Three people from Lausanne, Switzerland, including Carl Herbort who has been very supportive of BUS, have looked at the retinas of 28 Birdshot eyes and retrospectively evaluated the OCT findings of these eyes, to see what changes there are in the retina over a long period of time.
They looked at the OCT results in early Birdshot (less than 1 year), intermediate (1 to 6 years) and late (more than 6 years).
What they found was that in early Birdshot, the retinal thickness was significantly elevated (i.e. it was thicker than usual) because of the inflammation and vasculitis. The thickness begins to diminish in intermediate Birdshot and by late Birdshot, the retina is significantly thinned. They also observed that 92% of these eyes had developed an epiretinal membrane by late Birdshot. An epiretinal membrane is a thin sheet of fibrous tissue that grows over the retina. For those of us with Birdshot, an epiretinal membrane may develop because the vitreous (the jelly inside our eyes) pulls away from the retina due to the inflammation. Epiretinal membranes can cause visual problems, although most of us with an epiretinal membrane do not even notice any issues.
The interesting thing about this research is that if some-one has had a delayed diagnosis, their OCT results may help determine approximately how long they have had Birdshot for.
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