PURPOSE
To assess the results of a single eye bank preparing a high volume of Descemet membrane endothelial keratoplasty (DMEK) tissues using multiple technicians to provide an overview of the experience and to identify possible risk factors for DMEK preparation failure.
DESIGN
Cross-sectional study.
METHODS
SETTING
Lions VisionGift and Wilmer Eye Institute at Johns Hopkins Hospital.
STUDY POPULATION
All 563 corneal tissues processed by technicians at Lions VisionGift for DMEK between October 2011 and May 2014 inclusive.
OBSERVATION PROCEDURES
Tissues were divided into 2 groups: DMEK preparation success and DMEK preparation failure.
MAIN OUTCOME MEASURES
We compared donor characteristics, including past medical history.
RESULTS
The overall tissue preparation failure rate was 5.2%. Univariate analysis showed diabetes mellitus (P = .000028) and its duration (P = .023), hypertension (P = .021), and hyperlipidemia or obesity (P = .0004) were more common in the failure group. Multivariate analysis showed diabetes mellitus (P = .0001) and hyperlipidemia or obesity (P = .0142) were more common in the failure group. Elimination of tissues from donors either with diabetes or with hyperlipidemia or obesity reduced the failure rate from 5.2% to 2.2%. Trends toward lower failure rates occurring with increased technician experience also were found.
CONCLUSIONS
Our work showed that tissues from donors with diabetes mellitus (especially with longer disease duration) and hyperlipidemia or obesity were associated with higher failure rates in DMEK preparation. Elimination of tissues from donors either with diabetes mellitus or with hyperlipidemia or obesity reduced the failure rate. In addition, our data may provide useful initial guidelines and benchmark values for eye banks seeking to establish and maintain DMEK programs.
ObjectivesTo characterise and confirm the presence of Mansonella ozzardi microfilariae in the cornea by biomicroscopy and corneal confocal microscopy.DesignCross-sectional study.SettingsClinical practice study in patients from rural communities in Coari city on the Solimões river, Amazonas state, Brazil.ParticipantsThe eyes of 212 consecutive volunteer patients were examined using a flash light and their blood checked for the presence of microfilariae by an expert microscopist. Patients with suspicious corneal lesions (characterised as nummular keratitis) were submitted to biomicroscopy, fundoscopy and corneal confocal microscopy evaluation (CCME). In two patients, a biopsy of the limbal conjunctiva adjacent to the nummular keratitis was carried out and blood collected from the surgical wound for microfilariae investigation by thick blood film examination.Primary and secondary outcome measuresPositive correlation between corneal biomicroscopic and confocal lesions and M ozzardi microfilaremia.ResultsOf the 212 patients, 56 (26.4%) were positive for microfilaremia. 22 patients with nummular keratitis identified under flash light examination underwent biomicroscopy and CCME. Corneal lesions were positively correlated to microfilaremia (p=0.0001). At biomicroscopy, lesions were classified as quiescent or active. At CCME, lesions were categorised as circular or filiform. The associations between corneal lesions, CCME findings and microfilaremia are shown.ConclusionsWe describe M ozzardi microfilariae in the cornea and the associated eye pathology. Further studies using ocular tissue PCR and other imaging techniques would be helpful.
Purpose
MicroRNAs are small non-coding RNAs which regulate gene expression at the post-transcriptional level. We reported that levels of microRNA (miR)-29 family are decreased in Fuchs endothelial corneal dystrophy (FECD) patient corneas. The miR-29 family regulates production of extracellular matrix (ECM) proteins. Accumulation of ECM proteins in Descemet’s membrane is an important pathologic change in FECD. In this study, we transfected miR-29b into human corneal endothelial cells and tissues and evaluated ECM protein expression levels.
Methods
Immortalized Fuchs human corneal endothelial cell line (iFECD) was established by infection of FECD patient’s corneal endothelial cells with hTERT lentivirus. MiR-29b was transfected into iFECD and expression levels of ECMs (COL1A1, COL4A1, LAMC1) were evaluated with quantitative reverse transcriptase polymerase chain reaction (qRT-PCR) and Western blot. Expression level of LAMC1 protein in miR-29b transfected donor corneal endothelium was also evaluated by Western blot.
Results
Compared with control, miR-29b expression level after transfection of iFECD was increased to 335.6 (±91.0)% and ECM expression levels were significantly decreased. Compared with control, qRT-PCR demonstrated reduction of ECM to the following levels: COL1A1: 1.9 (±0.4)%; COL4A1: 7.1 (±1.7)%; LAMC1: 21.5 (±2.7)%. Western blot showed reduced protein expression: COL1A1: 4.8 (±3.2)%; COL4A1: 42.5 (±25.0)%; and LAMC1: 44.8 (±3.1)%. In miR-29b transfected corneal tissue, LAMC1 protein expression level was decreased to 14.4 (±20.5)%.
Conclusions
Over-expression of miR-29b decreased ECM protein production in human corneal endothelial cells. Thus, miR-29 replacement therapy might be a new treatment strategy for FECD aimed at reducing pathologic production of ECM proteins in Descemet’s membrane.
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