Consultation section: Glaucoma
This patient has 2 major issues—elevated IOP associated with the exfoliative glaucoma and a decreased visual field and image jump associated with IOL subluxation.
The elevated IOP is caused by exfoliative proteins decreasing the aqueous outflow and possibly also by a component of intermittent angle closure from weakened zonular fibers with intermittent pupillary block from the IOL. Gonioscopy should be performed to determine whether the angle is open, especially with indentation to test how lax the zonular fibers are in association with the angle width. If the angle is shallow, laser peripheral iridotomy might help lower IOP and decrease the IOP fluctuations that could be leading to visual field loss progression because of intermittent pupillary block by the IOL; this is a recognized problem, especially in the phakic exfoliative eye.
The patient has been on maximum medical therapy. If the patient continues to progress, trabeculectomy or glaucoma drainage implantation is recommended. Patients with high IOPs tend to have a good a response to SLT, although gonioscopy is critical to ensure the angle is open before considering SLT because the angle in the exfoliative glaucoma can often convert from being open to closed with progressive zonular laxity.
Intraocular lens subluxation (worse in the right eye than in the left eye in this patient) results in visual field loss but can also result in image jump, which is associated with the vision fluctuation the patient reported. Intraocular lens subluxation secondary to exfoliative glaucoma carries an increased risk for IOL prolapse into the vitreous cavity and an associated increased risk for retinal detachment. Over time, with progressive capsule phimosis (if there is a small capsulorhexis associated with cataract surgery) and weakening zonular fibers, IOL subluxation will worsen with a deteriorating vision field and image jump. The IOL and capsular bag can be stabilized by suturing a segmental CTR, suturing the IOL in place, or performing an IOL replacement to not only improve any visual field loss from the IOL subluxation and intermittent visual complaints from IOL movement with weakened zonular fibers but also to minimize the risk for IOL prolapse into the posterior chamber.© 2016 by Lippincott Williams & Wilkins, Inc.