Index of contrast sensitivity (ICS) in pseudophakic eyes with different intraocular lens designs.

PURPOSE: To evaluate the index of contrast sensitivity (ICS) in eyes after cataract surgery with various intraocular lens designs and to compare with the area under log contrast sensitivity curve (AULCSF). METHODS: The study comprised 395 eyes of 198 patients in the age of 73.1 ± 7.86 years receiving 11 different aspheric IOL designs (aberration-free and correcting) and a spherical (IOL) as control group. Follow-up examination after bilateral cataract surgery was completed within 71 ± 21.4 days after second IOL implantation. Patients underwent complete examination and biometry before surgery. The follow-up examination included visual acuity, pupil diameter, residual spherical aberration and mesopic as well as photopic contrast sensitivity (CS) measured with the Optec 6500 Functional Vision Analyzer. From the contrast sensitivity, we calculated the ICS according to Haughom and Strand. RESULTS: The median mesopic ICS was -144, -131 and -85, and the median photopic ICS was -289, -285 and -212 for the spherical, aberration-free and aberration-correcting IOL group, respectively. While we could not detect a significant difference between the aberration groups in some spatial frequencies, the ICS showed a significant difference between the aberration-correcting and the aberration-free or the spherical group, respectively. No significant difference was found between the aberration-free and the spherical group. CONCLUSIONS: The ICS is a useful index for evaluation of overall CS and comparison of different patient groups. With aberration-correcting IOLs, ICS was statistically better than with aberration-free or spherical IOLs, whereas the latter two showed no significant difference.

A serious refractive multifocal intraocular lens complication in Meniere's disease.

PURPOSE: To report an unfortunate case of patient selection for multifocal intraocular lens (MIOL) implantation. METHODS: Interventional case report. RESULTS: A 69-year-old woman with bilateral corticonuclear cataract underwent uneventful phacoemulsification with diffractive MIOL implantation within 1 week. She reported no previous medical history. A few days later she had persisting dizziness and experienced extreme photic phenomena, which progressively deteriorated. After intensive conversation, we discovered that our patient had a medical history of Meniere's disease. Bilateral intraocular lens exchange surgery was performed. One week after monofocal intraocular lens implantation, the patient was satisfied with the final visual outcome and did not report any visual complaints. CONCLUSIONS: Retinocortical processing of visual information is impaired in patients with peripheral vestibular disorders such as Meniere's disease. Therefore, these patients are probably not good candidates for MIOL implantation, which requires an intact sensory system with rigorous visuovestibular interaction.

Impact of fibronectin on surface properties of intraocular lenses.

PURPOSE: Physical properties of intraocular lens (IOL) surfaces determine biocompatibility. IOL hydrophobicity of commercially available IOLs with and without fibronectin (FN) coating can be determined by surface contact angle (SCA) measurements. SCA data of IOLs may allow for a rational selection of an IOL type as a function of underlying eye disease. SETTING: University Hospital of Saarland, Homburg (Saar), Germany METHODS: Thirteen IOL types were tested. IOLs were made of poly(methyl methacrylate)(PMMA), acrylate, or silicone. Select IOLs were surface modified by the manufacturer with heparin or a polysaccharide coating. SCA values of IOLs, either uncoated or precoated with FN, were determined using the sessile water drop method. RESULTS: SCA values ranged from 61.3 to 116.1 degrees for unmodified IOLs, with PMMA IOLs being more hydrophilic (median SCA, 74.1 degrees ), silicone IOLs more hydrophobic (median SCA, 113.3 degrees ), and acrylate IOLs intermediate (median SCA, 86.6 degrees ). Upon FN coating, all genuine acrylate lenses became significantly more hydrophilic while this effect was either nonsignificant or opposite on some PMMA and silicon IOLs. Heparin or polysaccharide surface modification resulted in significantly reduced SCA values. On acrylate IOLs, SCA values did not correlate with the aqueous content of the material. CONCLUSIONS: This study associates IOL materials, surface modifications, and the role of FN preadsorption with SCA values reflecting surface hydrophobicity versus hydrophilicity. It provides a rationale for specific IOL selection as a function of the clinical setting, and a basis for IOL development using tailored surface physicochemistry to enhance biocompatibility and to reduce susceptibility to implant infection.

Influence of fibronectin on the adherence of Staphylococcus epidermidis to coated and uncoated intraocular lenses.

PURPOSE: To determine the effect of the modification of intraocular lens (IOL) surface properties on the adhesion of Staphylococcus epidermidis caused by fibronectin (FN) as the predominant proadhesive glycoprotein of the eye's initial foreign body reaction. SETTING: University of Saarland, Homburg/Saar, Germany. METHODS: Eleven IOL types were tested. The IOLs were of poly(methyl methacrylate), acrylate, or silicone. Some were surface modified with heparin or polysaccharide coating. The IOLs, unadsorbed or preadsorbed with fibronectin (FN), were incubated with [(3)H]-thymidine-labeled S epidermidis Rp62a, and the amount of adherent microorganisms was determined. RESULTS: Attachment of S epidermidis adhesion to various types of IOLs, both unadsorbed and FN precoated, varied significantly. The attachment to highly adhesive IOLs was almost 4-fold greater than that to low-adhesive IOLs. Attachment to FN precoated IOLs was generally enhanced compared with attachment to unadsorbed IOLs. Heparin surface modification resulted in no or a modest reduction in bacterial adhesion compared with unmodified IOLs. Bacterial adhesion was highly statistically significantly less on IOLs with polysaccharide surface modification. CONCLUSIONS: There was significant variability in S epidermidis adhesion to IOLs as a function of design, material, surface modification, and FN preadsorption. Application of the findings may foster new developments to further reduce the major complication in cataract surgery, infective endophthalmitis.