AUDIT RESULTS

Capsule rupture during cataract surgery can have dire consequences, including cystoid macular oedema, rhegmatogenous retinal detachment and a higher risk for endophthalmitis. Beginning surgeons should therefore avoid high-risk cases, said Oliver Findl MD, at the 17th ESCRS Winter Meeting. “Posterior capsule rupture is actually the most common intraoperative complication. It is usually associated with the need for additional surgery, a greater number of follow-up visits and an increased frequency of postoperative complications,†said Dr Findl, Hanusch Hospital, Vienna, Austria and Moorfields Eye Hospital, London, UK, at a special symposium organised by the ESCRS Young Ophthalmologists' Forum.

He noted that the posterior capsule is only four microns in thickness, and although it is elastic and can withstand some stretching, it can be fairly easily penetrated with a sharp instrument or a vibrating phaco tip. Broken vitreolenticular barriers can cause the vitreous to move anteriorly, exposing the vitreous to traction, which can in turn lead to retinal breaks. There can also be an increased transfer of inflammatory substances from the anterior segment into the posterior segment potentially causing cystoid macular oedema.

In cases where posterior capsule rupture (PCR) actually leads to vitreous loss there is a 10 per cent incidence of cystoid macular oedema. The risk of rhegmatogenous retinal detachment is also high in such cases with reported incidences of five per cent to 15 per cent. The risk is highest in myopic eyes but is also quite significant even in non-myopic eyes.

The risk factors for capsule rupture include posterior polar cataracts, and white cataracts. In the literature, white cataracts have a tear incidence of 10 per cent and an incidence of vitreous loss of three per cent. The capsules of such eyes are wrinkled and less elastic, they also have a weaker zonular apparatus. Traumatic cataracts and eyes with pseudo-exfoliation are also at an increased risk of the complications, usually for reasons of zonular instability, and eyes that have undergone previous vitreoretinal surgery sometimes because of actual capsule trauma during the surgery.

The skill of the surgeon is also a critical factor. For example, the third-year resident in the US has a capsule rupture incidence of 3.1 per cent to 14.7 per cent, whereas among registrars in the UK the incidence is around 4.4 per cent. The incidence decreases with the increasing number of cases a surgeon has performed and is higher in developing countries, presumably because of the higher percentage of white cataracts.

Dr Findl recommended a grading system for cataracts that would divide them into groups according to their potential risk for PCR. Beginning surgeons should only perform cataract procedures in patients in the low-risk category.

“Posterior capsular rupture is widely regarded as the benchmark complication by which to judge the quality of cataract surgery. Ideally you want to audit your cataract results. This is true not only for those who are experienced, but also and especially for those who are just starting surgery. EUREQUO is a very valuable registry where you can enter your data and also benchmark yourself with your centre or your country,†Dr Findl added.