Ke-Hung Chien

MicroRNAs and cataracts: correlation among let-7 expression, age and the severity of lens opacity

Background Let-7 microRNA is an important regulator of cellular ageing and tissue senescence. The objective of this study is to evaluate the expression of let-7a/let-7b/let-7c microRNAs in human age-related cataracts. Aim To evaluate the correlation among the severity of lens opacity, the level of let-7a/let-7b/let-7c microRNA expression and patient age in the context of age-related cataracts. Methods The authors evaluated the mRNA level of let-7a/let-7b/let-7c microRNA in lens epithelia obtained from 174 eyes with age-related cataracts. The authors also recorded the patient age and the severity of lens opacity as classified according to the modified version of the Lens Opacities Classification System version III. Results Let-7b microRNA expression was demonstrated to be positively associated with patient age (R=0.472; p<0.001). A positive correlation was also observed between higher N, C and P cataract scores and higher expression of let-7b microRNA in patients with age-related cataracts (p<0.001). However, no significant correlation was observed between the let-7a and let-7c microRNA expression levels and either the severity of lens opacity or the patient age. Conclusion These findings suggest that microRNAs play a role in age-related cataracts. A local let-7b microRNA increase may represent a risk factor in the formation of age-related cataracts.

Correlation of MicroRNA-145 Levels and Clinical Severity of Pterygia

PURPOSE MicroRNA-145 (miR-145) has known anti-tumor properties and has been reported to be involved in regulating corneal epithelium differentiation. The exact role of miR-145 in ocular tissue remains unclear. In this study, we evaluate the effect of miR-145 expression levels on pterygium properties. SETTING Ophthalmology department of a tertiary medical center. DESIGN : Case series study. METHODS Information regarding patient age, pterygium recurrence and pterygium severity (extension [E], vascularity [V] and thickness [T]) were gathered from records. Expression levels of miR-145 were obtained through examination of excised pterygium tissue. Correlations between age, pterygium classification, and miR-145 levels were evaluated. RESULTS This study evaluated 253 patients (mean age 54.1±10.8 years). As pterygium severity increased, miR-145 levels decreased. Negative correlations were also found between miR-145 expression levels and pterygium extension (E) and vascularity (V). Thickness (T) had a weak negative correlation. There was only a mild negative correlation between patient age and miR-145 levels, which was only seen in patients with primary pterygium (not recurrent ones). Additionally, miR-145 expression was significantly higher in primary samples than in recurrent ones. CONCLUSIONS We demonstrated an association between miR-145 and pterygium characteristics, consistent with its known tumor suppression effect. Because the management of pterygium is often difficult, we suggest that miR-145 should be further studied as a potential treatment.

Correlation between microRNA-34a levels and lens opacity severity in age-related cataracts

PurposeMicroRNA 34a (miR-34a) is involved in regulating tissue senescence. However, the role of miR-34a in age-related cataracts is unclear. In this study, we evaluated the correlations among the severity of lens opacity, patient age, and miR-34a expression level in the lens epithelium of age-related cataracts for clarifying the role of miR-34a in the lens senescence.MethodsThis study was carried as a case control study in the Department of Ophthalmology, Taipei Veterans General Hospital, Taiwan. We recorded age of each patient at the time of their cataract surgery and information regarding lens opacity according to a modified version of the Lens Opacities Classification System III. Correlations among age, lens opacity, and miR-34a expression levels were evaluated.ResultsThis study evaluated 110 patients with a mean age of 73.19 years (SD±10.2). Older patients had higher nuclear cataract (NC), cortical (C), and posterior subcapsular cataract (P) scores (one-way analysis of variance (ANOVA), P<0.05). miR-34a expression levels were significantly different between each age group (ANOVA post hoc Bonferroni’s test, P<0.001), and there were moderate correlations between high NC, C, and P cataract scores and high miR-34a levels (Pearson correlation coefficient; R=0.606, 0.575, and 0.515, respectively).ConclusionsThe current study demonstrated positive correlations between high miR-34a levels and high lens opacity severity in NC, C, or P cataracts. These results suggest that miR-34a expression has a role in lens senescence.

Silibinin inhibits myofibroblast transdifferentiation in human tenon fibroblasts and reduces fibrosis in a rabbit trabeculectomy model.

Purpose:  To investigate the effect of silibinin in myofibroblast transdifferentiation and in animal trabeculectomy models.

Impact of Cylinder Axis on the Treatment for Astigmatic Amblyopia

PURPOSE To compare the effects of oblique astigmatism on refractive amblyopia in children aged 3-7 years with those having orthogonal astigmatism. DESIGN A retrospective review of medical records. METHODS The medical records of patients attending Tri-Service General Hospital in Taiwan from January 2003 to December 2010 were reviewed and summarized. Seventy-two children with oblique astigmatism-related refractive amblyopia (Group 1) and 82 children with orthogonal astigmatism (Group 2) were chosen. Characteristics such as baseline visual acuity (VA), the time course of VA improvement, refractive error, and family history were assessed. RESULTS Group 1 showed a worse baseline mean VA (±SD) of 0.61 (0.13) vs 0.52 (0.16) logMAR (P = .01), a slower rate of amblyopia improvement, and higher prevalence of parental oblique astigmatism (29% vs 5.5%; P < .01) than did Group 2. The cylinder power of astigmatism (in D) causing amblyopia in Group 1 of 2.48 (0.82) was lower than that in Group 2: 2.93 (0.71) (P = .006). However, Group 1 achieved a noninferior resolution of amblyopia (mean final VA 0.18 vs 0.16 logMAR) after longer treatment of 6.45 (2.44) vs 5.86 (2.92) months (P = .039). CONCLUSIONS A smaller degree of initial oblique astigmatism caused amblyopia than did orthogonal astigmatism. Although the children with oblique astigmatism achieved equal resolution rates after treatment, this took longer. Therefore, we should pay more attention to children with mild oblique astigmatism, as they are more likely to develop oblique astigmatism-related amblyopia. Moreover, early diagnosis and prompt treatment might help visual improvement.

Laminin modification subretinal bio-scaffold remodels retinal pigment epithelium-driven microenvironment in vitro and in vivo.

Advanced age-related macular degeneration (AMD) may lead to geographic atrophy or fibrovascular scar at macular, dysfunctional retinal microenvironment, and cause profound visual loss. Recent clinical trials have implied the potential application of pluripotent cell-differentiated retinal pigment epithelial cells (dRPEs) and membranous scaffolds implantation in repairing the degenerated retina in AMD. However, the efficacy of implanted membrane in immobilization and supporting the viability and functions of dRPEs, as well as maintaining the retinal microenvironment is still unclear. Herein we generated a biomimetic scaffold mimicking subretinal Bruchs basement from plasma modified polydimethylsiloxane (PDMS) sheet with laminin coating (PDMS-PmL), and investigated its potential functions to provide a subretinal environment for dRPE-monolayer grown on it. Firstly, compared to non-modified PDMS, PDMS-PmL enhanced the attachment, proliferation, polarization, and maturation of dRPEs. Second, PDMS-PmL increased the polarized tight junction, PEDF secretion, melanosome pigment deposit, and phagocytotic-ability of dRPEs. Third, PDMS-PmL was able to carry a dRPEs/photoreceptor-precursors multilayer retina tissue. Finally, the in vivo subretinal implantation of PDMS-PmL in porcine eyes showed well-biocompatibility up to 2-year follow-up. Notably, multifocal ERGs at 2-year follow-up revealed well preservation of macular function in PDMS-PmL, but not PDMS, transplanted porcine eyes. Trophic PEDF secretion of macular retina in PDMS-PmL group was also maintained to preserve retinal microenvironment in PDMS-PmL eyes at 2 year. Taken together, these data indicated that PDMS-PmL is able to sustain the physiological morphology and functions of polarized RPE monolayer, suggesting its potential of rescuing macular degeneration in vivo.

Relief of periorbital pain after acute angle closure glaucoma attack by botulinum toxin type A.

PurposeTo assess the efficacy and safety of botulinum toxin type A (BoNT-A) injection in patients suffering from intractable periorbital pain after acute angle closure glaucoma (AACG). Patients and MethodsIn this prospective randomized intervention study, 19 patients suffering from periorbital pain after an AACG attack were injected with BoNT-A or placebo for pain relief. Patients were assessed on days 1, 2, 7, 14, 30, 60, and 90. The main outcomes were mean change of visual analog rating scale (VARS) and index scores measured through a quality-of-life questionnaire (EQ-5D), and changes in the visual analog scale (VAS), all of which were assessed at each visit. A secondary outcome was the frequency and nature of adverse events and the number of patients who withdrew from the study as a result. ResultsIn the treatment group (n=10), the mean index score of EQ-5D and VAS changed significantly from the placebo group (by 0.299 and 2.61, respectively) from day 2 (P<0.01). The VARS of EQ-5D also disclosed significant changes from day 2 (17, P<0.01). In addition, efficacy was maintained mainly between days 2 and 60 but declined slightly by day 90. The most frequently reported treatment-related adverse events in the treatment and placebo groups were local tenderness (21%), subcutaneous hemorrhage (10.5%), and conjunctivitis (10.5%). No severe adverse events were reported during the study or follow-up period. ConclusionsBoNT-A is effective and well tolerated for the treatment of periorbital pain after an AACG attack. Its effects may be maintained for 3 months.

Lupus flare in a manifestation of consecutive hypotony maculopathy after trabeculectomy

Systemic lupus erythematosus (SLE) up-raises the surgical risk due to its unpredictable perioperative disease activity. Lupus flare represents an important issue because of its potential threat in organ damage and drug toxicity after adjusting the dosage of immune-modulating agents. A 34-year-old female was referred for trabeculectomy surgery for her poor-controlled steroid-related glaucoma with a 5-year history of SLE under systemic steroids control. Remission status was confirmed with normal serum complement levels. However, lupus flare with clinical ocular findings as hypotony maculopathy presented 1-week after uneventful surgery. Early and effective treatment with pulse corticosteroid therapy was conducted, and this patient recovered her ocular performance 1-month later except preexisting glaucomatous visual field deficits. SLE flare may be seen in any form of postoperative complications, even masked with consecutive hypotony maculopathy. This case reminds early detection of systemic lupus flare and different therapeutic plan is prompt in postoperative follow-up.

Rare case of optic fracture in a glass intraocular lens after neodymium-doped yttrium aluminium garnet capsulotomy

mangioma. Intralesional anti-VEGF treatment of capillary haemangioma has potential as an adjunct to surgery or as an alternative therapy in non-resolving cutaneous lesions. The regression of vascular tissue demonstrated can potentially reduce bleeding tendency, thus aiding surgical resection. Anti-VEGF treatment might even be considered in different forms of peri-orbital or orbital capillary haemangioma, such as infantile lesions, particularly where systemic treatment, such as propranolol, is not suitable. Further research on the use of anti-VEGF therapy in capillary haemangiomas is necessary.

Expression profiling of cell-intrinsic regulators in the process of differentiation of human iPSCs into retinal lineages

BackgroundDifferentiation of human induced pluripotent stem cells (hiPSCs) into retinal lineages offers great potential for medical application. Therefore, it is of crucial importance to know the key intrinsic regulators of differentiation and the specific biomarker signatures of cell lineages.MethodsIn this study, we used microarrays to analyze transcriptomes of terminally differentiated retinal ganglion cell (RGC) and retinal pigment epithelium (RPE) lineages, as well as intermediate retinal progenitor cells of optic vesicles (OVs) derived from hiPSCs. In our analysis, we specifically focused on the classes of transcripts that encode intrinsic regulators of gene expression: the transcription factors (TFs) and epigenetic chromatin state regulators. We applied two criteria for the selection of potentially important regulators and markers: firstly, the magnitude of fold-change of upregulation; secondly, the contrasted pattern of differential expression between OV, RGC and RPE lineages.ResultsWe found that among the most highly overexpressed TF-encoding genes in the OV/RGC lineage were three members of the Collier/Olfactory-1/Early B-cell family: EBF1, EBF2 and EBF3. Knockdown of EBF1 led to significant impairment of differentiation of hiPSCs into RGCs. EBF1 was shown to act upstream of ISL1 and BRN3A, the well-characterized regulators of RGC lineage specification. TF-encoding genes DLX1, DLX2 and INSM1 were the most highly overexpressed genes in the OVs, indicating their important role in the early stages of retinal differentiation. Along with MITF, the two paralogs, BHLHE41 and BHLHE40, were the most robust TF markers of RPE cells. The markedly contrasted expression of ACTL6B, encoding the component of chromatin remodeling complex SWI/SNF, discriminated hiPSC-derived OV/RGC and RPE lineages.ConclusionsWe identified novel, potentially important intrinsic regulators of RGC and RPE cell lineage specification in the process of differentiation from hiPSCs. We demonstrated the crucial role played by EBF1 in differentiation of RGCs. We identified intrinsic regulator biomarker signatures of these two retinal cell types that can be applied with high confidence to confirm the cell lineage identities.