Simplification of unsharp masking in retinal nerve fibre layer photography.

Fundus photography is now an established tool for showing early changes in the retinal nerve fibre layer (RNFL). RNFL defects may precede glaucomatous visual field defects by up to five years and any improvement in photography should aid RNFL defect analysis. We have found that the use of an unsharp mask has helped to visualise the RNFL and by using readily available darkroom materials the process of unsharp mask preparation has been simplified.