Immunofluorescence analysis of internal limiting membrane: Insights into formation of inner retinal dimples.

BACKGROUND

To investigate the relationship between components of internal limiting membrane (ILM) and inner retinal dimples (IRDs) after ILM peeling.

METHODS

This study included patients with full-thickness macular hole (FTMH), epiretinal membrane (ERM) and myopic foveoschisis (MF) who underwent pars plana vitrectomy with ILM peeling. The number of IRDs was determined using en face optical coherence tomography (OCT) at 1 month (1 M) and 12 months (12 M) after surgery. The status of Müller cells and the degree of laminin loss were evaluated using the average immunofluorescence intensity and fluorescence area of glial fibrillary acidic protein (GFAP), aquaporin-4 (AQP4) and laminin (LAMA1) antibodies at peeled ILM. Pearson correlation and multiple linear regression analyses were performed to detect the association between components of ILM and IRDs.

RESULTS

Twelve FTMH cases (12 eyes), 14 MF (14 eyes) cases and 9 ERM cases (9 eyes) were included. Pearson analysis showed that the number of IRDs at 1 M was correlated with the average fluorescence intensity of GFAP (+) (r = -0.440, p = 0.008), area of GFAP (+) (r = -0.640, p < 0.001), and average fluorescence area of LAMA1 (+) (r = 0.600, p = 0.004). IRDs at 12 M was correlated with the average fluorescence area of GFAP (+) (r = -0.706, p < 0.001). Multiple linear regression analysis found that only the average fluorescence area of LAMA1 (+) was significantly correlated with IRDs at 1 M (β = 0.517, 95 % CI: 0.182-0.982, p = 0.007).

CONCLUSION

The number of postoperative IRDs is correlated with the glial response status of Müller cells at inner retina and the degree of laminin attached with peeled ILM.