In 1979, Birch et al. reported that the morphology of erythrocytes in hematuria differs under the phase contrast microscope between patients with nephritis and those with urological diseases. However, a simple and objective examination method based on this morphological difference in erythrocytes has not been established. The objective of this study was to evaluate the usefulness of the laser microscope for the diagnosis of microhematuria. Characteristics of the test were evaluated in 88 patients with hematuria. The sensitivity and the specificity of the examination to nephritis were 98.1% and 100%, retrospectively. This urinalysis was carried out in 66 of 86 patients who were positive for urinary occult blood among 987 patients who underwent health screening, and the nephritis type findings were obtained in 50%.
This laser microscopic urinalysis is considered to be a simple and objective examination method. It is useful, especially because it makes urological evaluation unnecessary in about half the patients positive for occult blood in urine.