Posterior capsule opacification and lens epithelial cell layer formation: Hydroview hydrogel versus AcrySof acrylic intraocular lenses.

PURPOSE: To quantitatively compare the incidence of visually significant posterior capsule opacification (PCO) and lens epithelial cell (LEC) layer formation on the anterior surface of Hydroview hydrogel and AcrySof acrylic foldable intraocular lenses (IOLs) after implantation. SETTING: Single-surgeon ophthalmology practice, Orange Base Hospital, and Dudley Private Hospital, Orange, New South Wales, Australia. METHODS: This retrospective study comprised 166 eyes of 150 patients (after exclusions) who had cataract extraction and insertion of a foldable IOL in the capsular bag by a single surgeon using a standardized phacoemulsification technique from December 1997 to September 1998. The mean follow-up was 13.1 months (range 6.0 to 23.6 months). The eyes were divided into 2 groups based on the type of IOL implanted: Storz Hydroview H60M (81 eyes) or Alcon AcrySof MA30BA (85 eyes). A neodymium:YAG posterior capsule laser capsulotomy (PC YAG) was performed for an objective decrease in Snellen best corrected visual acuity (BCVA) of more than 1 line, significant visual symptoms, or both. This was used as a measure of visually significant PCO. An Nd:YAG anterior surface clearance (ASC YAG) was done for LEC layer formation anterior to the IOL to better visualize or facilitate treatment of PCO. The rates of PC YAG and ASC YAG after Hydroview and AcrySof IOL implantation were statistically compared. RESULTS: Forty-five eyes (55.6%) in the Hydroview IOL group and 3 eyes (3.5%) in the AcrySof IOL group required a PC YAG; the risk difference was 52.0% (P <.001). An ASC YAG was required in 27 eyes (33.3%) in the Hydroview group and 1 eye (1.2%) in the AcrySof group; the risk difference was 32.2% (P <.001). Survival analysis demonstrated that the only independent predictor of the incidence of PC YAG and ASC YAG over time was IOL type, with the Hydroview IOL group having a statistically significantly higher incidence of both procedures. CONCLUSION: There was a greater incidence of visually significant PCO and LEC layer formation on the anterior surface of Hydroview IOLs than of AcrySof IOLs.

Postoperative deposition of calcium on the surfaces of a hydrogel intraocular lens.

OBJECTIVE: To report clinical, pathological and histochemical features of 5 Hydroview intraocular lenses (IOLs) explanted from five patients who had visual disturbances caused by postoperative deposits on the lens surfaces. DESIGN: Noncomparative small case series with clinicopathologic and histochemical correlations. PARTICIPANTS: Five hydrophilic IOLs explanted from five different patients. All patients presented with decreased visual acuity and glare circa 12 months after uneventful phacoemulsification and IOL implantation, associated with a red-brown granularity on the optical surfaces of the IOLs. METHODS: The lenses were explanted, fixed in buffered formaldehyde and examined by gross and light microscopy. MAIN OUTCOME MEASURES: Staining of the IOLs with 1% alizarin red and with the von Kossa method (both stains for calcium). Two additional IOLs were also stained and included as controls. RESULTS: The optical surfaces of all five IOLs were covered by a layer of irregular granular deposits, composed of multiple fine, translucent spherical-ovoid granules. The deposits stained positive for calcium in all cases. No deposit or positive staining was observed on the IOLs haptics. Staining of the control IOLs was also negative. CONCLUSION: This is the first histopathological report of calcified deposits on the surfaces of this hydrogel IOL model. Further studies on other similar cases with this lens should be done to determine the incidence and possible mechanisms of this phenomenon.

Visually significant calcification of hydrogel intraocular lenses necessitating explantation.

PURPOSE: To report two cases of HydroviewR (Storz H60M) hydrogel intraocular lens (IOL) opacification necessitating explantation. To analyse the explanted lenses and compare them with a new lens in order to determine the cause of opacification. METHODS: Two cases are presented. Both patients complained of subjective decreases in vision approximately 1 year following uneventful cataract extraction and implantation of hydrogel lenses by the same experienced surgeon in the same institution. The reduced contrast sensitivity was thought to be due to failure of the hydrogel lenses which appeared opacified at the slit-lamp. They were then exchanged for acrylic lenses. Pre- and postoperative contrast sensitivity testing was performed using the VectorvisionR CSV-1000E instrument. A detailed comparative analysis of the opacified explanted lenses and a new lens was undertaken. This included surface microscopy, infrared spectral analysis, X-ray elemental analysis, scanning electron microscopy, and electron microscopy of lens slices. RESULTS: Lens exchange resulted in an improvement in subjective visual acuity (VA) and in objective contrast sensitivity testing. Analysis revealed deposits of calcium phosphate (hydroxyapatite) on the explanted lens' surfaces. CONCLUSIONS: The surface of the HydroviewR H60M intraocular lens is subject to opacification as a result of calcium phosphate (hydroxyapatite) deposition, thereby limiting the patient's visual outcome, and in some cases necessitating explantation. The reason for surface calcification requires further study.