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Ocular Hypertension Treatment Study (OHTS)

Background

Glaucoma is a leading cause of blindness in the United States.

2.5 million people in U.S. have glaucoma.

More than 130,000 are legally bind from glaucoma

Less than 50% of patients with glaucomatous visual field loss received appropriate diagnosis or treatment

The Study

The OHTS Study was completed in 2002. It studied the question: Do patients who have higher than normal pressures have more tendency to develop visual field defects. It found that there was a tendency to under diagnose in those who had thinner than normal corneal thickness.

In those that were treated:

Treatment produced 22.5±9.9% mean reduction in IOP (Intra-Ocular Pressure).

AT 60 months, cumulative probability of developing POAG (Primary Open Angle Glaucoma) was 4.4% in medication compared to 9.5% in observation group.

Little evidence of increased systemic or ocular adverse effects.

African Americans have a higher prevalence and incidence of POAG (Primary Open Angle Glaucoma).

OHTS data suggests that this racial effect may be due to thinner central corneas and larger cup/disc ratios.

Authors:

MA Kass, et al. Arch Ophthalmol. 2002;120:701-13.

MO Gordon, et al. Arch Ophthalmol. 2002;120:714-20

Possible Misinterpretations

While this data was significant in the management of open angle glaucoma, it is subject to some misinterpretation:

Treat all patients with elevated IOP (Intra-Ocular Pressure).

Glaucoma medications are harmless.

20% lowering of IOP is the correct target for ocular hypertension (elevated intraocular pressure).

Conclusions

Risk factors for developing POAG are clearly delineated; influence of race, gender, hypertension, heart disease, family history, blood pressure, and diabetes are all clear.