Fine structure of the human retina defined by confocal microscopic immunohistochemistry.

Introduction: Research in to the pathophysiology of the complex layers of retinal and sub-retinal cells is hampered by inadequate recognition of particular cells and tissues. A comprehensive panel of antibodies recognising retinal tissues is lacking. Our purpose was to determine the value of a panel of antibodies labelling various cells in the human retina.

Method: Five groups of antibodies labelled frozen sections of retinas: (1) protein kinase C-α, Glutamine Synthetase (GS) and ionized calcium-binding adapter molecule 1 (Iba1); (2) Parvalbumin, Calretinin and glial fibrillary acidic protein (GFAP); (3) Thy1, GS and Iba1; (4) Rhodopsin, GS and Iba1; and (5) Brn3a, Rhodopsin and protein kinase C-α. The distribution of these antigens were determined by confocal microscopy and calculated grey value of each antibody in each layer of the retina by Image J.

Results: Different antibodies determined certain retinal layers. Thy 1 is a good determinant of the ganglion cell layer, whilst GS is present in all layers except the photoreceptor layer. Brn3a is specific for the ganglion cell layer whilst parvalbumin marks the ganglion cell layer and the outer plexiform layer. Rhodopsin strongly marks the photoreceptor layer, but this is also marked weakly by GFAP.

Conclusion: The multiple labelling of human retinal cells brings further understanding of the biological characteristics and functions of these cells, and provides a theoretical basis for their possible role in diseases. In the growing field of human retina research, our data may provide a point of reference for future studies of the human retina.