The changes of ocular anterior segment configuration following phacoemulsification determined by anterior segment OCT

Cataract is a main blinding eye disease worldwide, follwed by glaucoma.Expension of lens volume occurs in early stage of age-related cataractous eyes, which is a risk factor of Primary angle-closure glaucoma, and phacoemulsification is a feasible approach to remove it.However, how to select the timing of operation and determine the prognosis is the major challenge for ophthalmologists.In order to evaluate the influence of phacoemulsification on ocular anterior segment configuration, we collected the information of 17 articles that quantitatively analyzed the ocular anterior segment parameter changes after phacoemulsification, determined by anterior segment OCT (AS-OCT) .Total 866 eyes that received phacoemulsification for age-related cataract were included in the following-up duration for 6 months, and the results showed that the mean anterior chamber depth (ACD), anterior chamber volume (ACV), anterior chamber angle (ACA), angle opening distance 500 μm anterior to the scleral spur (AOD500), angle opening distance 750 μm anterior to the scleral spur(AOD750), trabecular-iris space area 500 μm from scleral spur (TISA500), trabecular-iris space area 750 μm from scleral spur(TISA750), and angle recess area 750 μm anterior to the scleral spur (ARA 750) were increased, but the mean anterior chamber width (ACW) and iris thickness measured at 750 μm (IT750) were not significantly changed, while the postoperative iris curvature (I-Curv), iris cross-sectional area and convex hull of iris segments were decreased after phacoemulsification.In addition, the postoperative ACD, TISA500 showed positive correlations to preoperative lens thickness, and the ACD and AOD500 in 3 months after operation were positively correlated to the preoperative lens value (LV). This systematic review concluded that phacoemulsification could be used for the treatment of glaucoma by relieving pupillary block, reducing the iris oppression, deepening the anterior chamber and opening anterior chamber angle. Key words: Cataract/complications; Phacoemulsification; Postoperative complications; Glaucoma, angle-closure/physiopathology; Tomography, optical coherence; Ocular anterior segment; Systematic review