How can holography help microscopes examine deep narrow regions of an object?

Holography assists microscopes in examining deep, narrow regions of an object by overcoming the physical working distance limitations of standard microscope objectives.1

When a deep or narrow depression cannot be reached directly by a microscope, a hologram of the object can be created using coherent light. Once the hologram is reconstructed, it produces an aerial image of the original object. Because this reconstructed image exists in space, a microscope can be positioned to focus on the specific, otherwise inaccessible region within that image. This technique allows for detailed examination of areas that would be impossible to reach with traditional optical methods.1