[Intravitreal drug therapy for retinal vein occlusion--pathophysiological mechanisms and routinely used drugs]. / Intravitreale Medikamenteneingabe bei retinalem Venenverschluss--pathophysiologische Mechanismen und angewandte Substanzen.

The novel therapeutic principle of intravitreal drug therapy for retinal vein occlusion has become an integrated constituent of clinical practice over the last years. The two substance classes that have been evaluated in large randomised clinical trials so far are corticosteroids and inhibitors of vascular endothelial growth factor (VEGF). The reported treatment success of these intravitreally administered substances has lead not only to a paradigm shift in clinical care but has also advanced our understanding of the underlying pathophysiological principles of retinal vein occlusions. In this review the different substances are discussed, their mechanisms of action are analysed and the results of the large clinical trials available to date are critically evaluated. Furthermore, an approach to integrate these novel treatment options into the existing treatment regimes for retinal vein occlusions is suggested.

[Bilateral tumors of the eyebrows]. / Bilaterale Augenbrauentumoren.

We report about a 5-year-old boy who presented in our clinic with bilateral, slowly progressive solid tumors of the eyebrows. Histological examination of the excised tumors revealed the typical diversified picture of pilomatrixoma with basophilic and shadow cells. The bilateral or multiple manifestation of pilomatrixoma is uncommon and can be associated with myotonic dystrophy, sarcoidosis or Gardner's syndrome.

Z-suture: a new knotless technique for transscleral suture fixation of intraocular implants.

The presented Z-suture is a simple, rapid and safe knotless technique that facilitates transscleral suture fixation of various intraocular implants in the ciliary sulcus, such as sutured intraocular lenses, artificial iris prostheses and iris diaphragms. As the knotless approach reliably avoids suture erosion, external fixation can be performed without any protecting scleral flaps or lamellar grooves. The needle is simply passed through the sulcus and the emerging polypropylene suture is secured in the sclera using a zigzag-shaped intrascleral suture (Z-suture). Each pass starts directly adjacent to the exiting site. Five passes are sufficient to reliably fix the suture so that it resists even maximum tractive forces. Once this procedure is done, the suture can be cut without any knot. By avoiding suture knots, and hence the need for intrascleral flaps, this knotless approach may help to reduce suture-related complications such as scleral atrophy, suture erosion and infections.

[Optic atrophy subsequent to epiretinal triamcinolone deposits in an eye following inner limiting membrane peeling]. / Optikusatrophie nach epiretinalen Triamcinolon-Ablagerungen in einem Auge mit entfernter Membrana limitans interna.

BACKGROUND: Although current in vitro studies show local cytotoxicity of triamcinolone (TA) crystals if they are in direct contact with cells, a toxic effect of epiretinal TA deposits has not been reported yet clinically. For the first time, we present a case of potential cytotoxicity of epiretinal TA deposits in vivo. CASE REPORT: A 68-year old patient underwent a re-vitrectomy with peeling of a macular pucker and the internal limiting membrane (ILM) combined with an intravitreal injection of 25 mg TA due to a secondary macular pucker with cystoid macular edema. Postoperatively, pronounced epiretinal deposits of TA crystals were identified in the area of the posterior pole. Two months after the injection a consecutive optic atrophy with central visual field defect and severe reduction of the visual acuity to hand movements was apparent. CONCLUSION: Our case report indicates possible in-vivo toxicity of TA deposits in eyes subsequent to vitrectomy and peeling of the ILM. This is in accordance with previous in-vitro studies showing ILM and vitreous to be protective biological factors, but demonstrate pronounced cytotoxicity if TA crystals are allowed to directly adhering to denuded ganglion cells. Hence, we consider that TA injection should be carefully weighed in those patients with prior ILM removal.

[Injector implantation of a scleral-fixated intraocular lens]. / Injektorimplantation sklerafixierter Faltlinsen.

BACKGROUND: In this pilot study, a new injector technique for small-incision implantation of scleral-fixated intraocular lenses (IOLs) was evaluated for IOL stability and visual rehabilitation. PATIENTS AND METHODS: Secondary lens implantation was performed in 18 aphakic eyes using a new small incision technique with injector implantation. This allowed for haptic suturing with the lens body inside the cartridge. All patients were followed-up for best-corrected visual acuity, refraction, IOL evaluation and ultrasound biomicroscopy. RESULTS: In all eyes the IOL was stable without tilt or torque. Best-corrected visual acuity improved 2.2 ETDRS lines after 1 week and 3.1 lines after a mean follow-up time of 7.9+/-2.8 months. Two eyes were complicated with small, peripheral transillumination defects (n=2), but no pigmentary glaucoma occurred. CONCLUSION: By using a self-sealing tunnel incision and injector technique, significant fluid egress and consecutive transient hypotony is minimized throughout the whole procedure. The technique shows a high IOL stability without tilt and assures rapid visual rehabilitation.

[Bevacizumab for treatment of macular edema secondary to retinal vein occlusion]. / Bevacizumab zur Therapie des sekundären Makulaödems nach venösen Gefässverschlüssen.

Application of VEGF inhibitors represents a treatment option for macular edema secondary to retinal vein occlusion that targets the disease at the causal molecular level. First reports on intravitreal injections of bevacizumab show promising morphological and functional effects and demonstrate that bevacizumab is a potent antiedematous agent in this context. A significant reduction of the central retinal thickness followed by a rapid improvement of visual acuity may be achieved within days. In a pilot study with a review period of 3 months, we found a significant improvement of one or more lines in 93% and four or more lines in 27% of eyes. This was associated with a concomitant significant reduction in central retinal thickness, which, however, was not sustained by a single injection (64% reduction after 1 month and 28% after 3 months). No relevant adverse events were noted. The duration of action after intravitreal bevacizumab administration is currently unknown. Reinjections will be necessary to maintain a lasting beneficial effect. Prospective, controlled long-term studies are mandatory to develop standardized treatment protocols that allow a safe and effective application of this off-label therapy.

[Recommendation for the implementation of intravitreal injections--statement of the German Retina Society, the German Society of Ophthalmology (DOG) and the German Professional Association of Ophthalmologists (BVA)]. / Empfehlung für die Durchführung von intravitrealen Injektionen -- Stellungnahme der Retinologischen Gesellschaft, der Deutschen Ophthalmologischen Gesellschaft (DOG) und des Berufsverbands der Augenärzte Deutschland (BVA).

The intravitreal injection as a minimally invasive intervention has proved to be an effective therapy in the management of numerous vitreoretinal diseases. However, non-standardized performance of the procedure might cause severe complications. The recommendations for intravitreal injections discussed here are intended to contribute to a minimization of the risk for complications. Of particular importance are a meticulous preoperative antisepsis with povidone iodine, a sterile environment using a sterile lid speculum, drape and gloves, the use of an adequate injection technique and the exclusion of postoperative retinal non-perfusion.

[Ocular side effects and complications of intravitreal triamcinolone acetonide injection]. / Nebenwirkungen und Komplikationen der intravitrealen Triamcinolonacetonid-Therapie.

With the advent of intravitreal triamcinolone acetonid injections major focus was assigned to potential ocular side effects. The current discussion is dominated by the potential cytotoxicity of particular biologically incompatible components. Those are regarded as substantial pathogenetic factor of the sterile pseudoendophthalmitis that seems to be avoidable by meticulous purification of the commercially available preparations. Even sustained subretinal or epiretinal deposits disclosed no signs of retinal toxicity. Major ocular side effects comprise temporary corticosteroid glaucoma and progressive cataract formation. Infectious endophthalmitis represents a rare but serious complication that might be set into critical context with hygienic surgical standards applied. Due to steroid-induced immune suppression clinical signs of inflammation might be masked and a proper diagnosis delayed. Other rare complications reported include a transient central retinal artery occlusion, conjunctival ulcerations, retinal detachment and potential reactivation of a cytomegalovirus retinitis. In conclusion, ocular side effects and complications show a wide variety of clinical signs and underlying causal mechanisms. However, the consequences are mostly temporary and show a good response to therapeutic intervention.

Identification of Usher syndrome subtypes by ERG implicit time.

PURPOSE: Usher syndrome (US) is a recessively inherited disorder combining retinitis pigmentosa (RP) and a sensorineural hearing loss. The classification in subtypes is based mainly on auditory tests. The purpose of this study was to analyze implicit time (IT) differences in the electroretinogram (ERG) between RP alone, US I, and US II. METHODS: The data of 15 control subjects and of 15 patients with US I, 15 with US II, and 15 with RP with nonzero 33-Hz flicker ERG responses were analyzed. The ITs of three signal peaks (P1-P3) were evaluated. Sensitivity and specificity of a test to distinguish between US I and II based on timing differences were determined. Multifocal (mf)ERGs were used to assess differences in disease topography. RESULTS: Despite the similar amplitude loss with retinal eccentricity in the mfERG in all three groups, the peak delay in US I was negligible compared with that in US II and RP. In the flicker ERG data, US I and control subjects had almost identical peak times, and the same was true for subjects with US II and RP. Because of the slight overlap between US I and II, the diagnostic test achieved a sensitivity of 100% and a specificity of 93.3%. CONCLUSIONS: Substantial timing differences between US I and II and their usefulness for a diagnostic test were demonstrated. This finding may also be the basis for further investigations regarding the structural differences of retinal impairment between US I and II on a cellular level.

Evaluation of the rhodopsin knockout mouse as a model of pure cone function.

PURPOSE: To determine a time window in the rhodopsin knockout (Rho(-/-)) mouse during which retinal function is already sufficiently developed but cone degeneration is not yet substantial, thus representing an all-cone retina. METHODS: Electroretinograms (ERGs) were obtained from 14 homozygous Rho(-/-) mice and eight C57Bl/6 control mice. The same individuals were tested every 7 days, beginning as early as postnatal day (P)14. The ERG protocols included flash and flicker stimuli, both under photopic and scotopic conditions. Retinal and choroidal morphology was observed in animals of comparable age. RESULTS: Functionally, the developmental phase lasted until postnatal week (PW)3 in both the Rho(-/-) mice and the control animals. During PW4 to 6, the Rho(-/-) mice showed a plateau in ERG parameters with normal or even supernormal cone responses and complete absence of rod contributions. At PW7, there was a marked onset of degeneration, which progressed so that no ERG signals were left at PW13, when the control eyes still had normal ERG responses. Microscopically, cone degeneration paralleled the functional changes, beginning at approximately PW6 and almost complete at PW13, whereas retinal pigment epithelium (RPE) and choroid did not show any abnormalities. CONCLUSIONS: From PW4 to 6, Rho(-/-) mice appear to have normal cone and no rod function. Despite the missing rod outer segment (OS), the structure of retina, RPE, and choroid remained unchanged. Therefore, the Rho(-/-) mice can serve during this age period as a model for pure cone function. Such a model is particularly useful to evaluate rod-cone interaction and to dissect rod- from cone-mediated signaling pathways in vivo.