13.6  Retinal Dialysis

Retinal dialysis refers to detachment of the retina from the ora serrata. Over two-thirds occur secondary to blunt ocular trauma[1] and are therefore most common in young males. A retinal detachment may be present as well. The mechanism of these detachments differs from rhegmatogenous retinal detachment in the sense that the vitreous is typically attached in these eyes and the vitreous base is attached to the posterior portion of the retinal break. This gives rise to other typical characteristics of these cases: these detachments progress slowly and often present with demarcation lines[1] and the diagnosis is delayed over one month in 80% of cases. Three-quarters occur in the inferotemporal quadrant. Retinal dialysis should be treated with photocoagulation or cryopexy as prophylaxis for retinal detachment. Scleral buckling with a tire (e.g. no. 286 or 287) remains the treatment of choice for retinal detachment secondary to retinal dialysis, with up to a 98% reattachment rate. External drainage of subretinal fluid is usually not required unless the detachment is very extensive. Cryotherapy should be applied to the anterior horns and the posterior edge of the dialysis. The element should be placed to support the break, which will be relatively anterior at the vitreous base.