[Comparison of pars plana vitrectomy with ILM peeling and intravitreal triamcinolone in diffuse diabetic macular...

Visual outcome and anatomic results in patients with diffuse diabetic macular oedema (DDME) were evaluated after vitrectomy with internal limiting membrane (ILM) peeling versus intravitreal triamcinolone acetonide (TA).

A prospective, non-randomised pilot study included 41 eyes (35 patients) with clinically significant DDME. In 24 eyes (group A) we performed pars plana vitrectomy with ILM peeling. Seventeen eyes (group B) received an injection of 10 mg TA. Best corrected visual acuity and central macular thickness (measured with OCT) were determined preoperatively as well as 1 and 4 months postoperatively.

In group A, OCT showed a macular thickness of 403 +/- 142 microm preoperatively. Best corrected visual acuity was 0.24 +/- 0.18. One month after surgery, macular thickness decreased to 311 +/- 62 microm (p = 0.06 ns) and visual acuity was 0.17 +/- 0.14 (ns). Four months after surgery, macular thickness remained significantly lower compared with preoperative values, at 307 +/- 161 microm (p = 0.012). There was a tendency towards a higher visual acuity of 0.30 +/- 0.26 (p = 0.32 ns). Before TA injection, macular thickness in group B was 551 +/- 180 microm and visual acuity was 0.19 +/- 0.14. One month after TA, macular thickness decreased to 242 +/- 82 (p = 0.001) microm while visual acuity increased to 0.31 +/- 0.21 (p = 0.005). At 4 months follow-up, group B showed recurrence of macular oedema. Compared with the preoperative findings macular thickness was significantly lower (368 +/- 159 microm; p = 0,001). Best corrected visual acuity after 4 months was 0.27 +/- 0.17 and did not differ significantly from the preoperative visual acuity (p = 0.033 ns).

Intravitreal TA as a single treatment reduces the extent of DDME within a short time after surgery. These promising results may not be stable during long-term follow-up, necessitating in many cases a re-injection of TA. Macular oedema reduction after vitrectomy with ILM peeling, however, remains stable for more than 4 months and, therefore, offers more permanent results. However, none of these treatments facilitated a significant visual acuity restoration 4 months postoperatively.