Therefore, current guidelines for patients on mechanical ventilation in intensive care recommends keeping oxygen concentration less than 60%. Likewise, divers who undergo treatment of decompression sickness are at increased risk of oxygen toxicity as treatment entails exposure to long periods of oxygen breathing under hyperbaric conditions, in addition to any oxygen exposure during the dive. Ocular toxicity
Prolonged exposure to high inspired fractions of oxygen causes damage to the retina. Damage to the developing eye of infants exposed to high oxygen fraction at normal pressure has a different mechanism and effect from the eye damage experienced by adult divers under hyperbaric conditions. Hyperoxia may be a contributing factor for the disorder called retrolental fibroplasia or retinopathy of prematurity (ROP) in infants. In preterm infants, the retina is often not fully vascularised. Retinopathy of prematurity occurs when the development of the retinal vasculature is arrested and then proceeds abnormally. Associated with the growth of these new vessels is fibrous tissue (scar tissue) that may contract to cause retinal detachment. Supplemental oxygen exposure, while a risk factor, is not the main risk factor for development of this disease. Restricting supplemental oxygen use does not necessarily reduce the rate of retinopathy of prematurity, and may raise the risk of hypoxia-related systemic complications.Hyperoxic myopia has occurred in closed circuit oxygen rebreather divers with prolonged exposures. It also occurs frequently in those undergoing repeated hyperbaric oxygen therapy.
However, true psychogenic pain is considered to be rare. Some sources have assigned or categorized AFP as a psychosomatic manifestation of somatoform disorder, as defined in the Diagnostic and Statistical Manual of the American Psychiatric Association. Distinction should be made between somatoform disorder, where affected individuals are not inventing the symptom for some benefit, and other conditions like factitious disorder or malingering.Recent evidence in chronic facial pain research appear to suggest that a proportion of individuals who have been diagnosed with AFP have neuropathic pain,AFP is described as one of the 4 recognizable symptom complexes of chronic facial pain, along with burning mouth syndrome, temporomandibular joint dysfunction (TMD) and atypical odontalgia. However, there is a degree of overlap between the features of these diagnoses, e.g. between AFP and TMD and burning mouth syndrome. Atypical odontalgia is similar in nature to AFP, but the latter term generally is used where the pain is confined to the teeth or gums, and AFP when the pain involves other parts of the face. Other sources use atypical odontalgia and AFP as synonyms, or describe atypical odontalgia as a sub-type, variant, or intra-oral equivalent of AFP. Sometimes "phantom tooth pain" is listed as a synonym for AO, and sometimes it is defined as toothache which persists after a tooth has been extracted. It has been suggested that it is likely that these terms do not represent a single, discrete condition, but rather a collection of misdiagnosed and as yet unidentified causes.