NTG and thin corneas

[NoraBoneGirl]

Hi

I was diagnosed with NTG in my left eye over 20 years ago. Since then my pressures have been stable with apparently no cause for concern. Last year I had a severe infection in both eyes which has increased the pressure in my left eye from 11 to 14. I didn't think that was too bad as it had been 14 before and my consultant hadn't taken any action. This time my new consultant changed my drops from Latanoprost to Latanoprost with Timilol. He said the pressure was probably actually higher than 14, more like 20, as I have thin corneas. I have never been told before that my thin corneas affect my pressures.

Is anyone else's pressure affected by their thin corneas?

[muddledme]

Hello NoraBoneGirl,

I was told that I have thick corneas years ago which is supposed to help protect eyes against glaucoma damage, however I also have NTG and needed surgery when I did not respond to the medication.

There is quite a bit of information on google regarding thin and thick corneas and glaucoma. Perhaps your new eye consultant would inform you of the optimal pressures for your NTG. Your previous treatment seems to have worked very well for so many years so perhaps the new drops will correct the pressure.

Best wishes

[NoraBoneGirl in reply to muddledme]

Thank you for your advice and support.

[AlfredV]

I have thick corneas so have asked about this quite a bit. It is not that abnormal thickness affects eye pressures, its just that it affects the reading. So with thick corneas the pressure is probably lower than the reading, and with thin corneas it is probably higher than the reading. I've had some consultants say the difference could be about 2, I've heard others say you can't really know for sure.

I guess that how much thicker or thinner they are than average will have an affect on the difference between the reading and actual pressure.

[NoraBoneGirl in reply to AlfredV]

Thank you very much for your reply. Very helpful.

[KieranGlaucomaUK Administrator]

Hi there. I'd just like to echo what has been said above. The reason that he is suggesting this is because thin (or thick) corneas can lead to an error with the IOP reading. So it is not that thin corneas would cause high eye pressure, but it would be likely for the reading to come out lower than what it actually is.

It sounds like your eye specialist is estimating that your eye pressure is at 20 to be on the safe side of things and to avoid any risks. If your eye pressure is in fact 20, then this is why he is prescribing the combination drop instead of the latanoprost alone. It is good to hear that he is taking the necessary precautions to lower your eye pressures.

[NoraBoneGirl in reply to KieranGlaucomaUK]

Thank you for your reassurance.

[Iona57]

When my Glaucoma was first picked up at the cataract clinic, the cataract consultant said the pressure was just over 20, but he 'adjusted' the reading to 25 because of my thin cornea. My current glaucoma consultant doesn't think there is any benefit in 'adjusting' the reading to take account of a thin cornea. I suppose that once you are being treated for glaucoma, it's relative pressure that counts, ie, whether your pressures are going up and down, and what is your personal 'ideal' reading to prevent progression.

[NoraBoneGirl in reply to Iona57]

Thanks for your comments