Inert speciality gases have been used in eye surgery for more than 100 years, with the use of sulfur hexafluoride (SF6) and perfluoropropane (C3F8) still being the gold standard in eye surgery today.
Hans Strydom, Afrox’s Technical Services Manager for Special Products and Chemicals, spoke to gasworld about the use of HiQ gases for eye surgery, which are universally used by surgeons to repair retinal detachments and other conditions involving the human eye.
In South Africa, Afrox has supplied these gases to surgeons for many decades and has a vast amount of experience in high-quality gases for eye surgery, along with those for many other medical procedures.
“To treat a patient with a torn or detached retina, a bubble of one of these gases is injected into the vitreous humour, which is at the centre of the eye and filled with a transparent liquid called vitreous gel,” Strydom explains. “One of the key roles of the vitreous humour and gel is to keep the eye spherical and to maintain pressure on the retina to keep it in place.”
Nitrogen (N2) and oxygen (O2) in solution in the surrounding tissues of the eye pass relatively quickly into the gas bubble, which causes it to expand within the vitreous humour. This expanded bubble applies upward pressure on the detached retina, pushing it back into place. It also closes the retinal tear and prevents the gas from escaping from the vitreous humour.
Strydom continued, “With the break closed and the retina pushed back into place, the surgeon can then use either laser or cryotherapy (freezing) techniques to reattach the retina firmly into place.
Because of their low solubility in water, SF6 or C3F8 bubbles dissolve very slowly onto the vitreous gel, disappearing completely within a few weeks of the surgery. Both SF6 and C3F8 are chemically inert, colourless, odourless, and nontoxic, so they cause no permanent damage, enabling a quick and total recovery of the liquid vitreous and retinal structures.”
“But the gases used need to be of the highest quality as any impurities can have dire consequence for the outcome of the treatment. Several areas need to be quality checked during the manufacturing process and the transfer of these gases into cylinders.”
“Also, when the surgeon fills a syringe with gas for injection into a patient’s eye, the pressure in the cylinder must be reduced to just above atmospheric pressure using a regulator of the highest quality. These regulators are fitted with stainless steel diaphragms and precision valves. They also have a sintered metal filter to catch any particulate matter in the system.”
The introduction of these intraocular gases into routine clinical practice, along with other modern surgical techniques, has resulted in significant improvements in the treatment success rates for a wide range of eye diseases.