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Ceratectomia fotorrefrativa com excimer laser de fluoreto de argônio de 193 nm para a correção da miopia: estudo clínico

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Objetivo: avaliar a ceratectomia fotorrefrativa de zona única com excimer laser na correção de miopias. Métodos: utilizou-se o excimer laser Summit OmniMed para o tratamento da miopia em 167 olhos divididos segundo o equivalente esférico em três grupos: miopia leve (até -5,0 D), miopia moderada (entre -5,25 D e -7,0 D) e miopia alta (acima de -7,0 D). Resultados: Após um mês do tratamento, 100% dos olhos no grupo da miopia leve, 60% no da miopia moderada e 57% no da miopia alta apresentavam-se dentro de uma dioptria de emetropia. A acuidade visual sem correção de 0,8 ou mais foi atingida por 93%, 80% e 28,6% destes olhos respectivamente após nove meses. A principal complicação pós-operatória foi o desenvolvimento de opacidade corneana na frequência de 3,06%, 10,5% e 29,0% nos três grupos. Conclusão: Baseado nos resultados obtidos nesta série, ceratectomia fotorrefrativa por excimer laser é um procedimento seguro e eficaz para o tratamento de miopias leves e moderadas.
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http://dx.doi.org/10.5935/0004-2749.19970076
Ceratectomia fo torrativa com excimer laser de uoreto de
argônio de 193 nm para a correção da miia: estudo clínico
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















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•W -4


 
 

 




























3   

  


Ceratectomia fo torrativa com excimer laser de uoreto de
argônio de 193 nm para a correção da miopia: estudo clínico



RESULTADOS



















± 

TABELA 1

 


  
      


     
      
      
 

  
     


    
   

  
     
      
     
TABELA 2




�o.5
�o.a


















 
 

 
 
 
 
 
 



























± 

























± 
























± 





± 
± ± 
± 






























DISCUSSÃO













 


6












  
8.









6.



























SUMMARY


























 
 

ARQ. BRAS. OFT AL. 60(2), ABRIL/1997
Ceratectomia fo torrefrativa com excimer laser de uoreto de
argônio de 193 nm para a correção da miopia: estudo clínico





    
     

 

 
 




     
   
    
   
   

       
     

 

     
   

     
  
  
    
   
     
   
    

 


3 a 6 de Setembro de 1997

 
-GO

Prepare-se desde

de de 
 151
... Initial complications of two automated microkeratomes 1 A técnica da ceratectomia fotorrefrativa associada à ceratectomia lamelar pediculada (LASIK) para correção de miopia, astigmatismo e hipermetropia tem sido amplamente utilizada e divulgada nos dias de hoje. Este procedimento é utilizado com uma segurança cada vez maior, não só no que diz respeito à técnica cirúrgica (1)(2) como também à previsibilidade dos resultados, levando a uma melhora da acuidade visual não corrigida no período pós-operatório (3)(4) . ...
Article
Purpose: To describe per- and postoperative complications which occurred with the first use of two automated microkeratomes for the performance of LASIK. Methods: Retrospective study of first surgeries performed with two automated microkeratomes. Seventy eyes from 54 patients using Chiron's® microkeratome, Automated Corneal Shaper (ACS) model, from April 1997 to April 1998 and 100 eyes from 82 patients using automated microkeratome Moria® Carriazo-Barraquer (CB), from February 1999 to June 1999. Refractive ablation was performed with the Summit Apex Plus Excimer Laser (193 nm). We evaluated the per- and postoperative complications up to one month of follow-up. Results: Photoablation was not performed in three cases (4.3%) using ACS microkeratome and in one case (1%) using CB microkeratome. Most frequent complications found with ACS were: failure of automated return of microkeratome (7.1%), partial keratotomy (4.3%), presence of stromal folds (14.3%), central de-epithelialization (4.3%). With CB there were: descentered flap (3%), central desepitheliazation (5%), stromal folds (28%) and Sahara Sands syndrome (6%). Conclusions: Initial use of both microkeratomes was related to important per- and postoperative complications, which did not lead to loss of vision. Clinical knowledge of the alterations which occurred with the use of these instruments and a better experience of their utilization may reduce these complications.
... A eficácia e segurança da ceratectomia fotorrefrativa para o tratamento da miopia baixa já foi demonstrada por Hayashi et al. Em seu estudo, 100% dos olhos com EE préoperatório ≤ -5,00D, atingiram visão não corrigida melhor ou igual a 20/40, e 93% visão de 20/20 ou melhor ao exame de 9 meses pós-operatório 11 . ...
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Objetivo: Comparar, por meio de um estudo prospectivo e bilateral randomizado, a eficácia, segurança e previsibilidade das técnicas de ceratectomia fotorrefrativa (PRK) e "excimer laser in situ keratomileusis" (LASIK) para o tratamento da miopia baixa e moderada. Métodos: Foram incluídos dezessete pacientes (34 olhos) com equivalente esférico (EE) refracional entre -2,00 e -6,00 dioptrias (D). Cada paciente foi submetido a PRK em um olho e LASIK no outro. Ambos os olhos foram tratados no mesmo dia pelo mesmo cirurgião, com o excimer laser VISX 20/20B e o microceratótomo automatizado da Chiron. Resultados: No pré-operatório, a média do EE refracional foi semelhante nos dois grupos (-3,57±1,17D e -3,71±0,98D, para PRK e LASIK, respectivamente). Dor pós-operatória foi referida somente nos casos de PRK (8 olhos: 47,1%). O seguimento pós-operatório médio foi de 14±5 meses (6 a 24) para o grupo de PRK, e 14±6 meses (3 a 24) para o de LASIK. A média do erro refrativo residual foi semelhante nos dois grupos (-0,34±0,45D e -0,29±0,52D, para PRK e LASIK, respectivamente). No primeiro dia pós-tratamento, 15 olhos (100%) do grupo de LASIK e 2 (13,3%) de PRK apresentavam acuidade visual sem correção (AV s/c) ³ 20/40 (n=15). Ao último exame, 15 olhos (88,2%) de LASIK contra 11 (64,7%) de PRK atingiram AV s/c ³ 20/20 (n=17). Não houve perda da melhor acuidade visual corrigida. Conclusão: Neste estudo, tanto o PRK quanto o LASIK mostraram-se ser tecnicamente seguros, eficazes e previsíveis para a correção da miopia baixa e moderada. A técnica de LASIK foi a preferida na análise subjetiva dos pacientes, pela recuperação visual mais precoce associada a menor dor no pós-operatório.
... Initial complications of two automated microkeratomes 1 A técnica da ceratectomia fotorrefrativa associada à ceratectomia lamelar pediculada (LASIK) para correção de miopia, astigmatismo e hipermetropia tem sido amplamente utilizada e divulgada nos dias de hoje. Este procedimento é utilizado com uma segurança cada vez maior, não só no que diz respeito à técnica cirúrgica (1)(2) como também à previsibilidade dos resultados, levando a uma melhora da acuidade visual não corrigida no período pós-operatório (3)(4) . ...
Article
Full-text available
Purpose: To describe per- and postoperative complications which occurred with the first use of two automated microkeratomes for the performance of LASIK. Methods: Retrospective study of first surgeries performed with two automated microkeratomes. Seventy eyes from 54 patients using Chiron's® microkeratome, Automated Corneal Shaper (ACS) model, from April 1997 to April 1998 and 100 eyes from 82 patients using automated microkeratome Moria® Carriazo-Barraquer (CB), from February 1999 to June 1999. Refractive ablation was performed with the Summit Apex Plus Excimer Laser (193 nm). We evaluated the per- and postoperative complications up to one month of follow-up. Results: Photoablation was not performed in three cases (4.3%) using ACS microkeratome and in one case (1%) using CB microkeratome. Most frequent complications found with ACS were: failure of automated return of microkeratome (7.1%), partial keratotomy (4.3%), presence of stromal folds (14.3%), central de-epithelialization (4.3%). With CB there were: descentered flap (3%), central desepitheliazation (5%), stromal folds (28%) and Sahara Sands syndrome (6%). Conclusions: Initial use of both microkeratomes was related to important per- and postoperative complications, which did not lead to loss of vision. Clinical knowledge of the alterations which occurred with the use of these instruments and a better experience of their utilization may reduce these complications.
Article
Full-text available
The purpose of this study was to evaluate the refractive outcome and the stability of refraction after excimer laser photorefractive keratectomy (PRK). Forty-five eyes were treated in three different refractive groups: low myopes, 23 eyes, - 1.50 diopters (D) to - 6.00 D; intermediate myopes, 14 eyes, -6.10 D to - 10.00 D; and high myopes, 8 eyes, -10.10 D to - 18.00 D. At 9 months after surgery the low myopes had a mean refraction of - 0.14 D (range - 1.00 D to + 1.50 D) and were easy to refract. Intermediate myopes mean refraction was +0.14 D (range - 1.50 D to + 2.50 D). In the high myope group the mean refraction was - 0.47 D (range - 10.00 D to + 2.50 D) and four eyes (50%) lost more than two lines of spectacle corrected visual acuity. Refraction the high myopes was more difficult compared to the lower myopes. PRK produced good results for myopes from - 1.50 D to - 10.00 D. Myopes greater than - 10.00D are not stable at 9 months after PRK and are difficult to refract. [J Refract Surg. 1995;11 (suppl.):S265-S267.]
Article
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This study of 285 myopic eyes treated with photorefractive keratectomy (PRK), with a maximum follow up of 18 months, was designed to analyze the clinical subepithelial significance of corneal haze after excimer laser PRK. The treatment parameters included an ablation zone diameter from 3.6 to 5 mm, ablation rate from 0.22 to 0.25 µm pulse, fluence of 180 mJ/cmp 2, and frequency of 10 Hz. All patients used a standard topical corticosteroid regimen. A statistical analysis of the subjective haze grading showed a maximum at 3 months (mean grading, 1.03) and a decrease to 0.38 at 18 months. Haze is statistically greater with higher amounts of treatment (p=.003 between 2.00 D and 3.00 D groups, p =.0002 between 2.00 D and 6.00 D groups). In males (p =.0004), and in ablations less than 4.5 mm diameter (p =.0002) but no difference was found related to age. The overall frequency of clinically significant haze was 11.5% with a mean age of 35.1 years and a mean attempted correction of -5.71 D. This frequency increased to 24% in the 6.20 D to 9.90 D group and 38.6% in the 4.4 mm and less group, and it decreased to 8.6% in the 1.00 D to 6.00 D group and 6.6% in the 4.5 and 5 mm group. All patients with significant haze gave a history of discontinued use of corticosteroids. We suggest there exists a significant haze risk group in which the absence of steroid or discontinuation of corticosteroids will lead to significant haze. (Refractive and Corneal Surgery (suppl) 1993;9:S65-S70.)
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Prior to undertaking a study in sighted human eyes, we performed photorefractive keratectomy with the 193-nm excimer laser for the correction of myopia in nine legally blind eyes to evaluate safety, efficacy, predictability, and stability. In most cases, reepithelialization was complete by 5 days after surgery; no recurrent erosions were seen. By the end of the 6-month study, all of the corneas had a 0 or 1+ clarity score, on a scale of 0 (clear) to 5+ (opaque). Keratometry and pachometry demonstrated stable flattening of the corneas. One month after surgery, changes in refraction evaluated by retinoscopy showed fair predictability, with no significant increase in refractive or keratometric astigmatism, followed by some regression of effect by the end of the study, possibly caused by anatomical remodeling. The amount of regression appeared to be directly related to the amount of correction intended, suggesting that this effect would not be clinically important in the treatment of mild to moderate myopia.
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We report a case of a patient who received excimer laser ablation that was designed to flatten the cornea in a putatively blind eye. This was performed as part of the early human safety and efficacy 'blind eye' trials under the aegis of the Investigational Device Exemption granted by the Food and Drug Administration to Dr Trokel. Within 7 weeks of laser ablation, the patient, who had apparently been suffering from functional rather than physiologic blindness, had a visual acuity of 20/25 and then 20/20 without correction. After 6 months of follow-up, the cornea remained clear and the visual acuity appeared to be stable. This is, to our knowledge, the first report of good visual results in a human eye from central photorefractive keratectomy with the excimer laser for the correction of myopia.
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The excimer laser, which produces light in the far-ultraviolet portion of the spectrum, allows precise removal of corneal tissue through a photochemical laser-tissue interaction. This interaction is not thermal and does not involve optical breakdown; rather, it directly breaks organic molecular bonds without tissue heating. We used this process of ablative photodecomposition to remove corneal tissue in a series freshly enucleated cow eyes. Applying the far-ultraviolet light in short intense pulses permitted us to control the depth of the incision with great precision. We found that 1 joule/cm2 ablates corneal tissue to a depth of 1 micron. Adjacent tissue suffered no thermal damage and the stromal lamellae adjacent to the incision showed no evidence of disorganization.
Ceratotomia radial em miopias de grau intermediário
  • Rozenberg Russo
ROZENBERG, 1. & RUSSO, A. · Ceratotomia radial em miopias de grau intermediário. Rev. Bras. O.fia/mo!, 47: 147·9, 1988.
Com· plicações da ceratotomia radial. Rev. Bras. O.fia/mo
  • F M Vasconcelos
  • H T Bessa
VASCONCELOS, F. M. & BESSA, H. T. · Com· plicações da ceratotomia radial. Rev. Bras. O.fia/mo/., 46: 185·8, 1987.
Complicações da ceratotomia radial
  • F. M. VASCONCELOS
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Ceratotomiaradial em miopias de grau intermediário
  • I. ROZENBERG
  • A. RUSSO