A 68-year-old patient with normal-tension glaucoma has a mean IOP of 14 mmHg but progressive optic nerve cupping and visual field loss. The Collaborative Normal-Tension Glaucoma Study recommended treating such patients. What percentage IOP reduction was associated with slowing of visual field progression in CNTGS?
- A 10%
- B 20%
- C 30% ✓
- D 50%
Correct answer: C. 30%
Explanation
The CNTGS demonstrated that a 30% reduction in IOP (achieved primarily by medical therapy, laser, or surgery) significantly slowed visual field progression in normal-tension glaucoma patients compared to untreated controls. This 30% target reduction is a widely cited treatment goal for NTG. Smaller reductions did not show significant benefit in the trial.
Reference: Collaborative Normal-Tension Glaucoma Study (CNTGS), American Journal of Ophthalmology, 1998 ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
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