A new study published in Retina assessed the incidence, prognostic factors, and management of macular edema (ME) associated with silicone oil (SO) tamponade.
Give me some background.
ME is a major cause of reduced vision after intraocular surgery as well as a common complication after rhegmatogenous retinal detachment (RRD).
- In fact: Previous studies have demonstrated that the highest incidence of ME usually occurs with SO tamponade, and potentially depends on the interval between the operation and the SO removal.
Thus: While SO tamponade is beneficial in complex RRD cases wherein gas tamponade may result in poorer anatomical outcomes, considering the risk of adverse events is critical for success.
Next: Talk about the study.
In this retrospective, comparative, observational study, investigators included 112 patients (114 eyes) who underwent pars plana vitrectomy (PPV) and SO tamponade for RRD or persistent full-thickness macular hole (FTMH).
To evaluate the potential link between ME and post-RRD SO tamponade, the researchers analyzed:
- Demographic data
- Clinical characteristics
- Optical coherence tomography (OCT) findings
Findings?
ME developed in 64 of the 114 eyes (56.1%) during SO tamponade.
The main duration of SO tamponade was significantly longer in the ME group (665 days) compared to the non-ME group (239 days, p < 0.0001).
- Proliferative vitreoretinopathy (PVR) was present in 74 eyes (71.4%) in the RRD group.
In addition: 49% of eyes that did not develop ME during SO tamponade experienced ME after SO removal, with an average central macular thickness (CMT) increase of 39μm.
Were any other factors linked to ME?
Yes, actually. The researchers identified two more factors, including:
- Retinectomy (62% in the ME group vs. 29% in the non-ME group, [p = 0.0013])
- Longer duration of SO tamponade (p < 0.001)
Expert opinion?
The study authors outlined two key processes that can cause ME:
- Inflammatory: Associated with a disruption of the blood-retina barrier
- Mechanical: Induced by a mechanical traction of SO interaction with the retina surface, along with the blockage of Müller cells’ potassium ion buffering function—which contributes further to retinal swelling
Go on …
They reasoned that the results from this study “offer primary insight on the critical role of retinectomy and SO tamponade duration associated with higher odds of developing ME, with particular patients undergoing retinectomy showing a three-times higher risk of developing ME in comparison with patients who did not.”
Take home.
These findings indicate a high incidence of ME in eyes with SO tamponade, with prolonged SO tamponade and retinectomy being significant predictors of ME development.
The results emphasize the importance of careful monitoring and timely SO removal to minimize ME-related complications.