Artificial iris exchange

Preclinical biocompatibility and biosafety evaluation of a new foldable brown diaphragm intraocular lens: An in vitro and in vivo study

BACKGROUND

A new foldable brown diaphragm intraocular lens (IOL) was preclinically evaluated in vitro and in vivo by comparing its biocompatibility and biosafety with those of a commercially available IOL.

METHODS

The new foldable iris-diaphragm IOL is composed of hydrophobic acrylic material, with a transparent optical zone and surrounding brown diaphragm. Cellular experiments evaluating lens epithelial cell morphology, adhesion, and migration were conducted to exclude cytotoxic effects. Twelve New Zealand rabbits underwent implantation of a brown diaphragm IOL in one eye, whilst an additional 12 had a commercially available foldable IOL implanted, followed by slit-lamp evaluations of inflammatory reactions and capsular opacification. Corneal endothelial cells density was measured before and after implantation. Aqueous humour samples were obtained weekly for liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis to investigate dye leakage from the brown-diaphragm IOL. Following 12 weeks of observation, haematoxylin and eosin staining of ocular tissue and scanning electron microscopy (SEM) of the IOL surface were performed.

RESULTS

Results from in vivo experiments found no statistically significant differences between the two groups in terms of postoperative inflammation and capsular biocompatibility. No significant changes in corneal endothelial cell density were observed in either group before and after surgery. LC-MS/MS analysis showed that the target dye was not detected in aqueous humour samples. Histopathology of ocular sections and SEM imaging of IOL surfaces showed similar changes in both groups.

CONCLUSIONS

The newly invented IOL showed good biocompatibility and biosafety. Combined with its foldability and peripheral shading, it could be a new choice for patients with iris defects.

Artificial iris: state of the art

Surgical correction of traumatic aniridia aims to improve the quality of vision, compartmentalize the anterior and posterior chamber, and re-establish a satisfying cosmetic appearance. Various types of prosthetic iris devices (PIDs) are available, which differ in technical difficulty of implant and design: artificial iris (AI)-intraocular lens prosthesis, endocapsular capsular tension ring-based PID, and customized AI. The choice depends on the preexisting clinical condition after severe ocular trauma and on patient functional and cosmetic expectations. This systematic review of the literature compared anatomical and functional outcomes of various types of PIDs. Of 185 articles found in the literature, 70 fulfilled the eligibility criteria. 5 subgroups of PIDs were Ophtec, artificial iris from Ophtec BV, Morcher GmbH, HumanOptics AG, and other prosthesis. Both glare and aesthetic outcome improved postoperatively; in comparison with other PIDs, intraocular pressure rise was higher in the Morcher group (40%), whereas prosthesis dislocation was higher in the Ophtec group (39%).