Hello, does anyone know why the pressure readings vary so much? I felt my eye was wrong and had 3 optician appointments over 2 weeks. The pressures ranged from 21 to 28. I understand they can vary day to day and throughout the day.
But at my hospital appointment I went into one room where they took my pressure readings and told me they were 29 and 31. Then I went into the consultant room where they took readings and said it was 23. Then that I have thick corneas do don't need treatment yet. (I also have retinal bleeds in the eye that feels wrong).
How can two instruments vary so much in their readings and how can we trust the readings if they are so different?
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PurpleBanana3
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This is a question I’ve been grappling with. My pressures were 22/23 before referral to the hospital. I’ve been on Monoprist for two years. I’ve had three hospital appointments, each a year apart. How can they possibly know what’s going on if they only test once a year? Once I mentioned my pressures had been up when I had my eye test at the opticians and the nurse just laughed and said there can be all sorts of reasons for a spurious result.
This time at the hospital I had the pressures checked, and they were 28/29, and despite everything else being stable (Fields etc) they immediately said I needed to switch medication. I asked to see the doc to talk through what was going on and what my options are if pressures are actually higher generally. You’d think I’d asked for free Taylor Swift tickets!
I was referred by optician to eye hospital in 2014 with “high” eye pressures. The pressures were 18L and 20 R. Everything was checked and no abnormalities found. I was told I had small eyes and thick corneas which can lead to higher pressure readings. Over the years, my pressure readings have fluctuated, but in general, due to age, they have increased. I went onto Monoprost this 3 months ago, as my pressures were 28L and 31R, I wasn’t too worried, as everything was still fine with my eyes, but the consultant was worried about potential night time spikes and the potential for retinal nerve damage. Will see how the Monoprost goes, luckily, no side effects so far,
I would also say the equipment they use at the hospital where they numb your eye is the most accurate. The puff of air or the one that uses tiny probes used most frequently at the optician’s are less accurate and impacted by, eg thick cornea etc.
I had variable eye pressures over several appointments. They ranged from 20 to 28. It was then decided that I should use eye Monopost eye drops. Last visit pressures were in low twenties but they seemed happy that they were lower. I have never really understood what the implications are other than it is to prevent glaucoma developing. My eye pressures were never a problem at my tests at Specsavers and were only picked up when I had a pre-diabetic eye test.
I have exactly this issue too. Was told at the opticians that above 20 was too high and ideally they like to see mid teens and below. But consultant says my readings (20-23 usually) are "OK for your eyes". Why are they OK for my eyes? I do also have thick corneas and am also using Monopost.
I have very thick corneas so have some experience of these sorts of conversations. Typically they want to see your eye pressures at 20 or lower. Tonometers (devices that measure eye pressure) are calibrated based on standard cornea thicknesses. Thick corneas result in a higher reading than the true value and thin corneas do the opposite. This is true regardless of the type of device used to measure the pressure.
I've seen some consultants claim that there is a rule-of-thumb to work out the true value and others claim that it can only be estimated.
What is known is that your measurements of 20-23 are actually lower than that, but by how much I couldn't say. The good news is that an ophthalmologist can see if you have the beginnings of glaucoma and recommend what to do, regardless of eye pressures. It sounds like your ophthalmologist thinks your eyes are okay all things considered.
Hi, exactly the same thing happened to me. I had a pressure test at the hospital which was 26 in left eye. 14 in right. Few days later I had a private opticians appointment. Pressure was 12 LE and 14 RE. Optician referred me back to hospital as readings appeared to be fluctuating. For reassurance I also went to Specsavers, pressure was 12LE. 12RE.Consultant at the hospital was very unhelpful. He said he didn't trust optician's readings/equipment. He said he had the last word on the matter and I should go on Timolol indefinitely LE only. Seems strange that the 2 optician's readings were practically the same and the hospital much higher. I am doing as I am told and using the Timolol but not sure if I need to!!!
What a lovely, and very understandable, question ! There is a lot to read on the internet about diurnal IOP variation , particularly day/night/posture influences. You are correct, it would be much more useful to take measurements more frequently too, and discussion with your optometrist about achieving this would be useful. But regarding the reliability of actual measurement methods, well: The traditional Goldman tonometer, usually mounted on the slit lamp microscope is considered the reliable method upon which clinical decisions ae made. However it is subject to the skill of the person - and their actual vision, since it is the precise alignment of images that determines the judgement of taking the reading ! . Automated instruments are very good now, but can still be subject to a little variation in handling. IOP can vary with the pulse cycle so this can introduce a small element, depending on how quickly the instrument tales the measurement. And if measurements are taken very soon after we have sat down following movement this could influence. But, as you imply, the concern is the difference in approach by the clinicians whether and when to take action. The traditional judgement - is there any visual field loss - has been superceded (one hopes) by objective OCT monitoring. The effect of drops can diminish with long term use, hence the trend to delay use until damage is evident rather than always to reduce IOP over a certain level. The best approach, for all conditions, is for the patient to be well informed and to closely question the medics responsible about the options and the reasons for decisions.
It was the Goldman tonometer that gave the lower readings but much lower and only a few minutes later makes it seem that none of the other equipment should be used if it is so inaccurate.It seems that others may have started medication in my situation. I still have pain and a dark area I can see in the eye with the disc hemorrhages but none of the tests or scans could see a reason for it and suggested my eyes and sight were mostly good so I will just have to see if they say any different at my next 'glaucoma suspect' appointment.
I wandered this, when I had my final Checkup in Hereford eye clinic after my glaucoma operation they did not used the hand held one, they used the other sort where you rest your chin and they numb your eye it was 12 with that, my opticians used a hand held one with a drop in my operated eye and the same eye was 18, I asked him and he said that the other ones give a more accurate reading than the hand held. He said that the other equipment took up more space and he have not got the money and facilities to house it, I can understand that.
I have very variable pressure readings. The explanation I was given is this is due to me having closed angle glaucoma and not open angle glaucoma. As the lens moves in the eye, it's this that causes the pressure to change. I've had both the lenses in my eyes changed for thinner ones and this has decreased the pressures, but they still are very variable, despite continuing to use eye drops.Hope this helps.
I have had glaucoma for 5 years and every time I have had my pressure checked with the I-care it came out as higher than than measured by the doctor. (For some reason the technician quite often did a reading at the start of the appointment even though a Goldmann measurement was to be done later.)
I had my first experience of a virtual clinic this year and the pressure was measured at 21, where previously it was 16. I was fortunate however and I was given a follow up appointment with a doctor who measured the pressure at 16 again. He said the problem was that I was on maximum drops (Ganfort and Trusopt) and this meant the Icare measurement was inaccurate. I told him that this had been the case from the very beginning, when I was just on Latanoprost. so he said in future I will not be sent to the virtual clinic. I have this in writing so I hope it happens.
I was interested that Pley said they blamed it on having closed angle, which is what they finally decided I had after a couple of years of saying it was open angle.
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