[Observation of late postoperative opacification of hydrogel intraocular lens].
OBJECTIVE
To report clinical, histopathologic, ultrastructural, and chemical features of extracted hydrogel intraocular lens (IOL, Bausch and Lomb, H60M) from patients who had visual disturbances caused by postoperative opacification of the lens, and discuss the possible causes of this phenomenon.


METHODS
Four cases (4 eyes) were presented after uneventful phacoemulsification and IOL implantation. Two IOLs were removed from 2 patients (2 eyes) with severe decreased visual acuity. Clinical aspects of patients who had opacification of this IOL were observed. Extracted lenses were stained with alizarin red (special stains for calcium), examined by scanning electron microscope (SEM) and energy dispersive x-ray spectroscopy (EDS).


RESULTS
The extracted lenses showed positive staining for alizarin red, indicating that calcium was present on the surface. SEM disclosed coralliform deposits on the superficial substance of the IOL optic. EDS showed that the presence of calcium and phosphorus mainly in the opacification region.


CONCLUSIONS
The surface of the IOL is subject to opacification as a result of calcium phosphate deposition, thereby limiting the patient's visual outcome, and in some cases necessitating the extraction of the lens. These changes may be relevant to the nature of the materials used for the construction of hydrogel IOLs. This important clinical problem requires further studies.
Department of Ophthalmology, West China Hospital, Sichuan University, Chengdu 610041, China.
Guo-yuan
GY
Yang
Yi
Y
Liu
Long-qian
LQ
Liu
Jun-jun
JJ
Zhang
D000368:Aged; D000369:Aged, 80 and over; D002386:Cataract / Q000628:therapy*; D005260:Female; D006801:Humans; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate / Q000009:adverse effects*; D019654:Lens Implantation, Intraocular; D007910:Lenses, Intraocular / Q000009:adverse effects*; D008297:Male; D011183:Postoperative Complications / Q000209:etiology*; D011475:Prosthesis Failure
D020136:Hydrogel, Polyethylene Glycol Dimethacrylate