JUL 01, 2011
This nonrandomized prospective study evaluated the effect of systemic oxygen therapy on acute ocular chemical and thermal burns and compared outcomes with patients treated with conventional medical therapy. The results indicate that patients treated with oxygen therapy healed faster and showed increased corneal transparency and decreased corneal vascularization, as well as better visual acuity and fewer complications.
The study included 22 male patients (24 eyes) with grade III to IV acute ocular chemical and thermal burns who presented at one of two medical centers in Iran within three weeks of injury. All of them received conventional medical therapy, with the 12 patients (13 eyes) treated at one of the centers also receiving 100% oxygen via a mask at a flow rate of 10 L/minute for one hour twice daily.
Corneal epithelial defects healed significantly quicker in the oxygen group (15.23 ± 3.94 days) compared with patients receiving conventional treatment (59.9 ± 23.33 days) (P < 0.001). Vascularization of ischemic areas was complete in 14.54 ± 2.70 days in the oxygen group versus 45.09 ± 22.20 days with conventional treatment (P = 0.001).
In the oxygen group, the cornea was more transparent and less vascularized when examined at three and six months after injury. Mean final visual acuity was also better in the oxygen group, 0.40 ± 0.52 logMAR (range, 0 to 1.3) vs. 1.11 ± 0.83 (range, 0.1 to 3) (P = 0.018). Symblepharon or corneoscleral melting did not develop in any patient in the oxygen group, while three eyes in the conventionally managed group developed symblepharon, and one patient experienced corneoscleral melting.
The authors recommend the integration of oxygen therapy into the early routine management of acute ocular chemical and thermal burns. Early oxygen therapy may save partially injured ischemic limbal and conjunctival stem cells, promote corneal and conjunctival epithelialization, prevent corneal conjunctivalization, trigger scleral vascularization and prevent its melting or perforation. They say that with late intervention, despite complete destruction of limbal and conjunctival stem cells and their niche, oxygen therapy still may be effective at inducing angiogenesis and promoting corneal vascularization.