This past Wednesday I had a patient with a retinal hole, so I performed a technique called scleral depression. Basically what happens is that a small blunt ended instrument - usually a thin metal rod, or a even a cotton-tipped applicator - is pressed onto the eye either directly onto the globe or indirectly against the outer skin of the eyelid. What happens is that the tip applies pressure onto the retina from the outside and creates a greyish bump as you view inside the eye with the BIO.

So what is the point of this? Scleral depression is indicated for patients that have suspicious looking holes in the retina. Before I discuss the mechanics, one should understand how retinal holes work. Holes can be caused by different reasons, including idiopathic causes (in other words, no obvious cause), or they can be caused by the vitreous (the gel in the eye) tugging on a spot on the retina, eventually pulling a piece off and creating a hole. To make it simple, take a look at the picture I made below. The retina is the reddish brown layer at the top, and the retinal pigment epithelium and choroid are combined as the second (red) layer. On the bottom left picture, note the gap in the reddish brown upper layer - that is the retinal hole.



When you push onto the outside of the eye with the depressor (indicated as the grey rod above), any holes in the depressed area can do one of two things: either they can stay flat or the edges of the hole sort of "flap up". The ideal situation is that the edges of the hole should stay flat, and this indicates that fluid is not likely leaking into the hole. Earlier I mentioned that a hole can look "suspicious." When there is a white cuff around the hole, this means that there can be leakage since the edges of the hole are lifted. This is demonstrated in the picture on the bottom right, where fluid can fill underneath the retina as indicated by the arrows. This is a dangerous situation because if fluid continues to build up under the retina, a retinal detachment can follow and that can make for a bad day for the patient.

As I mentioned earlier, a scleral depressor is applied either directly onto the eyeball or on the eyelid. You can use the lids when you are doing inferior or superior views, but when you are doing lateral views then you must apply the depressor directly onto the globe since there is little to no skin to place the depressor on. Scleral depression requires a lot of dexterity since you often have to juggle between holding the patient's lid open, holding the depressor at the precise location, and aiming the the BIO light perfectly onto the lens and aligned with the small opening of the pupil that's oriented off to the side. Just as it sounds, this is a pretty advanced technique and most optometrists do not perform it; scleral depression is usually left to the ophthalmologists.

We at SCCO were taught this briefly before, and I was able to do it once through the eyelid then, but this time I performed it on a patient directly on the globe...that was pretty intense! Of course, before you apply the depressor it's important to give the patient some anesthetic on the eye. My patient did not feel uncomfortable so it was a great opportunity for me to practice, and I even had the opportunity for the staff doctor walk me through the procedure as I was depressing the patient's eye. I didn't get to depress the hole directly but I did get to see the greyish bump move around inside after a few minutes of struggling to get the the perfect alignment - scleral depression is super tough!!!

Ultimately all optometrists should refer any hole that has a risk of further damage to an ophthalmologist. Holes can be a serious matter; remember that this blog should not be used for any kind of medical advice. If you ever see a hole, you should always use your best judgement and consider what is taught from your professors and textbooks as to when you should refer or not.