Sir,

We report the spontaneous closure of a posterior capsule 1 week following Nd:YAG central posterior capsulotomy for capsular blockage syndrome, which developed following routine cataract surgery.

Case report

A 68-year-old nondiabetic, highly myopic man (with no other risk factors) underwent uncomplicated phacoemulsification cataract surgery. An MA50BM (Alcon Ft Worth TX) three-piece acrylic lens was implanted into the capsular bag. Postoperatively, capsular blockage syndrome type 2 was diagnosed:1 A small central Nd:Yag posterior capsulotomy was performed to allow the escape of fluid.

After 1 week later, the posterior capsule opening was found to have closed with recurrence of capsular blockage syndrome. A larger Nd:YAG posterior capsulotomy was created, and the opening confirmed at 1 week. The outcome capsular bag had deflated and the anterior chamber deepened, with posterior movement of the optic, which had become adherent to the posterior capsule. This outcome has not been described as a part of conventional management of capsular blockage syndrome. The opening was patent at 3 months (Figure 1) and fibrosis noted around the opening, with migration of lens epithelial cells.

Figure 1
figure 1

Photograph of lens capsule at 3 months after the capsulotomy.

Full size image

Discussion

Capsular blockage syndrome is well described, and occurs when viscoelastic is trapped between the lens and the posterior capsule. Intraoperative capsule blockage syndrome is type 1 and postoperative capsule blockage syndrome may be early (type 2, within 1 month) or late (type 3).1, 2

Masket first reported closure of a posterior capsulotomy with Elschnig pearls along its margin, thought to be due to excessive lens epithelial cell (LEC) proliferation.3 Kato et al4 reported string of pearls in 47.6% of patients within 1 year after Nd:YAG posterior capsulotomy, but found no increased rate in high myopes. Kurosaka et al5 report a 77% rate of Elschnig pearls at 2 years after Nd:YAG posterior capsulotomy, 20% requiring repeat laser. McPherson et al6 report a 0.7% incidence of re-opacification after Nd:YAG capsulotomy. All affected patients were younger than 50 years at the time of cataract surgery. De Groot et al7 showed that LECs can proliferate on the basal lamina of the anterior vitreous face and close a posterior capsulotomy. Chatterjee et al8 reported capsule re-opacification 8 months after Nd:YAG capsulotomy of a 48-year-old diabetic gentleman following routine phacoemulsification and posterior chamber intraocular single-piece polymethyl methacrylate lens implantation (requiring a repeat Nd:YAG capsulotomy). Oshika et al9 reported the closure of a capsulotomy in the presence of a glistenings with hydrophobic acrylic lens. Surgical capsulotomy closure has also been reported in eyes at risk (uveitic, young adults).10

We report spontaneous closure of a Nd:YAG posterior capsulotomy for capsular blockage syndrome 1 week post-surgery, requiring repeat capsulotomy. This may be due to phimosis, but more likely from LEC migration. Our case differs from routine posterior capsulotomy in timing and anatomy. Capsulotomy was performed early when LECs were still stimulated following surgery, and the capsule was not adherent to the optic. It is our experience of human lens capsule culture that LECs will rapidly migrate across the human capsule within 1 week.11 Potentially, LECs migrate onto exposed capsule or along the anterior hyaloid face, closing the capsulotomy opening. We recommend that, if a posterior capsulotomy is required in the early postoperative period, consideration be given to perform a larger initial capsulotomy.