Quiz: Persistent Corneal Edema – Why?

corneal edema why

This 70 year old patient had successful cataract surgery about one month ago. There were no complications. The patient has a history of Flomax use and dilates to about 6 mm with topical mydriatic medications. The pre-op vision was 20/60 with a 3+ nuclear cataract and 2+ posterior subcapsular changes as well. The stop-and-chop technique of nucleus removal was used and the patient received a monofocal single-piece IOL in the capsular bag. Again, there were no complications during surgery. On post-op day 1 the vision in this eye was 20/40 and now after one month of healing the vision is 20/25 with a close to plano refraction. When you look at the slit-lamp you see inferior corneal edema. Why?

When we change the lighting at the slit-lamp microscope and adjust our viewing angle we can see that there is a retained cataract fragment at the inferior angle. This small piece of the cataract is causing inflammation and focal corneal edema. What are the options now?

retained cataract fragment

For a retained cataract fragment, we need to determine if it is a piece of nucleus or a tuft of cortex. Nuclear pieces are denser and will require more time to dissolve in the inflammatory cascade, whereas cortical fragments tend to be wispy and cotton-like. The cortex will swell to double or triple the size when exposed to the aqueous.

Here are our options:

  • observation – this is reasonable for small cortical fragments that are not obstructing the vision. The eye will have prolonged inflammation but slowly over the course of a few weeks, the cortical piece will dissolve. The lens piece may cause focal corneal endothelial cell loss and iris synechiae.
  • YAG laser disruption – we can use the YAG laser to break the cortical fragment into smaller pieces. This will increase the surface area to volume ration and allow the lens material to dissolve faster. This is the same principle behind crushed ice melting faster than a large ice cube. Keep in mind that this will temporarily cause a high intra-ocular pressure (IOP) so topical IOP-lowering medications and oral acetazolamide may be required for a few days.
  • return to operating room – we can also return to the operating room and then, under sterile conditions, go back inside the eye and remove the piece. This is the quickest solution and most effective, but it does require a second trip to the operating room. The original incision can be used and this procedure takes just a minute or two.

How can we prevent a retained lens fragment at the time of cataract surgery? Do a thorough washout of the viscoelastic at the end of the procedure and if the patient does not full dilate, lift up the iris and look under it to ensure that no cataract pieces remain.

Click below for a video where we lift the iris at the end of the case to check for this:

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  1. The lens fragment or tuff of cortex, when it causes inflammation resulting in corneal oedema, there is only one option -surgically remove it. No question of observation or laser treatment. Even the fragment is not causing symptoms it should immediately removed.

  2. On what timeline do you return to the operating room for a retained nucleus fragment? One day? One week? Would you return sooner if the IOP was high and not coming down with medical management? How would the timeline change if it were just retained cortex?

    1. The sooner, the better. Even for retained cortex, the most I would want to wait is a week. If any nuclear pieces in the vitreous, refer to a vitreo-retinal colleague

  3. Timing of the procedure plays critical role in the ratio of success. The faster the batter. The challenge is in developing nations like India where the govt is spending a lot of money for making people aware of cataract surgery and other eye procedures but the situation of govt eye hospitals in b and c class cities is way to difficult.

    Since the majority of indian popluarion still live close to the povery line access to provate hospital is not a feasble option.

    I hope Professionals like Uday Devgan and Dr Narayan Bardoloi will come forward and push the IMA and Health bepartment to establish a PPP model in eye health domain

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