An intumescent white cataract is where the cortex has become opaque and liquified which increases the pressure within the capsular bag. When we try to perform a traditional capsulorhexis in these cases, this pressure gradient can push the nucleus up against the back of the anterior capsule, resulting in an irregular tear out often called the Argentinian Flag Sign.
The key in these cases is to neutralize the pressure gradient and decompress the capsular bag. This can be accomplished in many ways:
- The double-rhexis technique is where the anterior chamber is inflated with viscoelastic so that it achieves a pressure higher than the intra-capsular pressure. Then via a paracentesis a small central capsulorhexis is made, the capsular bag is decompressed, and then the main incision is created and a standard size capsulorhexis is performed.
- We can use a femtosecond laser or electro-mechanical device to quickly create the capsulotomy. Be aware that this can sometimes lead to an incomplete capsulotomy.
- The phaco probe can be used to punch a hole in the center of the capsular bag in order to aspirate the liquified lens cortex and release the pressure gradient.
- A small 27g needle can be used to puncture the anterior lens capsule and aspirate out much of the liquified cortex which will decompress the capsular bag and release the pressure gradient. Note that we still need the anterior chamber to be pressurized during this procedure to prevent an errant capsular tear out. Click below to see this technique.
Click below to see a resident perform this needle puncture technique:
Intumescent white cataract is a challenge, however when I try to do rhexis with the cystotome after decompressing the capsular bag I find it difficult because of the lack of support behind the capsule. However in that situation possibly the utrata forceps rhexis is a better option. Unfortunately I’m not that adept with the forceps and so to do the rhexis with capsulotomy needle I massage the globe sufficiently to reduce vitreous volume and then fill the Anterior chamber with Visco to create more space in the AC plus overfill it to equalize the pressure with that in the capsular bag. Would this be a strategy to follow or have I been lucky so far 🙂
Yes, if you fill the anterior chamber with enough viscoelastic that the AC pressure is higher than the pressure in the fluid-filled capsular bag, then you have a higher margin of safety. Use the double-capsulorhexis technique in this case, with just the cystotome.