Ahmed Valve for Elevated Intraocular Pressure Associated with Black Diaphragm Lenses for Aniridia

PURPOSE

To evaluate the Ahmed valve for decrease elevated pressure associated with black diaphragm lenses for aniridia.

METHODS

Drainage devices are useful to obtain good control of intraocular pressure in patients with aniridia and the authors often use them because of the poor results of medical therapy or filtering surgery. However, when the elevated intraocular pressure is associated with black diaphragm lenses for aniridia, most authors decide to carry out a filtering technique. The current authors opted for the implantation of an Ahmed valve in three patients, two with traumatic aniridia and the other with a congenital case. Every patient had a different kind of black diaphragm lens for aniridia.

RESULTS

The Ahmed valve controlled the intraocular pressure in levels below 20 mmHg for a follow-up year with no complications derived from its application.

CONCLUSIONS

Ahmed valve implantation was the best technique to decrease intraocular pressure in patients with aniridia. The authors have used it successfully for cases with elevated pressure associated with black diaphragm lenses for aniridia.

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.