Glaucoma - I can't measure intraocular pressure

RE: Glaucoma - I can't measure intraocular pressure

Robert Lowe — Thu, 01 Dec 2016 19:22:05 GMT

[quote user="robloxley"]

[quote user="Robert Lowe"]use a topical prostaglandin analogue 4x in the first hour[/quote]

Would I be wrong to use latanaprost as 1st line treatment rather than Trusopt, or rather when would you use eacH?

[/quote]

Trusopt only if you are not sure about lens stability. Both if you are happy about the lens being in the correct place with the prostaglandin aggressively in the first hour.

RE: Glaucoma - I can't measure intraocular pressure

Robert Lowe — Thu, 01 Dec 2016 19:20:06 GMT

[quote user="Martin Atkinson"]Is this a procedure that could help our species?[/quote]

Sadly not. The hole(s) fibrose really quickly in dogs and the disease is probably more trabecular meshwork failure rather than aqueous dynamics

RE: Glaucoma - I can't measure intraocular pressure

Rob Loxley — Thu, 01 Dec 2016 15:38:36 GMT

[quote user="Robert Lowe"]use a topical prostaglandin analogue 4x in the first hour[/quote]

Would I be wrong to use latanaprost as 1st line treatment rather than Trusopt, or rather when would you use eacH?

RE: Glaucoma - I can't measure intraocular pressure

Martin Atkinson — Thu, 01 Dec 2016 11:19:07 GMT

[quote user="Robert Lowe"]The types or surgical intervention are rapidly evolving and this should improve further over the next 5 years (micropulse transcleral laser to remodel the trabecular meshwork or ultrasound / laser ablation of the ciliary processes are two newer developments) [/quote]I had a laser iridotomy last year as I'm (apparently) at risk of closed angle glaucoma (narrow angles and optic nerve cupping) I was getting some eye pain and my intra-occular pressure was marginally raised (25-26mmHg). Even my optician can't see the hole in my iris and I suspect the consultant ophthalmic surgeon was being over-enthusiastic to put it nicely. However my intra-occular pressure has returned to upper teens- low 20's.

Is this a procedure that could help our species?

RE: Glaucoma - I can't measure intraocular pressure

Michael Woodhouse — Thu, 01 Dec 2016 00:17:37 GMT

We're a small rural mainly large animal practice and we have a Tonopen. I assumed they would be standard across small animal practices?

I'd be reluctant to lend it out, but would happily measure IOP for anyone at a normal consult fee.

RE: Glaucoma - I can't measure intraocular pressure

grumpyoldman — Wed, 30 Nov 2016 23:50:09 GMT

I really would persuade the clients to invest in a referral, even if its just another local practice where someone is interested with a few toys , we charge £11 for tonometry £15 fro slit lamp examination and £25 for gonioscopy in addition to the normal consult fees .The gonioscopy may be crucial in salvaging the second eye if they are serious about saving it.

RE: Glaucoma - I can't measure intraocular pressure

Robert Lowe — Wed, 30 Nov 2016 22:21:33 GMT

Is there a local practice (1st opinion or referral) that can lend a tonopen? Or can you send the case to a 1st opinion practice that has one for intraocular pressure measurement? Saying that I have had 1st opinion practices wanting to charge £140 for a glaucoma assessment as they wanted to work the case up themselves when I have tried to find more local sources of intraocular pressure measurement for our long-distance clients.

If the cornea is blue then this tends to indicate an intraocular pressure over 40mmHg in my hands. So a reduction in oedema is an indication that intraocular pressure is better controlled but not necessarily at a "safe" level.

Assuming that you have controlled it then I normally wait 1 month before giving up on vision and enucleating. Quick intervention can restore vision in a surprising number of acute glaucoma cases but the majority of cases that present are probably not acute.

Pre-emptive treatment of the contralateral eye has not been shown to increase time to failure but I still do it thinking that at least it might minimise the initial spikes and give me more time to intervene when the other eye goes. Time to onset of raised intraocular pressure in the other eye is on average 1-2 years after the first eye but can be next week.

More aggressive medication might then get you another 6-12 months and after that surgical intervention will get 50% of eyes through another 3 years or so with vision and intraocular pressure control. The types or surgical intervention are rapidly evolving and this should improve further over the next 5 years (micropulse transcleral laser to remodel the trabecular meshwork or ultrasound / laser ablation of the ciliary processes are two newer developments)

Sticking a needle in an eye is a risky (mind that lens) but effective way of rapidly reducing intraocular pressure but does not provide control of intraocular pressure. Probably better to look at Mannitol if you want to reduce intraocular pressure quickly or use a topical prostaglandin analogue 4x in the first hour.

RE: Glaucoma - I can't measure intraocular pressure

Beats — Wed, 30 Nov 2016 19:45:17 GMT

a schiotz tonometer will set you back £70 + P&P and mine has lasted me 10 years using it about twice a year... indeed i'd consider selling mine to you complete with instructions if you wanted and use the money for something more useful like a new set of nail clippers.

without a tonometer, you cannot check the iop in the other eye. However... do you need to know that to decide whether to attempt to prophylactically treat or not? A 20D lens shoved up against the eye under GA can be used as a cheap and cheerful gonioscope... but again, do you need gonioscopy in this case to decide whether to propylactically treat the remaining eye?

i have never seen a case of acute glaucoma that isn't blind, so generally only interested in pain relief - in a dog with acutely glaucomatous painful blind eye i usually enucleate = diagnosis and definitive treatment rather than attempt lifetime of drops to ameliorate discomfort. if i don't wish to enucleate for some reason, occ. inject intravitreal gentamicin instead.

i do check the other eye with schiotz, but if it's going to go, it's going to go in my limited experience, and I'll probably vainly recommend some prophylactic drops even if iop not high (if cause of first glaucoma likely to be bilateral).

i worked in one clinic that had a tonopen, but obviously didn't stock any drugs for treating a visual acute glaucoma in the unlikely event that one walked through the door and the "local" chemist was shut... the PSS required a tonomtere apparently, not a bottle of latanoprost in-date in fridge... (though could have aspirated still for starters, which is probably what i'd now do anyway)

RE: Glaucoma - I can't measure intraocular pressure

Kate Richardson — Wed, 30 Nov 2016 18:57:33 GMT

I am no expert, but you can do aqueocentesis as well to lower the pressure, presumably under sedation. Only seen this done in a cat, but was done for a different reason. Hopefully someone with more expertise than I can add more with respect to what drugs are most current/useful/effective.

Pain relief would also be a strong consideration

We are lucky enough to have a tonopen and it's pretty easy to use, occasionally a bit temperamental, but generall get on with it fine. No idea how much they cost!