Table 1. Sensitivity and specificity of the visual field test in identifying ptosis.

	Ptosis (+/− dermatochalasis)		Total
	Present	Absent
Visual field defect	84	3	87
No visual field defect	1	37	38
Total	85	40	125

Sensitivity: 84/85=98.8% (95% confidence interval: 93.6–100%)

Specificity: 37/40=92.5% (95% confidence interval: 79.6–98.4%)

Positive predictive value: 84/87=96.6% (95% confidence interval: 90.2–99.2%)

Negative predictive value: 37/38=97.4% (95% confidence interval: 86.2–100%)

False positive value: 3/40=7.5%