Abstract
Purpose :
Secondary angle closure glaucoma following pars plana vitrectomy (PPV) with the use of gas has been reported, but the underlying mechanisms are not well understood. Our group recently published a report of an aphakic patient who developed position-dependent angle closure following PPV with gas tamponade. We now add two more cases to demonstrate that this phenomenon is not infrequent in the setting of aphakia and carries important clinical implications for this subset of patients.
Methods :
This is a case series of three patients with aphakia who underwent PPV with gas tamponade. Two patients had undergone rhegmatogenous retinal detachment repair in the setting of trauma. One patient was previously aphakic from a congenital cataract, and two patients had been left aphakic following lensectomy during PPV. The gas tamponades used were perfluoropropane (C3F8) in two patients and sulfur hexafluoride (SF6) in one patient. Postoperatively, intraocular pressures (IOP) were measured in both upright and supine positioning.
Results :
All patients demonstrated dynamic angle closure with severe rise in IOP after supine positioning, with resolution upon upright positioning. In upright position, the three patients had an IOP of 32, 16, and 9 mmHg, respectively. Upon placing the patients in supine position, a large gas bubble was visualized overlying the pupils in a now shallow anterior chamber (AC), and IOP were remeasured to be 52, 41, and 37 mmHg, respectively. Upon return to upright positioning, the gas bubbles were observed to migrate posteriorly out of the AC (see Figure), and IOP were remeasured to be 25, 17, and 9 mmHg, respectively. Of note, all patients had iridodonesis on examination.
Conclusions :
Dynamic, positional angle closure can occur following PPV with gas tamponade in the setting of aphakia. This case series captures the dynamics of gas migrating into the anterior segment and causing intermittent acute angle closure with supine positioning. A common feature on exam was iridodonesis, which we suggest may be a key finding predisposing patients to this complication. We suggest aphakic patients following PPV with gas tamponade, particularly those with iridodonesis, should avoid supine positioning until the gas has fully dissolved.
This abstract was presented at the 2024 ARVO Annual Meeting, held in Seattle, WA, May 5-9, 2024.