Where is Bob?
My doctor had given me a referral to see the specialist Ophthalmologist at Raigmore Hospital in Inverness and I attended this appointment on Thursday 27th June 2013.
This appointment started with seeing a nurse in the eye clinic who measured the pressure of each of my eyes. The pressure was “normal” and pretty much in the middle of the range for normal which is good. She then applied anaesthetic eye drops to dilate my pupils. My vision began to become blurry upon the application of the eye drops and after about 20 to 30 minutes my pupils were very expanded and the lights in the hospital seemed very bright. The dilation of the pupils was required to allow the Ophthalmologist a chance to have a really good examination of my eye.
In my previous blog post I mentioned that my doctor had “noted a patch of about 0.5mm x 1mm on the retina of my right eye that he thinks may be an indication of a haemorrhage having taken place but it could be an abnormality that I have had for years that I did not know about.”
During the examination this patch had disappeared and hence haemorrhaging of the retina had occurred and has now cleared up. In some cases of retinal haemorrhages there can be a permanent loss of part of an individual’s field of vision therefore there will be a follow up consultation to assess whether I have done any permanent damage to my eyesight during my attempt on Everest.
It is perhaps not surprising but Raigmore hospital does not often have patients who have suffered retinal haemorrhages from exposure to high altitudes. In fact I was the first patient that the Ophthalmologist had ever seen with this causation factor.
We had a good discussion about the signs and symptoms experienced at the time of the loss of vision in my right eye at 26,000 ft on Everest. I also showed her a series of pictures that were taken of my eyes at the time.
She diagnosed that I had suffered “High Altitude Retinopathy (HAR)”. Retinal haemorrhages are one of the things that happens in High Altitude Retinopathy.
I asked her about whether this could happen again and she gave me the answer that I expected which is that I am predisposed to this condition and that I am likely to have a similar loss of vision if I am exposed to the same causation factors again. The principal cause of High Altitude Retinopathy is hypoxia (lack of oxygen) and hence a different oxygen strategy could provide the solution to getting me to the top of Everest.
I asked the eye specialist about whether using more oxygen could get me up Everest without loss of vision and it seems like this option may be viable. She certainly did not say “No – don’t try again” therefore I got the outcome that I wanted from the consultation. I now know what has caused it.
Following the appointment my eye pupils were still high dilated and I was almost blinded as I left the hospital from the bright light outside – although Inverness was overcast and drizzly I could barely see as I walked back to the railway station. Anyone that I spoke with must have thought that I looked stoned due to the massive size of my pupils.
On the train home I could not read anything and just had to wait for my eye pupils to contract again. Upon arrival in Forsinard I could see well enough to finish the journey home in my car.
Now knowing of the condition High Altitude Retinopathy (HAR) I could research it a bit further at home. It is not a term that I was familiar with. I had not previously heard it mentioned in warnings about altitude travel or altitude medicine.
During my internet browsing I found several medical papers that discussed the condition. These papers needed careful reading to determine whether they were discussing comparable scenarios to the one in which I had experienced.
One study (e.g. Goswami B L. High altitude retinal haemorrhage. Indian J Ophthalmol 1984;32:321-4) showed that retinal haemorrhage occurs in about 5% of subjects staying at high altitude (less than 20,000 feet). Another paper (Ophthalmology. 1999 Oct; 106(10):1924-6; discussion 1927) mentioned that nineteen of 21 climbers in their study who had ascended above 25,000 feet developed HAR of varying severities.
Therefore the likely chance of retinal haemorrhage appearing is strongly related to the height. I had no issues with my vision on previous expeditions to over 20,000 feet such as on Denali and Aconcongua but until my attempt on Everest I had never been above 23,000 feet. From the literature searches it appears that there is a high incidence of retinal haemorrhaging occurring but many individuals are not aware of it as it did not significantly affect their vision at the time.
According to various papers (e.g. “The Eye in the Wilderness” in Wilderness Medicine (Auerbach, ed Mosby publ)) there appears to be a link between the incidence of retinal haemorrhages with symptoms of acute mountain sickness (AMS) but when I had my loss of vision I had no other signs or symptoms of AMS. Strangely I had no headache, had a great appetite and was feeling really good apart from having loss of vision in one eye. This paper went on to mention that “Although High Altitude Retinal Haemorrhages (HARH) are often not associated with acute visual symptoms, they may result in a loss of visual acuity or paracentral scotomas. There is a reported case in which further ascent after the development of HARH resulted in additional lesions. HARH that results in decreased visual acuity should be a contraindication to further ascent.”
Without knowing it we had heeded the advice of this paper and I had not ascended further. It is likely that my eyesight would have got worse. Loss of vision high up on Everest could lead to a fatal fall due to the difficulties in climbing and perhaps due to attaching oneself to an old deteriorated rope or simply moving so much slower that all of the supplementary oxygen is used up and severe exhaustion sets in. Severe exhaustion, due to lack of oxygen, has taken the lives of many Everest mountaineers as they have just sat down on the route and fallen asleep never to wake again.
The papers say that High Altitude Retinal Haemorrhages resolve themselves over a period of 2 to 8 weeks after the altitude exposure is terminated and my eyesight recovery seems to be compatible in with this information.
The literature indicates that high altitude hypoxia causes dilatation of retinal vessels, which increases the retinal blood flow, subsequently damaging the retinal vessels and increasing the capillary permeability leading to various grades of retinal haemorrhages. The haemorrhages tend to be flame shaped and blotchy scattered all over the base of the eye. These effects are more in subjects who have stayed for a longer period at high altitude. Most probably the continued hypoxic stress causes more damage to retinal capillaries. With an Everest expedition you spend prolonged periods at high altitude and are more likely to encounter this issue. As it is related to hypoxia, the use of higher flow oxygen should help to reduce the probability of occurrence.
The most recent scientific paper on this subject, June 2013, concluded “The pathophysiology of high-altitude retinopathy remains obscure, but it appears that the physiological limits of the vessels involved are exceeded, and factors other than hypoxia may be involved, such as physical exertion, coughing, and the Valsalva effect,” (Reference: JAMA. 2013;309(21):2210-2212. doi:10.1001/jama.2013.5550).
For me to make a future attempt on Everest, this recce has taught me that I need to try to reduce the hypoxia experienced by using a higher flow rate of oxygen above about 25,000 feet and hence I will need to have more cylinders of oxygen available for my use.
I can not do much about the physical exertion as I have to physically haul my body up the mountain but I can reduce the amount of weight that I am personally carrying by paying for personal Sherpa assistance. When my vision started to deteriorate on the way up to the camp at 26,000 feet I was load carrying (food, sleeping bag, camping mat, extra warm clothing, etc).
It was interesting that the recent study mentioned coughing as a possible causation factor. I had been suffering from the dreaded Khymbu cough for many weeks at the time of my summit bid. The Khymbu cough comes from the bronchi in the lungs being dried out in cold, mountain air. I will need to investigate to see if there are ways to prevent, or at least reduce the severity of, this horrible debilitating cough. The other person on the expedition with me who had had a similarly bad cough lost their vision in descent from the summit so there could be a link here.
The Valsalva effect is when you are trying to exhale against a closed airway, as when blowing up a balloon or holding one’s breath while lifting weights. I don’t recall having any issues with exhaling when I had my oxygen mask on but it always felt easier to breathe when I didn’t have it on. I wouldn’t rule this out as another causation factor in the loss of my vision on Everest.
The literature (Reference: Am Fam Physician. 1998 Apr 15;57(8):1907-1914) also suggests that maintaining a good fluid intake helps to reduce hemoconcentration and this can help resolve High Altitude Retinal Haemorrhages. Other literature states that the treatment for HAR is treatment with oxygen, steroids, diuretics and immediate descent. At the camp at 26,000 feet after the vision issue had started I had cranked up my oxygen to 4 litres per minute (from 2 litres per minutes), drank plenty of fluids and popped some dexamethasone (which is a steroid) incase of High Altitude Cerebral Oedema (HACE) and this combination probably explained the significant recovery that I had achieved by the morning.
I am keen to find a solution to the loss of vision in my right eye on Everest so that I can safely reattempt to achieve my third life goal.
Mont Blanc took me two attempts and with Everest being so much harder I would have been really lucky to have got to the summit on my first attempt. I consider my 2013 expedition to Everest as a really good recce of how my body copes at exceptionally extreme altitude and now I can learn from this experience to improve my chances of success next time.
I will now need to investigate the costs associated with increased oxygen available, use of a personal Sherpa and which side of the mountain to reattempt Everest from. Perhaps attempting Everest from the easier south side, despite the increased objective danger lower down the mountain in the Khymbu icefall, may be a better option due to less time above 8,000m.
If I lost my vision on the south side it is less difficult technically so there would be a better chance of getting down alive. One friend completely lost his vision at the base of the Hillary Step during his summit bid but was able to be helped down and started to regain vision as he approached the South Col.
I will also need to discuss with my doctor about the use of Dexamethasone or other steroids as a prophylactic drug to help prevent the occurrence of High Altitude Retinopathy. The down side of using it prophylactically is that it could mask the symptoms of the fatal condition of HACE but perhaps experience to date has shown that I have not been susceptible to it so the risk of the condition being masked may be minimal. There are no easy answers and no easy way to attempt Everest but I think that the possibility of achieving my third life goal is still a real possibility one day.
I take great encouragement in the fact that in one paper I read that it said “Several climbers who have had clinical cases of HACE or HAR have returned to summit 8,000m peaks” and I will follow their advice of “We suggest that climbers who have experienced significant retinal haemorrhaging in the past should use caution when considering a return to high altitude” (Reference: High Altitude Medicine & Biology, Volume 4, Number 4, 2003, Clinical Review of “Going to High Altitude with Preexisting Ocular Conditions”).
So the Everest Dream is still very much alive. I have had a really good recce, been much higher than I had ever been before, now know more about my body and can start planning for another attempt in a few more years time.
Chris Bonington didn’t get to the top of Everest until his fourth attempt so I shouldn’t feel too bad about having survived Everest intact and able to attempt it for a second time. Nine people died on Everest this year and I was glad not to have added to that statistic, which could have happened, had I pushed on towards the summit on the existing oxygen strategy.
The hard thing for me will be to find the money for another attempt and putting my family and friends through yet another worrying time but achieving your goals is never always straightforward. Keep trying to achieve your own dreams and keep following my adventures towards the top of the world !