PjHfpose, To determine the effect of gain setting on the variability of ultrasound biomicroscopic (UBM) images. Methods. UBM was performed at 7 different gain sellings (60 to 90 dB, 5dB steps). Images were exported to an IBM-compatible PC in PCX format. The density of sciera and ciliary body were then assessed by determining the proportion of highly echogenic pixels within each sample. Results. 10 patients were enrolled (mean age, 42.7 ± 20.8 yrs; mean refractive error, -2.67 ±3.47 D). Scierai intensity showed logarithmic correlation with gain while ciliary body intensity showed linear correlation. Ciliary body density variability increased with gain settings over 80 dB, whereas scierai density variability increased with gain settings less than 70 dB. Conclusion. Although gain settings affect UBM image appearance and measured density, these effects can be minimized by using gain settings of 70 to 80 dB.
|Original language||English (US)|
|Journal||Investigative Ophthalmology and Visual Science|
|State||Published - Dec 1 1997|
ASJC Scopus subject areas
- Sensory Systems
- Cellular and Molecular Neuroscience