KEY POINTS:
It sounds like something out of a science fiction movie but if, as expected, Greg Somerville makes a successful return to the All Blacks it can be put down to cryotherapy.
The 29-year-old prop's run of bad luck continued last week when a stray finger in the eye in Canterbury's Air New Zealand Cup opener against Bay of Plenty caused a retinal tear.
Auckland optometrist Alan Saks said the best analogy to describe the retina was to think of the bladder in an old-fashioned soccer ball. Inside the bladder of the soccer ball was air, inside the retina is a vitreous jelly.
When the jelly shifts suddenly it can tear the retina allowing fluid to leak in behind the retina which can lead to the more serious affliction of retinal detachment.
"A retinal tear is usually a precursor to detachment," Saks said.
A top eye surgeon told the Herald on Sunday there were a number of options for fixing a retinal tear such as laser treatment or freezing ('cryo') therapy. With the type of injury Somerville had, the latter is used.
What it involves is freezing therapy to the wall of the eye which effectively welds the tear to the underlying layers.
The size of the 'iceball' is small, about 3mm in diameter.
Nitrous oxide is pumped into the end of a cryotheray machine, about the size of a match head, and as the gas escapes the temperature drops to about - 70 degrees so an iceball forms on the surface of the eye.
The ice is held in place by a gas bubble which sits in the eye for between 10-14 days before it is absorbed.
When the gas is absorbed, as a general rule, vision returns to normal and the area of the retina that was torn is as strong, if not stronger, than it was before the trauma.
People who suffer this type of injury are expected to return to full fitness in a month, which would put Somerville's recovery at August 28, a full 11 days before the All Blacks World Cup opener against Italy in Marseille, a game Somerville would almost certainly not be expected to start in.
There is no danger of the injury making him more susceptible to these type of injuries.
Somerville has had no further dialogue with the All Blacks selectors regarding his World Cup place.
At the time of the injury All Blacks assistant coach Steve Hansen said: "As far as Greg's availability for Rugby World Cup selection is concerned, we will monitor his progress over the next few weeks and the selectors will make a decision in due course."
It would be strange, however, if Graham Henry was to give up on the versatile veteran prop now after persevering with him through a lengthy rehabilitation from a ruptured Achilles.
Wellington's John Schwalger would be next in line, though he didn't cover himself in glory when he was last in the All Blacks camp, being part of the 'Custom St Six' who were caught partying until 4am two nights before the Bledisloe cup and Tri Nations decider against Australia.
The All Blacks have to declare their full 30-man squad by August 14.
