High IOP and a shallow anterior chamber unresponsive to peripheral iridectomy (PI) without phacodonesis or intumescence indicate malignant glaucoma (also called ciliary block glaucoma and aqueous misdirection syndrome). Although seen mostly after incisional glaucoma surgery, malignant glaucoma can occur after trauma. Plateau iris and choroidal hemorrhage must be excluded.
Preoperative UBM will show any ciliary body rotation, choroidal effusion, and clear collection of fluid behind the vitreous body. With its shorter AL, the fellow eye should be more hyperopic, yet the eyes’ refractions are identical. With an anteriorly displaced lens, the right eye should become more myopic. Possible explanations include inaccurate UBM associated with loculated fluid or a change in sound transmission through dense vitreous, poor refraction because of cataract, or a change in corneal curvature with edema. Because the PI did not deepen the chamber, use preoperative atropine cycloplegia for this to confirm the diagnosis. Check for a relative afferent pupillary defect for prognosis. If the ECC is low, use an enhanced balanced salt solution.
The malignant glaucoma treatment requires anterior aqueous flow to be reestablished, so performing an irido-zonulo-hyaloidectomy with vitrectomy is indicated while removing the cataract. Give a mannitol 0.25 g/kg push intravenously 15 minutes preoperatively for the deturgescence of the vitreous. If intraoperative gonioscopy confirms a deep chamber, a routine case will ensue except for the last step of the vitrectomy through the completed PI. If the chamber is still shallow with a closed angle, place a sutureless, 23-gauge trocar (transconjunctival using a limbus parallel scleral tunnel technique) 3.5 mm back from the limbus before other incisions, taking advantage of the firm eye and forward lens. In addition to the topical anesthesia, preplace a sub-Tenon bleb of lidocaine in the inferotemporal quadrant over the intended sclerotomy. Place a plug when not in use. Deepen the anterior chamber using preservative-free lidocaine hydrochloride 1.0% and epinephrine 1:4000 through a paracentesis to boost dilation to 5.0 to 6.0 mm, followed by a soft shell of dispersive OVD to flatten the lens dome. If the chamber does not deepen enough to safely perform capsulorhexis, soften the eye and deepen the chamber using a brief, dry pars plana vitrectomy (PPV) with the port facing posterior, avoiding the posterior capsule. Next, perform capsulorhexis, gentle hydrodissection, and vertical-chop phacoemulsification. Instill the OVD through the side port before exiting so the chamber will not shallow while instruments are being removed (inviting effusion or more misdirection).
Place a CTR in the clean bag. If there is no significant posterior pressure and no fibrosis beyond the central 5.0 mm, create a posterior capsulorhexis, defining the Berger space using a cohesive OVD inserted through a 30-gauge bevel-up needle opening. Place a 3-piece acrylic IOL in the bag, and use the buttonhole technique to seal the posterior segment and secure the lens centration. Alternatively, if the capsule polishes clean, place the IOL in the bag with the posterior capsule intact. Through the vitrector-enhanced PI, perform the zonulo-hyaloidectomy, making the eye unicameral to cure the malignant glaucoma. Instill an intracameral antibiotic to control inflammation, and confirm the absence of vitreous.
Postoperatively, stop the prostaglandin analogue immediately. Check the IOP the same day and 1 day postoperatively to avoid overtreatment and undertreatment. Atropinize initially, stopping at 1 week. As soon as is practical, perform a scleral depression examination of the retina to exclude tears and gonioscopy to look for peripheral anterior synechia and angle recession. The fellow eye is at risk for malignant glaucoma even though trauma was the presumed inciting factor. When cataract surgery is needed in the fellow eye, consider postoperative cycloplegia and careful observation.