Barbara Käsmann-Kellner

A randomized, double-blind, phase 2 study of erythropoietin in optic neuritis

Based on findings in animal models of autoimmune optic nerve inflammation, we have assessed the safety and efficacy of erythropoietin in patients presenting with a first episode of optic neuritis.

Monocular visual activation patterns in albinism as revealed by functional magnetic resonance imaging

Human albinism is characterized by a disturbance of the chiasmatic projection system leading to predominant representation of just one eye in the contralateral hemisphere. Patients show congenital nystagmus without perceiving oscillopsia. The purpose of the present study was to demonstrate the consequences of atypical chiasmatic crossing with monocular visual stimulation using functional magnetic resonance imaging (fMRI). Sixteen patients with albinism and fifteen normally pigmented controls were stimulated with a monocular visual activation paradigm using flickering checkerboards. In patients, we observed contralaterally dominated activation of visual cortices correlating to clinical albinism parameters. This confirms albinism as a continuous range of hypopigmentation disorders. Additionally, albinos showed activation of the superior colliculus and of visual motion areas although the stimulus was stationary. Activation of visual motion areas is due probably to congenital nystagmus without a conscious correlate like oscillopsia. Hum. Brain Mapping 23:40–52, 2004.

Biomechanical profile of the cornea in primary congenital glaucoma

Purpose:u2002 The aim of our study was to investigate the biomechanical properties of the cornea in primary congenital glaucoma (PCG) and to identify the potential ocular determinants, which affect the corneal biomechanical metrics.

Retinal Nerve Fibre Layer Thinning in Patients with Clinically Isolated Optic Neuritis and Early Treatment with Interferon-Beta

Background Optic neuritis is associated with neurodegeneration leading to chronic impairment of visual functions. Objective This study investigated whether early treatment with interferon beta (IFN-β) slows retinal nerve fibre layer (RNFL) thinning in clinically isolated optic neuritis. Methods Twenty patients with optic neuritis and visual acuity decreased to ≤0.5 (decimal system) were included into this prospective, open-label, parallel group 4-month observation. After methylprednisolone pulse therapy, 10 patients received IFN-β from week 2 onwards. This group was compared to 10 patients free of any disease modifying treatment (DMT). The parameter of interest was change in RNFL thickness assessed at baseline and at weeks 4, 8, and 16. Changes in visual acuity, visual field, and visual evoked potentials (VEPs) served as additional outcome parameters. Results RNFL thinning did not differ between the groups with a mean reduction of 9.80±2.80 µm in IFN-β-treated patients (±SD) vs. 12.44±5.79 µm in patients who did not receive DMT (baseline non-affected eye minus affected eye at week 16; pu200a=u200a0.67, t-test, 95% confidence interval: −15.77 to 10.48). Parameters of visual function did not show any differences between the groups either. Conclusions In isolated optic neuritis, early IFN-β treatment did not influence RNFL thinning nor had it any effect on recovery of visual functions.

Multifocal Visual Evoked Potentials Reveal Normal Optic Nerve Projections in Human Carriers of Oculocutaneous Albinism Type 1a

PURPOSEnIn albinism, part of the temporal retina projects abnormally to the contralateral hemisphere. A residual misprojection is also evident in feline carriers that are heterozygous for tyrosinase-related albinism. This study was conducted to test whether such residual abnormalities can also be identified in human carriers of oculocutaneous tyrosinase-related albinism (OCA1a).nnnMETHODSnIn eight carriers heterozygous for OCA1a and in eight age- and sex-matched control subjects, monocular pattern-reversal and -onset multifocal visual evoked potentials (mfVEPs) were recorded at 60 locations comprising a visual field of 44 degrees diameter (VERIS 5.01; EDI, San Mateo, CA). For each eye and each stimulus location, interhemispheric difference potentials were calculated and correlated with each other, to assess the lateralization of the responses: positive and negative correlations indicate lateralizations on the same or opposite hemispheres, respectively. Misrouted optic nerves are expected to yield negative interocular correlations. The analysis also allowed for the assessment of the sensitivity and specificity of the detection of projection abnormalities.nnnRESULTSnNo significant differences were obtained for the distributions of the interocular correlation coefficients of controls and carriers. Consequently, no local representation abnormalities were observed in the group of OCA1a carriers. For pattern-reversal and -onset stimulation, an assessment of the control data yielded similar specificity (97.9% and 94.6%) and sensitivity (74.4% and 74.8%) estimates for the detection of projection abnormalities.nnnCONCLUSIONSnThe absence of evidence for projection abnormalities in human OCA1a carriers contrasts with the previously reported evidence for abnormalities in cat-carriers of tyrosinase-related albinism. This discrepancy suggests that animal models of albinism may not provide a match to human albinism.

Can retinoscopy keep up in keratoconus diagnosis

PURPOSEnTo evaluate the diagnostic potential of retinoscopy in comparison with Amsler-grading, Pentacam and Ocular Response Analyzer (ORA) in classifying keratoconus stages.nnnMETHODSnClinical examination, retinoscopy, Pentacam and ORA were performed in 126 patients. Data of Amsler, retinoscopy, topographic keratoconus classification (TKC) of Pentacam and keratoconus match probability (KMP) of ORA were analyzed. Each of these four classification techniques quotes keratoconus into stage 0 (normal) to 4 (severe). Descriptive analysis and cross tables were used to compare the different devices.nnnRESULTSnFor retinoscopy the distribution in the five keratoconus grades normal/suspect/mild/moderate/severe (in numbers) was 34/33/34/17/8. For Amsler it was 37/36/35/12/4, for TKC 38/17/34/31/4, for KMP 32/34/32/15/9. The cross tables show large classification differences of all devices. Overall, classification of retinoscopy and Amsler/TKC/KMP is congruent in 51.6%/36.3%/39.8% of the cases. Of all eyes, Amsler was congruent with TKC/KMP in 54.0%/48.4%, and TKC and KMP were congruent in 53.3%. In a binary decision (normal vs. any stage of mild/moderate/severe) matching between retinoscopy and Amsler/TKC/KMP was 98.6%/88.8%/82.4%. Sensitivity/specificity for retinoscopy and Amsler, TKC, KMP was 98.8%/94.0%, 84.4%/100% and 80.0%/79.1%.nnnCONCLUSIONSnThe congruence of keratoconus classification was very poor of all the techniques tested in our study. This applies to objective measures such as TKC, KMP as well as clinical classification techniques such as Amsler and retinoscopy. Compared to TKC and KMP, retinoscopy underestimates keratoconus stages. In contrast, the performance of binary decisions (normal vs. keratoconus) shows a high sensitivity and specificity. Retinoscopy, however, showed a clear clinical use in confirming the diagnosis of keratoconus.

Human aniridia limbal epithelial cells lack expression of keratins K3 and K12

Abstract Aniridia is a rare disease of the eye that affects the iris, lens and the cornea. In about 90% of the cases, patients showed a loss of PAX6 function. Patients with aniridia often develop aniridia‐related keratopathy (ARK), due to limbal stem cell insufficiency. The aim of this study was to determine the differentiation status of limbal epithelial cells (LECs) in patients with ARK. Epithelial cells were isolated from the limbus region of two patients with aniridia and cultured in KSFM medium supplemented with EGF and BPE. Normal cells were obtained from limbus region of cadaveric control patients. Cells were analyzed with RT‐PCR, qPCR and Western blot to evaluate expression of the developmental transcription factor, PAX6, potential stem cell markers, &Dgr;Np63&agr; and ABCG2, and corneal differentiation markers, keratin 12 (K12) and K3. Conjunctival differentiation markers, keratin 13 (K13) and K19 were also investigated. Cells were immunostained to evaluate K3, PAX6, and p63&agr; protein expression. Protein coding sequence of PAX6 from patient LEC‐cDNA was cloned and sequenced. RT‐PCR showed that K3 and K12 transcripts were absent from patient cells, but present in healthy control preparations. Transcription levels of PAX6, ABCG2, and p63&agr; of aniridia patients show no differences compared to normal control cells. Western blot showed reduced PAX6, protein levels in aniridia‐LECs compared to control‐LECs. Immunostaining also showed reduced PAX6 and K3 expression in aniridia‐LECs compared to control‐LECs. One aniridia patient showed a loss of stop codon in half of the cloned transcripts. In the second aniridia patient mRNA degradation through nonsense mediated decay seems to be very likely since we could not identify the mutation c.174C > T (Refseq. NM_000280), or misspliced transcripts in cDNA. We identified decreased PAX6 protein levels in aniridia patients in addition to decreased K12 mRNA levels compared to control cells. This result indicates an altered differentiation of limbal epithelial cells of aniridia patients. Further studies are necessary to evaluate the mechanism of differentiation of limbal epithelial cells in aniridia. HighlightsEpithelial cells isolated from limbus region of aniridia patients can be expanded.Limbal epithelial cells of aniridia patients lack expression of K12 and K3.PAX6 mRNA expression may not correlate with protein expression in NMD mutants.Elongated PAX6 (loss of stop mutation) may be degraded in epithelial cells.

Clinical anatomy of the anterior chamber angle in congenital aniridia – and consequences for trabeculotomy/cyclophotocoagulation

Intraocular pressure lowering surgery in congenital aniridia glaucoma (CAG) can be complicated by dysgenesis of the limbal region, anterior chamber angle, iris, and lens. The anterior segments of 23 eyes (17 patients) with congenital aniridia were investigated under general anesthesia using ultrasound biomicroscopy (UBM). The structures of the anterior segment were examined: distance of ciliary body processes from the anterior chamber angle and positioning of Schlemms canal. A surgical plan was created on the basis of these data. Schlemms canal was detected in 21 of the 23 examined eyes. The mean distance from the anterior chamber angle was 1.3u2009±u20090.4 mm (range: 0.5–to 2.1 mm). The mean distance between the anterior chamber angle and the ciliary body was 561u2009±u2009301 µm (range: 270–1,300 µm). The mean prominence of the ciliary body towards the lens was 799u2009±u2009352 µm (range: 210–1,660 µm). This resulted in a precise UBM‐based trabeculotomy. In addition, the ciliary body was detected and coagulated ab externo with a diode laser probe (810 nm) using diaphanoscopy and UBM. An initial UBM examination of the anterior segment is essential in eyes with CAG scheduled for trabeculotomy or cyclophotocoagulation. Clin. Anat. 31:64–67, 2018.

Expression of retinoic acid signaling components ADH7 and ALDH1A1 is reduced in aniridia limbal epithelial cells and a siRNA primary cell based aniridia model

ABSTRACT PAX6‐related Aniridia is a sight‐threatening disease involving progression of secondary glaucoma and aniridia related keratopathy (ARK). Change or loss of limbal epithelial progenitors causes epithelial surface defects. We analyzed the effect of PAX6 on mRNA expression changes with a two‐step approach, as follows. First, we sequenced mRNA from limbal epithelial cells isolated from controls and aniridia patients. Second, we confirmed the bioinformatics and literature‐based result list for a small interfering RNA (siRNA)‐based primary aniridia cell model (PAX6 knockdown). With this approach, we expected that the genes directly influenced by PAX6 would be distinguishable from those affected secondarily by the ARK disease state. Therefore, epithelial cells were isolated from the limbus region of two patients with aniridia and cultured in keratinocyte serum‐free medium. Normal control cells were obtained from the limbus region of corneal donors. For the siRNA‐based aniridia cell model, cells were transfected with Lipofectamine and 5 nM siRNA against PAX6 or control treatment. All cells were lysed to yield DNA, RNA, and protein. Reduction of PAX6 protein was assessed by western blot. Aniridia and control Poly‐A–enriched RNA libraries were subjected to next‐generation sequencing. The differential analysis was a combination of quantification with RSEM and differential tests with edgeR. Gene lists were filtered by comparison to NCBI GEO datasets, annotated with DAVID, and manually annotated using a literature search. Based on the resulting filtered gene list, qPCR primers were purchased, and candidate genes (TP63, ABCG2, ADH7, ALDH1A1, PITX1, DKK1, DSG1, KRT12, KRT3, KRT13, SPINK6, SPINK7, CTSV, SERPINB1) were verified by qPCR on the siRNA‐based aniridia cell model. We identified genes that might be regulated by PAX6 and showed that SPINK7 mRNA, which codes for a protease inhibitor, is downregulated in patients as well as in our primary aniridia cell model. ALDH1A1 and AHD7 mRNA levels were reduced in limbal epithelial cells of aniridia patients, and both transcripts were downregulated by PAX6 knockdown in our cell model. This siRNA‐based aniridia cell model is a valuable tool for confirming identified PAX6‐affected genes that might promote ARK pathogenesis. The model recapitulated expression changes for SPINK7, ADH7, and ALDH1A1 that were also observed in patient samples. These results provide evidence that PAX6 might drive corneal epithelial differentiation by direct or indirect control of retinoic acid signaling processes through ADH7 and ALDH1A1. HighlightsPAX6 has an important influence on the differentiation process of limbal epithelial (stem) cells.PAX6 siRNA model recapitulates differentiation defects of aniridia limbal epithelial cells.Retinoic acid signaling components are potentially PAX6 related.SPINK protease inhibitors are downregulated in aniridia limbal epithelial cells.

MYCOPLASMA PNEUMONIA-ASSOCIATED CHOROIDAL NEOVASCULARIZATION-BEVACIZUMAB INTRAVITREAL INJECTION AND LASER TREATMENT.

Purpose: To report a rare case of bilateral subretinal granulomas with choroidal neovascularization after Mycoplasma pneumoniae atypical pneumonia. Methods: Presentation of a 7-year-old girl, who showed bilateral atypical subretinal granulomas with choroidal neovascularization. Visual acuity was 20/20 oculus dexter and 20/200 oculus sinister. Evaluation revealed a systemic Mycoplasma pneumoniae infection with pulmonary involvement. Successful ocular treatment was performed by intravitreal injection of Bevacizumab and laser photocoagulation. Results: Visual acuity was unchanged 36 months after treatment. No further subretinal lesions were seen oculus uterque. Conclusion: To the best of their knowledge and according to literature this patient report is the first one of subretinal granuloma formation after pneumonia due to mycoplasma infection. Since Mycoplasma pneumoniae is a common pathogen, especially in children and young adults, it should be considered in the differential diagnosis of any febrile illness accompanied by ocular signs.