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Evidence-based ophthalmology

The benefits of "facts first" highlighted in Ridley Medal lecture

Dermot McGrath

Posted: Friday, December 7, 2018


Rudy MMA Nuijts MD

Ophthalmology can benefit from more rigorous application of evidence-based medicine that integrates individual clinical expertise with the best available external clinical evidence from systematic research, said Rudy MMA Nuijts MD, PhD, in his Ridley Medal Lecture at the 36th Congress of the ESCRS in Vienna.
In a wide-ranging lecture entitled “Facts first – the search for evidence”, Dr Nuijts, Professor of Ophthalmology at the University Eye Clinic Maastricht, the Netherlands, focused on the challenges and benefits of using evidence-based medicine (EBM) to answer key questions in ophthalmic clinical practice.
EBM advocates the use of up-to-date “best” scientific evidence from health care research as the basis for making medical decisions. The quality of evidence used to answer a particular clinical question can be schematically represented by an evidence-based medicine pyramid, said Dr Nuijts. Systematic reviews and meta-analyses are at the top of the pyramid, representing the highest levels of evidence, while expert opinion is at the bottom and therefore regarded as the least influential.
At the heart of EBM is the concept that high-quality scientific research carries most weight, said Dr Nuijts.
To illustrate how this might work in real terms, Dr Nuijts took the example of four research initiatives taken in recent years to search for evidence for new innovations: toric IOLs, prevention of macular oedema after cataract surgery, long-term endothelial cell loss in phakic IOLs and corneal lamellar surgery.
For toric IOLs, three principal questions needed to be answered, said Dr Nuijts: do they outperform monofocal IOLs, is digital marking more accurate than manual marking and are they more cost-effective than standard IOLs? A prospective randomised controlled trial provided the answer to the first question.
“We showed that uncorrected distance visual acuity (UDVA) was 20/25 or better in 70% of the toric patients compared to just 31% in monofocal group. Spectacle independence was 84% in toric versus 31% in monofocal, so the toric lenses clearly outperformed monofocal lenses,” he said.
The picture was less clear cut, however, for manual versus digital marking.
“We found that digital markers were better but it was not statistically significant. Better technology did not transfer into better clinical outcomes for the patients at this stage,” he said.
Analysis also showed that toric lenses were less cost-effective than monofocal IOLs.
“The problem here stems from the generic nature of quality-of-life questionnaires, which are not sensitive to small health gains in specialty practice,” said Dr Nuijts.
The benefits of EBM were also to the fore in the landmark PREMED study, said Dr Nuijts, which concluded, among other findings, that a combination of a topical corticosteroid and a nonsteroidal anti-inflammatory drug (NSAID) is more effective than either agent alone in reducing the risk of developing cystoid macular oedema (CME) after cataract surgery in non-diabetic patients.
“The study outcomes paved the way for the first evidence-based clinical guidelines to prevent CME after cataract surgery in diabetic and non-diabetic patients,” said Dr Nuijts.
EBM has also been extremely helpful in assessing endothelial cell (EC) loss with iris-fixated IOLs, with Dr Nuijts’s team amassing data over 10 years from 507 eyes of 289 patients who received the Artisan myopia or Artisan toric iris-fixated phakic IOL.
“While we found a 1.04% explantation rate at 10 years, which is quite acceptable, over the total follow-up period this increases to 6% and the mean time of explantation is almost 12 years. So the message here is that we really have to follow-up these patients for longer than 10 years,” he said.
For endothelial keratoplasty, EBM helped answer the question of whether Descemet’s membrane endothelial keratoplasty (DMEK) delivers better outcomes than ultrathin Descemet’s stripping automated endothelial keratoplasty (DSAEK).
“Overall we found that there are some indications for which the visual outcomes are better with DMEK, but the incidence of complications are higher than with ultrathin DSAEK,” he concluded.
Rounding off his talk, Dr Nuijts quoted the American psychologist Carl Rogers, who said: “The facts are always friendly. Every bit of evidence one can acquire, in any area, leads one that much closer to what is true.”

Rudy MMA Nuijts: rudy.nuijts@mumc.nl