Closed microsurgery for diabetic traction macular detachment.

Ischaemic diabetic retinopathy may be complicated by multiple outgrowths of fibrovascular tissue on to the retinal surface within the most cortical part of the vitreous gel, typically along the major vascular arcades and nasal to the optic disc. Tangential traction, exerted by contraction of the coalescent epiretinal membranes, results in distortion, folding, and detachment of the underlying retina. This process is frequently exacerbated by traction along the detached posterior hyaloid interface between the vitreous base anteriorly and the epiretinal membranes into which the gel is incarcerated posteriorly (anteroposterior traction) or between individual sites of fibrovascular proliferation (bridging traction). A retinal break, usually sited immediately peripheral to the avulsed edge of a posterior fibrovascular membrane, may also contribute to retinal separation by allowing exchange of fluid between the retrohyaloid and subretinal spaces. The fovea, which is usually free of overlying vasoproliferation, may eventually become detached, with consequent serious impairment of vision. Closed microsurgical techniques can be used to eliminate each of the elements of vitreoretinal traction described above and to seal retinal breaks, thus allowing the macular retina to reattach with some restoration of central visual function. We present the results of closed microsurgery performed for diabetic traction macular detachment in the Surgical Vitreoretinal Unit at Moorfields Eye Hospital. The surgical prognosis is correlated with the extent of preoperative epiretinal fibrovascular proliferation.