Regression of Elschnig Pearls on the Posterior Capsule in a Pseudophakic Eye

Posterior capsule opacification (PCO) following cataract surgery is the manifestation of the migration and proliferation of lens epithelial cells on the posterior capsule. When PCO encroaches onto the visual axis, it causes light scatter and deterioration of vision. This condition is usually treated by a posterior capsulotomy with a Nd:YAG laser. There is a rare case, however, of a patient who had spontaneous regression of PCO from Elschnig pearl proliferation, with improvement of visual acuity.¹ We report a similar case of spontaneous Elschnig pearl regression taking place throughout 3 years.

In November 1997, a 75-year-old man visited us with blurred vision in his right eye, 3 years after cataract surgery. Cataract surgery was performed by a local physician in 1994, and the details of the operation were unknown. He had been treated with oral medication for hypertension and arrhythmia. Other medical history was unremarkable.

On examination, a single-piece polymethylmethacrylate intraocular lens (IOL) was seen in the posterior chamber and was associated with marked Elschnig pearls reaching the central region of the posterior capsule (Figure 1, A). Seemingly, the surgery had been performed using phacoemulsification with a "can opener" capsulotomy. The site of IOL implantation (inside or outside of the bag) could not be confirmed. No apparent operative complications were found. Despite the symptom of blurred vision, the patient's visual acuity was 20/15 OD with −0.75 diopters (D), and thus, a posterior capsulotomy was not performed.

In August 2000, he returned after the interval of 3 years with decreased vision in his left eye that was diagnosed as cataract. Slitlamp examination revealed that Elschnig pearls of the right eye significantly decreased (Figure 1, B). In particular, those behind the IOL optic disappeared almost completely. The posterior capsule was intact. The patient had not received any surgical, laser, or medical treatments for the right eye since the last visit. Corrected visual acuity was 20/15 with −1.0 D. The patient gave no report of blurred vision in his right eye. There was no pseudophakodonesis.

In October 2000, parts of Elschnig pearls showed a swing on eye movements (Figure 1, C). One month later, this portion disappeared completely (Figure 1, D).

The fellow left eye underwent phacoemulsification and implantation of a silicone IOL within the capsular bag in August 2000. There was no pseudoexfoliation and phacodonesis. Postoperatively, neither development nor regression of PCO has been observed in this eye until now.

Spontaneous regression of Elschnig pearls is very rare.¹ This is partly because significant PCO is usually treated by the Nd:YAG laser immediately when recognized. In this case, despite the blurred vision, the corrected visual acuity happened to remain at 20/15 OD, and the patient could manage well with that acuity, allowing for the observation of the long-term natural course.

There has been a reported case of spontaneous improvement in visual acuity after PCO,² but it was related to the displacement of a dense central area of Elschnig pearls by the progressive capsule contraction from fibrosis. Caballero et al³ reported several cases of spontaneous disappearance of Elschnig pearls after a Nd:YAG laser capsulotomy. Hollick et al⁴ demonstrated that lens epithelial cells that migrated onto the posterior capsule in the early postoperative period substantially regressed between 30 and 90 days postoperatively.⁴ They attributed this phenomenon to the tight adhesion between the IOL material and capsular bag. This postulate, however, does not apply to the case presented here because there was some space between the IOL optic and the posterior capsule as evidenced by the movement of Elschnig pearls, (Figure 1, C). It may be that the lack of tight contact between the IOL and the capsule led to the exposure of Elschnig pearls to the aqueous humor, resulting in the drop-off of loosened and inactive cells from the posterior capsule.

None of the authors has a proprietary or financial interest in any product mentioned.

Corresponding author and reprints: Tetsuro Oshika, MD, Department of Ophthalmology, University of Tokyo School of Medicine, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8655, Japan (e-mail: oshika-tky@umin.ac.jp).