Purpose
To determine the effect of using brilliant blue g (BBG) for complete internal limiting membrane (ILM) peeling during idiopathic macular pucker surgery on long-term visual acuity and optical coherence tomography (OCT) outcomes.
Methods
A retrospective, cohort study was performed on records from 66 patients with unilateral idiopathic macular pucker who underwent vitrectomy and membrane peeling by a single surgeon (SC) during the period from 1/1/08 to 12/31/12 with follow-up ≥2 years. Cases in which the ILM was stained with BBG to facilitate “double peeling” (n = 28) were compared to cases without the use of BBG (“single-peel,” n = 38). Comparison between the single and double peeling groups were made at 0.25, 0.5, 1, 2 and 3 years for best-correct visual acuity (BCVA) and spectral domain OCT topographic changes (dimpling of the nerve fiber layer (DNFL), persistent cystoid macular edema, macular hole formation, presence or absence of epiretinal membrane (ERM) tissue on OCT in the parafoveal region at last follow-up and change in macular thickness). For continuous variables, an independent 2-tailed t-test was used; and for binary variables, the Fisher exact test was used. Statistical significance was defined as p < 0.05.
Results
Patients in the single-peeling group were more likely to have epiretinal membrane remaining in the central fovea postoperatively (p = 0.0424) and less likely to develop DNFL defects (p = 0.0017). LogMAR BCVA was found to be marginally different (p=0.085) between the 2 groups at postop month 24 with the double peel group with better BCVA (0.176+/-0.162, mean+/-SD) versus the single peel group (0.326+/-0.420). Interestingly, decrease in CFT (from baseline) in the double peel group (-109.1+/-94.2µm) was less than the single peel group (-161.9+/-131.5 µm, p=0.090) at postop month 24. This difference was more pronounced at postop month 36 where the decrease in CFT (from baseline) in the double peel group (-57.8+/-91.9µm) was significantly less than the single peel group (-147.6+/-96.7µm, p=0.007).
Conclusions
BBG-assisted ILM peeling for idiopathic macular pucker results in a more thorough removal of residual ERM around the paracentral fovea however there is a greater likelihood of DNFL and a slower return of CFT to normal levels.