Thank you Elaine. Can we delve deeper on this issue. I have patients coming for HBOT who have diabetic retinopathy, proliferative, age related (wet) macular degeneration, glaucoma, some on Eylea, and I wanted to know if you feel that HBOT will worsen, neutral or help their conditions. When I read articles, there is indication that HBO can help diabetic macular edema by reducing the leakage (improving the blood-retina barrier), thickness of macular (vasoconstriction effect). There is one article for helping macular degeneration (dry) but then one indicating that maybe HBO will increase the VEGF in the eye and make proliferative disorders worse. Then one article mentions that HBO might reduce VEGF in the retina, and no evidence of increasing the VEGF in the vitreous has been found. Then two articles of the retina micro hemorrhages happening with HBO.
Not sure about glaucoma as HBO might increase the pressure in the anterior chamber but reduce it in the vitreous. Then the positive effect of increase oxygen transmission across the retina but the oxygen radicals could damage the retina. And should people undergoing HBO take oral anti oxidants.

Dr. Jacques,

You raise some very interesting questions. The answers to those questions are not entirely clear cut. I would second Elaine's answer to your original question and will try to add my perspective as well.

With respect to cataracts, I would point you to the UHMS Indications Manual 15th ed. Pages 365 and 366 discuss ocular complication including myopia, cataracts, and retinopathy of prematurity. In essence, at the number of treatment typically used in clinical hyperbaric medicine, new cataracts should not form. It is possible for pre-existing cataracts to worsen, and patients should be told about this possible HBO side effect.

With respect to Glaucoma, multiple studies from the diving literature and HBO literature indicate that intraocular pressure is reduced with increased ambient pressure (HBO chamber or diving). A meta-analysis from 2024 (https://doi.org/10.3389/fmed.2024.1365259) agrees with this.

With respect to macular degeneration and those on anti-VEGF meds, an very interesting Ukranian study from 2022 (https://doi.org/10.3389/fmed.2024.1365259) compared outcomes in patients with diabetic macular edema who were treated with Eylea or Eylea and adjunctive HBO.  The group treated with Eylea and adjunctive HBO showed greater improvements in in visual acuity and and more profound decrease in retinal thickness than the group treated with Eylea alone.

Finally, with respect to taking prophylactic anti-oxidants with HBO. Some HBO practioners will give patients Vitamin E as a anti-oxidative measure. Some people believe this MAY help decrease the risk of oxygen toxicity seizures. One expert opinion review (https://www.sciencedirect.com/science/article/pii/S188842961730050X) indicated that anti-oxidants should be considered in at risk patients. 

I have also included a wonderful review article from 2024 that address many of the points you raise (https://www.mdpi.com/2077-0383/13/1/29). I hope this helps to answer some of your questions.

Mike White 

Thank you Mike. The article on IOP reductions answers the concerns for patients with glaucoma. The reference you gave for the Ukrainian study is the same one as for the IOP. Could you see and send it again. This one is useful for alleviating concerns for patients on VEGF. There seems to be support for HBO to treat diabetic macular edema. I am not an eye expert, and still need to review the differences between, diabetic macular edema, diabetic retinopathy, non proliferative and proliferative and age related macular degeneration, wet and dry. And separately, if they have aneurysms, hemorrhages in the retina...
I have read the last two, and found the last one very good.
I did find two articles that indicate that HBO is safe after refractive cornea surgery, RF, Lasik, small studies, patients were at least one year post surgery.

My apologies, here is the link to the Ukrainian study:

https://www.ozhurnal.com/sites/default/files/en2022-4-3.pdf

thank you again Mike. Of note, they received 10 sessions of 95%O2 at 1.4 atmospheres for 45 minutes. Do you know if the "1.4 atmospheres" is atm gauge and hence equivalent to 2.4 ATA or meant to say 1.4 ATA? Any reasons for shorter time sessions.