Full-field accommodation in rhesus monkeys measured using infrared photorefraction.
Invest Ophthalmol Vis Sci
; 53(1): 215-23, 2012 Jan 20.
Article
em En
| MEDLINE
| ID: mdl-22125278
ABSTRACT
PURPOSE:
Full-field photorefraction was measured during accommodation in anesthetized monkeys to better understand the monkey as a model of human accommodation and how accommodation affects off-axis refraction.METHODS:
A photorefraction camera was rotated on a 30-cm-long rod in a horizontal arc, with the eye at the center of curvature of the arc so that the measurement distance remained constant. The resistance of a potentiometer attached to the rotation center of the rod changed proportionally with the rotation angle. Photorefraction and rotation angle were simultaneously measured at 30 Hz. Trial-lens calibrations were performed on-axis and across the full field in each eye. Full-field refraction measurements were compared using on-axis and full-field calibrations. In five iridectomized monkeys (mean age in years ± SD 12.8 ± 0.9), full-field refraction was measured before and during carbachol iontophoresis stimulated accommodation, a total of seven times (with one repeat each in two monkeys).RESULTS:
Measurements over approximately 20 seconds had <0.1 D of variance and an angular resolution of 0.1°, from at least -30° to 30°. Photorefraction calibrations performed over the full field had a maximum variation in the calibration slopes within one eye of 90%. Applying full-field calibrations versus on-axis calibrations resulted in a decrease in the maximum SDs of the calculated refractions from 1.99 to 0.89 D for relative peripheral refractive error and from 4.68 to 1.99 D for relative accommodation.CONCLUSIONS:
By applying full-field calibrations, relative accommodation in pharmacologically stimulated monkeys was found to be similar to that reported with voluntary accommodation in humans.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Refração Ocular
/
Técnicas de Diagnóstico Oftalmológico
/
Acomodação Ocular
/
Miopia
Tipo de estudo:
Prognostic_studies
Limite:
Animals
Idioma:
En
Revista:
Invest Ophthalmol Vis Sci
Ano de publicação:
2012
Tipo de documento:
Article
País de afiliação:
Estados Unidos