Biomedical subjects

Brian Haugen

Publications and source records attributed to Brian Haugen.

3 recordsLinked to original sources

PubMed2006

New photochromic foldable intraocular lens: preliminary study of feasibility and biocompatibility.

PURPOSE: To evaluate a new hydrophobic acrylic intraocular lens (IOL) with photochromic properties in vitro and in vivo in a rabbit model. SETTING: John A. Moran Eye Center, University of Utah, Salt Lake City, Utah, USA. METHODS: The photochromic optic change of 5 study IOLs was evaluated in vitro on ultraviolet (UV) light exposure. The tests were done in the dry state and during immersion of the lenses in a balanced salt solution. Six additional IOLs were implanted in the right eye of New Zealand rabbits. The left eyes were implanted with SA60AT or SN60AT IOLs (Alcon Laboratories, 3 each). After a clinical follow-up of 6 months, the rabbits were killed and their eyes enucleated. Three study IOLs and 2 control SN60AT IOLs were evaluated in vitro on UV exposure after explantation. The other IOLs and the rabbit eyes had histopathologic examination. RESULTS: On in vitro UV light exposure, the optic of the study IOLs changed from colorless to yellow, turning again colorless on discontinuation of UV light projection. The same photochromic change was also observed on UV light exposure throughout the clinical follow-up of 6 rabbits, as well as after explantation of the IOLs. Postoperative clinical inflammatory reactions and cellular reactions on the surface of the explanted IOLs were similar in the study and control groups. No sign of untoward toxicity was observed in the histopathological sections of the rabbit eyes in all groups. CONCLUSIONS: The new photochromic IOL turned yellow only on exposure to UV light; otherwise it remained clear. This lens was also found to be biocompatible.

Acrylic Resins↗

PubMed2006

A light adjustable lens with injectable optics.

The light adjustable lens (LAL) is an innovative intraocular lens optic composed of partially polymerized macromers with an appropriately bonded photosensitizer. The injectable technology and multifocality associated with the LAL can produce precise refractive correction and, it is hoped, the type of accommodative range that is taken for granted during youth. Combining these technologies with a lens material that behaves like the crystalline lens of 25-year-old could precisely return near and distance vision to older adults.

Accommodation, Ocular↗

PubMed2006

A light adjustable lens with injectable optics.

PURPOSE OF REVIEW: Technology exists today that could permit refractive precision unheard of at the present time plus the correction of higher-order aberrations and restoration of accommodation in presbyopic adults. RECENT FINDINGS: With the light adjustable lens, after surgery, the shape of the lens can be customized to treat spherical, cylindrical and other higher-order aberrations. The posterior surface of the lens can be adjusted to create both refractive multifocality and diffractive bifocality. It can be made out of a variety of materials, some of which can be injected into the capsule, filling it, thus replicating the original shape of a crystalline lens. While the current technique of bag filling does permit the less viscous materials to leak out of the bag this is a solvable problem. For example, a disc can fill an ordinary-sized capsulorrhexis opening, allowing removal of the cataract using standard techniques and filling behind this disc. Also the material, once injected, could be polymerized. Posterior capsule opacification is also potentially solvable with devices that completely destroy lens epithelial cells or through a polymerization process of the new lens material in which the reaction destroys the capsular cells and actually binds to the capsule. SUMMARY: It is apparent that light adjustable lenses plus injectable technology, and multifocality can produce precise refractive correction and, hopefully, the type of accommodative range that we take for granted when we are young. Combining these technologies with a lens material that behaves like a crystalline lens of a 25 year old could precisely return near and distance vision to older adults.

Accommodation, Ocular↗