Preliminary follow-up of disc changes by HRT in relation to visual field changes in glaucoma patients

The most accepted indication of definite optic nerve damage in glaucomatous patients is an abnormality in the visual field. Structural changes of the optic nerve head are an early sign of glaucoma, and significant glaucomatous disc changes may precede overt visual field defects. Purpose. The aim of the study was to relate disc and visual field changes in glaucoma patients using confocal laser scanning tomography (HRT) and computerized visual fields with the Humphrey perimeter. Methods. Glaucoma patients (POAG, PSX, and pigmentary glaucoma) were followed by HRT and Humphrey field analyzer for one year. A change of 4 DB in the mean defect on visual field tests and a change of 0.1 in the cup-to-disc (C/D) ratio on HRT were considered significant. Results. In most eyes, no change was detected in the visual field or C/D ratio. In about 10% of eyes, the C/D ratio increased without measurable visual field changes. Conclusions. Subtle disc changes as measured by confocal scanning laser tomography may precede computerized visual field changes and may serve as an indicator for medical strategy. More parameters, such as cup depth and rim volume, should also be assessed. One year is not a suitable follow-up time to detect changes in glaucoma patients. A study with a longer follow-up period on all these parameters is in progress.