ABSTRACT
OBJECTIVE: To study a new domestic potential acuity meter (PAM) for predicting visual acuity (PVA) in patients with cataracts and to compare the results to that measured by PAM-1000 and Lotmar. METHODS: One hundred and fifty cataract eyes were enrolled in this study. PVA was evaluated with three different dioptometers before the surgery and compared to actual best corrected visual acuity (BCVA) obtained two months after the surgery. RESULTS: PVA obtained from domestic PAM correlated well with BCVA. In 56 eyes with non-identical results between PVA and BCVA, 52 eyes were false-negative and 3 eyes were false-positive, indicating that PAM tended to underestimate postoperative BCVA. In severe cataract patients, the correlation between PVA obtained from these three dioptometers and postoperative BCVA was decreased. The identical rates (as compared with postoperative BCVA) for the results obtained from PAM-1000 and Lotmar were 64. 0% and 62. 7%, respectively. CONCLUSIONS: Domestic PAM is relatively reliable for predicting postoperative visual acuity. It is a valuable method in the examination of PVA before the cataract surgery.
Subject(s)
Cataract/physiopathology , Cataract/therapy , Vision Tests/instrumentation , Visual Acuity , Adult , Aged , Aged, 80 and over , Female , Humans , Male , Middle Aged , Postoperative Period , Retrospective Studies , Treatment OutcomeABSTRACT
An illumination system using LED sources for pocket-size projectors is designed. Its color gamut is much larger than the sRGB standard. The maximum theoretical efficiency of this system is 29.98% by non-imaging theory-based calculations. To analyze the system model, 1.5 x 10(6) rays are traced by using the LightTools software. The total light flux that illuminates the digital micromirror device is 44 lm and the American National Standards Institute 13-point uniformity on the surface is 91.55%, -91.15% with a system efficiency of 28.3%. The calculations are in good agreement with the simulation results. The illumination system can be used for personal pocket-size projectors providing a 15-20 in. (38-51 cm) color display with the brightness comparable with a laptop.
