Ring electrode for radio-frequency heating of the cornea: modelling and in vitro experiments.
Med Biol Eng Comput
; 41(6): 630-9, 2003 Nov.
Article
em En
| MEDLINE
| ID: mdl-14686588
ABSTRACT
Radio-frequency thermokeratoplasty (RF-TKP) is a technique used to reshape the cornea curvature by means of thermal lesions using radio-frequency currents. This curvature change allows refractive disorders such as hyperopia to be corrected. A new electrode with ring geometry is proposed for RF-TKP. It was designed to create a single thermal lesion with a full-circle shape. Finite element models were developed, and the temperature distributions in the cornea were analysed for different ring electrode characteristics. The computer results indicated that the maximum temperature in the cornea was located in the vicinity of the ring electrode outer perimeter, and that the lesions had a semi-torus shape. The results also indicated that the electrode thickness, electrode radius and electrode thermal conductivity had a significant influence on the temperature distributions. In addition, in vitro experiments were performed on rabbit eyes. At 5 W power, the lesions were fully circular. Some lesions showed non-uniform characteristics along their circular path. Lesion depth depended on heating duration (60% of corneal thickness for 20 s, and 30% for 10 s). The results suggest that the critical shrinkage temperature (55-63 degrees C) was reached at the central stroma and along the entire circular path in all the cases.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Ablação por Cateter
/
Córnea
/
Hiperopia
/
Modelos Biológicos
Tipo de estudo:
Prognostic_studies
Limite:
Animals
Idioma:
En
Revista:
Med Biol Eng Comput
Ano de publicação:
2003
Tipo de documento:
Article
País de afiliação:
Espanha