Use of a mirror needle holder with transsclerally sutured posterior chamber intraocular lenses.

A mirror needle holder has been designed to facilitate the passage of a needle through the ciliary sulcus during transscleral fixation of posterior chamber (PC) intraocular lens (IOLs). Two human postmortem eyes were used to demonstrate the efficacy of this mirror used as the needle holder. This method was compared with the current method of passing sutures without view of the ciliary sulcus. The mirror needle holder demonstrated precise passage of the needle into the ciliary sulcus by direct visualization of the ciliary processes and sulcus. This method may avoid the complications associated with transsclerally sutured PC IOLs during penetrating keratoplasty and secondary IOL placement.

Histologic effects of contact ultrasound for the treatment of glaucoma.

The histologic effects of a contact ultrasound applicator were compared with those of the immersion applicator that is currently used clinically for the treatment of glaucoma. The applicator coupling cone uses a distensible rubber membrane that can be inflated to control stand-off distance relative to the surface of the eye. This feature allows the focal point of the therapeutic beam to be placed at selective depths. Histologic comparisons of lesions in rabbit and pig eyes showed lesions in the sclera and ciliary body that were similar to those produced by the immersion transducer when the same focal position was used. Moving the focal point to a greater depth resulted in less superficial damage, yet still produced ciliodestruction. Damage to the blood supply of the ciliary body, as found in human cadaver eyes, may be an additional mechanism of action of therapeutic ultrasound, and perhaps of other transscleral high-energy modalities.

The effect of a new intraocular irrigating solution containing dextran on rabbit corneal endothelium.

This study investigated the effect of a balanced salt solution for intraocular irrigation containing 2% dextran 40. The effect of this solution was compared to that of a normal saline solution (0.9%) and balanced salt solution (Alcon). Following incubation of rabbit corneas for up to 72 h at 4 degrees C, the incubated corneas were studied by staining with Nitroblue Tetrazolium and by scanning electron microscopy. Insignificant changes occurred during the first 24 h of incubation. However, corneas stored in the dextran containing solution showed slightly smaller endothelial cells with tight junctions after 72 h. Endothelial cells showed progressive membrane rupture and eventual disappearance when incubated in normal saline for over 24 h at 4 degrees C.