Malignant glaucoma (MG) is a rare but serious event in angle closure glaucoma, typically after trabeculectomy or other filtering procedures. It is characterized by a shallow or flat anterior chamber and moderately or considerably elevated IOP and can lead to a disastrous outcome. It must be differentiated from overfiltration where the IOP is very low.
The paper by Thompson et al. retrospectively analyzed 64 eyes of 55 subjects that developed MG after surgical interventions within a 10 years period. The analysis of these cases considered multiple aspects with new information, but the main hitherto existing recommendations (cycloplegia, carbonic anhydrase inhibitors, hyperosmotics, Nd:YAG hyaloidotomy, anterior chamber reformation, and in particular vitrectomy) were confirmed. The removal of the lens as one of the mainstays of treatment was also discussed in this series, but 73% of the eyes were already pseudophakic and most of the surgically treated cases underwent simultaneous lens removal at surgery in anyway. Therefore the value of lens removal as part of the intervention in phakic eyes could not be separately analyzed, but can be considered as an essential part of surgical treatment strategy.
In their final statement the authors summarize that they "found that the time to maximal improvement in IOP and BVA was significantly longer than the time to anatomic improvement following treatment of MG. Eyes that underwent trabeculectomy prior to the onset of MG were at a significantly increased risk of prolonged time to recovery in anatomy, BVA, and IOP. Medical management that incorporated clinic-based interventions such as Nd:YAG laser hyaloidotomy, AC reformation, and addition of oral CAIs to maximal topical glaucoma therapy and cycloplegia may help to hasten recovery from MG. Timing of vitrectomy within 30 days may lead to faster improvement in anatomy, BVA, and IOP, but did not ultimately impact whether or not there was complete resolution. We recommend that vitrectomy be combined with lensectomy in phakic eyes to improve the likelihood of complete resolution of MG. Patients with known risk factors for MG should be considered for prophylactic pars plana vitrectomy at the time of cataract or glaucoma surgery, especially if they are undergoing trabeculectomy surgery."