Jürgen Strobel

Effect of heparin surface modification of polymethylmethacrylate intraocular lenses on signs of postoperative inflammation after extracapsular cataract extraction. One-year results of a double-masked multicenter study.

PURPOSEnA heparin surface modified posterior chamber intraocular lens (IOL) was compared with a conventional polymethylmethacrylate (PMMA) IOL regarding postoperative complications caused by inflammation.nnnMETHODSnFive hundred twenty-four patients from 10 different centers were included in a parallel group, double-masked, multicenter study.nnnRESULTSnThe cumulative number of patients with inflammatory cellular deposits on their IOLs during the first postoperative year differed significantly in favor of the heparin surface modified group, with 29.8% of the patients having cellular deposits compared with 48.8% of patients in the control group. Cellular deposits were observed most frequently at 3 months after surgery, and the difference between the groups was most pronounced and statistically significant at this time. The same results were seen at 1 year, but the difference was not significant. The number of cellular deposits per patient, however, was significantly lower in the heparin surface modified group at 1 year. Cumulatively, there were significantly more patients with posterior synechiae in the PMMA group than in the heparin surface modified group during the 1-year follow-up. Complications were few and comparable between the groups.nnnCONCLUSIONnThe results of this study indicate that heparin surface modification reduces the inflammatory response to PMMA IOLs.

Long term effects of lutein, zeaxanthin and omega-3-LCPUFAs supplementation on optical density of macular pigment in AMD patients: the LUTEGA study.

BackgroundThe primary objective of LUTEGA is to determine the long-term effect of a supplementation with fixed combination of lutein, zeaxanthin, omega-3-longchain-polyunsaturated-fatty-acids (O-3-LCPUFAs) and antioxidants on macular pigment optical density (MPOD) in patients with non-exudative age-related macular degeneration (AMD).MethodsThe LUTEGA study is a double-blind, placebo-controlled clinical trial. 172 patients with non-exudative AMD were enrolled and randomized to three treatment arms. Supplementation included either once (dosage D1) or twice daily (dosage D2) of 10xa0mg L / 1xa0mg Z/ O-3-LCPUFAs (thereof 100xa0mg DHA, 30xa0mg EPA)/ antioxidants, or placebo (P). After best-corrected visual acuity (BCVA) test, blood sample was collected and MPOD was measured using the 1-wavelength-reflection method and recording reflection images at 480xa0nm (modified VisucamNM/FA, Carl Zeiss Meditec, Germany). During 1xa0year of intervention, AMD patients were followed up after 1, 3, 6 and 12xa0months. 145 AMD patients (D1u2009=u200950, D2u2009=u200955, Pu2009=u200940) completed the study.ResultsAfter 12xa0months of intervention, the MPOD parameters (volume, area, maxOD, meanOD) increased significantly in treatment arms D1 and D2 (pu2009<u20090.001). Volume of MPOD showed the highest within-group difference and increased significantly in D1 and D2, and decreased significantly in P (pu2009=u20090.041). Between-group comparison of absolute changes of all MPOD parameters were significantly different between D1 and P as well as D2 and P with pu2009<u20090.001 at end point (tu2009=u200912). BCVA, measured in log MAR, improved in D1 and in D2 (pu2009<u20090.001). After 12xa0months of intervention, the mean improvement in BCVA was significant in D2 (pu2009=u20090.006) and D1 (pu2009=u20090.038) compared to P.ConclusionsThe supplementation of L, Z, O-3-LCPUFAs and antioxidants resulted in considerable increase in MPOD. There was no difference in accumulation of MPOD between both dosages. Thus, we believe that the used supplementation with L and Z seems to reach a saturation level in retinal cell structure. Additionally, the constant supplementation of L, Z, O-3-LCPUFAs and antioxidants in AMD patients seems to be useful, because MPOD reduces without supplementation. We conclude that the supplementation caused an increase of MPOD, which results in an improvement and stabilization in BCVA in AMD patients. Thus, a protective effect on the macula in AMD patients is assumed.

Different parameters of the corneal endothelium of the human eye

Abstract Endothelial cell photographs of pseudophakic eyes were analyzed by computer measurement of cell area, circumference and density, and the ratio of cell circumference to cell area. A hexagon was defined as the most space-efficient component of the endothelial cell mosaic. Postoperative changes in cell parameters varied with the type of cataract extraction and style of intraocular lens.

Determination of absolute size of fundus objects

BackgroundCreating multiple beam interference fringes on the retina using the retina fringe projector (RFP) provides us with a scale which can be used to determine the absolute size of objects at the fundus.MethodsThe procedure is tested on an model eye, the optical parameters of which are varied in order to simulate different refraction conditions. The RFP was used to determine the size of a known object at the model fundus; the result was then checked against the real value of the object. In a second series of measurements, the RFP fringes were included in fundus photos of 52 patients with varying levels of ametropia, taken at the University Eye Clinic in Jena using the FF450 fundus camera (manufacturer: Carl Zeiss Meditec AG) for diagnostic purposes. The distance between the fringes was determined using both the RFP and the Littmann method.ResultsThe differences to the real value of the fundus size of a known object deviated on average by 1 to 2%, and always remained under 3% in the model eye. A very good correlation between RFP and Littmann methods results could be found in the clinical part of the study. The resulting deviations are below 2.5%.ConclusionIntegration of a RFP in a fundus camera permits measurement of absolute values of the retina, regardless of the type of observation or documentation. Knowing the real size of fundus objects holds a potential in many clinical classification scales of fundus objects such as drusen or vessels, or in optimizing photodynamic therapy spot size measurement.

Macular Pigment Density Measurement in Patients with Age-related Macular Degeneration

Macular pigment is key to the healthy eye. Direct determination of macular pigment optical density using single-wavelength reflectometry with a fundus camera has allowed to identify changes in macular pigmentation in patients with dry or exudative macular degeneration. This approach could be useful for individualised patient follow-up, particularly in those with age-related macular degeneration.