Table 1

Magnitude and percentage disagreement for intraobserver and interobserver assessments of cup-disc ratios

Ref		Method of assessment		Sample		No of eyes (approx)		Observers		Intraobserver differences		Interobserver differences
Ref		Method of assessment		Sample		No of eyes (approx)		Observers		V-CDR	H-CDR	Other	V-CDR	H-CDR	Other
14	Stereo-disc photographs	Glaucoma Normals	40	1 ophthalmologist	12.5% ⩾±0.2	17.5% ⩾±0.2
15	Sequential Stereo-disc photographs	Population study	330	2 graders							Shortest CDR 24% > ±0.1 Longest CDR 27% > ±0.1
10	Sequential stereo disc photographs	Population study	19	2 ophthalmologists			Overall CDR 50% ⩾±0.1
16	Sequential stereo disc photographs	Glaucoma OHT Normals	214	2 experienced ophthalmologists	8% ⩾±0.2	10% ⩾±0.2			18% ⩾±0.2	20% ⩾±0.2
17	Simultaneous stereo disc photographs	Glaucoma	35	2 ophthalmologists	4.5% ⩾±0.2	5% ⩾±0.2			13% ⩾±0.2	6% ⩾±0.2
11	Simultaneous stereo disc photographs	Glaucoma Normals	75	6 glaucoma experts	4% ⩾±0.2				11% ⩾ ±0.2
12	Simultaneous stereo disc photographs	Glaucoma Normals	75	6 ophthalmologists 6 residents 6 optometrists	5% ⩾±0.2 9% ⩾±0.2 14% ⩾±0.2				20% ⩾±0.2 28% ⩾±0.2 29% ⩾±0.2
18	Simultaneous stereo disc photographs	Glaucoma Normals	15 15	3 ophthalmologists					9% ⩾±0.2	12.5% ⩾±0.2

V-CDR = vertical cup-disc ratio; H-CDR = horizontal cup-disc ratio; OHT = ocular hypertension.