Eye Pressure: Air Puff vs. Handheld Measurements

Q: Eye Pressure: Air Puff vs. Handheld Measurements

Hello： <br>1. <br>Methods of measuring intraocular pressure： The accuracy of air puff and handheld tonometers can be influenced by various factors, including the operator's technique and the machine's precision. <br>Since you mentioned that your intraocular pressure was elevated

Issues related to intraocular pressure?

Hello, doctor.
Every time I measure my intraocular pressure using the air puff tonometer, the readings are consistently high (around 22 mmHg), but when the doctor uses the handheld rebound tonometer, the readings fall within the normal range.
I understand that being tense and closing my eyes tightly can cause an increase in intraocular pressure.
If I am nervous and my heart rate increases, will that affect my eye pressure?
1.
Should I rely on the readings from the air puff tonometer or the handheld tonometer? The air puff readings are always higher, which makes me feel uneasy.
2.
Does an increased heart rate affect intraocular pressure?
3.
With a corneal thickness of 580 micrometers, is an intraocular pressure of 22 mmHg considered normal?
4.
Since I have had my optic nerve and visual field checked for three years without any issues, can I assume that I can be at ease?

Chean, 20~29 year old female. Ask Date: 2023/11/13

Dr. Gao Pilin reply Ophthalmology

Hello:
1.
Methods of measuring intraocular pressure: The accuracy of air puff and handheld tonometers can be influenced by various factors, including the operator's technique and the machine's precision.
Since you mentioned that your intraocular pressure was elevated during air puff measurements, it is advisable to refer to the readings from a handheld rebound tonometer when possible, as this method is generally less affected by stress.
2.
Heart rate and intraocular pressure: An increased heart rate may lead to elevated intraocular pressure.
This is because intraocular pressure is regulated by the production and drainage of intraocular fluid, which can be influenced by cardiac activity and hemodynamics.
Staying calm and taking deep breaths during intraocular pressure measurement can help achieve more accurate readings.
3.
Corneal thickness and intraocular pressure: Corneal thickness is an important factor that affects intraocular pressure measurements.
For the same intraocular pressure, a thinner cornea may register a lower pressure value, while a thicker cornea may show a higher pressure value.
Considering your corneal thickness is 580 micrometers, an intraocular pressure of 22 may be within the normal range.
4.
Optic nerve and visual field: The fact that your optic nerve and visual field examinations have shown no issues in the past three years is a positive sign, allowing for some reassurance.
However, it is still recommended that you undergo regular ophthalmic examinations to ensure visual health.

Reply Date: 2023/11/13

More Info

Understanding eye pressure is crucial for maintaining ocular health, especially for individuals who have experienced fluctuations in their intraocular pressure (IOP) readings. Your concerns regarding the differences between air puff (non-contact tonometry) and handheld (applanation tonometry) measurements, as well as the impact of stress and heart rate on eye pressure, are valid and warrant a detailed explanation.

1. Air Puff vs. Handheld Measurements: The air puff tonometer measures eye pressure by delivering a quick burst of air to the cornea. This method can sometimes yield higher readings, particularly if the patient is anxious or tense during the measurement. In contrast, the handheld applanation tonometer, which involves gently flattening a small area of the cornea, tends to provide more consistent and reliable readings. Given your experience of consistently higher readings with the air puff method, it would be prudent to rely more on the handheld measurements, especially since they have shown to be within the normal range for you.

2. Impact of Heart Rate on Eye Pressure: Stress and anxiety can indeed lead to an increase in heart rate, which may indirectly affect IOP. When the heart rate increases, it can lead to changes in blood flow dynamics and potentially increase the production of aqueous humor (the fluid inside the eye). This can result in transient increases in eye pressure. Therefore, it is advisable to remain calm and relaxed during eye pressure measurements to obtain the most accurate readings.

3. Corneal Thickness and Eye Pressure: Corneal thickness plays a significant role in interpreting eye pressure readings. A corneal thickness of 580 micrometers is considered average. With an IOP of 22 mmHg, this reading is on the higher end of the normal range, especially if you have a thicker cornea. It is important to note that for individuals with thicker corneas, the IOP readings may need to be adjusted downward, while thinner corneas may require upward adjustments. Therefore, while 22 mmHg may seem concerning, it could be within a normal range for you, particularly if other factors are taken into account.

4. Long-Term Monitoring of Eye Health: The fact that you have undergone regular eye examinations over the past three years without any issues related to your optic nerve or visual fields is a positive sign. This suggests that your eyes are functioning well and that there are no immediate concerns regarding glaucoma or other ocular diseases. However, it is essential to continue regular check-ups, as eye health can change over time. Regular monitoring will help ensure that any potential issues are caught early.

In conclusion, while your air puff measurements may be higher due to anxiety or other factors, the handheld measurements provide a more reliable assessment of your eye pressure. Stress and heart rate can influence IOP, so maintaining a calm demeanor during measurements is beneficial. Your corneal thickness and the absence of any significant issues over the past three years are reassuring, but ongoing monitoring is key to maintaining your ocular health. Always consult with your eye care professional for personalized advice and recommendations based on your specific situation.

Similar Q&A

Which Eye Pressure Measurement Method is Most Accurate?

Hello Doctor, I recently went to a clinic to measure my intraocular pressure and found a significant difference in the results from two measurements taken on the same day. One measurement using the air puff method exceeded 20, while a subsequent measurement using a topical anesth...

Dr. Gao Pilin reply Ophthalmology
Hello ILK: Typically, the measurements obtained from a contact tonometer are more accurate, so your intraocular pressure should be normal. If you have had two fundus examinations after seeing flashes of light and both were normal, there is no need for concern. However, please mon...

Understanding Intraocular Pressure Measurements After Laser Eye Surgery

Dear Dr. Gao, two years ago I underwent laser vision correction surgery. However, the tonometer used in the clinic (the one that blows air) shows an intraocular pressure reading that seems to require an adjustment of about 5. For example, if the measured intraocular pressure is 1...

Dr. Gao Pilin reply Ophthalmology
Hello, After undergoing laser vision correction surgery, the intraocular pressure measured with a traditional applanation tonometer (air puff) may be underestimated. However, it is difficult to estimate how much should be added to determine the actual intraocular pressure. In...

Understanding the Differences in Eye Pressure Measurement Techniques

Hello Doctor: I have been experiencing consistently high intraocular pressure and have been using eye drops for treatment. Recently, after moving and changing doctors, I discovered that the new clinic measures intraocular pressure using two different methods: one while looking st...

Dr. Gao Pilin reply Ophthalmology
Hello Fei Fei: When you look up, the movement of your eyeballs may cause the extraocular muscles or surrounding tissues to exert pressure on the eyeball, which can lead to an increase in intraocular pressure.

Understanding Eye Pressure Measurement: Safety Concerns and Procedures

Hello, Doctor Gao. Today, during the process of measuring my intraocular pressure by the nurse, I was very nervous, which resulted in poor readings. My eye was measured more than 15 times using the air puff tonometer, and I saw several flashes of blue light, but there was no air ...

Dr. Gao Pilin reply Ophthalmology
Hello, Xiaomi: The use of jets and blue light will not cause harm to the eyes, so please rest assured.