Rationale for early lens extraction in the treatment of primary angle closure disease

PURPOSE. To demonstrate the advisability of early lens extraction in the treatment of primary angle closure disease in clinical practice.METHODS. The study presents three clinical cases with patients at different stages of primary angle closure disease (PACD). The first one is related to the development of a bilateral acute attack of primary angle closure (PAC) that happened in the intensive care unit during treatment for acute respiratory distress syndrome (ARDS) associated with COVID-19 pneumonia in a patient with a previously undiagnosed PACD. The second case demonstrates the progression of glaucomatous optic neuropathy (GON) in early primary angle-closure glaucoma (PACG) after laser peripheral iridotomy (LPI) and delayed selective laser trabeculoplasty (SLT) in a patient with increased lens thickness. The third example illustrates the progression of advanced PACG in the right eye (OD) and moderate PACG in the left eye (OS) due to formation of goniosynechiae after bilateral LPI, which required transscleral diode cyclophotocoagulation (TSCP) in OD and trabeculectomy in OS. Subsequently, bilateral cataract phacoemulsification with intraocular lens implantation (CPE+IOL) and SLT were performed.RESULTS. In the first clinical case, advanced PACG developed in both eyes within 2 months. After bilateral LPI, trabeculectomy, compensation of intraocular pressure (IOP) was achieved, visual functions stabilized. In the second clinical case, 5.5 years after LPI and SLT, an increase in the thickness of the lens was revealed (in OD by 0.2 mm, in OS by 0.48 mm). GON did not progress in OD (thinning rate of the retinal nerve fiber layer was 0.94 µm/year, p=0.32) and the progression rate in OS was -1.04 µm/year (p=0.018). Taking into account the lens-involved mechanism of PACD progression, bilateral CPE+IOL was recommended. In the third clinical example, IOP remained elevated after bilateral LPI, TSCP in OD and trabeculectomy in OS as a result of goniosinechiogenesis, and therefore CPE+IOL also did not lead to its decrease. After bilateral SLT, compensation of IOP was achieved without local hypotensive therapy (IOP measured by Icare: OD 18.0 mm Hg, OS 15 mm Hg).CONCLUSION. In order to preserve visual functions, CPE+IOL is highly recommended at the very beginning of PACD, before the formation of GON and goniosynechiae. This is dictated by the dominant role of the lens-involved mechanism in PACD formation, as demonstrated in the described clinical examples.