Late-Onset Capsular Block Syndrome Following Multifocal Intraocular Lens Implantation: A Case Report

To report a case of capsular block syndrome (CBS) occurring two years after multifocal intraocular lens (IOL) implantation, highlighting its clinical presentation, diagnosis, and successful management with Nd:YAG laser posterior capsulotomy.

An ophthalmology clinic where the patient presented with progressive blurred vision and floaters in the right eye following previous cataract surgery with multifocal IOL implantation at a medical center.

A 71-year-old patient presented with a gradual decrease in vision to BCVA 0.7 (OD) and floater perception (OD) 12 years after undergoing phacoemulsification with multifocal IOL implantation.

Slit-lamp examination revealed a well-centered posterior chamber IOL (PCIOL) with mild posterior capsular opacification (PCO) and a characteristic retrolental accumulation of milky white fluid, consistent with capsular block syndrome (CBS). The intraocular pressure was within normal limits, and no signs of intraocular inflammation or other secondary pathology were noted. Given the classic clinical presentation, a diagnosis of late-onset CBS was made.

The patient underwent Nd:YAG laser posterior capsulotomy, which resulted in immediate resolution of the fluid accumulation and improvement in visual acuity. Post-procedure follow-up confirmed symptomatic relief, improved visual function (BCVA 1.0), and no recurrence of fluid accumulation.

Capsular block syndrome (CBS) is a rare but significant postoperative complication of cataract surgery, even years after IOL implantation. The accumulation of fluid behind the IOL can lead to visual disturbances that mimic other ocular conditions. Early recognition through slit-lamp examination is crucial, and Nd:YAG laser posterior capsulotomy remains an effective and minimally invasive treatment to restore visual clarity. Long-term postoperative monitoring is essential for patients with multifocal IOLs to detect and manage late-onset CBS promptly.