PMMA Sclerals

[Drew Radcliffe]

Hi All

Forgot to ask a question or two at moorfields the other day so was hoping someone might be able to guide me.

Moorfields have made me a fenestrated PMMA scleral lens from an impression to try for a while. If I get on with it they will make an RGP of the same.

I know the Oxygen transfer rate for PMMA is virtually nil, I know that poor oxygen transfer can cause vasuclarisation of the cornea if left unchecked. Has anbody previously been given a guide to the maximum daily wear times for this type of lens? Are there any obvious associated symptoms to look out for so I can be proactive and take them out if need be?

Thanks

Drew

[jayuk]

Drew

Varies from eye to eye......some may be ok upto 12 hours a day, others 30 mins.......

With regards to vascularisation...many times its not visible to the naked eye...and its often picked up under the slit lamp...however I am led to believe that this occurs over time...ranging from few weeks to few months...... so I guess kinda hard one to answer..

[rosemary johnson]

Hi there,
I used to wear fenestrated PMMA sclerals.
the fenestrations are there to allow ocygen interchange. They're the best way, with PMMA, of allowing air in and out I experienced with PMMA.
Wearing time varies with the wearer, the weather, hay fever, colds, phase of the moon, etc.
Signs that the wearing time is running out and you should take them out - well, nothing surprising, really. Eye hurts, eye looks red in mirror, eye getting sticky, can't see out of it so well as one used to be able to.
Good luck with the sclerals - hope they work out for you.
Rosemary