Trabeculectomy in patient with prior vitrectomy: helpful hints?!

On Tuesday 16th March 2010, @robschertzer said:

#surgery 71 yo asian M trabMMC traumatic #glaucoma s/p Si oil mini-port PPV; went better than expected. 1st Q from pt-when can play badminton again (trauma was from shuttecock!) Vid to follow.​

​Badminton shuttle cock

I frequently encounter patients who have had multiple prior intraocular surgeries and are in need of glaucoma surgery. Although tempting to jump right to a glaucoma drainage implant, would it be possible in certain patients to opt for a mitomycin trabeculectomy and save the glaucoma drainage implant if really needed at a later date? In previous years, I probably would have gone right to an Ahmed Glaucoma Valve for the patient referred to in my tweet but on clinical examination, despite at least two vitrectomies (one including silicone oil,) there appeared to be adequate conjunctiva present superiorly to perform a trabeculectomy. I suspect that the advent of small-guage vitrectomy may be part of the reason that this was possible for this patient.

Here is the movie of this particular surgery with a voice-over commentary describing the steps and the thought processes. One point being made is the use of a 30-guage needle to help dissect the scarred conjunctiva off the underlying sclera. Also notice how shapeless the eye becomes by the end of surgery when placing the last suture; this is from the prior vitrectomy. In some patients, the overlying conjunctiva is too damaged from the previous surgeries, but this was not the case for this patient. I was therefore able to perform a mitomycin trabeculectomy and have adequate conjunctiva to achieve a filtering bleb.

Although I expected this surgery to take longer because of the prior surgery, it was still completed in under 20 minutes and looks even better massively edited for this posting.