Case Report: Pars plana filtration in the treatment of nanophthalmos patients with secondary angle closure glaucoma

Nanophthalmos is a rare developmental ocular disorder of congenital origin, manifesting as a notably reduced globe volume, shortened axial length, shallow anterior chamber, thickened sclera, and significant hyperopia. These anatomical features predispose affected individuals to angle-closure glaucoma as a result of anterior segment crowding. Traditional treatments for nanophthalmos-related angle-closure glaucoma often involve complex combined surgeries, which are not only technically demanding but also easily cause postoperative complications, such as malignant glaucoma and choroidal leakage. This case series presents three middle-aged and elderly female patients (a total of four eyes) with nanophthalmos-related angle-closure glaucoma. Common clinical findings included an axial length ≤ 20.5 mm, high intraocular pressure (IOP > 21 mmHg; 1 mmHg = 0.133 kPa), shallow anterior chamber, and diminished visual acuity. Based on the pathogenesis of postoperative malignant glaucoma, we implemented a modified surgical technique termed pars plana filtration (PPF). This procedure involves partial excision of the ciliary body to establish an alternative aqueous drainage route, thereby reducing anterior vitreous and posterior segment pressure. Compared to traditional combined surgeries, the PPF approach offers technical simplicity, minimized tissue invasiveness, and a shorter learning curve for ophthalmic surgeons. Our study describes successful implementation of this surgery without postoperative complications observed. These findings suggest that PPF may represent a safe and effective surgical alternative for managing nanophthalmos-related angle-closure glaucoma. Nevertheless, further larger-scale studies are needed to validate its long-term effectiveness and generalizability.