Glaucoma affects more than 2 million people in the United States. It is usually characterized by damage to the optic nerve as a result of elevated intraocular pressure (IOP). A larger number of individuals, ocular hypertensives (OH), have elevated IOP and no clinical evidence of damage, but are at higher risk of developing glaucoma. Perimetry is an important clinical procedure for detecting, evaluating and monitoring glaucoma, although substantial optic nerve damage can occur prior to visual field loss. Thus, more sensitive clinical test procedures are needed. The goals of this project are: To evaluate psychophysical indicators of early glaucomatous damage to the optic nerve. * Short-wavelength-sensitive perimetry (SWSP) We have found that visual field deficits can be detected approximately two years earlier by SWSP than by standard automated perimetry (AP). However, this was m a small, selected group of patients. We now propose to determine, in a five-year follow-up study of a large sample of ocular hypertensive patients, the relative sensitivity, specificity and effectiveness of SWSP for early identification of the patients who will later develop AP visual field loss. * Temporal modulation perimetry (TMP) Sensitivity losses for high temporal flicker frequencies have also been proposed as an early indicator of glaucomatous damage. We have recently developed an automated TMP procedure that demonstrates abnormal results in some OH and most early glaucoma patients. A longitudinal study of TMP is needed to determine its efficacy for predicting AP visual field loss and progression in glaucoma. Longitudinal comparisons of TMP, SWSP and AP in the same patients will characterize the amount of early glaucomatous loss that is common to all tests (nonselective loss) and the amount of early loss attributable to individual tests (selective loss). We will examine selected groups of age-matched normal controls, OH patients and early glaucoma patients with TMP, SWSP and AP over a five year followup period. * Displacement threshold perimetry (DTP) Displacement thresholds appear to be disrupted in patients with ocular hypertension and early glaucoma. We propose to design a perimetric test based on displacement thresholds and assess its efficacy as a clinical test of early glaucomatous damage. To develop Integrated Modular Perimetry Strategies (IMPS) for automated perimetry (AP). Improvements m test strategies enhance the diagnostic utility of AP. We will use KRAKEN, our computer simulation model of perimetry, to construct rapid, heuristic test strategies (IMPS) for (1) optimal detection, (2) baseline evaluation and (3) followup of field loss and assess the robustness of these procedures to various visual field characteristics, patient errors and response fluctuations. The strategies employed in IMPS will be similar to those developed for RIOTS which have been successful in substantially reducing test time in AP without sacrificing accuracy.