Videokeratograph (VKS) for monitoring corneal curvature during surgery
Arq. bras. oftalmol
;
65(1): 37-41, jan.-fev. 2002. ilus, graf
Artigo
em Inglês
| LILACS
| ID: lil-308685
ABSTRACT
Purpose:
We have developed an instrument for computerized surgical videokeratography. A corneal central region of approximately 7.00 mm in diameter may be analyzed, providing the surgeon with information of the power and the astigmatism.Methods:
The system is based on a fiber optic Placido disc projecting cone, which is attached to the objective lens of aZeiss compatible surgical microscope. At the beam splitter we installed a monochromatic high resolution camera. A frame grabber is installed on a PC and images are digitized at a 480x640 resolution. Image processing is used for edge detection of rings.Results:
Calibrating curves based on 4 spherical surfaces were generated and approximately 3600 points are calculated for each examination. Preliminary measurements on 10 healthy corneas were compared with those of an EyeSys System 2000 Corneal Topographer. Mean deviation was 0.05 for radius of curvature, 0.24 D for the power and 5.0 degrees for the cylinder.Conclusions:
This surgical V KS, with some hardware and software improvements, may be used to reduce residual astigmatisms in conventional cataract and keratoplasty. It could also be used to gather preoperative data in corneal topography assisted LASIK.
Texto completo:
DisponíveL
Índice:
LILACS (Américas)
Assunto principal:
Topografia da Córnea
Limite:
Humanos
Idioma:
Inglês
Revista:
Arq. bras. oftalmol
Assunto da revista:
Oftalmologia
Ano de publicação:
2002
Tipo de documento:
Artigo
País de afiliação:
Brasil
Instituição/País de afiliação:
Eyetec Equipamentos Oftálmicos/BR
/
Universidade Federal de Säo Paulo/BR
/
Universidade de São Paulo/BR
Similares
MEDLINE
...
LILACS
LIS