An optometrist who failed to spot abnormalities in the eyes of a boy who later died has been found guilty of gross negligence manslaughter.

Eight-year-old Vincent “Vinnie” Barker died on 13 July 2012 – about five months after he had a routine eye test at Boots opticians in Upper Brook Street, Ipswich.

The conduct of locum optometrist Honey Rose, 35, fell so far below the standards expected that it was “criminal”, prosecutor Jonathan Rees QC said at the beginning of the trial.

Suffolk police said the jury at Ipswich crown court found Rose, of Newham, London, guilty of manslaughter through gross negligence.

Jurors heard postmortem examinations showed the cause of death was hydrocephalus – a buildup of fluid on the brain which led to an increase in pressure within his skull and, ultimately, his collapse and death.

Opening the prosecution case, Rees said: “The prosecution allege that Vinnie’s death was preventable and would have been prevented had the defendant, Ms Rose, done her job properly.”

He added: “At the heart of the prosecution case against the defendant is the allegation that the defendant’s failure to detect the swollen optic discs and refer Vinnie on for further investigation was grossly negligent on her part.”

Rees said it is agreed that at the time of Vinnie’s examination on 15 February 2012 there were “obvious abnormalities” in both of his eyes.

The jury heard photographs taken by another member of staff of the back of his eyes shortly before he was examined by Rose suggested he had bilateral papilloedema – the optic disc at the back of each eye was swollen because of the raised pressure within his skull.

Rees added: “The prosecution say that the abnormalities in his optic discs would have been obvious to any competent optometrist who had examined them.”

He said this would have led to him being “urgently referred for further investigation” because of swollen optic discs signifying the patient may be suffering from papilloedema, “a life-threatening condition”.

The jury was told Rose’s failure to detect the swelling of Vinnie’s optic discs was a significant contributory factor to his death.

In a statement, Vinnie’s parents, Ian and Joanne Barker, said: “The outcome of this case does not change our life sentence; we will never be able to fully accept that our special little boy is never coming home.

“The void left in our lives will never heal and the ripple effect to those around us is immense. As parents the distress of witnessing your child’s life from start to end in just eight short years is excruciatingly hard and nonsensical.

“The decision of a jury or judge cannot bring Vinnie back or undo the devastation of his death. A guilty verdict would never make us winners, our loss is simply too great.

“Our main concern has always been the accountability of those we entrust with our own health and the health of those we love. It is the responsibility of individuals and the organisation they work for to perform their duties to the expected levels of good practice without exception.

“The actions of professionals or their failure to act to a standard at which they are required to perform should not go without consequence.”

Suffolk police senior investigating officer Det Supt Tonya Antonis said: “If this case makes the optometry profession reflect on their practices and review their policies to prevent it happening to anyone again, or encourages other parents to take their children to get their eyes tested with the knowledge that any serious issues would be picked up, then it will be worthwhile.”

Rose will be sentenced at Ipswich crown court on 25 August.