Dislocation of cannula during cataract operation

The scene

A patient with bilateral cataracts was seen by an ophthalmologist MDU member. The member initially performed surgery on the left eye, which was uneventful, and the patient later returned for surgery on their right eye.

During this second procedure there was an inadvertent dislocation of an irrigating cannula used to hydrate the cataract incision. The patient developed a posterior capsule rupture and required an anterior vitrectomy and insertion of an anterior chamber intraocular lens implant (10L) in place of the previously inserted posterior chamber 10L.

The claim

The patient claimed that the MDU member had been negligent in failing to ensure the cannula had been correctly secured. If it had not been for this negligence, the patient claimed they would not have needed sutures and the anterior vitrectomy, also alleging they were at increased risk of developing cystoid macular oedema (CMO) and retinal detachment.

The member turned to the MDU for assistance. Responding to the claim, we obtained expert evidence that advised this complication of cataract surgery is recognised but rare, and can occur when the Luer lock disengages or is not correctly locked in the first place.

In this case, the expert evidence held that the incident may have occurred for one of three reasons:

1. the cannula had not been properly secured onto the syringe, either by the MDU member or by another member of the surgical team;
2. there was a manufacturing fault either of the flanges on the cannula hub, or of the screw thread on the syringe;
3. the forces that built up at the junction between the syringe and cannula, coupled with occlusion of the cannula tip, were so great as to drive the cannula off the syringe despite correct fixing and good manufacture.

The outcome

Having considered all the available evidence, the expert instructed by the MDU was of the opinion that, on the balance of probabilities, the incident was more likely to be due to the first reason. The expert further advised that there is extensive knowledge of this clinical risk and the safety steps that can be taken to avoid it, which have been highlighted by the Royal College of Ophthalmologists, government agencies such as the MHRA and within ophthalmic literature.

With regard to causation, the expert instructed by the MDU advised posterior chamber IOLs are safer than anterior chamber 10Ls. Also, posterior capsular rupture adds additional risks to the outcomes of cataract surgery and can be associated with post-operative complications such as CMO, raised intraocular pressure and enhanced risk of retinal detachment.

From the evidence obtained it was clear that the MDU member was not solely responsible for the incident.

Thanks to our negotiations, we agreed to split the cost of the claim evenly between the MDU ophthalmologist and the other surgical team member involved, who was not a member of the MDU, and accepted shared responsibility. The claim was settled before court proceedings were issued for £6,000 damages and with costs totalling £7,500, with the MDU only paying half of this.

This page was correct at publication on 19/06/2019. Any guidance is intended as general guidance for members only. If you are a member and need specific advice relating to your own circumstances, please contact one of our advisers.