Normal Intraocular pressure is?

Appeared in: HPSSC - 2015

Explanation

The normal range for intraocular pressure (IOP) in a healthy adult eye is between 10 and 21 mm Hg.
This pressure is crucial for maintaining the shape of the eyeball and the health of its internal structures.
It is determined by the balance between the production of aqueous humor by the ciliary body and its drainage through the trabecular meshwork and canal of Schlemm.
The option "Less than 20 mm/Hg" is the best description of this normal physiological range among the choices provided.

Option B: This range is too high. It includes pressures from 22 to 24 mm Hg, which are classified as ocular hypertension, not normal.
Option C: This defines elevated IOP, also known as ocular hypertension. It is a significant risk factor for developing glaucoma.
Option D: This indicates a pathologically high IOP, which is a strong indicator of glaucoma and poses a high risk for optic nerve damage and vision loss.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Normal Intraocular Pressure (IOP) Range as background academic context rather than a clinical decision trigger.
Nurses play a key role in health screenings which may include identifying patients at risk for glaucoma (e.g., those with a family history, diabetes, or older age).
Patient education is a critical nursing function. This includes explaining the importance of regular eye examinations for early detection of high IOP and teaching patients with glaucoma the correct technique for instilling eye drops to manage their condition and prevent vision loss.
Accurate measurement of IOP via tonometry is essential. Nurses in specialized settings may perform or assist with this procedure.

How to Approach the Question

This is a factual recall question that asks for a specific normal physiological value.
First, access your knowledge base to recall the standard range for intraocular pressure (IOP). The accepted medical range is 10 to 21 mm Hg.
Next, carefully evaluate each of the given options against this established normal range.
Analyze Option A ('Less than 20 mm/Hg'): This fits comfortably within the 10-21 mm Hg range.
Analyze Option B ('Less than 25 mm/Hg'): This is too broad and includes abnormally high pressures.
Analyze Options C and D ('More than 20 mm/Hg' and 'More than 25 mm/Hg'): These clearly describe abnormal, elevated pressures.

Concept Tested & Keywords

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E6 Nursing Brunner Adult Health 3SA Vol 2 Part 1 p. 94-96

E6 Physiology Guyton 4SAE Part 3 p. 146-148

Practise the full HPSSC - 2015

Attempt every question from this paper in a timed mock, then review the full solution for each one.