| Popis: |
In the past 10 years, many investigators have shown eccentric (off-axis) photorefraction to be useful for screening preverbal children for amblyogenic factors, such as anisometropia, high hyperopia, strabismus and media opacities. Several studies (Kaakinen, 1986–7; Molteno 1983; Duckman, 1987; Hay, 1983; Morgan, 1987) have demonstrated the effectiveness of photographic screening with 35mm film; however, these systems do not allow for immediate abnormality identification, nor verification of proper alignment and photographic technique. Only a few have screened for astigmatism (Kaakinen, 1983, 1987 and Wanger, 1988). Screening cameras utilizing instant film have been developed by Kaakinen (1986), Day (1986), Hsu-Winges (1989) and Wanger (1988). The use of instant film allows for easy retesting if improper alignment occurs and allows for immediate detection of abnormalities. |
