Retinal Nerve Fibre Layer OCT for Glaucoma Diagnosis - Gold Standard or Just a Piece of the Puzzle?

Early diagnosis and accurate monitoring are essential in treating glaucoma effectively and avoiding further irreversible loss of retinal ganglion cells. Glaucoma is a complex disease; initial progression is usually asymptomatic, and regular clinical and imaging examinations are extremely important. Imaging the retinal nerve fibre layer (RNFL) using spectral domain optical coherence tomography (SD-OCT) has established itself in recent years as an easy-to-perform and reproducible diagnostic method. This imaging technique allows precise analysis of the RNFL in monitoring retinal nerve fibre thickness. The present article will discuss the anatomical principles, changes to be expected in the RNFL with glaucoma compared to normal control scans, and options in analysing disease progression. We will also be discussing limitations to the method as well as additional OCT imaging techniques available. Awareness of potential sources of error makes it easier to achieve an accurate analysis of RNFL scans. Tips on interpreting RNFL scans should help ophthalmologists using the available data effectively towards reaching informed decisions on disease treatment and management in glaucoma patients.