Hydrophilic acrylic intraocular lens clouding: a clinicopathological review

PURPOSE

An analysis is made of a serious late complication (opacification) of different models of hydrophilic acrylic intraocular lenses (IOLs).

METHODS

Seven lenses were explanted from seven patients treated for cataracts with phacoemulsification and implantation of different types of hydrophilic acrylic IOLs (five SC60B-OUV from MDR, one Aquasense from OII, and one H60M Hydroview lens from Bausch & Lomb) who developed important vision impairment in the late postoperative period (1 to 3 years) due to lens opacification. The explanted lenses were subjected to exhaustive study involving photographic analysis, scanning electron microscopy, and energy dispersive X-ray spectroscopy.

RESULTS

Light and scanning electron microscopy revealed diffuse, variable-size granular deposits within the optic of the SC60B-OUV lens, and on the anterior and posterior optic surfaces of the H60M Hydroview lens, though without affecting the haptics in any of the models. Dispersive energy X-ray spectroscopy of the deposits revealed the presence mainly of calcium and phosphorus salts.

CONCLUSIONS

Hydrophilic acrylic IOL opacification is a serious late complication of unknown etiology. The condition is more frequent among diabetic patients, and the only management option is IOL explantation and replacement with a lens of some other material. More frequent and longer follow-up is required of those patients wearing lenses for which cases of opacification have been documented, particularly in the presence of predisposing factors (diabetes, uveitis). Caution is required with new lenses, avoiding their generalized use until they have successfully passed the test of time.

[Contrast sensitivity to intraocular lens TECNIS Z-9000]

PURPOSE

To evaluate the increase in contrast sensitivity to intraocular lens TECNIS Z-9000 (Pfizer) compared with other intraocular lenses.

METHOD

We implanted a TECNIS Z-9000 lens in 18 patients who had another type of intraocular lens implanted in their other eye. We then tested contrast sensitivity under both mesopic and photopic conditions using the VCTS (Vision Contrast Test System) provided by Vistech Consultants Inc.

RESULTS

There was an improved contrast sensitivity at low and medium frequencies, following TECNIS-Z 9000 lens implantation, however this improvement did not reach statistical significance. There were significant differences at high frequencies, which are directly related to the quality of visual function.

CONCLUSIONS

TECNIS Z-9000 lens implantation (with a modified anterior surface) achieves a significant improvement in contrast sensitivity, meaning in practice an increase in the quality of visual function.