Temporary Blindness

[aviayu]

If y'all will indulge me for a minute, I'd like to summarize what we have so far, along with the short version of some consultations:

A healthy 50 year old male with no significant past medical history makes a dive, breathing gas unknown but presumed to be air or nitrox. He reports no difficulty equalizing his ears or sinuses, and equalizes via the Toynbee (pinch and swallow) maneuver vs. the Valsalva maneuver. On descent he noticed decreased vision in his right eye but assumed it to be related to mask fogging and continued his descent. At 22 meters (72 FSW) he reported complete loss of vision in the right eye. He continued his descent, and at a depth of 26 meters (85 FSW) he reported a complete loss of vision.
He immediately made a controlled ascent with the assistance of the dive guide, and reported an improvement of vision at a depth of 7-8 meters (23-26 FSW) with complete resolution of symptoms upon reaching the surface. At the surface, it was noted that his eyes were red and the area around his eyes was swollen. There was a small amount of blood around the seal of the mask. The divemaster on the boat diagnosed mask squeeze, but the diver and his buddy are not sure, as they have seen severe mask squeeze and that diver's appearance was different. Exact description of the appearance of his eyes is lacking, and there are no photographs.
Complete exam by an ophthalmologist an unknown time after the dive reveals no abnormalities. Intraocular pressures are normal, and a fundoscopic exam of the retinas is unremarkable.

DocV and Cutlass, does this sound pretty accurate to y'all?

What we've already pretty much ruled out:
1. O2 toxicity.
2. Open angle glaucoma, narrow angle glaucoma, normal pressure glaucoma, and bad glaucomb-over.
3. Acute retinal detachment.

So far, I've spoken with two of our attendings, Dr. Jake Freiberger and Dr. Richard Moon; chief DAN medic Dan Nord; and CAPT Frank Butler, USN (RET) CAPT Butler is a well-known Navy diving medical officer with a specialty in ophthalmology. Here are the opinions:

Before hearing the results of the ophthalmology visit, Dr. Freiberger believed this was a mask squeeze, worrisome for possible glaucoma aggravation.

Dr. Moon believes it's a mask squeeze complicated by sinus squeeze and retinal ischemia, but worrisome for non-diving-related CNS causes like embolic shower to the optic center.

Dan Nord said it sounds like a mask squeeze/sinus squeeze.

CAPT Butler believes the blood in the mask is key, and that this is barotrauma of the sphenoid sinus, probably complicated by mask squeeze. His rationale is that the sphenoid sinus is immediately adjacent to the optic chiasm and there are other case reports of peripheral neuritis related to barotrauma, though none like this. He sent me an image, which is attached. The sphenoid sinus is labeled SpS, and the optic canals are noted.

None of the practitioners I consulted with had heard of a similar case.

Recommendations:
Dr. Freiberger: follow up with an ophthalmologist; already completed.

Dr. Moon: Follow up with a neurologist to rule out non-diving-related neurological causes.

CAPT Butler: See if the ophthalmologist or another practitioner will order a CT scan of the sinuses. Depending on how far out from the injury the CT is performed, it may show residual blood/fluid in the sphenoid sinus and would probably be diagnostic in that case.

Questions that remain: Aviayu, what day did you make the dive, and how long after the dive did you see the ophthalmologist? Can you verify again that you have had no acute or chronic sinus problems, perhaps allergies, a cold, or infection? Are you a smoker? Finally, if it's been a short enough time since the dive (less than a week or so), would it be possible for you to get a CT scan of your sinuses?

This is a fascinating case. Aviayu, I think we'd all like to see this through to a conclusion and I know all the practitioners here will help in any way possible.

Clear and add some thing:

No blood came out at seal of mask, there were some blood patch on contacting part with mask on the face.
My nose always come out of blood when i dived over about 20m depth.
I usually dive at warm water area and normally take 3mm wetsuit or no wetsuit. Even i wore 7mm wetsuit with hood , i did still feel cold at that my accident dive.

For your question:
I dived in Paihia of New ZeaLand in January,2011. I just saw the ophthalmologist 3 days ago.
Yes, i have had no acute or chronic sinus problems, allergies, a cold, or infection, but i may need to double check if i have chronic sinus problems.I do not smoke.
That happened in my first dive in Paihia, at 2 hours later i did a second dive to 18m deep and no problem. I felt too uncomfortable on eyes, so i cancelled my second day's dive.
I will consider to get a CT scan of my sinuses.

 

[Kiwi303]

Your nose bleeds every time you dive (rec) deep? I would leave it to the docs to comment but as a layman, I would be suspecting something is odd in your PERSONAL physiology. Given all the comments, a CT scan to determine your innards arrangement sounds on the cards to me.

 

[Duke Dive Medicine]

Clear and add some thing:

No blood came out at seal of mask, there were some blood patch on contacting part with mask on the face.
My nose always come out of blood when i dived over about 20m depth.
I usually dive at warm water area and normally take 3mm wetsuit or no wetsuit. Even i wore 7mm wetsuit with hood , i did still feel cold at that my accident dive.

I think that being cold on the dive, while uncomfortable, probably didn't have anything to do with your symptoms. Bleeding from the nose every time you dive below about 20m, though, is more evidence for some kind of chronic sinus problem. A physician who is an ear/nose/throat specialist should be able to help you and will hopefully recommend a CT scan.

For your question:
I dived in Paihia of New ZeaLand in January,2011. I just saw the ophthalmologist 3 days ago.
Yes, i have had no acute or chronic sinus problems, allergies, a cold, or infection, but i may need to double check if i have chronic sinus problems.I do not smoke.
That happened in my first dive in Paihia, at 2 hours later i did a second dive to 18m deep and no problem. I felt too uncomfortable on eyes, so i cancelled my second day's dive.
I will consider to get a CT scan of my sinuses.

You mentioned that your vision returned to normal after you reached the surface. Were there any residual deficits at all, or was it completely normal? Did you have any vision problems later that day, or at any time after the dive?

 

[aviayu]

I think that being cold on the dive, while uncomfortable, probably didn't have anything to do with your symptoms. Bleeding from the nose every time you dive below about 20m, though, is more evidence for some kind of chronic sinus problem. A physician who is an ear/nose/throat specialist should be able to help you and will hopefully recommend a CT scan.



You mentioned that your vision returned to normal after you reached the surface. Were there any residual deficits at all, or was it completely normal? Did you have any vision problems later that day, or at any time after the dive?

I know i need to see the doctor on my nose, but i would like to know the chronic sinus problem can really cause the serious problem like my case, i saw the article " Neurological Consequences of Scuba Diving with Chronic Sinusitis" , my symptom was quite different than the cases in the article.

No any residual deficits left at all after that happened and feel completely normal. Also my vision did not feel any different than before.

I only did one dive after that accident dive, that was happened just 2 hours later than that accident dive and met with no problem.

 

[Duke Dive Medicine]

I know i need to see the doctor on my nose, but i would like to know the chronic sinus problem can really cause the serious problem like my case, i saw the article " Neurological Consequences of Scuba Diving with Chronic Sinusitis" , my symptom was quite different than the cases in the article.

No any residual deficits left at all after that happened and feel completely normal. Also my vision did not feel any different than before.

I only did one dive after that accident dive, that was happened just 2 hours later than that accident dive and met with no problem.

Aviayu,

What we have done so far is to analyze your dive profile, your symptoms and their time of onset and formulate what we call a "presumptive diagnosis", which means that based on all the information you've given, this is what we think happened.

Though nobody I've spoken with so far has heard of blindness related to sinus squeeze, facial baroparesis is a well-documented phenomenon. It happens when excess pressure in the middle ear causes impingement on the facial nerve. So, we know that nerves that are located next to air-filled spaces in the body can be affected by changes in the air pressure inside those spaces.

http://archive.rubicon-foundation.org/dspace/bitstream/123456789/3018/1/4082348.pdf

http://archive.rubicon-foundation.org/dspace/bitstream/123456789/3094/1/3307083.pdf

Your symptoms were different than those of the diver in the case report I sent to you, but his blindness was thought to be related to excess pressure inside his sinus impinging on the retinal artery.

I spoke with another of our attending physicians, Dr. Bret Stolp, this morning. He also thinks that your blindness symptoms were related to sinus barotrauma, but may also have been from retinal ischemia from mask squeeze. If you have a CT scan and it does not show any chronic sinus problems, this may be the answer.

Another question came up in conversation with doctormike, a Scubaboard member who is an ENT physician. May I ask, do you have chronic nosebleeds, or does your nose only bleed when you dive deeper than about 20 meters?

 

[doctormike]

I spoke with another of our attending physicians, Dr. Brett Stolp, this morning. He also thinks that your blindness symptoms were related to sinus barotrauma, but may also have been from retinal ischemia from mask squeeze. If you have a CT scan and it does not show any chronic sinus problems, this may be the answer.

What a fascinating case, and DDM has done a terrific job of summarizing and sorting the data, as well as managing the consultations! I know that I am late to this thread, but I just though that I would throw in my thoughts for whatever it is worth.

The red eyes are important, since it is the one piece of objective data that we have at this point, and it does suggest a real barophenomenon (is that a word?).

Ophtalmological complications of sinusitis are usually infectious, with a cellulitis (soft tissue infection) or abscess forming in the space around the eye due to communication between the ethmoid sinuses (the ones at the root of the nose between the eyes) and this area. Interestingly, these are less common in patients with chronic sinusitis - the theory is that the valveless communicating veins between the sinuses and the orbits get scarred with ongoing inflammation. The same thing has been observed with things like brain abscesses following infections in the frontal sinuses (the ones in the forehead).

If you had a break or hole in the lamina paprycea (the wall between the ethmoid sinuses and the orbit), you might get transient increase in intraorbital pressure or even a hematoma (collection of blood), although I wouldn't think that the latter would improve with ascent. I haven't heard of this before, but I do see that paper from the Laryngoscope. However, they do not really explore the ophthalmological implications of the one diver who had blindness, since it is just a case report and the patient's complication after sinus surgery involved inner ear pathology (which really has nothing to do with the sinuses, I believe). I'm not sure what the relationship of his mucocele would be to the orbits, I would need to see that scan, which the authors do not provide.

I don't know much about retinal ischemia, but I do know that visual loss is a fairly late sign in periorbital abscess. The eye can tolerate a lot of proptosis (being pushed forward) before this happens. The visual changes could be due to retinal blood flow problems with increased intraorbital pressure, or due to stretching of the nerves due to proptosis. On the other hand, in cases of abscess, that happens over days and not minutes, so perhaps visual loss would be more likely with a dive accident. I would defer to the ophthalmologists on this one, I'm a bit out of my depth here. My job is usually to just drain the sinus abscess and hope that the eyes get better with decompression…!

I think that Captain Butler may be on to something there... the transient nature of the blindness and it's response to ambient pressure is key. The optic nerves could be exposed if the bony wall covering them was dehiscient (missing) - something that we seen with the facial nerve in the ear which can cause a facial paralysis. On the other hand, the theory that this was caused by pressure related changes in the blood flow to the retina due to a mask squeeze makes sense as well. A CT scan would be very helpful in this situation.

Finally, I suppose there could be some sort of transient neurological condition, such as a TIA, perhaps associated with an underlying intracranial abnormality, given the transient and pressure related aspects of the case. An embolic shower would be less likely to have those reversible aspects, IMHO, but then again, I am not a neurologist..!

I guess the best test to rule out an anatomical problem in the central nervous system would be a brain MRI. The sinus CT scan could be expanded to include the brain, but things can be missed on CT, especially if no contrast is used (as would be the case for a sinus CT).

However, I really think that this is more likely to be an ophthalmological problem (along the lines of Dr. Stolp's last conclusion) rather than a neurological one.

Mike

 

[aviayu]

Aviayu,

What we have done so far is to analyze your dive profile, your symptoms and their time of onset and formulate what we call a "presumptive diagnosis", which means that based on all the information you've given, this is what we think happened.

Though nobody I've spoken with so far has heard of blindness related to sinus squeeze, facial baroparesis is a well-documented phenomenon. It happens when excess pressure in the middle ear causes impingement on the facial nerve. So, we know that nerves that are located next to air-filled spaces in the body can be affected by changes in the air pressure inside those spaces.

http://archive.rubicon-foundation.org/dspace/bitstream/123456789/3018/1/4082348.pdf

http://archive.rubicon-foundation.org/dspace/bitstream/123456789/3094/1/3307083.pdf

Your symptoms were different than those of the diver in the case report I sent to you, but his blindness was thought to be related to excess pressure inside his sinus impinging on the retinal artery.
==
I spoke with another of our attending physicians, Dr. Bret Stolp, this morning. He also thinks that your blindness symptoms were related to sinus barotrauma, but may also have been from retinal ischemia from mask squeeze. If you have a CT scan and it does not show any chronic sinus problems, this may be the answer.
*
Another question came up in conversation with doctormike, a Scubaboard member who is an ENT physician. May I ask, do you have chronic nosebleeds, or does your nose only bleed when you dive deeper than about 20 meters?

i have e-mailed some my exam. results to you, kindly give me your opinion on it. my ophthalmologist's analysis based on that results i sent to you is i have retina arteriosclerosis . what do you think? That may cause the trouble?

i am arranging to see the ENT doctor, just suppose no serious problem on my nose (because i do not think my nose has a serious trouble), that means the retinal ischemia from mask squeeze caused the accident(i do think so), also i already saw two ophthalmologist (they do not know much about dive), both said the retinal ischemia should be the reason causing the temporary blindness theoretically, but why million of divers in the world come out no more temporary blindness report based on retinal ischemia, that is what i am wondering about.

Up to now, no nose bleedding in my daily life or when i do other exercises. My nose only bleed when i dive deeper than about 20 meters.

 

[cutlass]

This case report differs in history and presentation, but the mechanism appears to be in the ballpark; viz., pressure on the optic nerve from an irregularity in the sphenoid. I

In the Discussion, mention is made of the possible detection benefits of thin-slice CT over the then more common (in 1998) 3mm slices. That appears to have changed since. In traumatic vision loss with afferent pupillary defects, we'll typically look for thin-section CT of the orbit and optic canal. For suspected orbital floor fractures, coronal or sagittal views are typical and work well even with significant soft-tissue swelling.

 

[Duke Dive Medicine]

This case report differs in history and presentation, but the mechanism appears to be in the ballpark; viz., pressure on the optic nerve from an irregularity in the sphenoid. I

In the Discussion, mention is made of the possible detection benefits of thin-slice CT over the then more common (in 1998) 3mm slices. That appears to have changed since. In traumatic vision loss with afferent pupillary defects, we'll typically look for thin-section CT of the orbit and optic canal. For suspected orbital floor fractures, coronal or sagittal views are typical and work well even with significant soft-tissue swelling.

Nice pull. This is a great reference.