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Notes: Abstract  Background: The production of intraocular antibodies is considered a specific marker for active infectious uveitis. The aim of our study was to evaluate the diagnostic value of aqueous humor analysis in consecutive patients referred to a tertiary clinical center.  Methods: We analyzed 91 paired aqueous humor/serum samples from 89 patients with intraocular inflammation. In 71 patients aqueous humor analysis was used as a positive or negative confirmation of the suspected cause, whereas in 18 patients the clinical diagnosis was completely uncertain. A modified micro-ELISA technique was used to detect intraocular IgG production against Toxoplasma gondii, varicella zoster virus, herpes simplex virus and cytomegalovirus. Statistical analysis was performed using the ”Cohen’s kappa” test.Results: Specific intra-ocular antibody production could be detected in 12 (66.7%) of 18 patients with uncertain diagnosis. Subsequently initiated therapy led to clinical improvement in 10 patients, whereas 2 patients remained unchanged. In 2 (2.8%) of 71 patients aqueous humor analysis led to revision of the initially suspected etiology and to a change of therapy. Statistical analysis showed a significant accordance of diagnosis and aqueous humor analysis (P〈0.01).  Conclusion: In patients with infectious uveitis, analysis of intraocular synthesis of specific antibodies is a valuable tool to establish the etiology rapidly and allows initiation of targeted antimicrobial treatment.

Notes: Abstract  Background: The intrastromal corneal ring (ISR) is a refractive device recently introduced for clinical application that is implanted in the mid-peripheral corneal stroma in order to correct myopia without invasion of the central optical zone. First clinical results of intracorneal ring segment implantation were published recently. These results reveal striking similarities to our own experimental data, only briefly published up to now. The aim of this study is to present the refractive and histopathological data of ISR implants in rabbits and to compare these results with the clinical data actually available. Methods: Expansion/constriction effects were evaluated with a ring of constant size (7.5×0.5×0.2 mm) in channels of 7.0, 7.5, or 8.0 mm in diameter, volume effects by implantation of 7.5-mm rings with varying thickness (0.2, 0.3, 0.4 mm) into a channel of 7.5 mm, respectively. Refractive power was measured preoperatively and at day (D) 7, D14, D30 for the first and the second experiment, plus D60, D90 for the second experiment. Histological evaluations of the induced morphological changes were additionally performed at all time intervals. Results: Significant (P〈0.05) flattening of the cornea was obtained in all but the first (constant ring, 7.0-mm channel) implants postoperatively at D7 and/or D14, with mean dioptric changes up to –5.03±2.92 compared with controls. However, from D30 on, there was no statistically significant difference between operated and control eyes. Biomicroscopy and histology of the implanted eyes revealed good biocompatibility, with only rare major complications such as stromal abscess or massive neovascularization. Conclusions: Although our implantation technique differs slightly from that employed in the recent FDA studies, our results tend to confirm the maximal achievable refractive change of about –5 dpt with this procedure. Furthermore, this study is the first to demonstrate that in rabbits, ISR implantation has only a short-term effect on refractive power. Our results indicate that long-term refractive follow-up may be necessary in human eyes prior to the introduction of ISRs as a routine procedure in refractive surgery.

Notes: Abstract  Background: Migration and proliferation of lens epithelial cells (LECs) are based on interactions between cellular integrins and extracellular matrix proteins (ECMs). We were able to design polymers substituted with COO– and SO3 – groups that counteract LEC proliferation through modification of the integrin/ECM interaction. The objective of this study was to compare the cell proliferation-inhibiting properties of differently substituted copolymers with those of a homopolymer. Methods: Polymers were synthesized by radical polymerization and characterized by nuclear resonance spectroscopy. Second- passage rabbit LECs were cultured either on PMMA homopolymers (control) or on substituted PMMA copolymers. Cells were counted on days 2, 7, and 17. Cell vitality was evaluated by trypan blue staining. Experiments were run in quadruplicate. Statistical analysis was performed using the Wilcoxon test and the Mann-WhitneyU-test. Results: Compared with control, cells cultured on copolymers grew to significantly lower cell numbers. The inhibitory effect became evident at day 2 after seeding and persisted throughout the experiment. Different ratios of COO–/SO3 – substitutions yielded different grades of inhibition. No toxic effect was seen on rabbit LECs. Conclusions: The tested copolymers inhibit cell proliferation and are nontoxic. Further evaluation could lead to the development of new intraocular lens materials that prevent secondary cataract.

Notes: Abstract  · Background: The proliferation of vascular endothelial cells and ultimately angiogenesis is inhibited by blocking integrin-mediated cell–matrix interaction. To asses the therapeutic potential of αv-integrin antagonists LM609 and cRGDfV in neovascularization of the anterior segment, their inhibitory effect on angiogenesis was studied in two rat models for corneal neovascularization. · Methods: Corneal neovascularization was induced in Wistar rats (n=51) either by silver nitrate burns or intrastromal implantation of polymer pellets containing 400 ng of fibroblast growth factor (bFGF). Animals were treated with subcutaneous injections of a cyclic αv-integrin antagonist (cRGDfV, 15 mg/kg body wt) or saline twice daily. Additional animals received intrastromal implants containing 400 ng bFGF together with either Lm609 (mAb, anti-αvβ3) or control antibody. Four days later, the animals were killed and the percentage of the surface area covered with vessels determined using digital image analysis. · Results: Systemic treatment with cRGDfV resulted in a significant reduction of corneal vessel growth in animals with bFGF-induced corneal vascularization. In corneas with silver nitrate burns, systemic cRGDfV treatment showed no significant reduction of vascularization compared with controls. Pellets containing bFGF and LM609 mAb induced significantly less neovascularization than pellets containing bFGF and control mAb. · Conclusion: Our results suggest that in the rat cornea, αvβ3 ligation does inhibit bFGF-induced neovascularization. A chemical burn of the cornea induces angiogenisis which is not inhibited by blocking αv-integrins. This suggests an angiogenic pathway independent of αv-integrins.

Notes: Abstract  Background: Genetic manipulation of the donor cornea ex vivo prior to transplantation may allow modulation of the allogeneic immune response following penetrating keratopasty. In this study we investigated the effect of adenovirus-mediated gene transfer of the Th2 cytokine interleukin-4 (IL-4) to rat corneas in an experimental keratoplasty model. Methods: Ex vivo manipulation of Wistar-Furth rat corneas was performed using E1/E3- deleted adenoviral vectors transferring the gene for rat IL-4 (AdrIL-4) under control of the CMV promoter. Following transfection with AdrIL-4 (2×108 pfu) in DMEM/2% FCS for 3 h, donor corneas were transplanted in MHC class I/II-incompatible Lewis rats. Fifty-two Lewis rats were randomly assigned to receive either nontransfected grafts (n=32), AdrIL-4-transfected grafts (n=8), or syngeneic grafts (n=12). Results: The rejection rate of AdrIL-4-transfected grafts (85.7%) could not be reduced as compared to controls (62.9%). In addition, the mean survival time of AdrIL-4-transfected grafts (12.6±4.5 days) did not differ (P〉0.05) from that for untreated transplants (14.1±3.8 days). Conclusions: Our results indicate that overexpression of IL-4 is not sufficient to reduce the rejection rate of corneal allografts in an ex-perimental keratoplasty model. Further investigations are necessary to identify the reasons for failure and establish more efficient modulatory approaches.