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AimThis study aimed to test whether human platelet lysate (HPL) has neurotrophic ability for corneal nerve regeneration.MethodsWe measured the neurotrophic factors in human peripheral serum (HPS) and two commercially available HPLs, UltraGRO and PLTMax. In vitro, we compared the growth rates, neuronal differentiation and immunostaining of neuron markers in mouse neuroblastoma cell line (Neuro-2a) and primary culture of mouse trigeminal ganglion cells that were cultivated in different concentrations of fetal bovine serum, HPS and HPL. In vivo, we created corneal wounds on Sprague Dawley rats with a rotating burr and evaluated the effects of topical HPL on wound healing and corneal nerve regeneration by in vivo confocal microscopy and corneal aesthesiometry.ResultsHPLs had significantly higher concentrations of various neurotrophic factors compared with HPS (pConclusionHPL has significantly higher concentrations of neurotrophic factors compared with HPS. It showed not only in vitro but also in vivo corneal neurotrophic abilities. Our results suggest that HPL may have a potential role in the treatment of diseases related to corneal nerve damage or degeneration.

Background/aimsTo evaluate the utility rate, indication, outcome, and cost of refrigeration and glycerol cryopreservation for storing anterior corneal buttons during endothelial keratoplasty for subsequent use in tectonic lamellar patch grafting.MethodAnterior corneal buttons collected after precutting or prestripping during endothelial keratoplasty from January 2014 to December 2019 were preserved using the following protocol: (1) refrigeration for up to 4 weeks at 4°C in Optisol-GS and (2) glycerol cryopreservation for up to 2 years. The utility rate, outcome and cost of these cryopreserved anterior corneal buttons were retrospectively examined.ResultsDuring the 6-year study period, 26 anterior corneal buttons were refrigerated and 49 were cryopreserved for extended use. The utility rates for the refrigerated and cryopreserved anterior corneal buttons were 69.2% and 73.5%, respectively. Their average preservation periods were 0.53±0.05 and 12.76±0.94 months, respectively. Noninfection-related perforation was the leading indication for using the extendedly preserved anterior corneal buttons. The average postoperative follow-up periods were 10.03±2.91 and 14.35±2.17 months for refrigerated and cryopreserved anterior corneal buttons. Secondary keratoplasty was required by 7 of 18 (38.9%) and 6 of 36 (16.7%) patients receiving refrigerated and cryopreserved anterior corneal buttons, respectively. None of our patients developed graft infection from donor tissues.ConclusionCryopreservation can safely extend the utility of anterior corneal buttons. This method not only reduced the wastage of the limited donor tissue but also was cost-effective.

BackgroundThis study examined whether corneas from bacteremic donors could be used for corneal transplant.MethodsCorneas donated to the National Eye Bank of Taiwan between 1 January 2014 and 30 June 2017 were included in this study. All the corneas had corneoscleral rim cultures during the retrieval process and were hypothermic preserved in the Optisol-GS storage medium. A microbial work-up flow chart was used for the sterility check of all grafts. Bacteremic donors were defined as those whose last blood culture before corneal donation was positive. The microbial contamination rates, the endothelial cell densities, the tissue utility rates and early complications after transplants were compared between the corneas from bacteremic versus non-bacteremic donors.Results697 corneas from 356 donors were analysed, 70 of which were from bacteremic donors. The microbial contamination rates of the corneas from bacteremic and non-bacteremic donors (7.1% vs 9.1%)(p=0.30) were close. None of the contaminated corneas grew the same bacterial strains as those from their blood cultures. The corneas from bacteremic donors and non-bacteremic donors have similar endothelial cell densities (2931±297 cells/mm2 vs 2903 ± 470 cells/mm2) (p=0.63). Corneas from bacteremic and non-bacteremic donors shared a similar utility rate (98.6% vs 99.4%)(p=0.41). None of the corneas caused infectious complications after transplants.ConclusionOur study showed that corneas from bacteremic and non-bacteremic donors have equally low contamination rates and are of the same quality in terms of endothelial cell density and safety.

Background/aimWe investigated the microstructural changes in white matter of adults with amblyopia using diffusion spectrum imaging with systematic tract-based automatic analysis of the whole brain.MethodsTen adults with amblyopia (six women and four men, 33.6±10.6 years old on average) and 20 age- and sex-matched normal-sighted controls were enrolled. The mean generalised fractional anisotropy (GFA) was measured in 76 white matter tracts and compared between the experimental and control groups using a threshold-free cluster-weighted method andt-test. A 2-percentile cut-off was used to identify segments with the greatest differences between the two groups.ResultsParticipants with amblyopia had significantly lower GFA values than the controls in 11 segments located in nine white matter tracts, which included the following: left arcuate fasciculus, left frontal aslant tract, left fornix and left inferior fronto-occipital fasciculus of the association fibres; left thalamic radiations of the auditory nerve and bilateral optic radiations of the projection fibres; and genu and middle temporal gyrus of the callosal fibres. Amblyopic participants had statistically higher GFA values in the bilateral uncinate fasciculus than those of the controls.ConclusionThis preliminary study using whole-brain tractographic analysis of white matter reveals association between abnormal early visual processing and alterations in brain architecture, which may be related to various higher-level deficits, such as audiovisual integration and hand−eye coordination in patients with amblyopia.

AIMS—To further understand the effect of refractive error on the corneal dimensions and function. METHODS—Corneal curvature, corneal thickness, and axial length measurements were performed, as well as specular microscopy and fluorophotometry, on patients with various refractive statuses. 216 subjects, mean age 22.2 (SD 4.2) years, were examined. Patients with previous contact lens wear history, external eye diseases, as well as previous ocular surgeries, were excluded. RESULTS—The corneas were flatter in eyes with longer axial length (r = −0.22, p = 0.003). Eyes with more myopic spherical equivalent had longer axial length (r = −0.90, p