Microanatomy of Internal Limiting Membrane

Microanatomy of Internal Limiting Membrane P.V. Lyskin, V.D. Zakharov, M.I. Zgoba The S . Fyodorov Eye Microsurger y Federal State Inst i tut ion , Moscow Introduction. Currently there are only fragmentary and inconsistent studies of the vitreoretinal interface and the internal limiting membrane (ILM). It the available literature we did not succeed in searching for the necessary data on the actual anatomy of the ILM in various areas of the retina. In order to clarify microanatomy of the vitreoretinal interactions we performed our own studies. Purpose. To clarify microanatomy of the ILM in its central and peripheral areas by means of the scanning electron microscopy (SEM) imaging. Material and methods. A study of peculiarities of the ILM area using cross-sections of the human eye from the extreme periphery of the retina close to ora serrata, and to the equatorial and macular areas by means


Introduction.
Currently there are only fragmentary and inconsistent studies of the vitreoretinal interface and the internal limiting membrane (ILM).It the available literature we did not succeed in searching for the necessary data on the actual anatomy of the ILM in various areas of the retina.In order to clarify microanatomy of the vitreoretinal interactions we performed our own studies.
Purpose.To clarify microanatomy of the ILM in its central and peripheral areas by means of the scanning electron microscopy (SEM) imaging.
Material and methods.A study of peculiarities of the ILM area using cross-sections of the human eye from the extreme periphery of the retina close to ora serrata, and to the equatorial and macular areas by means of SEM imaging.
Results.Results of our studies show that the ILM at the periphery of the retina is 4-5 µm thick, has a loosely organized fibrous structure, and has no distinct boundary with retina.Fibrils of the vitreous at the periphery of the retina braided into the retina in a parallel manner rather than perpendicularly.Approaching the center, the fibrous structures at the retinal surface become denser and thinner.Closer to the equator, there is formed the ILM structured as a membrane of 1 µm thickness.In the macular zone the ILM has the least thickness of 250 nm.In the macular zone the ILM is mono-structural without any signs of pores or similar formations.A kind of finding was a micro-anatomic pattern at the joint site between vitreous and retina at the far periphery where, there were no distinct boundary between the retina, ILM, and vitreous with boundary region formed by the layer of sparsely packed collagen fibrils.Refined data fairly prove ILM thinning on the way from periphery towards the center.Офтальмохирургия. 2019;1:39-43. Fyodorov Journal of Ophthalmic Surgery. 2019;1:39-43.

Рис. 3 .
Fig. 3. SEM of the retina in the ILM area SEM of the retina in the ILM area corresponds to the area 1 on the schematic eye.No evident boundary between the retina and ILM.Structure corresponding to the ILM consists of parallel sparsely packed fibers.Thickness of the fibrous structure corresponding to the ILM is shown with a double-arrow.The thickness is 4.5 µm

Fig. 6 .
Fig. 6.Equatorial area (area 4 on the scheme).Boundary between the retina and ILM became more evident.ILM is almost monostructural.Thickness of the fibrous structure denoted by two arrows is 1.5 µm

Fig. 5 .Fig. 7 .
Fig. 5. SEM of the para-equatorial area of the retina (area 3 on the scheme).Thickness of the fibrous structure is denoted by two arrows is 1.5 µm