Pressure testing

[PBX142]

Does anyone find that the air puff pressure testing method is not as accurate as when the Goldman tonometer is used? In that case, what have been the differences in pressure? Which has registered higher readings? Thanks!

[Amandeep_GlaucomaUK]

Hey PBX142,

The air puff pressure test is a method of measuring your eye pressures called non-contact tonometry, this is where your eye pressures are measured without anything touching the front surface of your eye. Your pressures on occasion can vary more with this test, for example if you are holding your breath or are nervous your eye pressures can vary each time the reading is done. With majority of the population this method is accurate and reliable. This is because with the air puff method the eye pressures results tend to be between the normal range of 10-21 mmHg. Goldmann is a method called contact tonometry, this is where your eye pressures are measured by a tonometer touching the front surface of the eye. This is the gold standard and the most reliable method of measuring your eye pressures. When your eye pressures measure higher then 21 mmHg with the air puff method then Goldmann is done to confirm whether your eye pressures are that high. Goldmann is also done in most hospitals on patients as it is the golden standard in hospital for glaucoma monitoring. In some cases, the air puff test and Goldmann test will yield the same result. In other cases, the Goldmann test will have a higher or lower reading. I hope this helps.

Amandeep

Glaucoma UK Advisor

[PBX142 in reply to Amandeep_GlaucomaUK]

Hi Amandeep, thanks for your very full reply! I am very familiar with the two methods, but I just wanted to know if anybody on this forum had had differences in pressure, and what they were - that was all. The Goldman is a more accurate reading and on researching it appears that the Goldman results are generally around a couple of points lower than the air puff. It would be helpful though, as ever, to have some personal input on this from others.

[EthelPledge94 in reply to Amandeep_GlaucomaUK]

Hi Amandeep I have narrow angles and ocular hypertension so my pressures are always on the high side. Puff test and other readings always give between a 25-30 pressure. The GAT machine usually gives a reading of 20-23 which consultant says is stable for me at present as I have had a successful iridotomy. I hope that helps.

[Dorset22 in reply to Amandeep_GlaucomaUK]

Thank you for such a full answer. I have raised eye pressures and have Monopost eye drops. I always wondered why I had both tests. It is never explained and is good to know what is happening.

[warwickshire_singh]

I never like it when they measure pressure via the puffer! The last time I had it done, the Puffer said 17, but the tonometer said 8!

[Loki666]

I’ve been having regular pressure tests for decades now and found the Goldman tests are the most consistent, but my consultants allow a ‘correction’ to the result as I have thick corneas, around 3.

The puff tests are really unreliable, I assume because of the cornea issue as well as the operators, being done generally by assistants in opticians, also as the pressures were sometimes around 20 to 25.

After micro shunt surgery I bought an iCare Home2 tonometer so I could see what was happening. Those results were initially a bit concerning as the readings were pretty high. On doing a side by side test on two occasions with my consultant at his surgery it appeared that the results were consistent, all be it always reading 6 higher than the Goldman.

Being a contact tester I was expecting more reliable results than the puff machines and once you’ve sort of calibrated the machine’s results with a Goldman I think it is safe to follow the pressure trends with some confidence.

Hope that’s of interest?

[KayGeeBee]

I have low pressures (too low in one eye) and the air puffer always reads a few mmHg lower than the blue-light at the slit microscope, say 5 vs 8 respectively. My consultant thinks the blue light in this situation reads a bit high, but treats both only as a guide, meaning its somewhere around 5 to 8, and too low as I have hypotony and a choroidal detachment, which is the real evidence for the pressure being too low. I investigated iCare Home 2 a while back and it is only spec'd down to 7 because they can't guarantee accuracy below that, so it seems that low pressures are tricky to measure.

[Alprof]

Hi. PBX142In my case the consultant always checks the reading from the buffer by doing a second test by a Goldman. The result is always considerably lower using the former . I think most consultants do not trust the buffer and that is one reason for repeating the test in the office. As for the Icare the consultant advises not to buy it. She thinks that it causes worries all the time the IOP goes up which is normal during the day. She says it might be an obsession

[PBX142 in reply to Alprof]

Considerably lower using the puffer, not higher?

[Alprof in reply to PBX142]

I mean considerably lower using the Goldman

[hirsey12]

I’ve always found the puffer test at the opticians to be a few points lower than the hospital Goldman test. Last time it was 14 and 15 but 19 and 20 at the hospital.

[Alprof in reply to hirsey12]

It was fluctuation rather than differences specially if the two tests is not at very short interval.

[Daytripper56]

Yes sure it's usually few numbers higher just a rough guide really

[YoungontheOutside]

I queried this set my last virtual clinic because my readings, sometimes quite a bit lower with the puffer, and that is the only machine are using. I was told both puffer and Goldman are necessary, but at the virtual clinic they only check with the Goldman if the puffer results are high.

[anonimouse5]

At my clinic about half the time they use I-care initially and then the doctor uses Goldmann. The I-care is usually about 5 points higher, and just serves to wind me up before seeing the doctor. On my last visit it was even stranger as I-care gave readings of 23/26 and Goldmann 21/18 - actually the wrong way round! I did enquire once why they did both tests and the doctor said he would rather they didn't as it just causes confusion.

[countrygirl1]

My pressures are always lower with the puffer test and I think that's why it took a while for my glaucoma to be picked up at the opticians. The nurse/Opticians assistant always says its in normal range, then if tested with Goldmann my pressures will be about 3-4 higher. I have been told this is because I have thinner than average corneas.