Combined 23-G Pars Plana Vitrectomy and Lensectomy in the Management of Glaucoma Associated with Nanophthalmos

Abstract

Purpose: To investigate the surgical results of 23-G pars plana vitrectomy (PPV) combined with lensectomy (PPL) in nanophthalmic patients with angle closure glaucoma. Methods: This prospective nonrandomized study included consecutive patients with nanophthalmic glaucoma recruited for 23-G PPV combined with PPL. Best-corrected visual acuity (BCVA), intraocular pressure (IOP), the number of antiglaucoma medications, and surgery-associated complications were recorded. Surgical success rates were evaluated at each follow-up. Prognostic factors for success were also assessed using logistic regression analysis. Results: This study enrolled 21 eyes of 21 patients. The mean follow-up was 18.6 ± 7.0 months. At the final follow-up visit, the mean IOP was significantly reduced (from 47.4 ± 5.7 to 18.6 ± 3.6 mm Hg). The mean number of antiglaucoma medications dropped from 5 to 0. BCVA improved in 3 (14.3%) eyes. The complete success rate (IOP >6 and <21 mm Hg without antiglaucoma medication) was 71.4, 66.7, and 71.4% at the 6-month, 12-month, and final follow-up visit, respectively. Conclusions: Nanophthalmic glaucoma can be effectively managed with the combined surgery of 23-G PPV and PPL. IOP control was achieved with elimination of pupillary block and deepening of the anterior chamber. This surgical procedure proved to be safe in eyes with a potential risk of vision-threatening complications.

The Pathogenesis and Treatment of Complications in Nanophthalmos

“…The nanophthalmic eye has a short axial length and a shallow anterior chamber, but the size of the lens is normal [ 25 ]. This results in an increase in the lens/eyeball volume ratio from 4% under normal conditions to 10–30% at the pathological level [ 17 , 26 , 27 ]. ACG is often present in NO patients between the ages of 40 and 60 years, which may be related to the thickening of the lens with age [ 28 ].…”

“…One of such options is combination with sclerectomy, punch sclerostomy, and vortex decompression. Intraocular surgery in NO is usually accompanied by some intraoperative and postoperative complications, such as uveal effusion, which is considered a serious threat to vision [ 17 , 27 , 55 , 56 ]. The sclera of a nanophthalmic eye is usually thick, and the thickened sclera may compress the vortex vein and reduce the permeability of the sclera.…”

“…The sclera of a nanophthalmic eye is usually thick, and the thickened sclera may compress the vortex vein and reduce the permeability of the sclera. A sudden decrease in intraocular pressure during surgery may trigger the rapid development of uveal effusion [ 27 ]. Sclerectomy and vortex decompression during surgery can relieve this compression, and punch sclerostomy can drain choroidal effusion, but complications such as uveal effusion can still occur in some nanophthalmic patients after these interventions [ 17 , 55 , 57 , 58 ].…”

“…The removal of the lens can reduce the contents of the eyeball to deepen the anterior chamber, which can eliminate pupillary block and establish aqueous outflow reconstruction [ 59 ]. In addition, the excision of the anterior vitreous can create enough space for the iris lens diaphragm to move backwards, which can solve the adhesion of the vitreous to the iris or lens [ 27 , 56 ]. Therefore, a combination of vitrectomy and lensectomy is considered a suitable method to solve this complicated situation.…”

“…Therefore, a combination of vitrectomy and lensectomy is considered a suitable method to solve this complicated situation. The anterior chamber of the nanophthalmic eye is very shallow and often has corneal oedema, so phacoemulsification is not considered a treatment option [ 27 , 60 ]. The use of mechanical cutting, instead of ultrasound energy, in crystal removal can minimize the damage to endothelial cells.…”