Hyperbaric Chamber and Its Ophthalmic Applications

Introduction Hyperbaric Oxygen therapy (HBOT) has been used for centuries by physicians and surgeons but only recently, it has been used to treat ophthalmic disorders. Treatment of ophthalmic disorders is an off label use of hyperbaric oxygen therapy. Having been tried in a large number of animal experiments and clinical trials, the HBOT is now gaining acceptance by the medical fraternity and is being utilised for a variety of systemic and ocular diseases. This form of therapy is given in a device called Hyperbaric chamber. Hyperbaric oxygen therapy has been defined by Committee on hyperbaric medicine, Undersea and Hyperbaric Medicine Society, as breathing 100% oxygen at a pressure greater than one atmosphere absolute(ATA).1 The concept of breathing oxygen under pressure is old, as, in 1662, Henshaw a British clergyman, used organ bellows to change the atmospheric pressure in a sealed chamber called the Domiciliumin, in which both hyperbaric and hypobaric environments could be created. He used it for promoting good health and for treating diseases.2 Almost two centuries later, hyperbaric therapy was revived in France by a French physicians Junod (1834) and later by Pravaz (1837) to treat pulmonary and a variety of other diseases. In 1879, Fontaine performed surgeries in a pressurised mobile operating room.3 However, HBOT use was not substantiated by any evidence or scientific proof. In 1860, it was introduced in North America by Dr Orville J Cunningham who started treating Spanish Influenza cases in the hyperbaric chamber. In 1928, he built a five story high steel sphere, 68 feet in diameter with 12 bedrooms containing all amenities of a good hotel. A variety of diseases were treated in this “hotel” but was dismantled in 1937 lack due to lack of scientific evidence for the use of hyperbaric oxygen therapy.4 In 1930s, the US navy began using hyperbaric oxygen therapy for treating decompression sickness. The biggest boost to using hyperbaric oxygen therapy came from Netherlands with Boerema’s work on animals which was so successful that a large operating hyperbaric chamber was built in Amsterdam to conduct complicated heart and lung surgeries. Boerema and his team successfully treated clostridial myonecrosis and severe anemia in pigs.5 Another luminary who contributed immensely in the uses of hyperbaric oxygen therapy is Richard A. Neubauer, who opened the Ocean Hyperbaric Neurologic center in Lauderdale by the Sea, for treating patients with central nervous system disorders. Hyperbaric oxygen therapy has been used for centuries but it has been accorded more scientific reasoning only recently. Ophthalmic applications of this therapy is an off label use of hyperbaric oxygen but results of its use in Central Retinal Artery Occlusion and many other devastating ocular infections is paving the way for increasing acceptability by ophthalmologists. Recent protocols of therapy are being enunciated and safer hyperbaric chambers are being manufactured to help patients and doctors use this hereto underutilised modality of treatment.