Hyperbaric Oxygen Treatment for KC

[Matthew_]

A very kind colleague has passed a document to me. It was penned by a Professor Giacomo, an Opthamologist at "La Sapienza" University of Rome. The paper discusses the treatment of KC in Hyperbaric units that is, a compression chamber using O2. Throughout my diving career, I have been told that oxygen is the cure to most ills and I am inclined to agree. Pure oxygen, breathed at depth (but not too much) assists rapid tissue regeneration. In this case, oxygen has been administered at pressure to assist in tissue preparation prior to a graft, with the unexpected result that the cornea was partly flattened by the treatment as well as the expected result that epithelium loss was stemmed.VA was increased from 1/10 to 4/10 (is that good?). Over a period of treatment (several years), the original patient's VA improved by 6 dioptres (now that is good). Another 23 patients have been treated since all with significant flattening of the cornea and consequent improvement in eye sight.
I have some more stuff about why the treatment is reported to work and I will post this later tonight. But in the meanwhile, has anyone else heard of this?

[Asif]

1/10 is equivalent to 6/60 (top letter), and 4/10 is 6/15. 6/6 - 6/5 are considered normal for most people. I have never come across what you just mentioned but would be very interested in any arcticles/docs/info you have on this. I will pm you my email address

[Hari Navarro]

I'm just on my way out but I did a quick check and found this study... but this particular study speaks to refractive changes following hyperbaric treatment...

Refractive change during hyperbaric oxygen therapy. A clinical trial including ultrasound oculometry.
Acta Ophthalmologica Scandinavica. 80(2):188-190, April 2002.
Fledelius, Hans C. 1; Jansen, Erik C. 2; Thorn, Jens 3

Abstract:
Purpose: To record changes in refraction and refractive parameters associated with a standard hyperbaric oxygen treatment protocol consisting of a 95 min session at > 95% oxygen at 2.5 atmospheres (ATA) given daily Monday to Friday, to a total of 30 sessions.

Patients and methods: Seventeen of the 26 patients included were able to attend for ophthalmic assessment at time zero (to) and after 20 treatments (t20). Thirteen patients also had a post-treatment follow-up. Most patients were being treated for osteoradionecrosis after radiotherapy of ENT cancers, and drop-outs for the eye exam were common. Refraction was determined subjectively and by refractometry, before and after tropicamide 1% eyedrops. Refractive parameters were assessed by keratometry and by A-scan axial ultrasound measurement.

Results: Results are given for the 17 patients with to and t20 assessments. The induced refractive change ranged from 0 to 1.5 D. When observed, refractive changes were myopic in nature. The shift averaged 0.58 D according to the refractometer and 0.49 D as subjectively assessed, with corresponding median change values being 0.62 and 0.39 D. The differences between 0 D and these values, although small, were statistically highly significant.

Conclusions: The refractive changes associated with hyperbaric oxygen therapy were smaller than the literature had led us to expect. No significant change in axial eye length measurements was found, and keratometry readings reflected only minimal change, although this was statistically significant on a 0.05 level. Therefore it is most likely that lens changes, whether in internal refractive indices or curvatures, accounted for the transitory shift towards more myopic/less hyperopic values.

Hari

[Matthew_]

Well there you are...

I got the good Professore's name wrong, he is Prof Giacomo Modugno.

In our opinion, this is a disorder that feeds upon itself. It causes a weakening of the internal limiting factor and the Descemet membrane which yields to normal intraocular pressure. The corneal parenchyma is squeezed against the epithelium, the internal stromal pressure starts to increase and so it slows the metabolic exchanges in a tissues that lacks vessels already. Because of the significant edema, hypoxia appears; that is followed by the necrosis and connectivisation of the corneal stroma and its thickening and consequent loss of transparency because of the disorder in the disposition of the corneal cells.
At this point, a vicious cycle has taken hold with an ever increasing vitiation and the results that we have all had occasion to see in the course of our professional lives.
HBO therapy breaks this chain: it reaches the diseased corneal tissue through perfusion (in avascular tissue its diffusion increases 12-14 times, while in vascularised tissue it increases only 3-4 times); its oxidative activity compensates for the cellular repiratory insuffinciency, reduces the edema (through vascoconstriction) and by stimulating ATP production, activates reparative and healing processes, releasing them from any nervous and/or hormonal stimulation."

I now also know that this procedure is being trialled in the UK at Hyperbaric Medicine Units. I intend to look deeper into this; I will let you all know what I discover.

[Matthew_]

Hari,
Unless I am mistaken, the study you have quoted was not for KC per se but myopia. Am I right or did I miss something (wouldn't be the first time! )

[Hari Navarro]

Hi Matthew,
No I think you are right... its not at all specific to keratoconus. The only link is the use of Hyperbaric O2 treatment in association with eye treatment (It was just something I came across after a quick internet search ). By the way I have sent a few inquires about the procedure to Rome, hope to hear something soon.

Regards,
Hari

[Hari Navarro]

Hi Matthew,
I have had a couple of replies from people in Rome who know directly of this doctor and his work. Lets just say that going by what they said I would investigate 'fully' this option before proceeding. Obviously no snap judgement can be made by just two replies... and of course it is always very interesting to review novel approuches to KC treatment. The more information we have the better.

Hari

[Matthew_]

Right-oh! I am still investigating, I will proceed with caution. However, O2 never really hurt anyone apart from pulmonary and cerebral oxygen toxicity! Sorry, being flippant but O2 is toxic at pressure but this would be very carefully monitored in a Hyperbaric unit. There is no long term damage that could be done, there really is no harm in trying unless I set my hopes on it curing my KC which would be foolish. I will let you all know how it goes.
Interestingly enough, when I was diving O2 and O2 rich mixes at roughly the pressure outlined in the document, I never had KC. When I stoped diving these mixes because I was doing a management job, I developed the KC. This could be a complete coincidence.