Cataract surgery in post-vitrectomized eyes & post-trabeculectomy eyes with pathological myopia

Added: 2026-05-07

[00:00:00]This film is intended for eye surgeons for training and education purposes.

[00:00:05]Viewer discretion is strongly recommended.

[00:00:09]>> [music] >> Cataract surgery is routine, but once in a while we get some cases where a little bit of a planning becomes critical. Now, this is an young patient who has undergone vitrectomy for retinal detachment and then he has undergone trabeculectomy for the glaucoma aspect as well. He has pathological myopia and he also has significant astigmatism. So, these are the cases where we need to have a definite strategy and a game plan to work around this case. In this video, I'll walk you through how I approach this case and what are the priorities which we need to take care of and the subtle intraoperative decisions that will make a big difference. So, the patient is in his late 30s. He's relatively young. He has a functioning trabeculectomy bleb, pathological myopia, history of vitrectomy for retinal detachment, but the silicone oil has apparently been removed. He has a significant corneal astigmatism as well.

[00:01:07]So, before even entering the OT, we need to define our priorities. So, these are my priorities in order. Number one, preserve the bleb function. Maintain chamber equilibrium is going to be very challenging in this patient simply because because of the low scleral rigidity the patient would be having because he's young, pathological myopia, and then also he's vitrectomized. Number three, zonular barrier would be affected. So, there's always a risk of uh having some sort of a a fluid misdirection and the posterior capsule bulging up. And lastly, I need to achieve a refractive precision as much as possible with a toric lens. So, the number one priority will be to protect the bleb. So, it's precious and fragile.

[00:01:52]So, damage can happen even before we start the surgery. It can happen during draping, while placing the speculum, or even from an instrument contact during the surgery. So, what can we do differently? You know, apply a dollop of a viscoelastic directly over the bleb and it acts like a mechanical barrier and a cushion. Ensure the incisions are well away from the bleb and gently handling during the speculum placement and removal. So, remember that in this scenario, I would define a successful cataract surgery wherein we can preserve the functioning of the bleb. Now, moving on to the fluidic strategy, the core decision where This is where we need to understand how the fluid mechanics work in this particular eye.

[00:02:37]Now, this is an eye where the sclera is going to be slightly elastic because he's myope, young, and also there's vitrectomized eye. All these factors can cause chamber instability. So, you need to have the right balance. On the contrary, in a post-vitrectomy eye, high infusion pressure can in fact be not so healthy for the bleb. The fluid high infusion pressure can ensure that the fluid can overfilter through the bleb and it can also cause a bleb dysfunction and failure. So, we need to have the right balance in this situation.

[00:03:11]Ensure that the During surgery, the pressure always is maintained low. At the same time, we don't compromise on the chamber stability. So, in this case, my settings would be bottle height would be 50 cm, flow rate is 30 versus my usual 60, and vacuum is 400 versus my usual 600. This is for the quadrant removal part of it. So, this ensures that the fluidics are controlled, there is minimal surge, and I have stable anterior chamber. The key point in this is ensure that everything happens very slowly and slow is smooth and smooth is safe.

[00:03:46]I wanted to do this surgery in the topical anesthesia, but as soon as the draping was done, the patient was really anxious and felt that the draping procedure itself was painful. So, I needed to give a 1 ml of posterior subtenon's injection and unfortunately, we have a small subconjunctival hemorrhage. So, just giving a small nick at the conjunctiva relieves the blood off and because we don't want any bleeding to happen in the near vicinity of the bleb. So, anyway, this is far off, it should not bother me much. The side ports are made, the capsule is stained using trypan blue and care is to be taken that we don't overinflate the chamber while staining because it can go across the zonules into the retrocapsular space. OVD is placed into the eye and the main 2.8 mm incision is created. At all these steps, I'm careful that I don't impinge on the area of the bleb. So, we want to have a very well-centered rhexis, 5 mm, and that's what I have got here. It ensures a good toric IOL centration and that ensures excellent postop refractive outcomes.

[00:04:54]Hydrodissection is very gentle and controlled and it Remember in vitrectomized eyes, because there's a loss of support, every step would behave slightly differently.

[00:05:07]Now's the time to deal with the nucleus first and this is where a fluidic discipline matters most.

[00:05:13]We don't want a high infusion pressure, so I kept a bottle height of about 50 and reduced the flow and vacuum to compensate for it. And the nucleus is divided into smaller fragments using the direct vertical chop maneuver and each of these quadrants is emulsified in a very controlled manner.

[00:05:31]So, until the last piece was emulsified, we could ensure that there was a near zero chamber fluctuation and the emulsification was safe.

[00:05:41]The cortex aspiration is slow and deliberate and again, at every step we ensuring that the chamber is maintained well.

[00:05:48]The patient had a significant astigmatism and although this is an eye which has undergone surgery previously, I still thought that I would like to go ahead with a toric lens and the lens is placed in the bag and the OVD in front and behind the lens is being evacuated out by just irrigating it. During the last stages of you know, removal of the OVD, I can see some microbubbles, possibly the silicone oil coming up and they're just being cleaned up. Although the patient had prior silicone oil removal, the residual microbubbles can still persist. So, no need to panic.

[00:06:27]Just stay calm and just gentle aspiration would do the job for us.

[00:06:35]And the lens is carefully aligned to the premarked axis. So, even in these relatively complex cases, I think we can attempt to provide the best possible refractive outcomes what can get. And these are the postop pictures day one.

[00:06:51]There is some amount of AC reaction, the cornea is clear though.

[00:06:55]I can see these white microparticles, probably they are emulsified silicone oil. Just come up, I guess. The pressure is 14, the bleb looks healthy, there's no inflammation. One week later, the eye is quiet, the bleb is stable, and we have a very good visual recovery. The patient's best corrected visual acuity is 6/6 and So, the key takeaway from this case, you know, I'd be happy if you remember only a few things. Number one, protect the bleb at all costs. Ensure that the chamber stability is never compromised. At the same time, I would prefer always to work at a low infusion pressure. And this is very critical because we don't want fluid to gush in forcefully into that internal ostium and into the functioning bleb. So, accordingly, adjust the fluidics. The bottle height is low, so are the vacuum and a flow rate and the procedure is slowed down a bit, but it's still worth it. And expect surprises in these post-vitrectomized eye, especially in such situations where the eye is myopic and patient is relatively young. So, you've got a very elastic sclera to deal with. And of course, lastly, I would not compromise on any refractive planning even in these cases. This was the thought process regarding planning and implementation of performing cataract surgery in an eye with a functioning trabeculectomy bleb. I hope you found this useful. Thank you for watching.