The history poses the question of managing a dense, subluxated posterior polar cataract. I would use a combination of strategies based on the principles of managing a dense cataract, subluxated cataract, and posterior polar cataract.
The surgical paradigms are as follows:
- Using a closed chamber technique to reduce the stress on the zonules and capsule.
- Stabilizing the bag during lens removal to reduce the stress transmitted during phacoemulsification and to prevent aspiration of the capsule into the phaco tip.
- Performing inside-out delineation to create a mechanical cushion of cortex–epinucleus that protects the posterior capsule during subsequent stages of emulsification.
- Using a step-by-step chop-in-situ and lateral separation technique to divide the nucleus without transmitting stress to the compromised zonules and produce multiple small fragments.
- Doing slow-motion phacoemulsification to maintain a closed chamber to reduce forward bulge of the nucleus and maintain a stable anterior chamber.
During the preoperative examination, I would inform the patient of the possibility of relatively longer operative time, dropped lens material, likely delayed visual recovery, and a secondary posterior segment intervention.
Intraoperatively, I would use topical anesthesia. I would inject OVD through the paracentesis created in the superior and inferior clear cornea using the soft-shell technique to compartmentalize the anterior and posterior segments; this would be followed by a single-plane temporal clear corneal incision. I would use a 15-degree slit knife to initiate the capsulorhexis, which would be completed using a forceps. I would stabilize the bag using 3 to 4 Grieshaber iris hooks introduced through the paracentesis. These hooks stabilize the bag by anchoring the capsulorhexis margin. I would avoid corticocleaving hydrodissection and rotation.
When performing phacoemulsification, before removing the probe or irrigation handpiece, I would inject high-viscosity OVDs through the side port to prevent forward movement of iris–lens diaphragm. I would sculpt using supraoptimal power, a low flow rate of 16 cc/min, and a low bottle height. Once adequate depth is achieved, I would do inside-out delineation by injecting fluid within the lens substance from the right and left walls of the crater. A golden ring would indicate the end point of delineation. Next, I would divide the delineated nucleus into multiple small pieces using the chop-in-situ and lateral separation technique. This would be followed by emulsification of the fragments using the slow-motion technique within the confines of the cortex–epinucleus cushion. Use of interrupted mode of energy (ie, burst or pulse mode) dissipates less US energy and causes the least damage to the anterior segment structures. I would perform all procedures while the iris hooks fixate the bag.
If the posterior capsule is intact, I would introduce a prethreaded single-eyelet Cionni CTR through the main incision and implant it in the bag in the plane between capsule and cortex–epinucleus. I would rotate it to place the eyelet at the clock hour corresponding to the area with the most zonular dialysis. The suture would remain attached to the ring. I would then remove the iris hooks. If required, I would perform multiquadrant corticocleaving hydrodissection to facilitate bimanual I/A of cortex but would avoid capsule polishing. Next, I would suture the Cionni ring to sclera. If the anterior capsulorhexis is small or eccentric, I would enlarge it using the initial and definitive capsulorhexis technique to remove excessive capsule. I would implant an AcrySof Natural IOL (model SN60AT) in the bag.
If the posterior capsule is ruptured, I would inject a dispersive OVD through the side port before retracting the instrument from the eye. This would be followed by a bimanual vitrectomy performed using low bottle height. I would convert the posterior capsule tear to a posterior continuous curvilinear capsulorhexis (PCCC). If the PCCC is small and central, I would implant a Cionni ring and AcrySof IOL in the bag, described as above. If the PCCC is large, I would not implant a Cionni ring but rather scleral fixate a poly(methyl methacrylate) IOL with eyelets. The leading haptic would be implanted in the bag, while the trailing haptic would be scleral fixated in the sulcus. I would not excise the capsular bag because even if the peripheral bag contracts, the central visual axis remains unaffected.
I would remove the OVD with a vitrector if a vitrectomy is needed or with bimanual I/A if there is no vitreous prolapse. The main incision and all the paracentesis would be sutured. I would inject pilocarpine to confirm absence of vitreous in the anterior chamber.
The postoperative regimen would include separate topical steroid, antibiotic, nonsteroidal antiinflammatory drug (NSAID), cycloplegic, and IOP-lowering eyedrops. Oral NSAID/steroids would be given depending on the postoperative inflammation. Fundus evaluation of the peripheral retina would be done at the earliest possible time.
I would postpone cataract surgery in the right eye until the patient reports dimness of vision. When cataract surgery is performed, the steps would be similar to those used in the left eye, except that corticocleaving hydrodissection with complete rotation would be performed. If required, I would do multiquadrant hydrodissection. I would implant a Cionni CTR at an early stage after rotating the nucleus. I would thread the ring until the end of the surgery to prevent it from inadvertently dropping into the vitreous.