Slit Lamp, Corneal anatomy

[KLPM]

Most of the book descriptions I've seen says that you should examine the different layers of the cornea using the slit lamp. My question is I can see a bright, dark and bright band which I presume corresponds to the anterior surface, stroma, posterior surface of the cornea. But I can't really definitely say "that's the epithelium, Bowman membrane, stroma, Desmecet (?), endothelium".

Is it easier with an actual slit lamp? I am sure there are many aspects of the slit lamp I don't understand so please forgive my ignorance.

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[namams]

Most of the book descriptions I've seen says that you should examine the different layers of the cornea using the slit lamp. My question is I can see a bright, dark and bright band which I presume corresponds to the anterior surface, stroma, posterior surface of the cornea. But I can't really definitely say "that's the epithelium, Bowman membrane, stroma, Desmecet (?), endothelium".

Is it easier with an actual slit lamp? I am sure there are many aspects of the slit lamp I don't understand so please forgive my ignorance.

You'll only see the epithelium, stroma and endothelium. Bowman's layer and Descemet's membrane are too small for the microscope to resolve.

 

[orbitsurgMD]

Most of the book descriptions I've seen says that you should examine the different layers of the cornea using the slit lamp. My question is I can see a bright, dark and bright band which I presume corresponds to the anterior surface, stroma, posterior surface of the cornea. But I can't really definitely say "that's the epithelium, Bowman membrane, stroma, Desmecet (?), endothelium".

Is it easier with an actual slit lamp? I am sure there are many aspects of the slit lamp I don't understand so please forgive my ignorance.

The relative demarcations you are referring to are all you will see at the common magnifications at the slit lamp biomicroscope. The boundaries are inferred, since the resolution is not at the level typically seen in histological examination with light microscopy, and there is no tissue staining, obviously. If there is specific pathology present, you may see more of those features at those specific levels (like guttata in the endothelium), making those boundaries more clear. Even with the 30x mag--the highest available on any conventional slit lamps--resolution is not all that much better. A specular microscope will take you to the cellular level of the individual cells of the endothelium, which is what enables endothelial cell counting in patients with endothelial disease. If you are working in a big clinic, you might ask around to see if they have one that is working.

Most eye departments have Haag-Streit type slit lamps which with the standard eyepieces give you 10x and 16x mag. If the lamp has a complete accessory kit, there should be a pair of higher mag 16x eyepieces (standards are 10x) which with the 1.6x objectives will get you to 25x mag. If you have a Zeiss or Zeiss clone, those have a 30x, so maybe a little more detail. Remember, with the higher mag, field is much smaller, brightness is lower and the depth of field is much shorter.