Normal Tension Glaucoma

[flint]

Why is Normal Tension Glaucoma (NTG) "Not Acceptable"?

FAA Glaucoma Worksheet- "NOT acceptable: Normal Tension Glaucoma, secondary glaucoma due to inflammation, trauma, or the presence of any other significant eye patholog..."

I had a traumatic eye injury with an IOL lens implant due to traumatic cataract over 20 years ago, which was all reported on my FAA medicals. I maintained a 1st class afterwards for a few years before I stopped flying. Vision has slowly diminished to 20/200ish in that eye and now appears stable. I have 20/20 in the good eye. I know that at the very least, I will need to apply for a SODA.

5 years ago, extensive testing was performed and everything was negative. Doctors statement was "I favor low-tension glaucoma superimposed on previous trauma". IMO, this was a theory based on "exclusion". My pressures always test in the 10 to 14 range without using any medicated drops (both eyes). My most recent eye exam with a different O.D. said that both eyes look healthy except that 1 optic nerve is very pale, and in his opinion, it is not glaucoma (pressure 10).

Anybody have any opinions? Which direction to go to satisfy the FAA? Is it better to go back for a NTG diagnosis, or try to link it back to the 20 year old (previously reported) injury. Is it a lost cause either way? I am sure the FAA needs some official diagnosis for the vision loss. I thought NTG would be a good diagnosis until I saw "Not Acceptable" on FAA Glaucoma Worksheet.

 

[benw571]

Why is Normal Tension Glaucoma (NTG) "Not Acceptable"?

FAA Glaucoma Worksheet- "NOT acceptable: Normal Tension Glaucoma, secondary glaucoma due to inflammation, trauma, or the presence of any other significant eye patholog..."

I had a traumatic eye injury with an IOL lens implant due to traumatic cataract over 20 years ago, which was all reported on my FAA medicals. I maintained a 1st class afterwards for a few years before I stopped flying. Vision has slowly diminished to 20/200ish in that eye and now appears stable. I have 20/20 in the good eye. I know that at the very least, I will need to apply for a SODA.

5 years ago, extensive testing was performed and everything was negative. Doctors statement was "I favor low-tension glaucoma superimposed on previous trauma". IMO, this was a theory based on "exclusion". My pressures always test in the 10 to 14 range without using any medicated drops (both eyes). My most recent eye exam with a different O.D. said that both eyes look healthy except that 1 optic nerve is very pale, and in his opinion, it is not glaucoma (pressure 10).

Anybody have any opinions? Which direction to go to satisfy the FAA? Is it better to go back for a NTG diagnosis, or try to link it back to the 20 year old (previously reported) injury. Is it a lost cause either way? I am sure the FAA needs some official diagnosis for the vision loss. I thought NTG would be a good diagnosis until I saw "Not Acceptable" on FAA Glaucoma Worksheet.

Hopefully one of the docs will be by shorty to give you some guidance on this

 

[flyingron]

"normal tension" means your pressures are normal. You're going to have to ask your doctor why he decided to do that. Normally it meant that either you had visible optic nerve damage or a problem with your measured visual fields. It's not acceptable on the normal issuance glaucoma guidelines because it indicates that there's some pathology of the eye other than the normal open angle glaucoma. You'll have to go through a SI, but you'd have to do that anyhow because you don't have normal binocular vision. I suspect you're going to need a full opthomologic workup on both eyes and humphreys visual fields at the minimum.

 

[flint]

You'll have to go through a SI, but you'd have to do that anyhow because you don't have normal binocular vision.

Thank You for the guidance. If the FAA grants a SI in my situation, I assume it will be for student pilot privileges until I pass the SODA flight review. How many months will the temporary medical be issued for?

 

[bbchien]

Thank You for the guidance. If the FAA grants a SI in my situation, I assume it will be for student pilot privileges until I pass the SODA flight review. How many months will the temporary medical be issued for?

it is issued “valid only for medical flight test”.

Seriously you meed to stop being inexpensive (CHEAP) heck it’s your EYES, and get to a board certified Ophthalmologist for current status. You have asked an Optometrist(who is like a COM pilot) to answer an ATP question! With the right report and Humphrey VF, this might be fully issuable in the AME office.

 

[flint]

Seriously you meed to stop being inexpensive (CHEAP) heck it’s your EYES, and get to a board certified Ophthalmologist for current status.... With the right report and Humphrey VF, this might be fully issuable in the AME office.

Thank you, I appreciate your candidness. I know its time to repeat the full round of specialists and testing previously performed. Possible NTG is not my only issue, but searches have answered many of my other questions. I asked because NTG is the topic I can't seem to find much discussion about, relating to FAA medicals. I think I have a good picture of it now. I am drafting up my next 2 year plans & goals. I am budgeting time and finances for this endeavor. I am assessing if this is a reasonable goal to obtain over the next 2 years.

The forum has taught me not to make the mistake of trying to tackle the medical cert alone. When I have everything in order, I can only hope that you (Dr. Bruce) will be able to review my case and consider taking me on as a client.

it is issued “valid only for medical flight test”.

I still do have 1 question. How long from the issuance of the medical "valid only for medical test flight" until expiration?

 

[Chaperral]

Agree you need to see an ophthalmologist, either neuro or glaucoma specialist. Low tension glaucoma seldom or never occurs in one eye. It's a bilateral disease, maybe worse in one eye, but never in one eye. Something else is going on for sure, hopefully only in the "bad" eye.,

 

[flyingron]

NTG doesn't imply a specific pathology, which is why it's an issue. The FAA is going to want to know what is really going on. Some of the things that present as NTG can be spontaneously debilitating, for example.

 

[flint]

Agree you need to see an ophthalmologist, either neuro or glaucoma specialist. Low tension glaucoma seldom or never occurs in one eye. It's a bilateral disease, maybe worse in one eye, but never in one eye. Something else is going on for sure, hopefully only in the "bad" eye.,

I will start setting up appointments with the specialists.

I was examined by a top neuro-ophthalmologist, retna specialist, & glaucoma specialist. Extensive testing was performed including MRI, full cardio, nutrition check, infectious diseases, & full blood work. The explanation was: everything else was excluded, so favoring NTG as cause of optic neuropathy. All of this was 5 years ago. To date, annual O.D. eye exams have shown no change in acuity, normal field of vision, and normal optic nerve imagery in the good eye.

 

[flint]

NTG doesn't imply a specific pathology, which is why it's an issue. The FAA is going to want to know what is really going on. Some of the things that present as NTG can be spontaneously debilitating, for example.

That makes sense. I will make appointments with specialists for a current evaluation. Hopefully this time they will be able to pinpoint a specific pathology acceptable to the FAA.

I am curious though, if glaucoma is a specific pathology, isn't NTG a pathology too? After all, its proven that certain ethnic groups just happen to get glaucoma at lower pressures without any additional underlying cause.

I have only had minor eye pain dx as dry-eye, and the vision loss has been slowly progressive over decades, which started after the non-impact, penetrating injury & IOL surgery. Since the vision loss has been so slow, I don't even notice it until I get an eye exam because of 20/20 in good eye and vision cues from the bad eye.

 

[flyingron]

The one the glaucoma worksheet covers (which allows the AME to make an on-the-spot) approval is a specific form of glaucoma that the FAA has evaluated and set up criteria for. It's pretty much a restriction in the fluid drainage from the eye that if left untreated can damage the optic nerve. It's very slow progerssing and gives a lot of time at the intervals medicals are good for to reevaluate.

NTG is a broad category of glaucoma things and it could be that you have normal drainage most of the time and it suddenly blocks. This can cause severe nausea or pain, vomiting, loss of vision, etc... So the FAA is going to want to know just what you have going on when you've got a NTG diagnosis. It's like saying you have a "heart problem" without any further explanation rather than saying you have well-treated hypertension.

 

[flint]

The one the glaucoma worksheet covers (which allows the AME to make an on-the-spot) approval is a specific form of glaucoma that the FAA has evaluated and set up criteria for. It's pretty much a restriction in the fluid drainage from the eye that if left untreated can damage the optic nerve. It's very slow progerssing and gives a lot of time at the intervals medicals are good for to reevaluate.

NTG is a broad category of glaucoma things and it could be that you have normal drainage most of the time and it suddenly blocks. This can cause severe nausea or pain, vomiting, loss of vision, etc... So the FAA is going to want to know just what you have going on when you've got a NTG diagnosis. It's like saying you have a "heart problem" without any further explanation rather than saying you have well-treated hypertension.

Excellent explanation. Thank you. So, am I understanding correctly that NTG is more a symptom than a diagnosis?

 

[flyingron]

Well, technically it's a diagnosis, but it's just not a very specific one.

 

[Chaperral]

NTG is a specific diagnosis that requires treatment. It is a diagnosis of exclusion, meaning a lot of other possible causes need to be ruled out. I am surprised that a neuro ophthalmologist or glaucoma specialist would give you that diagnosis without treating it. The treatment is just like any glaucoma, lowering the pressure(to below normal) even though the pressure is normal. Like previously suggested, there are many other types of glaucoma, but all need treated once one determines the type. There are also neurological and vascular diseases that can masquade as unilateral glaucoma. I would revisit your neurophthalmologist and/or glaucoma specialist.They might not be able to determine the cause, but they should not use the term NTG if they cannot determine the etiology.

 

[flyingron]

The manner of treating NTG depends on the pathology. It doesn't indicate a specific pathology only that the pressure is not elevated outside the normal range. The treatment can be anything from beta blockers to surgery of some sort. I agree that the diagnosis looked kind of weak. It would help if there was some indication of why they guessed NTG. Was their indications on the optic nerve? Loss of visual field? Signs of outflow disfunction? what.

 

[flint]

If you have a perfect Humphrey visual field in the “standards” eye, ...... the REAL deal Humphrey 24-2 visual fields, each eye separately).

Is there any possibility of an SI if the "standards" eye is not perfect? I ordered all my old records and have been looking over the Humphrey visual fields. 1 test indicated "outside of normal limits", and later test said "within normal limits", but Doc's handwritten note said "better, but still possible nasal step" . I have an appointment in January to get a current evaluation.