Abstract
Purpose: :
Recent studies report the presence of dissociated optic nerve fibers layer (DONFL) appearance associated with vitreoretinal interface remodeling after internal limiting membrane peeling for idiopathic macular hole. Here we evaluate the frequency and anatomic/functional significance of these defects, and their association with intraoperative brilliant blue G (BBG) dye.
Methods: :
A retrospective cohort study was conducted of all patients who underwent pars plana vitrectomy with internal limiting membrane (ILM) removal for repair of idiopathic macular holes by a single vitreoretinal surgeon (SC) over a 4 year-period and followed for a mean of 18.1 months (range 5 to 50). Half received intraoperative BBG. Anatomic and functional outcomes were assessed by spectral domain optical coherence tomography (OCT) and logMAR best-corrected visual acuity (BCVA), respectively.
Results: :
Thirty-two eyes from 30 patients were included in the study. At 1, 3, and 12 months post-operatively, 20%, 70%, and 86% of the eyes were noted to exhibit surface dimpling associated with the DONFL appearance, respectively. Ultimately, 96% of the group developed this appearance, with a mean onset of 143 days (range 20 to 766) after surgery. Among the 16 eyes that received BBG intraoperatively, 15 (94%) demonstrated dimpling. Among the 16 eyes that underwent removal of ILM without BBG, 12 (75%) demonstrated dimpling. Of the 5 eyes without dimpling, 4 (80%) had detectable ILM on OCT, while 1 had incomplete closure of the macular hole. Final central macular thickness (CMT) among affected eyes was 250 +/- 46 (mean +/- standard deviation, in microns) vs 241 +/- 58 among unaffected eyes (p > 0.695, unpaired, two-tailed t-test). Final post-operative BCVA among those with dimpling was 0.24 logMAR, a gain of 0.39 logMAR from baseline, as compared to 0.18 logMAR (0.32 logMAR gain) among those without dimpling (p > 0.410).
Conclusions: :
Macular hole surgery may be associated with a late-onset DONFL appearance, which do not appear to affect post-operative BCVA, gain in BCVA, or OCT CMT. Patients that underwent BBG-assisted ILM removal showed a greater frequency of dimpling, which may be a reflection of a more thorough removal of the ILM scaffold, since eyes without this appearance tended to demonstrate persistent ILM, regardless of use of intraoperative BBG.
Keywords: macular holes • retina • imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound)