TABLE 5. Comparison of Methods for Glaucoma Screening
| Screening Method | Advantages | Disadvantages |
| Intraocular pressure measurement | ||
| Tonometry | Detects persons with high intraocular | At usual referral levels: |
| pressure, who are at increased risk of developing glaucoma damage | · At least one-third to one-half of cases will be undetected by initial testing | |
| · Many persons will have positive screening tests | ||
| · Very few persons screening positive have or will develop glaucoma. | ||
| Structural assessment | ||
| Ophthalmoscopy | Potential for high sensitivity and high specificity | Observer variation is a major factor influencing sensitivity and specificity. |
| Imaging methods and techniques, for | Potential for high sensitivity and high | Highly trained personnel are required. |
| example, stereophotography, retinal fiber layer assessment | specificity, as well as standardization and reproducibility | Special and costly instrumentation required; no techniques yet validated for large-scale screening |
| Functional assessment | ||
| Perimetry; various methods and perimeters | Potential for high sensitivity and high specificity | Costly and potentially time-consuming, depending on the perimeter and testing |
| Automated instruments do not require highly | algorithm used | |
| trained personnel and permit standardized testing Promising new approaches offer shorter testing times and enhanced feasibility. | No techniques yet validated for large-scale screening |