Medical applications utilising gases are wide and varied and include patient care, research and the manufacture of pharmaceutical products.

Sulphur Hexafluoride (SF6) is a man-made gas comprising of one sulphur and six fluoride atoms. Key properties of the gas are that it is extremely chemically stable and has a relatively high density. Commonly used within the electrical industry as an insulating medium, the properties of the gas also make it highly suitable for use in ophthalmology.


Ophthalmology is the surgical or medical care of any conditions that affect the eye or its appendages. This can include; cataracts, genetic eye disorders, trauma or disease. The retina is a light-sensitive layer of tissue that lines the inner surface of the back of the eye. Metabolic tissue works to support the retina of the eyeball.

However, this tissue can pull away, resulting in a macular hole or retinal detachment. Either one of these conditions can lead to distorted or impaired vision. Reparations can take place during a procedure called a vitrectomy.


During a vitrectomy, an ophthalmologist (medically trained eye specialists), will remove the vitreous humour, a clear gel-like substance that lies behind the iris. In doing so, they will gain access to the back of the eye, where they may repair the damaged retina.

SF6 and its use within Ophthalmology

At the end of the vitrectomy surgery, the ophthalmologist is required to fill the space left by the vitreous gel. This can be achieved by injecting a small amount of SF6 gas into the eye, in order to maintain the pressure required to allow the retina to remain in place and adequately heal. Due to the high density of the SF6 gas the body is unable to absorb it for 3-4 weeks. In comparison, air takes only 1-3 weeks, which does not allow the eye sufficient time to repair.

Why is gas analysis essential?

In order to validate their techniques, it is important that ophthalmologists analyse the composition of the SF6 gas prior to its use in surgery. In doing so higher precision, purity, traceability, accuracy and performance can be achieved.

Cambridge Sensotec is an established manufacturer of the Rapidox range of high precision gas analysers. The company collaborated with specialists in ophthalmology to develop a bespoke Rapidox SF6 6100 analyser, which is capable of analysing a minimal amount of SF6 gas.

As a privately owned company, staffed by highly skilled technologists, Cambridge Sensotec is perfectly placed to react to its customers specialised gas analysis requirements. Dynamic and flexible, the company is able to design and supply solutions to suit a variety of gas analysis applications.