Secondary acute angle closure glaucoma after 25-gauge pars plana vitrectomy for a macular hole: a case report

Background: Posterior synechiae of the iris rarely cause secondary angle-closure glaucoma after pars plana vitrectomy, mainly reported in cases with high postoperative inflammation. The face-down position with gas tamponade can cause acute angle-closure glaucoma in phakic eyes owing to relative pupillary block. This report presents a rare case of pseudophakic eye with secondary acute angle-closure glaucoma after 25-gauge pars plana vitrectomy and long-term vitreous gas tamponade for a macular hole.

Case presentation: A 61-year-old Japanese female patient presented with a chief complaint of right-sided visual impairment that had persisted for several months. Slit-lamp examination revealed deep anterior chamber and moderate nuclear sclerotic cataracts in both eyes. The axial length of the eye was 23.53 mm right eye and 24.05 mm left eye, and the fundus examination revealed a full-thickness macular hole (stage 3) in the right eye. The patient underwent simultaneous cataract surgery and pars plana vitrectomy with 7-mm diameter 3-piece monofocal intraocular lens implantation, internal limiting membrane peeling, and air tamponade. There were no complications during surgery. Due to non-closure of the macular hole, a second pars plana vitrectomy with internal limiting membrane inverted flap and SF6 gas tamponade was performed 13 days later. The patient maintained face-down position after both surgeries, and 6 days after the second surgery, intraocular pressure was elevated to 53 mmHg, and acute angle-closure glaucoma with iris bombe was diagnosed in the right eye. A laser peripheral iridotomy was performed, resulting in a deepened anterior chamber, normalized intraocular pressure, and a closed macular hole.

Conclusions: This case presents a rare occurrence of secondary acute angle-closure glaucoma in a pseudophakic eye after 25-gauge minimally invasive pars plana vitrectomy and SF6 gas tamponade for macular hole. The cause was presumed to be posterior synechiae of the iris or relative pupillary block due to forward pushing of the intracapsular intraocular lens by vitreous gas. In cases where surgery is repeated without achieving macular hole closure, necessitating long-term face-down position, where vitreous gas is retained for an extended period, or when a large-diameter intraocular lens is implanted, secondary acute angle-closure glaucoma should be considered. This applies even when the 25-gauge pars plana vitrectomy is performed not for a highly invasive proliferative diabetic retinopathy but for macular hole repair, especially if the patient has a pseudophakic eye.