Does the Optic Disc Grading Done Visually by Your Doctor Agree With Optic Nerve Testing Which is Done by Machines?

The Disc Damage Likelihood Scale (DDLS) has been shown to be a reproducible method for clinicians to evaluate the optic nerve for glaucomatous damage and is highly correlated to diagnosis of glaucoma, severity of glaucoma as evidenced by visual field loss and Heidelberg Retina Tomography (HRT) evaluation. In comparison with the commonly used cup-disc ratio, the DDLS has less inter-observer variation and captures glaucomatous aspects of the optic nerve not assessed by the cup-disc ratio. The optic nerve imagers do not have the potential to completely replace the clinical examination of the optic nerve since they do not assess many critical features such as optic nerve pallor, hemorrhages, asymmetry of disc size, edema, etc. The DDLS presents the opportunity to provide a system to clinicians to increase the quality and objectivity of clinical optic nerve evaluation. The purpose of this study is to investigate the correlation of the DDLS grading to OCT, HRT and HVF testing of glaucomatous and normal optic nerves.

Inclusion criteria

• Vision 20/50 or better
• Less than 3 diopters of astigmatism
• 3 diopters or less of myopia or hyperopia
• Pattern Standard Deviation on HVF less than 2.5dB in normals
• Pattern Standard Deviation on HVF greater than 2.5 db in glaucoma patients

Exclusion criteria

• Abnormalities of cornea or ocular media
• Significant ocular pathologies affecting visual field
• History of hypotony
• Ocular surgery within 6 months
• Nystagmus
• Unreliable visual fields
• OCT signal strength scan less than 6