16.
Vitrectomy with or without ILM-Peeling
in Diabetic Macular Edema
Horst Helbig (Regensburg)
The gold standard for the treatment of diabetic macular edema (DME), based on the results of
large randomized controlled clinical trials, still is laser coagulation. Clinical experience however
has shown disappointing results in diffuse forms of DME. Vitrectomy is the standard of
care for complications of proliferative diabetic retinopathy. It has been observed however, that
diffuse DME improved after vitreous surgery, especially when a taut attached hyaloid membrane
was removed from the macula. Many case series have been described so far, showing
more or less reduction of DME after vitrectomy. Functional results however were disappointing
in most series. Another unsolved question is, whether the ILM should be removed. Small comparative
case series do not give clear answers.
Introduction of OCT in the preoperative diagnostics has shown that in some cases vitreofoveal traction is present, not visible
on biomicroscopy alone. In other cases however no tractive component is present and DME nevertheless improved after
vitrectomy. Possibly, removal of a cytokine depot in the vitreous on the retinal surface and improvement of oxygen supply to
the inner retina may contribute to the observed therapeutical effects.
In contrast to intravitreal drug injections, vitrectomy offers a long term positive effect without the necessity for repeated
treatments. On the other hand, the potential for complications is high with vitreous surgery. Recent developments have introduced
new therapeutic options for the treatment of diffuse DME but the optimum strategy has not been defined yet. Clinical
trials are urgently needed to compare the effects of laser, vitrectomy and intravitreal injections of anti-VEGF drugs and
triamcinolone.