The illumination when assessing with the slit lamp is crucial, as for example when assessing the fluid reservoir thickness that we need to note and compare with that observed during the next follow-up visits, verifying further lens settlement. The ocular surface area we are assessing, if not well illuminated, may not be clear (Figure 1).
Figure 1. Assessment of the fluid reservoir thickness. The area assessed is not well denoted. It is not clear if it is the central, mid-peripheral, or peripheral corneal area.
By slightly illuminating the eye, it is possible to see and document exactly the area we are evaluating (Figure 2).
Figure 2. Illuminating the eye, we can document the exact area we are assessing. Upper Image- Central cornea. Lower image- Peripheral cornea.
How to do this?
Some slit lamps have a lamp attached, so you just have to turn it on and position it near the eye you are observing (Video 1).
If the slit lamp does not have this built-in light, it is possible to buy a seperate lamp and position it on your slit lamp. It will light up the eyes and make the evaluation easier (Figure 3).
Examples of lamps to add to your slit lamp:
https://www.amazon.com/LuminoLite-Rechargeable-Brightness-Bookworms-Players-USB/dp/B073RFW8WD/ref=sr_1_22?dchild=1&keywords=Topelek%20light&qid=1612118176&sr=8-22&fbclid=IwAR3iCRP8E_r-1IzluQ6OMBPq0Gjf69U37hwpE9L-gbX_JEzqyw5iaKGqTIU
Figure 3. A led lamp positioned on the slit lamp to illuminate the eye during the evaluation.