Clinical Optic Disc Evaluation in Glaucoma

Examination of the optic nerve head (ONH) is essential for the diagnosis of glaucoma and assessment of its progression. Slit-lamp biomicroscopy with a handheld lens is the best method of ONH examination since it provides good stereopsis and magnification. ONH stereo photographs are complementary and may identify findings missed on slit-lamp examination. As a result of its subjective nature, a standardised approach should be utilised for clinical ONH evalaution, including an assessment of ONH size and careful evaluation of the neuroretinal rim contour, the presence of retinal nerve fibre layer (RNFL) defects and optic disc haemorrhages. Other aspects, such as peripapillary chorioretinal atrophy, vessel alterations and asymmetry between fellow eyes, might help differentiate normal from glaucomatous eyes. Progressive changes in the appearance of the ONH or RNFL are best identified with optic disc photographs or automated devices. The findings of clinical ONH evaluation are of greater value when corroborated with other aspects of clinical examination and clinical test.