Epiretinal membrane removal in diabetic eyes: comparison of viscodissection with conventional methods of membrane peeling

Abstract

Aims: To compare conventional methods of epiretinal membrane peeling with viscodissection.

Methods: 154 eyes with proliferative diabetic retinopathy (PDR) that underwent pars plana vitrectomy with membrane dissection (89 traditional, 65 viscodissection) were studied retrospectively. Incidence of retinal breaks (RBs), length of time under anaesthesia, postoperative intraocular pressure, retinal reattachment rate, and final visual acuity (VA) were measured.

Results: To compare cases of similar complexity, a "complexity score" was defined. The average complexity score for cases done with and without viscodissection was 4.7 and 3.2, respectively. The mean frequency of RBs in eyes undergoing viscodissection was 0.43 (SD 0.5) v 0.14 (0.35) RBs/eye without viscodissection. In complex cases, the frequency of posterior/peripheral RBs was 0.31 (0.47)/0.13 (0.34) RBs/eye, respectively, with viscodissection v 0.12 (0.33)/0.23 (0.43) RBs/eye without viscodissection. None of these differences were statistically significant. The average preoperative/postoperative VA (logMAR) in the viscodissection cohort was 1.7/1.3 (range 0.3 to >1.9/0.1 to >1.9) v 1.4/1 (range 0.48 to >1.9/0.1 to >1.9) in the non-viscodissection cohort, among eyes with 6 months of follow up. Anaesthesia duration was significantly shorter for cases done without viscodissection (p=0.03), but cases done with viscodissection were significantly more complex than cases done without viscodissection (p<0.0001).

Conclusion: Viscodissection appears to be a safe and effective alternative technique in eyes with PDR. Owing to the retrospective nature of the study, additional studies are warranted.

Figure 1

Surgical indications: all cases (154 eyes). Tractional retinal detachment (TRD) in 33 (21.5%) eyes. Traction-rhegmatogenous retinal detachment (TRRD) in 19 (12.3%) eyes. Traction retinal detachment with vitreous haemorrhage (TRD+VH) in 75 (48.7%) eyes. Non-clearing vitreous haemorrhage (VH) in 20 (13%) eyes. Neovascular glaucoma with vitreous haemorrhage (NVG/VH) in three (2%) eyes. Macular oedema with a taut thickened posterior hyaloid face (ERM/CMO) in four (2.5%) eyes.

Figure 2

Distribution of cases by complexity score and surgical technique. Cases done with viscodissection were significantly more complex than those done with pick and scissors dissection alone. See text for details.

Figure 3

Anatomical outcomes. Outcome is reported for those cases with 6 or more months of follow up (101 eyes total). With 6 months or more follow up, the retina was fully attached in 36/43 eyes (84%) done with viscodissection and 55/58 eyes (95%) done without viscodissection.

Figure 4

Visual outcome (expressed as logMAR) after vitrectomy: viscodissection v no viscodissection. (With logMAR, better visual acuities correspond with smaller numbers.) Data are reported for eyes with 6 months of follow up (n=43, viscodissection; n=58, no viscodissection).