Retinal nerve fibre thickness measured with optical coherence tomography accurately detects confirmed glaucomatous damage

Aim: To assess the accuracy of optical coherence tomography ( OCT) in detecting damage to a hemifield, patients with hemifield defects confirmed on both static automated perimetry ( SAP) and multifocal visual evoked potentials ( mfVEP) were studied. Methods: Eyes of 40 patients with concomitant SAP and mfVEP glaucomatous loss and 25 controls underwent OCT retinal nerve fibre layer ( RNFL), mfVEP and 24- 2 SAP tests. For the mfVEP and 24- 2 SAP, a hemifield was defined as abnormal based upon cluster criteria. On OCT, a hemifield was considered abnormal if one of the five clock hour sectors ( 3 and 9 o'clock excluded) was at < 1% ( red) or two were at < 5% ( yellow). Results: Seventy seven ( 43%) of the hemifields were abnormal on both mfVEP and SAP tests. The OCT was abnormal for 73 ( 95%) of these. Only 1 ( 1%) of the 100 hemifields of the controls was abnormal on OCT. Sensitivity/ specificity ( one eye per person) was 95/ 98%. Conclusions: The OCT RNFL test accurately detects abnormal hemifields confirmed on both subjective and objective functional tests. Identifying abnormal hemifields with a criterion of 1 red ( 1%) or 2 yellow ( 5%) clock hours may prove useful in clinical practice.