Retrospective cohort study looks at adverse intraoperative and postoperative events following cataract surgery for patients with prior intravitreal injections and incisional retinal procedures

The project, presented by Colton Hill, MPH, on behalf of the Dean McGee Eye Institute, looks at complication rates during cataract surgery or after cataract surgery for patients with prior intravitreal injections or incisional retinal procedures.

This transcript has been lightly edited for clarity:

Hi, my name is Colton Hill. I'm a second year medical student at the University of Oklahoma and presenting on behalf of Dean McGee Eye Institute. Our research project was accepted to the 2022 ASCRS meeting.

Our project looks at complication rates during cataract surgery or after cataract surgery for patients with prior intravitreal injections or incisional retinal procedures. Dr. Kamran Riaz is the research advisor and mentor for this project. No financial disclosures are necessary for this project.

This project follows the understanding that studies have found that there was an increased risk of posterior capsular tear during cataract surgery for patients with prior intravitreal injections, that there has also been an increased risk of zonular compromise for patients who had had prior pars plana vitrectomy or PPV.

Our purpose is to assess all risks of intraoperative or postoperative events associated with cataract surgery for patients with prior intravitreal injections or prior incisional retinal procedures (IRPs).

This is a retrospective cohort study that covers patients in the last 10 years at Dean McGee Eye Institute, who had had prior injections or incisional retinal procedures. We assessed charts and operative notes for 588 eyes for this study, collected necessary demographics and pre and post cataract surgery visual acuity data. We were notably interested in posterior capsular tear, retain lens fragments, zonular compromise, and we also looked at whether a patient had to return for any emergency surgery or a surgery within six months that had to do with an adverse event of the cataract surgery.

Our patient population included a fair distribution of approximately 50% women and men, as well as right and left eyes; there were 472 eyes that were included in the study.

Most [patients] had prior injections, and many of them had had prior PPVs.

Of note, if a patient experienced an adverse event, nearly 50% of them experienced multiple adverse events. There were many who experienced more than one, [and] even up to six adverse events. The most common was an increased risk for adverse events for patients who had injections versus those who did not. And that was a 30% increased occurrence.

I do note that there is not statistical significance associated with this, likely because of the low event rate, the low complication rate inherent to cataract surgery.

There's not a simple relationship between the number of injections and adverse events. Adverse events peak around two injections, and then level off for larger numbers by setting it up where we either look at whether you had an injection versus not not how many injections you had, we know that there's a difference. But it would be a good investigation to look into this further to kind of break them down into ranges such as patients who had had one to six injections and look at that versus those with more than 10 injections and see if there's a clinical difference there.

We also note that there may be different reasons that this may occur, [and] this requires further investigation.

Our conclusions were that there was a 5.3% occurrence rate in this study. So 5.3% of eyes experienced at least one adverse event, and there was 30% more for patients who had had prior injections versus not. This suggests a need for physicians to counsel patients who had had prior injections planning to do cataract surgery.

Also for the surgeons themselves to plan ahead with possibly having a retinal surgeon for backup, and to have the necessary equipment if an adverse event does occur, including backup lenses and tension segment.

However, these findings were not statistically significant. We can't rule out that it was due to chance.

The low event rate - inherent to cataract surgery - really means that we need to expand our data collection efforts in order to establish the research study power to look at this event with enough clarity.

The strengths of this study were that we manually assessed 588 eyes, the operative notes, we found that when we used automated EMR analysis, that we missed quite a few of the adverse events. So we would definitely suggest manual chart review for any further study.

This was a single institution. And we would like to work with other institutions who we know are out there working on this exact problem, because I think that if we increase the numbers, and also the locations, the distribution of patients in different parts of the country, we would get a better picture of exactly what the association is if there is one between prior injections or other procedures and adverse events during cataract surgery.

Special thanks to Dr. Kamran Riaz for his continued research, mentorship and help and advisory role in this project and others. We also think the donors of Dean McGee, and Dean McGee Institute itself, for allowing us to team up to pursue this project.

If you have any questions please email me at colton-hill@OUHSC.edu.