Outer Retinal Optical Coherence Tomography Changes Associated with Intraocular Silicone Oil Administration

On this episode of the JVRD Author’s Forum podcast, retina specialist Alan J. Ruby discusses his study, “Outer Retinal Optical Coherence Tomography Changes Associated with Intraocular Silicone Oil Administration,” published in Journal of VitreoRetinal Diseases (JVRD).

Host Timothy G. Murray speaks with Dr. Ruby about the use of OCT imaging in patients undergoing silicone oil removal following retinal detachment repair. The discussion explores how subtle outer retinal and ellipsoid zone changes identified on preoperative OCT imaging frequently resolved after silicone oil removal, even when visual outcomes did not always correlate with the imaging findings.

Dr. Ruby explains how the study evaluated both macula-on and macula-off retinal detachments and highlights the importance of obtaining OCT imaging while silicone oil remains in the eye. The conversation also examines longstanding questions surrounding unexplained vision changes after silicone oil use, the potential role of imaging in guiding the timing of oil removal, and why routine postoperative imaging may improve surgical planning and patient management.

For more information, visit www.ASRS.org/JVRDForum.

Welcome to ASRS’s Journal of Vitreoretinal Diseases (JVRD) Author’s Forum. As the official peer-reviewed scientific journal of the American Society of Retina Specialists (ASRS), JVRD delivers rigorous, clinically meaningful research that informs and advances retina care worldwide. Join Editor-in-Chief Dr. Timothy Murray as he engages leading investigators in thoughtful discussions about the latest studies published in JVRD — highlighting practical insights, clinical pearls, and the real-world impact of emerging innovations in our field.

Transcript

SPEAKER_01 0:03

Welcome to ASRS's Journal of Vitrial Diseases Authors Forum. I'm your host, Dr. Timothy Murray, editor-in-chief of JVRD. On each episode of the JVRD Authors Forum, I will interview innovative retinal researchers on their studies featured only in JVRD and how these studies will impact our patients' care in our clinics. Tune in to hear directly from investigators about the clinical implications of the newest and highest quality research in the field of retina. Welcome to JVRD's Author Podcast. I'm pleased to be joined tonight by Dr. Alan Ruby, Associate Retinal Consultant of Royal Oak, Michigan. We're going to discuss his paper, Outer Retinal Optical Coherence Tomography Changes Associated with Interocular Silicone Oil Administration. Welcome, Dr. Ruby. Thank you, Dr. Marie. It's a pleasure to be here. So, you know, I think all of us have had these kind of concerns of silicone oil with visual compromise over time. And it's been hard to assess what that etiology has been.

SPEAKER_00 1:21

So it's interesting. I have historically always done OCT on my patients right prior to removing the silicone oil because luckily you can get a pretty good idea as to what the macula looks like. There's any edema or an epiretinal membrane that you may need to address at the time of the surgery. So as we started looking at these pre-operatively, we realized we were starting to see some changes in them that we could not readily explain. And the interesting thing was a lot of them post-operatively, the changes went away. So that was sort of the impetus for the study.

SPEAKER_01 1:52

And so I thought you did this in a nice way. You looked at macula on and macula off eyes, thinking that there's a potential difference. You evaluated them with OCT and you looked afterwards, followed pre-visual acuity and post-visual acuity. What do you think the main take-home points for this were?

SPEAKER_00 2:09

It's interesting because this is one of those times where the clinical findings, the OCT findings, and the final outcomes did not necessarily match. Because one would assume that if you saw OCT findings before the oil was removed that you thought maybe contributing to the decreased vision, that those changes in OCT would portray a poorer visual outcome. But instead, what we actually found is that the majority of these changes went away after the oil was removed that did not seem to impact the final visual acuities. Very, very different than a lot of things that we see in OCT that typically will predict what final visual acuity outcomes are. So we thought that was incredibly interesting. It really had not been reported before, if for no other reason than none of the other studies had looked at OCT pre-operatively with the oil in, and then subsequently when the oil was taken out.

SPEAKER_01 3:04

So one of the things that we've discussed is potential fluctuations of interocular pressure during oil placement or oil direct damage to the optic nerve. It didn't seem clear to me that those had any role in what you were looking at.

SPEAKER_00 3:22

No, and that was really interesting because if you look back at most of the other reports that have been shown to look at OCT post-operatively, a lot of them suggested that there was some type of change in the ganglion cell layer. And we at we just did not see that. Really, with the changes that we saw with the oil in the eye were more ellipsoid zone changes. And then subsequently, when the oil was removed, some of those ellipsoid changes actually got worse in the short run, but universally in the macula-on cases, they all went away. And the majority of the macula off cases, they also went away. So I think the take-home message here is that unless you're looking at OCT findings while the oil is in the eye to see what was there before the oil was taken out, it's almost impossible to try to explain what the decrease in vision was actually from. And I think that's the big take-home message is that especially looking at ganglion cell layer, there's a little bit of subjectivity. Obviously, you can measure it objectively, but it's very hard to say necessarily that that mild change in the thickness of the ganglion cell layer was consistent with the decreased vision, which we're saying was unexplained after the oil removal.

SPEAKER_01 4:32

And I think you made a really key point here, which is that we have great imaging technology, and it always surprises me when people don't use that in their post op patients. I'm kind of most interested in anatomical, you know, microscopic level imagery in my post-op patients to guide some of the treatments afterwards.

SPEAKER_00 4:55

Yeah, I 100% agree with you because I think there really is no great data on when to take oil out. You know, we have sort of historically relied on, oh, you should keep it in for three to six months, but there's really no real data to drive that. And with the advent of OCT, it really gives us the ability to look into the eye with the oil still in and see if there are any changes in the foveal region, which may suggest there's something going on that may have an impact on our outcome. So if we do see something there, we do see thickness or we see subfoveal lucencies, which we had seen on many of these OCTs, maybe that indicates we should be thinking about taking the oil out earlier in hopes to reverse those changes.

SPEAKER_01 5:38

But it didn't seem to be dependent on oil duration in your study. I mean, patients did really well regardless.

SPEAKER_00 5:46

They did. And again, you know, one of the shortcomings of the study is simply that there were many different surgeons who contributed patients. Therefore, we don't have a way of getting into the minds of these doctors as to whether or not when they saw these changes, did that in any way influence the timing of the removal? So while the OCTs could be looked at while the oil was in, we don't have a breakdown as to when the OCT findings were actually noticed when the oil was taken out and the subsequent change in resolution of those images and the difference that was seen on OCT. So you're 100% correct. The only thing we know is they all went away.

SPEAKER_01 6:24

Right. Which I love, but then some of your patients had a permanent decline in vision in the macula off group, even though the OCT findings resolved.

SPEAKER_00 6:36

Is that was the oil in any way contributory to that decrease in vision, or was it just contributed from the macula off status of the retina? Because one of the inclusion criteria was that once your macula was off, if you had a second surgery, at that time of the second surgery, the macula had to be attached at the time of the surgery to be included in this study group.

SPEAKER_01 6:57

So one one of the things I wondered about is that you had 13 patients over a period of eight years. So why was that number so small? Is it just the lack of imaging?

SPEAKER_00 7:11

Yeah, it really was. You know, we had uh 295 patients who had had oil during the surgery at the time of the initial detachment repair. So during those eight years, almost 300 patients who had had the procedure done, but because only a limited number of physicians do OCT imaging with the oil in, that limited the number. And the other thing was we eliminated any patient that had PVR stage C or D andor adjuvant therapies, including PFO or any stain. So, as we all know, the majority of the patients in most of our practices get oil for recurrent detachments with PVR, etc., or tractional detachments, more complicated procedures that usually indicate the need for oil. We deliberately excluded all of those to try to eliminate any confounding factors and looked only at those patients who had had primary oil for maculon detachment, all of whom had a vitreous hemorrhage or the MACOF detachments that we had talked about, none of whom had PVR.

SPEAKER_01 8:13

So I think really the biggest take-home for me, and it's something you and I do routinely already, is image your patients with or without oil on their follow-up visits to get a better idea of what's going on in the macula. I'm surprised that that's not a routine. Does that surprise you?

SPEAKER_00 8:31

It totally surprises me because we all have had those patients where we go in and take the oil out, and then there's a question in your mind: is there perisilicone proliferation? Is there an epiretinal membrane? Do I need to stain? Do I need to address it? And when you have the OCT pre-operatively, it really gives you a good image and it makes you much more able to plan for that surgery. In other words, you're not needlessly trying to remove something that you're seeing a reflection of intraoperatively, when in fact, on an OCT, you would have been able to see it was just a normal interface between the retina and the oil. So I 100% agree with you.

SPEAKER_01 9:07

So for me, when I see my post ops, silicone oil or not, I usually get white-field imaging and OCT as a routine. I kind of feel like in this day and age, that should be the minimum standard.

SPEAKER_00 9:21

Yeah, no, I completely agree with you. I just think that we miss a lot on our clinical exam and in the operating room that much clearer could be delineated pre-operatively and help us plan, either, as you said, with OCT, wide field imaging, because we all know a lot of these patients, the view intra-operatively can be compromised by the cornea, by the lens, or other variables that make your ability to take care of the pathology less than ideal. And I think having the pre-operative imaging where you're able to delineate that with OCT findings, et cetera, just makes planning better and I would suspect make the outcome better.

SPEAKER_01 9:57

Dr. Ruby, thanks for joining us. I think this was an excellent clinically relevant study that has potential to impact patient care across the board, both in and out of the U.S. Thanks for joining us. Thank you. Thanks for tuning in to the JVRD Authors Forum. You can watch and listen to more episodes on the ASRS YouTube channel and on popular podcast directories, including Apple Podcasts and Spotify. Visit www.asrs.org forward slash JVRD forum on the ASRS website to learn more. See you soon.