Subjective versus objective vertical cup-disc-ratio assessment in open angle glaucoma patients.

Purpose To evaluate the difference in assessment between fundoscopic and confocal scanning vertical cup-disc-ratio (VCDR) in open angle glaucoma patients. Methods Data from a single eye of normal tension (NTG) and primary open angle glaucoma (POAG) patients from the Leuven Eye Study were included: age, gender, visual field mean deviation (MD), fundoscopic and HRT III VCDR assessment as well as mean retinal nerve fiber layer thickness (mRNFL). Differences within groups were assessed by paired sample t-tests. Receiver operator curves (ROC) were constructed to assess and compute the likelihood ratio and positive predictive value. Results 303 eyes (161 POAG and 142 NTG) were included. The average VCDR clinically assessed was significantly larger than the value derived from the HRT III software (0.81 ± 0.14 versus 0.61 ± 0.16, p < 0.001) and this difference remained statistically significant in both groups. In advanced glaucoma (MD > −12 dB), the area under the curve for HRT III and fundoscopic VCDR was respectively 0.80 ± 0.05 versus 0.84 ± 0.04 for NTG and 0.66 ± 0.044 versus 0.82 ± 0.033 for POAG. To predict a MD of maximum -12 dB with 80% certainty in NTG patients the VCDR needs to be at least 0.79 and 0.88 for HRT III and fundoscopic VCDR values, whereas in POAG patients these numbers are 0.88 and 0.93, respectively. Conclusions Clinical assessment of VCDR renders significantly higher values than HRT III derived values. Fundoscopic assessment of the optic nerve can predict better the visual field damage compared to the HRT III assessment. [ABSTRACT FROM AUTHOR]