as avaliação PO, tanto no PRK (23,6 ± 8,1 vs 19,4 ± 10,1; P < 0,002) quanto no LASEKb (22,4 ± 8,7 vs 18,9 ± 9,7; P = 0,01), entretanto não houve diferença entre os grupos. A opacificação corneana (OC) PO foi pequena nos dois grupos. Somente no 1o mês foi observado diferença estatística entre os grupos, com maior intensidade da OC no grupo do LASEKb (0,18 ± 0,3881) quando comparado ao PRK (0,08 ± 0,2109) (P = 0,039936). A maior intensidade foi observada no 3o mês, com redução gradativa até o 12o mês. CONCLUSÃO: Dentro das condições deste estudo, conclui-se que o PRK e o LASEKb mostraram resultados semelhantes, exceto que o PRK apresentou menor tempo cirúrgico, reepitelização corneana mais rápida e menor OC no 30o PO. / PURPOSE: Comparatively evaluate the results of two techniques of surface excimer laser refractive surgery, photorefractive keratectomy (PRK) and butterfly laser-assisted subepithelial keratectomy (BLASEK). SETTING: Sadalla Amin Ghanem Eye Hospital, Joinville, Santa Catarina, Brazil. METHODS: This is a prospective, randomized and double-masked study including 102 eyes from 51 patients. Each patient was randomized to have one eye operated on with PRK and the other with BLASEK. Patients were followed for 1 year. RESULTS: There were no significant differences between the groups regarding uncorrected distant visual acuity (VA) (p= 0.5593). On the 12th post-operative (PO) month, 98.04% of the eyes in the PRK group and 96.08% in the BLASEK group reached uncorrected VA of 20/20. The predictability, efficacy, safety and stability did not present statically significant difference between groups. The safety index was of 1 for PRK and 0.996 for BLASEK. One eye of the BLASEK group lost one line on the 12th PO month. The percentage of the eyes that presented spherical equivalent at 12 months in the range of ±0.50 D was 94.1% in the PRK group and 86.3% in the BLASEK group (p = 0.1883). While in the range of ±1.0 D it was 100% in the PRK group and 98% in the BLASEK group (p = 0.3125). There were no retreatments. The mean surgical time was 304.86 + 58.77 seconds (approximately 5 minutes) in PRK and 608.35 + 76.88 seconds in BLASEK (approximately 10 minutes) (P < 0,001). The mean reepithelization time in the PRK group was 4.35 ± 0.48 days (range, 4 to 5 days), and in the BLASEK group was 4.75 ± 0.72 days (range, 4 to 6 days) (P < 0.002). Pain scores and ocular discomfort were not statistically different between groups, although there was a trend towards a lower pain level with PRK (3.31 ± 4.09 vs. 4.43 ± 4.27; P = 0.18). Schirmer test values were significantly reduced from preoperative levels through 12 months with both PRK (23.6 ± 8.1 vs. 19.4 ± 10.1; P < 0.002) and BLASEK (22.4 ± 8.7 vs. 18.9 ± 9.7; P = 0.01), however there was no difference between groups in any time point. Haze incidence was slight in both groups. Only in the 1st PO month statistical difference between the groups was observed, with higher intensity in the BLASEK group (0.18 ± 0.3881) when compared to the PRK (0.08 ± 0.2109) (p = 0.039936). The highest intensity was observed on the 3rd month, with gradual reduction until the 12th month. CONCLUSION: In the conditions of this study, it can be concluded that PRK and BLASEK showed similar results, except that PRK presented shorter surgical time, faster corneal reepithelization and less haze at 30th PO days.

Chez les patients asthmatiques, on retrouve un remodelage de la matrice extracellulaire des poumons, caractérisé par une augmentation du collagène ou fibrose de la couche sous-épithéliale des voies respiratoires. Le souffle, maladie inflammatoire chronique des voies respiratoires inférieures des chevaux matures, présente des similarités physiopathologiques avec l’asthme humain, incluant le remodelage. Ceci nous conduit à l’hypothèse que la fibrose de la couche sous-épithéliale pourrait être une composante des lésions pulmonaires chez les chevaux affectés, ce que notre étude avait pour objectif d’évaluer. Des biopsies pulmonaires périphériques réalisées par voie thoracoscopique ont été obtenues chez 5 chevaux témoins et 6 chevaux atteints du souffle, avant (T0) et après une stimulation antigénique de 30 jours avec du foin moisi et de la paille. Avant le début de l’étude, les sujets étaient en rémission clinique et ne démontraient aucun signe clinique de maladie. Un examen microscopique des échantillons prélevés a été réalisé après traitement au picrosirius-rouge, colorant spécifique des fibres de collagène. La surface du collagène de la couche sous-épithéliale a été mesurée et corrigée en fonction de la taille de la voie respiratoire en utilisant des techniques morphométriques standards. Les chevaux atteints de souffle ont une surface de collagène plus grande dans la couche sous-épithéliale (p<0.1) en comparaison avec les chevaux témoins. La fibrose de la couche sous-épithéliale demeure inchangée chez les chevaux malades après la stimulation antigénique de 30 jours. À T0, la fibrose de la couche sous-épithéliale est associée positivement aux variations maximales de pression pleurale et à la résistance pulmonaire chez les chevaux atteints de souffle. Les résultats de cette étude suggèrent qu’une fibrose de la couche sous-épithéliale est présente dans les voies respiratoires périphériques des chevaux atteints de souffle et contribue au déficit de fonction résiduel pulmonaire observé lors de rémission clinique. / Extracellular matrix remodelling is present in the human asthmatic lung, and is characterized by increased collagen or fibrosis of the subepithelial area of the airway. Heaves, a naturally occurring chronic lower airway inflammatory condition in horses shares aspects of pathophysiology with asthma, including features of airway remodelling. We thus hypothesize that airway fibrosis is a characteristic of remodelling in heaves. The aim of this study was to evaluate the presence of fibrosis in the subepithelial area of the peripheral airways of heaves-affected horses. Peripheral lung biopsies acquired under thoracoscopic guidance were obtained from 5 control and 6 heaves-affected horses, both before (T0) and after a 30 day antigenic challenge with mouldy hay and straw. Prior to the study, diseased horses were in clinical remission and exhibited no clinical signs of disease. Obtained samples were microscopically examined using picrosirius-red, a collagen specific histological staining technique. Collagen area in the subepithelial layer, e.g. the region between the airway smooth muscle and the epithelial layer was measured, and corrected for airway size using standard morphometric techniques. In comparison with controls, heaves-affected horses had an increased collagen content in the airway subepithelial area (p<0.1). No change in fibrosis of the subepithelial area was observed in diseased horses after the 30 day antigenic challenge. Peripheral airway subepithelial collagen at baseline was positively associated with maximal changes in transpulmonary pressure and pulmonary resistance in horses with heaves but not in controls. Results of this study indicate that fibrosis of the subepithelial area is present in the peripheral airways of heaves-affected horses, and may play a role in residual lung function deficits observed in diseased horses even while in clinical remission.

OBJETIVO: Avaliar comparativamente os resultados de duas técnicas de cirurgia refrativa de superfície com excimer laser, ceratectomia fotorrefrativa (PRK) e ceratectomia subepitelial borboleta assistida à laser (LASEKb). LOCAL: Hospital de Olhos Sadalla Amin Ghanem, Joinville, Santa Catarina, Brasil. MÉTODOS: Realizou-se um estudo prospectivo, randomizado e duplo-cego envolvendo 102 olhos de 51 pacientes. Cada paciente teve aleatoriamente um dos olhos operado com a técnica do PRK e o outro com LASEKb. Os pacientes foram acompanhados por 1 ano. RESULTADOS: Não houveram diferenças significativas entre os dois grupos na acuidade visual (AV) para longe, sem correção, (P = 0,5593). No 12o mês pós-operatório (PO), 98,04% dos olhos no grupo do PRK e 96,08% no grupo do LASEKb atingiram AV sem correção de 20/20. A previsibilidade, eficácia, segurança e estabilidade não apresentaram diferença estatisticamente significativa entre os grupos. O índice de segurança foi de 1 no PRK e 0,996 no LASEKb. Um olho do grupo do LASEKb perdeu uma linha de visão. A porcentagem de olhos que apresentou EE aos 12 meses na faixa de ±0,50 D foi de 94,1% no grupo do PRK e de 86,3% no grupo do LASEKb (P = 0,1883). Enquanto que na faixa de ±1,0 D foi de 100% no grupo do PRK e 98% no grupo do LASEKb (P = 0,3125). Não houve necessidade de reoperações. O tempo médio de cirurgia na técnica PRK foi de 304,86 + 58,77 segundos (aproximadamente 5 minutos) e na técnica LASEKb de 608,35 + 76,88 segundos (aproximadamente 10 minutos) (P < 0,001). O tempo médio de reepitelização no grupo do PRK foi de 4,35 ± 0,48 dias (variação, 4 a 5 dias) e no grupo do BLASEK foi de 4,75 ± 0,72 dias (variação, 4 a 6 dias) (P < 0,002). Os níveis de dor e o desconforto ocular PO não foram estatisticamente diferentes entre os grupos, entretanto houve uma tendência para menor dor no PRK (3,31 ± 4,09 vs 4,43 ± 4,27; P = 0,18). Houve uma redução estatisticamente significativa nos valores do teste de Schirmer em todas as avaliação PO, tanto no PRK (23,6 ± 8,1 vs 19,4 ± 10,1; P < 0,002) quanto no LASEKb (22,4 ± 8,7 vs 18,9 ± 9,7; P = 0,01), entretanto não houve diferença entre os grupos. A opacificação corneana (OC) PO foi pequena nos dois grupos. Somente no 1o mês foi observado diferença estatística entre os grupos, com maior intensidade da OC no grupo do LASEKb (0,18 ± 0,3881) quando comparado ao PRK (0,08 ± 0,2109) (P = 0,039936). A maior intensidade foi observada no 3o mês, com redução gradativa até o 12o mês. CONCLUSÃO: Dentro das condições deste estudo, conclui-se que o PRK e o LASEKb mostraram resultados semelhantes, exceto que o PRK apresentou menor tempo cirúrgico, reepitelização corneana mais rápida e menor OC no 30o PO. / PURPOSE: Comparatively evaluate the results of two techniques of surface excimer laser refractive surgery, photorefractive keratectomy (PRK) and butterfly laser-assisted subepithelial keratectomy (BLASEK). SETTING: Sadalla Amin Ghanem Eye Hospital, Joinville, Santa Catarina, Brazil. METHODS: This is a prospective, randomized and double-masked study including 102 eyes from 51 patients. Each patient was randomized to have one eye operated on with PRK and the other with BLASEK. Patients were followed for 1 year. RESULTS: There were no significant differences between the groups regarding uncorrected distant visual acuity (VA) (p= 0.5593). On the 12th post-operative (PO) month, 98.04% of the eyes in the PRK group and 96.08% in the BLASEK group reached uncorrected VA of 20/20. The predictability, efficacy, safety and stability did not present statically significant difference between groups. The safety index was of 1 for PRK and 0.996 for BLASEK. One eye of the BLASEK group lost one line on the 12th PO month. The percentage of the eyes that presented spherical equivalent at 12 months in the range of ±0.50 D was 94.1% in the PRK group and 86.3% in the BLASEK group (p = 0.1883). While in the range of ±1.0 D it was 100% in the PRK group and 98% in the BLASEK group (p = 0.3125). There were no retreatments. The mean surgical time was 304.86 + 58.77 seconds (approximately 5 minutes) in PRK and 608.35 + 76.88 seconds in BLASEK (approximately 10 minutes) (P < 0,001). The mean reepithelization time in the PRK group was 4.35 ± 0.48 days (range, 4 to 5 days), and in the BLASEK group was 4.75 ± 0.72 days (range, 4 to 6 days) (P < 0.002). Pain scores and ocular discomfort were not statistically different between groups, although there was a trend towards a lower pain level with PRK (3.31 ± 4.09 vs. 4.43 ± 4.27; P = 0.18). Schirmer test values were significantly reduced from preoperative levels through 12 months with both PRK (23.6 ± 8.1 vs. 19.4 ± 10.1; P < 0.002) and BLASEK (22.4 ± 8.7 vs. 18.9 ± 9.7; P = 0.01), however there was no difference between groups in any time point. Haze incidence was slight in both groups. Only in the 1st PO month statistical difference between the groups was observed, with higher intensity in the BLASEK group (0.18 ± 0.3881) when compared to the PRK (0.08 ± 0.2109) (p = 0.039936). The highest intensity was observed on the 3rd month, with gradual reduction until the 12th month. CONCLUSION: In the conditions of this study, it can be concluded that PRK and BLASEK showed similar results, except that PRK presented shorter surgical time, faster corneal reepithelization and less haze at 30th PO days.