Streaks (schlieren) as a sign of rhegmatogenous detachment in vitreous surgery.

Schlieren or streaks can be observed as light passes through incompletely mixed fluids having different refractive indices. During vitreous surgery, the vitreous humor is replaced by an aqueous solution whose density and refractive index differ from those of subretinal fluid. The observation of schlieren during vitrectomy therefore suggests the presence of subretinal fluid and a retinal hole. After observing this sign, a careful search should be made for the retinal break if it has not been previously diagnosed.