Spectral Transmission of Clear and Yellow pHEMA IOL Pre-Post 6 Months Implantation in Rabbits

Abstract

Purpose: : To compare the spectral stability and biocompatibility of yellow and clear IOLs.

Methods: : A 300-600 nm portable testing system was designed using a fiber optic spectrometer (#SM240, Spectral Products-CVI, Putnam, CT) and a deep blue-white LED source with diffuser, iris diaphragm, voltage regulator and a transparent table supporting a sterile BSS filled Petri dish to hold the sample. Sterile IOLs of both types underwent spectral analyses. The study adhered to the ARVO Statement for the use of animals in research and followed ISO/DIS 11979-5 and approved institutional animal care guidelines. 12 NZW rabbits were implanted with IOLs having the same physical dimensions; 6 received a clear and 6 a yellow pHEMA IOL (Quatrix, 20D, Croma-Pharma, Austria) and underwent weekly ophthalmic exams for 6 months. Following euthanasia, a ring conforming to the anterior sclera was bonded with cyanoacrylate to the enucleated globe which was sectioned leaving an intact rim containing the lens or IOL in the capsular bag, zonules, ciliary body, anterior vitreous, hyaloid membrane, and sclera. The tissue sections underwent Miyake and shadowphotography exams and spectral transmission measurements. The IOLs were explanted and additional spectral measurements carried out. All tissues underwent histology.

Results: : Surgery and follow-up were uneventful. As with Acrysof and other IOLs (Fujiwara et al, ARVO IOVS 2001;42(4):S285 & 2001;42(4):S285) all eyes had PCO at 1 month. Both IOLs were equally biocompatible. No clinical and histology differences could be found between the 2 groups. Miyake and shadowphotography at 6 months showed de novo lens fibers in all eyes reducing transmission and impacting the spectra compared to the crystalline lens of unoperated contralateral eyes. There were no significant differences between the spectra of explanted and control IOLs.

Keywords: intraocular lens • optical properties