Snowflake opacification of poly(methyl methacrylate) intraocular lens optic biomaterial: a newly described syndrome

Large-scale opacification of a hydrophilic/hydrophobic intraocular lens

PURPOSE

To determine the prevalence and risk factors related to the opacification of the LS-502-1 intraocular lens.

METHODS

Cross-sectional study including patients submitted to cataract surgery between January 2010 and March 2012, with implantation of the LS-502-1 intraocular lens. Past medical history was registered and a complete ophthalmologic evaluation, that included best-corrected visual acuity, slit-lamp examination and fundoscopy, was performed. Anterior segment photographs were taken whenever intraocular lens opacification was present.

RESULTS

One hundred and sixty-nine eyes of 154 patients were included, mean age 78.5 ± 7.9 years. The average follow-up after intraocular lens implantation was 65.6 ± 10.0 months. Intraocular lens opacification was seen in 53.3% (n = 90) and presented as one of four different patterns: peripheral (15.6%, n = 14), central (4.4%, n = 4), diffuse (71.1%, n = 64) and superficial white deposits (8.9%, n = 8). There was no statistically significant association with systemic or ophthalmic conditions. In patients with bilateral implantation, intraocular lens opacification in one eye was significantly related to intraocular lens opacification in the fellow eye. A significant variability in opacification was found across intraocular lens serial numbers: the odds ratio for opacification in intraocular lens with serial number beginning with 200003 was 6.0 when comparing with the remaining lenses.

CONCLUSION

The opacification prevalence of the LS-502-1 intraocular lens was 53.3%, which is the highest ever described for any intraocular lens model. Our results suggest that this occurrence is secondary to an interaction between unknown patient variables and problems related to intraocular lens manufacturing and storage procedures.

Transient intraocular lens opacification during phacoemulsification surgery

Purpose

To report an interesting case of intraoperative opacification of intraocular lens (IOL).

Methods

This study is a report of a 61-year-old male patient who suffered from nuclear sclerosis cataract and had undergone phacoemulsification surgery. During surgery, intraoperative opacification of IOL (Cristal, Cristalens), which was a foldable, 13 mm, one piece, square edge and hydrophilic acrylic IOL, occurred. This phenomenon caused a surprise and a decision to explant the IOL, but the surgeon decided to keep the IOL in place. After a day, it was completely clear.

Results

The surgery was completed successfully without any complications, and the IOL was completely clear the day after surgery.

Conclusion

Acute, transient IOL opacification with unproven etiology may occur during cataract surgery.

Clinical Case Notes. Snowflake degeneration of an intraocular lens

Snowflake degeneration of intraocular lenses is a recently recognized late postoperative complication of cataract surgery. All known cases reported to date in the literature have involved polymethyl methacrylate (PMMA) lens optic material. Reported herein is an atypical variant of snowflake degeneration of a PMMA posterior chamber intraocular lens in an 81-year-old woman, 7 years post implantation. The aetiology of the atypical late opacification of the intraocular lens is this case is unclear, and no clinical risk factors appear to have been identified.

Calcification postopératoire des lentilles intraoculaires acryliques hydrophiles : aspects cliniques et pathologiques

PURPOSE

The aim of this study was to evaluate the clinical aspects of ten eyes with calcified hydrophilic acrylic intraocular lenses and pathological data obtained from seven explanted lenses.

MATERIAL AND METHODS

Forty-seven eyes of 40 patients received the same implant in the first 6-month period of 2001. Ten eyes showed intraocular lens opacification detected 6-18 months after the operation: seven lenses were explanted and three were left in place because they were not causing a decrease in visual acuity or glare at light. Five of ten eyes were diabetic. The explanted lenses were examined under the light microscope and the electron microscope. The elemental analysis of the lens surfaces was made by energy dispersive spectrometry.

RESULTS

The light microscopy showed an irregular surface covered by a gray-white opacity. The electron microscopy detected multiple granulations on the front and back surfaces of the lenses including some portions of the haptics. The size and density of these granulations were smaller on the back surface. The energy dispersive spectrometry showed the presence of calcium and phosphate on both surfaces. The spikes of calcium and phosphate were smaller for the back surface of the lenses.

DISCUSSION

Calcification was predominantly seen on the surfaces that were in contact with aqueous not covered with anterior capsule. Half (5/10) of the cases were diabetic even though 18% of all patients receiving this lens were diabetic. The presence of diabetes is very common in other series. These data suggest the role of a metabolic factor influencing the milieu of the lens in this calcification process.

CONCLUSION

Calcification of the hydrophilic acrylic lenses is a relatively serious complication, but the conditions leading to its appearance and the physiopathology have not yet been fully elucidated. The surgeon should be very careful in the choice of the intraocular lens to implant, and even more so if the patient is diabetic.