Hold The Front Page

A recent newspaper article in the UK (1) has claimed that one multifocal IOL in particular, the Oculentis Mplus X, may be faulty and is under investigation for poor outcomes. But were the claims made actually justified?

The headline makes for worrying reading: “Top eye clinic faces claims” (in this case, Optical Express) because the IOLs “have caused loss of vision”, with quotes from dissatisfied patients like “I wanted better eyesight, but it’s all blurred now. It’s a nightmare,” (1). Moreover, Moorfields Hospital in London reported to the UK’s Medicines and Healthcare products Regulatory Agency (MHRA) that “four out of its six patients who had the implant reported a worrying loss of quality of vision”.

Concerning stuff. But remember, there are a myriad of reasons why a patient might experience sub-optimal postoperative optical outcomes even with the best surgeon and an optimal IOL, and one of the consequences of the optical compromises that have to be made to give patients multiple focal points can sometimes be adverse events like nighttime glare and halo. This is partly a numbers game – however small an adverse outcome rate an IOL may have, as the sheer volume of IOL implants increases, the number of recipients who feel they haven’t got what they expected will begin to stack up.

So how can you control for all of the factors? In this case, that would be very difficult – this is the real world, not a trial performed under experimental conditions. Is this a cluster or a trend? Surely the regulators would have spotted undue ocular adverse event rates?

Oculentis was robust in its response to these “untrue and highly defamatory” allegations (2,3), adding that “There is no MHRA inquiry into the Mplus X lens. In terms of the incident reports, as of today we have been referred a total of five reports from the MHRA.” In terms of the Moorfields cases, the manufacturer of the Mplus lens range explained that, “The first incident report about the Mplus X lens […] simply registers concerns expressed by three patients who reported post-operative sub-optimal distance vision. The report notes that the view of the responsible consultant was that after the surgery the patients all scored 6/6 on the Snellen chart and had excellent near vision (a 6/6 score being equivalent to 20/20 vision). The report has already been closed by the MHRA without them deeming it necessary to conduct further investigation. There have been no complaints to any regulator about the lenses worldwide, other than to the MHRA” (3). They also make the point that anecdotes are not evidence: “Whilst Oculentis sincerely regrets if the two individuals referred to have not achieved the improvements which they expected as a result of the surgery they have undergone, the anecdotes of two individuals cannot in any way justify an assertion that the lens itself which they have been prescribed is ‘faulty’” (2).