Applanation Tonometry
Applanation tonometry is a widely used diagnostic technique in ophthalmology for accurately measuring intraocular pressure (IOP), which is a critical factor in the diagnosis and management of glaucoma and other ocular conditions.
Purpose and Indications
The primary purpose of applanation tonometry is to assess IOP, as elevated pressure within the eye is a significant risk factor for optic nerve damage and vision loss in glaucoma. It is indicated in routine eye examinations, glaucoma screening, monitoring disease progression, and assessing treatment efficacy.
Conducting the Examination
During applanation tonometry, a specialized instrument called a tonometer is used to gently flatten a specific area of the cornea, known as the central corneal apex. The force required to flatten the cornea is directly proportional to the IOP, allowing for accurate measurement.
Interpretation and Findings
Applanation tonometry provides a numerical value representing the IOP in millimeters of mercury (mmHg). Normal IOP typically ranges between 10 and 21 mmHg, although individual variation exists. Elevated IOP may indicate increased risk for glaucoma, while low IOP may suggest hypotony or other ocular conditions.
Clinical Significance
Accurate measurement of IOP through applanation tonometry is essential for early detection, diagnosis, and management of glaucoma. Monitoring IOP over time helps ophthalmologists assess disease progression and adjust treatment strategies to preserve vision and prevent vision loss.
