Visual Fields in the OCT Era - Dr. Graham Lakkis

[AdminWolf]

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Visual Fields in the OCT Era: Dr. Graham Lakkis (55861-GL)



Watch the entire presentation & earn COPE credit at CEwire2018!

 

[Charles A McBride]

Such an outstanding lecture! The last summary slide is amazing.

Question: If one follows the Crabb protocol based on the UKGTS of three VFs at diagnosis followed by three VF's at the two year mark, and determines the patient has a "non-catastrophic" rate of field progression, how often would you recommend one has his/her patients perform fields going forward?
-Charlie

Charles McBride, O.D.
Beaverton, OR

 

[Graham Lakkis]

Hello Charlie,

Glad you found the presentation interesting. I hold the regular participants here on OD Wire in high esteem regarding their optometric knowledge, and was a little worried you already “knew it all” and would find the lecture too basic.

 

[Graham Lakkis]

Such an outstanding lecture! The last summary slide is amazing.

Question: If one follows the Crabb protocol based on the UKGTS of three VFs at diagnosis followed by three VF's at the two year mark, and determines the patient has a "non-catastrophic" rate of field progression, how often would you recommend one has his/her patients perform fields going forward?
-Charlie

Charles McBride, O.D.
Beaverton, OR

It depends on the size of the error bars in the calculations of progression rate made by the perimeter.

For example if the progression rate is -1.00dB/year +/- 2 dB then the true rate could be anywhere from +1 to -3 dB/ yr. I would keep testing frequently until I had greater confidence in the result. If it was -1 +/- 0.1 dB/year I would be happy to just do an annual VF.

The whole purpose of this information is to get us to do a really quick 24-2 Sita fast/er VF frequently rather than a 30-2 Sita Standard VF once every year or two.

 

[Michael R. Young O.D.]

Excellent lecture on Visual Fields and Glaucoma. Should be required viewing for anyone treating Glaucoma.

I will be changing my protocol for VF use based on this lecture.

My only concern is whether the patient's insurance will be willing to pay for VF testing 3 months in a row.

I hate working for free and the patients always think their insurance should pay for testing instead of them.

 

[Steve Silberberg]

Hello Charlie,

Glad you found the presentation interesting. I hold the regular participants here on OD Wire in high esteem regarding their optometric knowledge, and was a little worried you already “knew it all” and would find the lecture too basic.

Yes Graham: WE are changing are protocols based on the research as to when do fields. The one problem: Will Medicare and insurances pay for 3 baseline fields

 

[Graham Lakkis]

Everybody, don't get too hung up about what Medicare allows. Insurance/Government often lags behind best practice till it become standard of care.

Remember, the purpose of "clustering" VF tests close to each other (rather than evenly spacing them every 6 to 12 months) is that the disease process would not have progressed at all in the 4 weeks between VF's, so any variability is due to the patient's responses, not disease progression. Therefore the perimetry software can get a much more valid statistical significant determination of true disease progression in a much shorter time by comparing the average VFI/MD in each cluster with that performed 1, 2 and 3 years later where glaucoma could have worsened.

If the patient will not pay the small fee out-of-pocket, then it would be reasonable to perform VF's at Months 0 and 1, 12 and 13, 24 and 25. This will still give you 6 clustered VF's in 2 years so you can more accurately and rapidly determine progression rate.

 

[Joe DiGiorgio O.D.]

Very Nicely done Graham

I made a summary of most of the slides in your presentation. With the permission of @Graham Lakkis and @AdminWolf, I will be happy to post it on this thread.

 

[Joe DiGiorgio O.D.]

I am curious to ask others: I tried 24-2 SITA Fast, but it seemed it was quite fast/rushed for many patients so we switched back to SITA STD. Can any others comment of your successes with SITA-Fast? Perhaps I need to rethink my protocol. Taking a VF test is dreadful and any way we can increase the patient alertness and accuracy is noble.

 

[Laurence Craig Thomas]

Another example of science being ahead of guidelines, rules and regulations.

I find it interesting to see the initial acceptance of everything Dr. Lakkis had to say, but alternatively, I sometimes find resistance among the ODwire membership when similar statements are made about clinical information in other domains.

Dr. Lakkis, great lecture.

 

[Jonathan Warner]

Sounds like this will be a great lecture when I get to it.

Are we able to print pages off these presentations?

 

[Graham Lakkis]

I am curious to ask others: I tried 24-2 SITA Fast, but it seemed it was quite fast/rushed for many patients so we switched back to SITA STD. Can any others comment of your successes with SITA-Fast? Perhaps I need to rethink my protocol. Taking a VF test is dreadful and any way we can increase the patient alertness and accuracy is noble.

Joe,

I believe that SITA Fast has smaller brightness steps between presentations when thresholding a point in space compared to SITA Standard which is what makes it quicker. Otherwise the timing of the stimuli is the same.

I use SITA Fast all the time and patients are universally happy with it. Much shorter test times.

 

[Joe DiGiorgio O.D.]

Joe,

I believe that SITA Fast has smaller brightness steps between presentations when thresholding a point in space compared to SITA Standard which is what makes it quicker. Otherwise the timing of the stimuli is the same.

I use SITA Fast all the time and patients are universally happy with it. Much shorter test times.

I will need to go back and try it again. We sometimes do fields on each other on Wednesdays. Probably not tomorrow as we are pretty booked. I thought the timing was quicker and the patient seemed more rushed on SITA Fast. Will be taking another look.

May I post my notes?

 

[Charles A McBride]

Joe,

I believe that SITA Fast has smaller brightness steps between presentations when thresholding a point in space compared to SITA Standard which is what makes it quicker. Otherwise the timing of the stimuli is the same.

I use SITA Fast all the time and patients are universally happy with it. Much shorter test times.

When SITA Fast was first introduced I recall hearing that the stimuli were presented faster depending on the response time. Would be curious to know if this is true. I'll try and test it tomorrow.

 

[Graham Lakkis]

Another example of science being ahead of guidelines, rules and regulations.

I find it interesting to see the initial acceptance of everything Dr. Lakkis had to say, but alternatively, I sometimes find resistance among the ODwire membership when similar statements are made about clinical information in other domains.

Dr. Lakkis, great lecture.

There should never be blind acceptance of any scientific theory, including those I presented, which are not my work but those of respected colleagues.

In fact Andrew Anderson who is an OD/PhD at our institution doesn’t necessarily agree this is the best approach:

Detecting glaucomatous progression with infrequent visual field testing.
Anderson AJ, et al. Ophthalmic Physiol Opt. 2018.
Show full citation
Abstract
PURPOSE: Previous work has investigated whether a significant regression slope in the first 2 years for the summary index Mean Deviation (MD) is predictive of rapid (≤-2 dB/year) glaucomatous visual field progression. This work assumed six visual fields were obtained as per management guidelines, but in clinical practice commonly only two or three fields are measured.

METHODS: We simulated visual field series (N = 100 000) spaced annually in the first 2 years and then biennially. We calculated positive and negative predictive values (PPV & NPV).

RESULTS: Prediction values at 2 years were slightly less than those obtained using six visual fields. An addition of an appropriate slope based criterion materially improved PPV, with little detrimental effect.

CONCLUSION: Infrequent visual field testing does not dramatically alter predictive values at 2 years, but does substantially delay when significant progression may first be detected.

© 2018 The Authors Ophthalmic & Physiological Optics © 2018 The College of Optometrists.

 

[Allan Panzer]

As usual I have a couple of questions...

I see you are on line.

I understand the three tests initially, what I cannot determine is why on earth...you would wait two years for additional testing?

Especially if they are rapid..makes zero sense to me.

Second..I realize you glanced over the Octopus instrument.

I have utilized it for many years..got my first VF in 1983..hmmm
Next one in 1994. Octopus 123
Does 24-2 in less than two minutes.

Does 10-2 in less than two minutes.

HFA just has better PR...not necessarily a better instrument.

I feel this at the least needs to be mentioned..

Not glanced over in thirty seconds.

Excellent presentation..
Just my two cents.

 

[Graham Lakkis]

As usual I have a couple of questions...

I see you are on line.

I understand the three tests initially, what I cannot determine is why on earth...you would wait two years for additional testing?

Especially if they are rapid..makes zero sense to me.

Second..I realize you glanced over the Octopus instrument.

I have utilized it for many years..got my first VF in 1983..hmmm
Next one in 1994. Octopus 123
Does 24-2 in less than two minutes.

Does 10-2 in less than two minutes.

HFA just has better PR...not necessarily a better instrument.

I feel this at the least needs to be mentioned..

Not glanced over in thirty seconds.

Excellent presentation..
Just my two cents.

Hello Allan, yes I'm online responding to your comments on the LASIK/glaucoma thread!

1. You need between about 2 years (in a good test taker) and 4 years (in a poor test taker) for the VFI/MD to change more than the natural variability of the visual field testing process. If you look at the table from Chauhan in my lecture, you can see that the detection time is quicker when the rate of deterioration is greater, which makes sense as the change in MD/VFI will be much greater than normal fluctuation.

Dave Crabb in his paper on this theory even mentions that if you simply can't wait the two years, it is OK do another VF at month 12, but it doesn't really speed up your calculation of the progression rate. In fact having equally spaced fields over the course of 2 years makes it harder to differentiate test variability from disease progression and increases your chance of false positives.

2. No disrespect to the Octopus perimeter. I didn't have much to say because I have never seen one here in Australia or know of anyone using one either. Same as the Heidelberg edge perimeter, never seen one. It was mentioned because, like the Medmont, I believed it tested more central points than the HFA without having to run separate macular VF.

In Australia, Medmont and Humphrey have the market stitched up, with the occasional Oculus EasyField and Matrix

 

[Joe DiGiorgio O.D.]

There should never be blind acceptance of any scientific theory, including those I presented, which are not my work but those of respected colleagues.

I felt you had all your key points well referenced by highly credentially authors.

 

[Allan Panzer]

1. You need between about 2 years (in a good test taker) and 4 years (in a poor test taker) for the VFI/MD to change more than the natural variability of the visual field testing process. If you look at the table from Chauhan in my lecture, you can see that the detection time is quicker when the rate of deterioration is greater, which makes sense as the change in MD/VFI will be much greater than normal fluctuation.

I met Chauhan when I went to BC back in 1994...an amazingly smart guy. It was interesting.all these heavy weights in Glaucoma and there was this guy...from a strip center in Texas..almost laughable.

The father and son Sampaolisi or however you spell that kept asking me..so who are you? And "why" are you here?

But I digress..i think the common sense question is..if a person is a rapid changer and you wait two years, surely you miss something.

I think what you really miss is the opportunity to emphasize that there may be a problem.

Every time I turn around 18 months have gone by instead of twelve.

The Sampaolisis' actually checked IOP every hour for 15 hours a day. They got to their offices at 7:00 and left late in the night.

I'm not an academian..but its sometimes fun to hang out with some really smart people.

So, when I bought the HRT in 1994 from John Hawley..hmmmmm an Aussie..now with Optovue....he got me the invite.

Cause I was stinking crazy to spend $53K back then on unproven technology.

 

[Joe DiGiorgio O.D.]

if a person is a rapid changer and you wait two years, surely you miss something.

I think what you really miss is the opportunity to emphasize that there may be a problem.

Allan what is your typical protocol for frequency of VF testing?

 

[Lloyd Pate]

Allan what is your typical protocol for frequency of VF testing?

Here is what I follow. It is the consensus of the World Glaucoma Association.

"
Baseline data collection (no previous VFs available) – first two years

1. In clinical practice, at least two reliable VFs is optimal in the first six months.
   Comment: In clinical scenarios, where the lifetime risk of visual disability is high, such as those who already have advanced damage, three baseline VFs may be necessary.
   Comment: A good baseline of reliable VFs is essential to be able to monitor for progression.
   Comment: Unless there are obvious learning effects, high false-positive errors, rim artifacts, or other obvious artifacts, examinations should not be removed from the analyses.
2. At least two further VFs should be performed within the next 18 months.
3. VF testing should be repeated sooner than scheduled if possible progression is identified on the basis of an ‘event’ analysis.
   Comment: In patients at risk of visual disability, performing six VFs in the first two years enables the clinician to rule out rapid progression (2 dB/year or worse) and establishes an ideal set of baseline data.
   Comment: the identification of possible progression may be on the basis of an ‘event’ criterion such as the Glaucoma Progression Analysis (in the Humphrey perimeter software) or ‘Nonparametric Progression Analysis’.
4. Establish a new baseline after a significant therapeutic intervention (e.g., surgery). Comment: the new baseline can be the last fields that defined the previous progression ‘event’.

Follow-up data collection (after the initial two years)

1. The frequency of follow-up VFs should be based on the risk of clinically significant progression (based on extent of damage and life expectancy).
2. In low and moderate risk patients, subsequent VF frequency should be one VF per year (unless there is a long follow-up) and, as a rule, repeated sooner if possible. Progression is identified on the basis of an ‘event’ analysis, or if other clinical observations are suggestive of possible progression or increased risk of progression.
   Comment: relevant clinical observations include structural progression (clinically noted or measured by imaging), a splinter hemorrhage, or inadequate IOP control.
3. In high risk patients, subsequent VF frequency should be two VFs per year and repeated sooner if possible progression is identified on the basis of an ‘event’ analysis, or if other clinical observations are suggestive of progression or increased risk of progression.
   Comment: following confirmed progression (by an ‘event’), the frequency of testing should be based on the estimated rate of progression, risk factors and other clinical indicators of progression, stage of disease and life expectancy.
   Comment: patients who have been stable for a long period, or who are progressing so slowly as to be at little risk for reaching disabling levels of field loss, and other clinical parameters indicate low risk of progression, may have VF testing less frequently than 1 VF per year."

https://wga.one/wga/consensus-8/

 

[Allan Panzer]

Allan what is your typical protocol for frequency of VF testing?

Since you asked me and Lloyd answered...
I'll tell you.

My usual is to have them return a week later, then three months later. If that is questionable, they return six months later.

The difference is that unlike most of you, I try to get all of my OHT patients SLT.

That way I can watch with a bit more comfort. BTW...there are studies that state that Hysteresis demonstrates who will best benefit from drops...or SLT..can't remember and I'm not that good at quickly finding those suckers...but I remember seeing one recently.

And in another ten years maybe..everyone will realize the benefit of SLT for compliance..

And just maybe you'll say..

Damn, that Panzer guy was doing that ten years plus ago..

I am sad that we feel we must utilize drops so that we can keep them in the "fold".

I'd rather a seeing patient who abandoned me than a blind one I was caring for.

 

[Joe DiGiorgio O.D.]

And in another ten years maybe..everyone will realize the benefit of SLT for compliance..

I sure hope you work at least 20 more years so we can find you that your theories were right.

I am sad that we feel we must utilize drops so that we can keep them in the "fold".

It would be nice if we could Laser then right in the office. I am sure SLTs would go up about 10,000%.

 

[Joe DiGiorgio O.D.]

Thank you Lloyd and Allan.

 

[Troy Cassidy]

Graeme:
1. Just to be clear, you go for SITA Fast as your default field right from the start?
2. You mentioned SITA FastER - have you got this installed on your machine? Thoughts?
Thanks

 

[Allan Panzer]

If you listened to the lecture, he said the "faster" was only available on the HVF3 and had not been released to the public yet..

Maybe it will be out soon..In the mean time the very old Octopus 123 does a full threshold in less than two minutes..
Just an observation.

 

[Allan Panzer]

I sure hope you work at least 20 more years so we can find you that your theories were right.



It would be nice if we could Laser then right in the office. I am sure SLTs would go up about 10,000%.

They do in some states..
Louisiana for instance..Kentucky is another state that allows it..

But alas, Illinois and Texas sort of lag behind.

 

[Troy Cassidy]

If you listened to the lecture, he said the "faster" was only available on the HVF3 and had not been released to the public yet..

Maybe it will be out soon..In the mean time the very old Octopus 123 does a full threshold in less than two minutes..
Just an observation.

I ask because I know Graeme has an HFA3, and I am waiting on the SITA Faster release here in NZ. I have been told "soon", and I wondered whether Australia got sorted out before us, as is sometimes the case.

I would love to hear Graeme's lecture, but not sure I want to pay US$179 for material that gives me no CE credit with my Board.

 

[Allan Panzer]

Interesting take...
Now let me give you my take..

I get all the CE for free I want here in H-town. Every OMD in town has some free CE so other than the UHCO course I have to take...so they can get some money. I could easily not listen to the CEwire2018.

I could also not pay that whopping $49 to be a supporting member.
What I did was to wait til the courses cost more because lets face it...its a donation.

If you want to learn something, you don't worry about CE.

Do you ever read journals? Do you ever listen to podcasts? Ask questions on ODwire?

Why?

I mean, you don't get CE from lots of those.

Is that all that drives you?

CE or bust...can't waste any of that money on something you might actually learn from. Or something that might make sure you have a forum to ask questions on..

Nope, its all about the CE for that huge investment.

Lets just say I'm not impressed with your response..Is that polite enough..

Cause Panzer isn't polite.
Never has been....never will be.

 

[Allan Panzer]

I would love to hear Graeme's lecture, but not sure I want to pay US$179 for material that gives me no CE credit with my Board.

No you wouldn't...that's just talk...

 

[Lloyd Pate]

Interesting take...
Now let me give you my take..

I get all the CE for free I want here in H-town. Every OMD in town has some free CE so other than the UHCO course I have to take...so they can get some money. I could easily not listen to the CEwire2018.

I could also not pay that whopping $49 to be a supporting member.
What I did was to wait til the courses cost more because lets face it...its a donation.

If you want to learn something, you don't worry about CE.

Do you ever read journals? Do you ever listen to podcasts? Ask questions on ODwire?

Why?

I mean, you don't get CE from lots of those.

Is that all that drives you?

CE or bust...can't waste any of that money on something you might actually learn from. Or something that might make sure you have a forum to ask questions on..

Nope, its all about the CE for that huge investment.

Lets just say I'm not impressed with your response..Is that polite enough..

Cause Panzer isn't polite.
Never has been....never will be.

I think your blood sugar must be low. You are a little cranky tonight.

 

[Troy Cassidy]

I'm not sure what exactly you've taken such umbrage to, given that I was actually asking a question on ODWire. I've learned a lot from posters on this site. Including you. This has been a good clinical thread. I'll not disrupt it further.

 

[Allan Panzer]

I would love to hear Graeme's lecture, but not sure I want to pay US$179 for material that gives me no CE credit with my Board.

Let me help you out.

I'm taking umbrage to the fact that you feel $179US is just too much to pay for vast knowledge you can gain, but since it does not get you any hours, its just too expensive.

How much is knowledge worth?

When I go to a major meeting, I have to travel, pay a hotel, pay for hours and when its all said and done I might get a tiny pearl. I feel its worth every penny just to gain that information. Sometimes I feel I happened to come home empty handed.

In this case you can sit in your bed and listen. But not get hours...Oh my!

Is that clear enough?

If my attitude scares you off, Oh well..I think we all need to be willing to pay to help the board survive.

Just so folks like you can ask questions without listening to the lecture.

 

[Angel Adolfo Camblor]

I believe Dr. Farkas stated you can sign up as a student, but you will not be subjected to a test at the end (so no credit). It's free that way and I don't believe he minds or he would not have put that info out there. So kudos to OdWire for sharing the knowledge.

I paid for mine,.... only because I need the CE hours.

Also many thanks to Dr. Panzer for sharing, truly! Net positive, reading your posts, but I think Lloyd is correct. Tad bit grumpy to friend Troy.

Time to get me some protein.

 

[Troy Cassidy]

Thanks Angel. I did get a heads up about this earlier, and watched Graham's excellent lecture tonight. Which did, admittedly, answer my questions.

 

[Graham Lakkis]

Graeme:
1. Just to be clear, you go for SITA Fast as your default field right from the start?
2. You mentioned SITA FastER - have you got this installed on your machine? Thoughts?
Thanks

Troy,

Zeiss had an information evening about SITA Faster (and Clarus) before Christmas last year, but I haven't received the upgraded software yet.

In reality, SITA Fast is usually quick enough to be comfortable for most patients.

 

[Joe DiGiorgio O.D.]

Graham

Thanks for all the great input and guidance.

So to review the STD/Fast/Faster protocol:

Do you baseline your suspects with SITA Std? then at some point do you transition to "Fast"

Thank you again.

 

[Joe DiGiorgio O.D.]

For reference purposes here was one of the review slides from Graham's presentation:

 

[Lloyd Pate]

For reference purposes here was one of the review slides from Graham's presentation:

View attachment 17431

One study with the differences.

RESULTS:
The sensitivity of SITA standard and SITA fast in detecting glaucomatous defects overall was 98% and 95%, respectively. In the subset of mild glaucomatous field defects (26 patients), sensitivity of SITA standard was 92% versus 85% with SITA fast. Sensitivity was 100% for both algorithms in moderate to severe glaucomatous defects. Specificity for glaucoma defects using SITA standard and SITA fast was 96% for both algorithms. SITA standard reduced test-taking time from full threshold by 52% in normal subjects and 47% in glaucoma patients (P < 0.001). SITA fast reduced test-taking time by 72% in normal subjects and 65% in glaucoma patients (P < 0.001). Mean deviation values were 0.4 dB and 0.8 dB better in SITA standard and SITA fast fields, respectively, in normal subjects (P < 0.001), and 0.7 dB and 1.2 dB in SITA standard and SITA fast fields, respectively, in glaucoma patients (P < 0.001) compared with full threshold values.

https://www.ncbi.nlm.nih.gov/pubmed/12045043

 

[Troy Cassidy]

Troy,

Zeiss had an information evening about SITA Faster (and Clarus) before Christmas last year, but I haven't received the upgraded software yet.

In reality, SITA Fast is usually quick enough to be comfortable for most patients.

I was at the Auckland leg of that tour, but the speaker spent a lot of time talking about Clarus, and skimmed over SITA Faster only very briefly. Other than the important point that GPA works right through the 24/2 Std/Fast/Faster range of tests, he didn't give much information. Your lecture was far more informative.

I suppose what I was getting is whether there is a reason to do SITA Fast once you have SITA Faster available? Your lecture suggests the validity is equivalent.

It would be great if you could offer your clinical impressions once you have the software upgrade.