Hopefully you are aware of this but angle closure glaucoma in all its variants acute, chronic, intermittent tends to run in families (and of course occurs almost exclusively in hyperopic/farsighted people). So it is critical that all your blood relatives know about your acute glaucoma problem and have their own eyes checked regularly especially after age 40 by an Eye MD ophthalmologist whom they have told about your problem.
Their also is a higher incidence of OPEN angle glaucoma in eyes that have had LPI and/or acute/chronic/recurrent angle closure glaucoma
JCH MD
Surface irregular astigmatism due to very superficial scarring or corneal epithelial disease such as basement membrane disorder is relatively easily treated and can be done in USA. Uses eximer laser to remove superficial cornea then put on bandage contact lens. One of most common causes of irregular astigmatism is people who have had RK surgery. It can be helped but because the scars extend 90% through the cornea cannot be eliminated. Keratoconus is a common cause and cannot be treated with laser. I suspect irregular astigmatism due to a glaucoma trabeculectomy would not be able to be treated in US or elsewhere since the corneal warping comes from the large incision at the limbus Superiorly.
I think he buried the lede and that the major question after those details is: "In the mean time I need to find out more about correction of irregular astigmatism and whether there are any laser options. ". I haven't had reason to explore the various laser surgery options in detail, just in passing I'm aware the laser systems continually make advances in analyzing corneal topography and planning how to treat it, but I don't know the current state of the art and its limits. His profile indicates he is in the UK (the mention of a trifocal as an option gave a clue he is outside the US) so he'd likely have access to newer tech than we have.
I would avoid any type of multifocal or accommodating IOL in an eye with irregular astigmatism. The safest and least likely to cause troublesome ghosting, dysphotopsia, flare, glare, etc would be a high quality aspheric monofocal IOL. If the surgeon thinks a toric might be acceptable you might consider that. Know that aligning a toric IOL in the proper axis is much more difficult with irregular astigmatism and a trabeculectomy bleb. Know also that there is some risk of the bleb failing during the healing process and your glaucoma could get worse not better.