Diabetes Mellitus: Pan-retinal Photocoagulation
These gray-white spots are full-thickness wipe-outs of retina and choroid. The white color is from underlying sclera.
These spots are caused by laser photocoagulation burnsa deliberate treatment of proliferative diabetic retinopathy called scatter laser photocoagulation (pan-retinal laser photocoagulation). A wider view of the fundus would reveal burns scattered throughout the retinal periphery. In this patient, laser therapy has eliminated retinal neovascularization within three months.
How does this rather primitive "carpet-bombing" of the retina work? Perhaps by killing off ischemic retina, which elaborates an angiogenesis factor. Whatever the mechanism, collaborative NIH trials have proven this technique highlythough not uniformlysuccessful.
This retina had impressive before treatment. Three months after treatment, you can see that all new blood vessels are gone.
The chorioretinal scars you see here are more often caused by inflammation or trauma. To avoid confusion with other yellow-white spots in the retina, check out Yellow-White Things in the Retina.