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Background: Cystoid macular edema (CME) is the most frequent cause of severe loss of visual acuity in uveitis. Among the systemic corticosteroids and immunosuppressive agents, the local use of intravitreal triamcinolone acetate (TA) is evaluated., Methods and Patients: Intravitreal injections of 10 mg TA were performed in ten eyes of six patients with persisting uveitic CME in spite of systemic cortisone or immunosuppressive therapy., Results: The mean follow-up time was 9.8 months (range: 3-18). Visual acuity increased from 0.58 logMAR to 0.21 logMAR. In two eyes of one patient, repeated intravitreal injections of TA were necessary. Side effects included a increase of intraocular pressure (IOP) up to 25 mmHg or more in 30% of the eyes. In these three eyes, IOP was successfully controlled by local antiglaucomatous therapy (IOP < or = 20 mmHg). The dosage of systemic steroids had to be augmented in two eyes. In no patient was injection-related endophthalmitis, vitreous hemorrhage or retinal detachment observed., Conclusions: Intravitreal TA is an effective local therapy for CME due to uveitis without systemic side effects. It cannot replace the systemic basal therapy of uveitis, since the long-term effects are limited. It can be used as a bridging therapy until a systemic immunosuppression is started. It may, furthermore, be a therapeutic option when side effects of immunosuppressive agents are expected.

Purpose: To study the integration and differentiation of heterotopically transplanted neural precursor cells in the retina of adult mouse mutants displaying apoptotic degeneration of photoreceptor cells., Methods: Neural precursor cells were isolated from the spinal cord of transgenic mouse embryos ubiquitously expressing enhanced green fluorescent protein. Cells were expanded in vitro and transplanted into the retina of adult wild-type and age-matched beta2/beta1 knock-in mice. Beta2/beta1 knock-in mutants display apoptotic death of photoreceptor cells and were generated by placing the cDNA of the beta1 subunit into the gene of the beta2 subunit of Na,K-ATPase. The integration and differentiation of grafted cells in recipient retinas was studied 1 or 6 months after transplantation., Results: Mutant retinas contained more donor-derived cells than wild-type hosts. Moreover, in mutants, donor cells integrated into deeper retinal layers. In both genotypes, grafted cells differentiated into astrocytes and oligodendrocytes. Only a few ganglion cell axons were myelinated by donor-derived oligodendrocytes 1 month after transplantation, whereas extensive myelination of the nerve fiber layer was observed 6 months after transplantation. Unequivocal evidence for differentiation of grafted cells into neurons was not obtained., Conclusions: Heterotopically transplanted neural precursor cells are capable of integrating, surviving, and differentiating into neural cell types in normal and dystrophic retinas of adult mice. The particular environment of a pathologically altered retina facilitates integration of transplanted precursor cells. In principle, neural precursors may thus be useful to substitute for or replace dysfunctional or degenerated cell types. Results of the present study also indicate that replacement of retinal cell types is likely to require more appropriate donor cells, such as retinal precursor cells.