Pores of the internal limiting membrane: A common finding in vitreo-maculopathies

PURPOSE: To describe presence and distribution of pores of the inner limiting membrane (ILM) in eyes with vitreomaculopathies.

METHODS: Inner limiting membrane specimens were harvested from 117 eyes of 117 patients during vitrectomy with membrane peeling from eyes with vitreomacular traction syndrome, idiopathic and secondary epiretinal gliosis, and idiopathic full-thickness macular hole. All specimens were processed as flat-mounts for immunocytochemistry and examined by phase-contrast, interference, and fluorescence microscopy. Demographic and clinical data were correlated.

RESULTS: Inner limiting membrane pores were found in all vitreomaculopathies. They were identified in 47 (40.2%) of 117 eyes being most evident with antilaminin. In eyes with full-thickness macular hole >400 µ m, pores were seen in more than half of all eyes. They occur as numerous and uniformly distributed defects of the flat-mounted ILM with a mean diameter of 9.5 ± 2.4 µ m. Edges of ILM pores are round with an irregular contour and no specific cellular pattern. Pores were distinguished from retinal vessel thinning and iatrogenic artefacts.

CONCLUSION: Contrary to previous reports, ILM pores are a common finding in vitreomaculopathies easily visible with antilaminin staining. Further studies are needed to clarify whether their presence correlates with differences in disease progression or imaging before and after vitrectomy with ILM peeling.