Bakiah Shaharuddin

Hospital Universiti Sains Malaysia Experience in Orbital Floor Reconstruction: Autogenous Graft Versus Medpor

PURPOSE A normally restored orbital structure after reconstructive surgery would accelerate the return of orbital function. The aim of the present study was to compare the outcomes of 2 orbital implants: autogenous grafts and porous polyethylene (Medpor). MATERIALS AND METHODS A longitudinal study was conducted of all patients who had undergone orbital floor reconstruction using an autogenous graft or Medpor. The study participants were divided into 2 groups, and the postoperative outcomes were assessed clinically. RESULTS Of the 26 patients, 14 (53.0%) had undergone surgery with an autogenous graft and 12 (46.2%) with Medpor. Postoperatively, no diplopia in the primary gaze was noted in any patient. However, down gaze and peripheral diplopia was found in 11.5% and 26.9% in the autogenous group and in 3.8% and 26.9% in the Medpor group, respectively (P = 1.24). Enophthalmos was present in 11.4% of the autogenous graft group and 15.3% of the Medpor group (P = .465). The Hess chart findings were abnormal in 11.4% of both groups (P = .062). Restriction of movement was observed in 1 patient (3.8%) from the autogenous group and 7.7% of the Medpor group (P = .574). CONCLUSIONS Orbital floor reconstruction using an autogenous graft or Medpor showed comparable results.

Human limbal mesenchymal stem cells express ABCB5 and can grow on amniotic membrane

AIM To isolate and characterize limbal mesenchymal stem cells (LMSCs) from human corneoscleral rings. MATERIALS & METHODS Cells were isolated from corneoscleral rings and cultured in a mesenchymal stem cell (MSC)-selective media and examined for differentiation, phenotyping and characterization. RESULTS LMSCs were capable of trilineage differentiation, adhered to tissue culture plastic, expressed HLA class I and cell surface antigens associated with human MSC while having no/low expression of HLA class II and negative hematopoietic lineage markers. They were capable for CXCL12-mediated cellular migration. LMSCs adhered, proliferated on amniotic membrane and expressed the common putative limbal stem cell markers. CONCLUSION Limbal-derived MSC exhibited plasticity, could maintain limbal markers expression and demonstrated viable growth on amniotic membrane.

Prediction error and accuracy of intraocular lens power calculation in pediatric patient comparing SRK II and Pediatric IOL Calculator

BackgroundDespite growing number of intraocular lens power calculation formulas, there is no evidence that these formulas have good predictive accuracy in pediatric, whose eyes are still undergoing rapid growth and refractive changes. This study is intended to compare the prediction error and the accuracy of predictability of intraocular lens power calculation in pediatric patients at 3 month post cataract surgery with primary implantation of an intraocular lens using SRK II versus Pediatric IOL Calculator for pediatric intraocular lens calculation. Pediatric IOL Calculator is a modification of SRK II using Holladay algorithm. This program attempts to predict the refraction of a pseudophakic child as he grows, using a Holladay algorithm model. This model is based on refraction measurements of pediatric aphakic eyes. Pediatric IOL Calculator uses computer software for intraocular lens calculation.MethodsThis comparative study consists of 31 eyes (24 patients) that successfully underwent cataract surgery and intraocular lens implantations. All patients were 12 years old and below (range: 4 months to 12 years old). Patients were randomized into 2 groups; SRK II group and Pediatric IOL Calculator group using envelope technique sampling procedure. Intraocular lens power calculations were made using either SRK II or Pediatric IOL Calculator for pediatric intraocular lens calculation based on the printed technique selected for every patient. Thirteen patients were assigned for SRK II group and another 11 patients for Pediatric IOL Calculator group. For SRK II group, the predicted postoperative refraction is based on the patients axial length and is aimed for emmetropic at the time of surgery. However for Pediatric IOL Calculator group, the predicted postoperative refraction is aimed for emmetropic spherical equivalent at age 2 years old. The postoperative refractive outcome was taken as the spherical equivalent of the refraction at 3 month postoperative follow-up. The data were analysed to compare the mean prediction error and the accuracy of predictability of intraocular lens power calculation between SRK II and Pediatric IOL Calculator.ResultsThere were 16 eyes in SRK II group and 15 eyes in Pediatric IOL Calculator group. The mean prediction error in the SRK II group was 1.03 D (SD, 0.69 D) while in Pediatric IOL Calculator group was 1.14 D (SD, 1.19 D). The SRK II group showed lower prediction error of 0.11 D compared to Pediatric IOL Calculator group, but this was not statistically significant (p = 0.74). There were 3 eyes (18.75%) in SRK II group achieved acccurate predictability where the refraction postoperatively was within ± 0.5 D from predicted refraction compared to 7 eyes (46.67%) in the Pediatric IOL Calculator group. However the difference of the accuracy of predictability of postoperative refraction between the two formulas was also not statistically significant (p = 0.097).ConclusionsThe prediction error and the accuracy of predictability of postoperative refraction in pediatric cataract surgery are comparable between SRK II and Pediatric IOL Calculator. The existence of the Pediatric IOL Calculator provides an alternative to the ophthalmologist for intraocular lens calculation in pediatric patients. Relatively small sample size and unequal distribution of patients especially the younger children (less than 3 years) with a short time follow-up (3 months), considering spherical equivalent only.

Tualang honey improves human corneal epithelial progenitor cell migration and cellular resistance to oxidative stress in vitro

Stem cells with enhanced resistance to oxidative stress after in vitro expansion have been shown to have improved engraftment and regenerative capacities. Such cells can be generated by preconditioning them with exposure to an antioxidant. In this study we evaluated the effects of Tualang honey (TH), an antioxidant-containing honey, on human corneal epithelial progenitor (HCEP) cells in culture. Cytotoxicity, gene expression, migration, and cellular resistance to oxidative stress were evaluated. Immunofluorescence staining revealed that HCEP cells were holoclonal and expressed epithelial stem cell marker p63 without corneal cytokeratin 3. Cell viability remained unchanged after cells were cultured with 0.004, 0.04, and 0.4% TH in the medium, but it was significantly reduced when the concentration was increased to 3.33%. Cell migration, tested using scratch migration assay, was significantly enhanced when cells were cultured with TH at 0.04% and 0.4%. We also found that TH has hydrogen peroxide (H2O2) scavenging ability, although a trace level of H2O2 was detected in the honey in its native form. Preconditioning HCEP cells with 0.4% TH for 48 h showed better survival following H2O2-induced oxidative stress at 50 µM than untreated group, with a significantly lower number of dead cells (15.3±0.4%) were observed compared to the untreated population (20.5±0.9%, p<0.01). Both TH and ascorbic acid improved HCEP viability following induction of 100 µM H2O2, but the benefit was greater with TH treatment than with ascorbic acid. However, no significant advantage was demonstrated using 5-hydroxymethyl-2-furancarboxaldehyde, a compound that was found abundant in TH using GC/MS analysis. This suggests that the cellular anti-oxidative capacity in HCEP cells was augmented by native TH and was attributed to its antioxidant properties. In conclusion, TH possesses antioxidant properties and can improve cell migration and cellular resistance to oxidative stress in HCEP cells in vitro.

Limbal side population cells: a future treatment for limbal stem cell deficiency.

Corneal blindness carries a morbidity that affects quality of life and is often associated with an increased economic burden. In this review, we focus on the severe and painful condition of limbal stem cell deficiency, an important cause of corneal blindness. Conventional corneal transplantation usually results in graft failure and is contraindicated in this condition. Ex vivo-expanded limbal epithelial transplantation has been used as a cellular-based therapy to regenerate and reconstruct the ocular surface as a mode of treatment. Enrichment methods for stem cells are a strategy to improve the outcome of limbal stem cell transplantation. Here we discuss the side population assay as a functional assay to enrich for stem cells as an important source of limbal stem cells. The challenges in ex vivo-expanded limbal stem cell transplantation are wide and varied and will be addressed in this review with regard to improving the clinical outcomes of cultivated limbal stem cell transplantation.

Limbal side population cells; a future treatment for limbal stem cell deficiency

Introduction: Anterior cruciate ligament (ACL) injuries are very common; in Germany incidence of ACL ruptures is estimated at 32 per 100 000 in the general population and in the sports community this rate more than doubles. Current gold standard for anterior cruciate lig- ament repair is reconstruction using an autograft [1]. However, this approach has shown some limitations. A new method has been her- alded by the Knee Team at the Bern University Hospital (Inselspital) and the Sonnenhof clinic called Dynamic Intraligamentary Stabilization (DIS), which keeps ACL remnants in place in order to promote biologi- cal healing and makes use of a dynamic screw system [2]. The aim of this study was to investigate the cytocompatibility of collagen patches in combination with DIS to support regeneration of the ACL. The spe- cific hypothesis we tested was whether MSCs would differentiate towards TCs in co-culture. Materials and methods: Primary Tenocytes (TCs) and human bone marrow derived mesenchymal stem cells (MSCs) were harvested from ACL removed during knee prothesis or from bone marrow aspirations (Ethical Permit 187/10). Cells were seeded on two types of three dimensional carriers currently approved for cartilage repair, Novocart (NC, B. Brown) and Chondro-Gide (CG, Geistlich). These scaffolds comprise collagen structures with interconnecting pores originally developed for seeding of chondrocytes in the case of CG. ~40k cells were seeded on punched zylindrical cores of 8 mm in O and cultured on CG or NC patches for up to 7 days. The cells were either cultured as TC only, MSC only or co-cultured in a 1:1 mix on the scaffolds and on both sides of culture inserts (PET, high density pore O 0.4 mm, BD, Fal- con) with cell-cell contact. We monitored DNA content, GAG and HOP-content, tracked the cells using DIL and DIO fluorescent dyes (Molecular Probes, Life technologies) and confocal laser scanning and SEM microscopy as well as RT-PCR of tenocyte specific markers (i.e. col 1 and 3, TNC, TNMD, SCXA&B, and markers of dedifferentiation ACAN, col2, MMP3, MMP13). Finally, H&E stain was interpreted on cryosections and SEM images of cells on the scaffold were taken. Results: ThecLSMimagesshowedcellproliferationoverthe7dayson both matrices, however, on CG there were much fewer MSCs attached than on NC. SEM images showed a roundish chondrocyte-like pheno- type of cells on CG whereas on NC the phenotype was more teno- cyte-like (Fig. 1). Gene expression of both, MSC and TC seem to confirm a more favorable environment in 3D for both patches rather than monolayer control.Hydroxyapatite (HA), [Ca10(PO4)6(OH)2], products are well-known as implantable ceramics for hard tissue reconstitution. HA is based on calcium phosphate, and its chemical composition and crystal structure are similar to the mineral component of human bones and teeth. The aim of this study was to evaluate the bioactivity of natural HA/hardystonite nanobiocomposites soaked in simulated body fluid (SBF). Novel natural HA/hardystonite nanobiocomposite was fabricated with 0 wt.%, 5 wt.%, 10 wt.%, and 15 wt.% of hardystonite in natural HA using ball mill for 20 minutes. The composite mixture was compacted in cylinder steel mould with 10 mm diameter under 20 MPa pressure. The discs pressed were soaked in cell laboratory, Falcon, containing SBF solution by 21 days. Samples weight loss and solution Ph were measured after 1, 3, 7, 14 and 21 days .Also, SBF solution Ca ion concentration were measured for solutions SBF after 21 day. X-ray diffraction (XRD), scanning electron microscopy (SEM) and EDS were performed to characterize the nanocomposite samples. ICP technique was utilized to evaluate Ca ion concentration released in solution SBF. Maximum bioactivity occurred in the sample containing 10 wt.% of hardystonite, which was probably due to two reasons; first, the maximum amorphous glassy phase amount, and second, the minimum crystallinity of nanobiocomposite.

Controversies in Corneal Epithelial Stem Cell Biology

The loss or dysfunction of corneal epithelial stem cells, or limbal stem cells as they are more commonly known, results in the painful and blinding disease of limbal stem cell deficiency. In 1997, it was proposed that limbal stem cell deficiency could be treated by transplanting cultured limbal stem cells containing human limbal epithelium. The area of limbal stem cell biology therefore now encompasses not only the basic science of stem cell biology but also the area of translational research and cell therapeutics. Ranging from the laboratory to the clinic, there are still many controversies in limbal stem cell biology. In this chapter we describe and outline some of the questions that remain to be answered.

Assessment of optic disc parameters among healthy adult Malays by Heidelberg Retinal Tomograph II

Background:  This study aims to assess the optic disc characteristics in healthy adult Malays and to correlate them with age, gender and refractive errors.

Spontaneous Bilateral Anterior Lens Dislocation in an 8-Year-Old Girl

The authors describe recurrent lens dislocation into the anterior chamber in a young girl with homocystinuria. The patients 12-year-old sister died after a cerebrovascular accident caused by the same disease. This report highlights the importance of early dietary restrictions and treatment.

Assessment of optic disc parameters among healthy adult Malays by Heidelberg Retinal Tomograph II: Optic disc parameters in Malays by HRT II

Background:  This study aims to assess the optic disc characteristics in healthy adult Malays and to correlate them with age, gender and refractive errors.