Postoperative opacification of the peripheral optic region and haptics of a hydrophilic acrylic intraocular lens

Postoperative opacification of polymethylmethacrylateintraocular lens

Background: Opacification of ophthalmic devices has been previously reported in silicone scleral buckle, Molteno implant, and intraocular lens opacification. However, there is no report on polymethyl methacrylate (PMMA) intraocular lens (IOL) calcification. Objective: Report the clinical feature, histopathologic and spectrophotometer analysis of opacified three-piece PMMA IOL. Method: A 60-year-old diabetic patient reported decreased visual acuity in her right eye, which had undergone phacoemulsification with PMMA IOL implantation. The ophthalmic examination revealed a white homogeneous opacification of posterior surface of the IOL. The explanted IOL was analyzed using scanning electron microscopy, energy dispersive spectroscopy, and alizarin red staining. Results: The scanning electron microscope analysis showed granular deposits on posterior surface of the IOL. Using energy dispersive spectroscopy analysis, calcium and phosphate peaks were revealed, which was confirmed by positive for alizarin red staining. Conclusion: This case report provided evidence of PMMA IOL calcification caused by calcium and phosphate deposits. The possible etiologies were extrinsic and/or intrinsic factors.

Clinicopathological correlation of 3 patterns of calcification in a hydrophilic acrylic intraocular lens

We present 3 cases of opacification in the Biocomfold 92S intraocular lens (IOL), with a documented increase in the opacification over time in 1 case. Histopathological analysis revealed the opacification was caused by calcification in the IOL's optic material. The pattern of calcium deposition, however, was different in each IOL. The causative mechanisms for this complication are unclear. Further research is warranted.

Causes of intraocular lens opacification or discoloration

Various pathologic processes may lead to clinically significant opacification or discoloration of the optic component of intraocular lenses (IOLs) manufactured from different biomaterials and in different designs. Factors such as the patient's associated conditions, the manufacturing process, the method of IOL storage, the surgical technique and adjuvants, or a combination of these may be involved. The complication may be observed intraoperatively or postoperatively from a few hours after implantation to many years after surgery, depending on the processes involved. Based on a review of the literature as well as our own laboratory analyses, the following types of processes were identified: formation of deposits/precipitates on the IOL surface or within the IOL substance; opacification by excess influx of water in hydrophobic materials; direct discoloration by capsular dyes or medications; coating by substances such as ophthalmic ointment and silicone oil; and a slow, progressive degradation of the IOL biomaterial.

Intraocular lens opacification after nonpenetrating glaucoma surgery with mitomycin-C

A 58-year-old woman had successful phacoemulsification with intraocular lens (IOL) implantation in January 2001. Two years later, nonpenetrating glaucoma surgery with mitomycin-C (MMC) 0.02% was performed for uncontrolled glaucoma. Two months later, opacification of the anterior IOL surface was observed. The IOL was removed and a hydrophobic acrylic AcrySof IOL (Alcon) implanted. The opacified IOL was studied by flame atomic absorption spectrometry, which showed the presence of calcium carbonate. A new IOL of the same model was placed in an aqueous solution with calcium carbonate and basic pH, and the same opacification developed. We hypothesize that the change in aqueous humor pH after glaucoma surgery and the characteristics of the IOL precipitated deposition of calcium.