Analysis of the reasons for high intraocular pressure caused by acute pupillary block after phacoemulsification and its management

Abstract

Objective To study the causes of acute high intraocular pressure (HIOP) caused by pupillary block after phacoemulsification with intraocular lens (IOL) implantation and the treatments to manage the condition.Methods Seventeen patients (17 eyes) with early postoperative acute HIOP caused by pupillary block who underwent cataract phacoemulsification with IOL implantation in Taizhou Eye Hospital between January 2000 and December 2011 were retrospectively analyzed.Among the 17 cases,5 cases were caused by onset IOL pupillary capture and 12 cases by capsular block syndrome (CBS).Conservative approaches were adopted that included tropicamide phenylephrine eye drops for mydriasis and 250 ml of intravenous drip with 20％ mannital to the concentrated vitreous for the 5 cases of acute pupillary block HIOP caused by onset IOL pupillary capture.For the other 12 cases with CBS,Nd:YAG laser was used for anterior capsulotomy to cut the margin of the continuous circular capsulorhexis (CCC) in 2 cases and anterior peripheral capsulotomy was performed in 5 cases.Radialization was performed surgically to cut the margin of the CCC in 2 cases and supplied the CCC to enlarge the diameter in 3 cases.And finally,aspiration-irrigation was performed to flush the anterior chamber and the capsule.Intraocular pressure (IOP),visual acuity,position of IOL,and the conditions of the anterior chamber and capsule were measured after treatment.Results The patients were followed up for 2-3 months after treatment.Pupillary block disappeared,IOP was normal,visual acuity improved,the anterior chamber deepened and the position of the IOL was normal in all operated eyes.At the last follow-up,IOP was 11-19 mmHg (mean 0.85±0.15 mmHg)and best corrected visual acuity (BCVA) was 0.7-1.0 in 5 cases with IOL pupillary capture.IOP was 12-18 mmHg (mean 15±3.0 mmHg) and BCVA was 0.8-1.0 in 12 cases with CBS.Conclusion IOL pupillary capture and CBS can that induces acute pupillary block HIOP.Applying mydriasis can effectively resolve acute pupillary block HIOP caused by the IOL pupillary capture.Using ND:YAG laser and operation are the effective measures to treat acute pupillary block HIOP caused by CBS. Key words: Phacoemulsication; Intraocular lens; Pupillary capture; Capsular block syndrome; Pupillary block high intraocular pressure