Accession Number : ADA186818

Title :   A-Scan Ultrasound Measurement of Ocular Changes during Accommodation.

Descriptive Note : Master's thesis,

Corporate Author : AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH

Personal Author(s) : Smith, Dennis L

PDF Url : ADA186818

Report Date : Apr 1987

Pagination or Media Count : 225

Abstract : An A-mode ultrasound unit was used to investigate how the principle refractive surfaces of the eye changed during the act of accommodation. Sixteen volunteers took part in an investigation where changes were studied in both the cyclopleged and noncyclopleged state. Measurements of axial length, anterior chamber, lens thickness, and vitreous chamber depth were made at three different accommodation response levels over time. These results showed no significant change in axial length or vitreous chamber depth of the eye from cycloplegia to any accommodative response level. The depth of the anterior chamber and thickness of the lens showed significant changes at each of the three accommodative response levels. The results are consistent with the Helmholtz-Fincham theory of accommodation. This study also demonstrated the time course of action of two drops of 1% cyclopentolate with full cyclopentolate cycloplegia reached between 35 and 45 minutes for subjects with dark irides.

Descriptors :   *EYE, *PHASE MEASUREMENT, DEPTH, LENGTH, LENSES, REFRACTION, SURFACES, THESES, THICKNESS, VITREOUS STATE, VISION, RESPONSE(BIOLOGY), MEASURING INSTRUMENTS, DIAGNOSTIC AGENTS, ULTRASONIC TESTS, RETINA, FOCUSING, LIGHT

Subject Categories : Medicine and Medical Research
      Anatomy and Physiology

Distribution Statement : APPROVED FOR PUBLIC RELEASE