shutterstock_1540676213_800

A Pinch of Posterior Segment Insight Spices up this PIE Just Right

No first day of any ophthalmic conference is complete without delving into posterior segment complications, and we wouldn’t let you down. So, we were treated to three fantastic back-of-the-eye talks that both open the door for further questions and provide valuable takeaways.

Retinal findings in COVID-19, and post-COVID subretinal abscess

Since the beginning of the pandemic, questions about just how COVID-19 affects the eyes have been flying around the medical world. Can the virus infect the eyes? Can the virus spread via tear shedding? Does it infect corneal tissue? Can it lead to retinopathy?

While we’ve got more answers now than we did last year, there are still plenty of questions up in the air. Prof. Gemmy Cheung, head and senior consultant of the Medical Retina Department at Singapore National Eye Centre (SNEC), and advisory board member of PIE magazine, turned our attention to the retinal effects of COVID-19 — and, in contrast to Prof. Cheung, they’re often not pretty.

Early findings reported cotton wool spots, microhemorrhages and optical coherence tomography (OCT) hyperreflectivity in healthcare workers who had contracted COVID-19. But much more data has been released since then — though we’re still not entirely sure what to make of it all.

As Prof. Cheung pointed out, some 203 articles on PubMed appear when you search for the terms “Retina” and “COVID” or “Sars-CoV-2.” Of those, however, not all contain adequate data, so Prof. Cheung summarized the highlights of 26 of them for our viewing pleasure.

Of the cases with controls, there was a significantly higher rate of cotton wool spots than hemorrhages — and while the retinal hemorrhage rate was higher in COVID-19 patients than controls, it wasn’t statistically significant.

However, a paper by Prof. Cheung and her colleagues noticed a significant trend in microvasculature and tortuous veins in the eyes of COVID-19 patients — including relatively young, healthy patients with mild infections. In other patients with more severe cases that required treatment, ocular effects could be attributed to treatments rather than the virus.

Other OCT scans are striking: Some comparisons between COVID-19 patients and controls published by the Canadian Journal of Ophthalmology clearly indicate something terrible has happened to the eyes of the patients. They look completely different from the controls, and Prof. Cheung noted that if she had seen them with no context, she would have assumed they belonged to patients with poorly controlled diabetes. Even patients with mild symptoms still can experience retinal problems.

Dr. Alay Banker, director of Banker’s Retina Clinic & Laser Centre in Ahmedabad, India, continued the COVID-19 discussion with a particularly interesting case involving a fungal infection following COVID-19 infection. The findings suggested an infection by Bipolaris fungus — a fungus associated with numerous other conditions not limited to the eye. The takeaway here is that doctors should make sure to conduct follow-ups with their COVID-19 patients and keep an open mind when it comes to infections — because sometimes the cause of the infection can be surprising, like it unfortunately was in this case.

There’s clearly much more to be learned — and you’d better believe we’re going to continue to cover this topic.

The Goldilocks zone of retinal fluid

Prof. Mark Gillies, with the University of Sydney and general Australian extraordinaire, challenged a conventional theory in treating wet or advanced neovascular age-related macular degeneration (nAMD). Essentially, when it comes to treat-and-extend (T&E) or pro re nata (PRN) regimens, the theory so far has been this: All fluid in the retina should be treated.

Prof. Gillies suggests this assumption is flawed, and we should reconsider it. This is potentially big news, and we’re all ears.

He shared a study that followed macular atrophy (MA) within five years of treatment, where 10% of patients had MA within one year of treatment, 42% at five years and 49% at nine years. After five years, the numbers stabilized. Dry lesions were the main risk factor for MA — specifically, the driest lesions were four times more likely to develop MA than active lesions.

So, low levels of fluid and disease activity are the strongest predictor of MA. Contrary to the goals of T&E and PRN, it may be beneficial to allow some fluid to protect against atrophy.

Not all fluid is made the same, however. Subretinal fluid appears to be well tolerated, whereas intraretinal fluid was associated with significantly worse outcomes. This is a very interesting takeaway, and will make for a great deeper investigation.

Editor’s Note: A version of this article was first published in Issue 2 of CAKE & PIE POST, C&PE 2021 Edition. The CAKE & PIE Expo 2021 was LIVE on June 18-19. All sessions are available on demand until July 19 at expo.mediamice.com upon login.

Subscribe
Notify of
guest
0 Comments
Inline Feedbacks
View all comments