Accelerated corneal crosslinking with 20'-soaking hydroxypropyl methyl cellulose/riboflavin vs conventional crosslinking with 30'-soaking dextran/riboflavin.

PURPOSE: To evaluate and compare functional and structural outcomes of accelerated corneal crosslinking (A-CXL) using riboflavin with hydroxypropyl methyl cellulose (HPMC) vs conventional corneal crosslinking (C-CXL) using riboflavin with dextran. SETTING: American University of Beirut Medical Center, Beirut, Lebanon. DESIGN: Retrospective analysis. METHODS: Retrospective analysis of 83 eyes of 73 patients with mild to moderate keratoconus. First group (n = 44 eyes) underwent C-CXL using a 30-minute riboflavin/dextran soaking between June 2014 and March 2016. Second group (n = 39 eyes) underwent A-CXL using a 20-minute riboflavin/HPMC soaking between April 2016 and December 2017. Patients were evaluated preoperatively and at 1, 3, and 12 months postoperatively. Main outcome measures were simulated keratometry (simK), maximum axial keratometry (Kmax), demarcation line depth, and haze intensity measured using optical coherence tomography-based image analysis software. RESULTS: Demarcation line (DL) was 298.30 ± 64.60 µm and 335.61 ± 99.76 µm for C-CXL and A-CXL groups, respectively ( P = .04). Haze profile was similar for both groups. The mean simK values were reduced from 46.93 ± 3.50 and 46.44 ± 2.93 preoperatively to 46.18 ± 3.65 and 45.54 ± 2.78 at 12 months postoperatively, for C-CXL and A-CXL, respectively ( P = .003 for both groups). The mean Kmax decreased from 52.46 ± 4.82 and 51.50 ± 3.87 preoperatively to 51.30 ± 4.42 and 50.30 ± 3.52 postoperatively, for the C-CXL and A-CXL, respectively ( P < .001 for both groups). There was no difference in the simK and Kmax changes between the C-CXL and A-CXL groups ( P = .814 and P = .913), visual acuity, and refraction between the 2 groups ( P > .05). CONCLUSIONS: A-CXL with a 20-minute riboflavin/HPMC soaking produced deeper DL and similar corneal haze, topographic, refractive, and visual results to C-CXL with a 30-minute riboflavin/dextran soaking.

The prolyl hydroxylase inhibitor GSK1120360A reduces early brain injury, but protection is not maintained in a neonatal rat model of hypoxic ischaemic encephalopathy.

Hypoxic-ischemic encephalopathy (HIE) in newborns is associated with high morbidity and mortality, with many babies suffering long-term neurological deficits. Currently, treatment options are limited to therapeutic hypothermia, which is not appropriate for use in all babies. Previous studies have shown protective effects of increasing the transcription factor-hypoxia-inducible factor-1 (HIF-1) in animal models, by using mild hypoxia or compounds that act as prolyl hydroxylase inhibitors (PHIs). Here, we aimed to examine the neuroprotective actions of an orally active, small molecule PHI, GSK1120360A in a neonatal rat model of hypoxia-ischemia (HI) compared to another PHI, desferrioxamine (DFX). Sprague-Dawley rats underwent HI surgery on postnatal day 7 (P7), where unilateral carotid artery occlusion was performed followed by hypoxia (8% oxygen, 3 h). Initial testing showed that GSK1120360A and erythropoietin levels were detectable in plasma at 6 h following oral exposure to GSK1120360A. For the short-term neuroprotection study, pups were assigned to receive either saline (s.c), desferrioxamine (DFX-200 mg/kg, s.c), methylcellulose (1%, oral) or GSK1120360A (30 mg/kg, oral) immediately after HI. Histological analysis showed that GSK1120360A in this setting reduced brain injury size 7 days after HI, compared to the methylcellulose vehicle control group. DFX had no significant effect on injury size compared to saline group at the same 7 day timepoint. In the long-term neuroprotection study, pups were randomly assigned to be administered methylcellulose (1%, oral) or GSK1120360A (30 mg/kg, oral) immediately after HI. On P42, rats underwent behavioural testing using the forelimb grip strength, grid walking and novel object recognition tasks, and brains were collected for histological analysis. Long-term behavioural deficits were observed in grid walking, grip strength and novel object recognition tests after HI which were not improved in the GSK1120360A treatment group compared to the methylcellulose group. Similarly, there was no improvement in injury size on P42 in the GSK1120360A study group compared to the methylcellulose group. Here, we have shown that GSK1120360A can reduce brain injury at 7 days but that this neuroprotective benefit is not maintained when examined at 5 weeks after HI.

Superior outcome of corneal collagen cross-linking using riboflavin with methylcellulose than riboflavin with dextran as the main supplement.

PURPOSE: To compare the effect of corneal collagen cross-linking (CXL) on progressive keratoconus using 0.1% riboflavin with either dextran or methylcellulose as the main supplement. METHODS: In a comparative case series, CXL was performed in 40 patients (40 eyes) using a riboflavin solution containing either dextran (dextran-riboflavin; n = 20) or methylcellulose (methylcellulose-riboflavin; n = 20). Changes in central corneal thickness (CCT), Scheimpflug tomography, maximal keratometry reading (Kmax ), visual acuity (VA) and endothelial cell density (ECD) were recorded. Stromal changes one month after surgery were analysed using optical coherence tomography (OCT) and in vivo confocal microscopy (IVCM). RESULTS: The CCT was significantly higher in the methylcellulose-riboflavin group during the CXL procedure. The IVCM demarcation line depth was 274 ± 80 (SD) µm in the dextran-riboflavin group and 442 ± 80 µm in the methylcellulose-riboflavin group (p < 0.001). Complete absence of keratocytes in the pre-endothelial stroma was found in none of the corneas treated with dextran-riboflavin and in 42% of the corneas treated with methylcellulose-riboflavin. Visibility of the OCT demarcation line was significantly lower in the methylcellulose-riboflavin group. Kmax and corrected distance visual acuity were improved in the methylcellulose-riboflavin group and stable in the dextran-riboflavin group after 2 years. Endothelial cell density (ECD) was stable in both groups. CONCLUSION: We found deeper structural changes in the methylcellulose-riboflavin group than in the dextran-riboflavin group. This may be explained by different riboflavin solution properties and raises safety concerns. The study also indicates improved effect using methylcellulose-riboflavin than dextran-riboflavin, possibly explained by deeper stromal CXL effect.

Assessment and treatment options for patients with constipation.

Constipation is a common complaint for people of all ages, with prevalence increasing with age and during pregnancy. Women are more likely to be affected than men. Severity of constipation varies from person to person; most people experience short periods of constipation during their lives, including possibly after surgery, while others have constipation as a chronic long-term condition that can significantly affect their quality of life. There are a number of factors that can contribute to developing constipation including diets low in fibre, changes in lifestyle, side effects of certain medications and low fluid intake. People can successfully treat constipation by making changes to their diet and lifestyle. However, medication may be required to manage constipation for some.

[MITOCHONDRIA-TARGETED ANTIOXIDANTS IN THE PREVENTION OF THE CORNEA EROSION WHEN PERFORMING SURGERY UNDER GENERAL ANESTHESIA.]

Despite the use of modern methods of prevention, at least 10% of patients operated on for ophthalmic indications not develop corneal erosion as the indirect complication of general anesthesia. OBJECTIVE: To reduce the number of ophthalmic complications of general anesthesia by prophylactic use of new mito- chondria-targeted antioxidants - Vizomitin (eye drops). MATERIALS AND METHODS: 70 patients, which was supposed to perform the average duration of operations under general anesthesia were randomized into 3 groups depending on the method specific (pharmacological) prevention of corneal erosions: (1) control (specic (pharmacological) prevention was not carried out), (2), using preparation "natural tear, and (3) "Vizomitin" preparation. Postoperative biomicroscopy was performed to assess the condition of the cornea, tear film stability was measured and the height of the tear meniscus. RESULTS: When using eye drops "Vizomitin" value is an indicator of stability of the tear film on the 3rd day after the operation more than in the control group of patients by 51% (p = 0.012) and patients groups, natural tear by 57% (p = 0.013). Surgical interventions performed under general anesthesia, leading to an increase in the number ofpatients with decreased tear meniscus height index of the control group with 4 to 7 patients (p = 0.30) in the group of natural tear from 3 to 11 patients (p = 0.008) . In the group with drug "Vizomitin" the number of such patients is reduced from 7 to 1 (p = 0.018). CONCLUSION: In the surgical procedures under general anesthesia eye drops "Vizomitin" effectively prevents the devel- opment of corneal erosion.

Safety and feasibility of the use of a bevacizumab-methylcellulose mixture as an adjunct to glaucoma surgery: a pilot study.

Bevacizumab, a monoclonal anti-vascular endothelial growth factor antibody, has been suggested as a potential healing therapeutic following glaucoma surgery. Here, we aimed to improve the bioavailability of bevacizumab when used as an adjunct therapy to non-penetrating deep sclerectomy (DS) by using a bevacizumab-methylcellulose mixture (BMM). Ten previously non-operated eyes in ten patients diagnosed with primary open angle glaucoma underwent DS with a subconjunctival injection of 0.3 ml of BMM (bevacizumab 3.75 mg incorporated into 4% methylcellulose) at the surgical site. Bevacizumab release was evaluated in vitro using size-exclusion high performance liquid chromatography (HPLC). Intraocular pressure (IOP), bleb morphology, corneal endothelial cell count (CECC), and complications were evaluated at 6 months after surgery. Using HPLC, bevacizumab was detected in BMM for up to 72 h. Moreover, all surgical blebs remained expanded with hyaline material during the first week. A significant IOP reduction (mean ± SD= -10.3 ± 5.4 mmHg, P<0.001) and diffuse blebs were observed at the final follow-up period. Although CECC was slightly reduced (-7.4%), no complications were observed. In conclusion, bevacizumab was released from BMM, and the use of this innovative mixture yielded good results following DS with no complications. Further studies are required to determine its efficacy prior to establishing BMM as an adjunct treatment for penetrating and non-penetrating glaucoma surgeries.

Safety and feasibility of the use of a bevacizumab-methylcellulose mixture as an adjunct to glaucoma surgery: a pilot study / Segurança e viabilidade do uso de uma mistura de bevacizumabe-metilcelulose como terapia adjuvante à cirurgia anti-glaucomatosa: um estudo piloto

ABSTRACT Bevacizumab, a monoclonal anti-vascular endothelial growth factor antibody, has been suggested as a potential healing therapeutic following glaucoma surgery. Here, we aimed to improve the bioavailability of bevacizumab when used as an adjunct therapy to non-penetrating deep sclerectomy (DS) by using a bevacizumab-methylcellulose mixture (BMM). Ten previously non-operated eyes in ten patients diagnosed with primary open angle glaucoma underwent DS with a subconjunctival injection of 0.3 ml of BMM (bevacizumab 3.75 mg incorporated into 4% methylcellulose) at the surgical site. Bevacizumab release was evaluated in vitro using size-exclusion high performance liquid chromatography (HPLC). Intraocular pressure (IOP), bleb morphology, corneal endothelial cell count (CECC), and complications were evaluated at 6 months after surgery. Using HPLC, bevacizumab was detected in BMM for up to 72 h. Moreover, all surgical blebs remained expanded with hyaline material during the first week. A significant IOP reduction (mean ± SD= -10.3 ± 5.4 mmHg, P<0.001) and diffuse blebs were observed at the final follow-up period. Although CECC was slightly reduced (-7.4%), no complications were observed. In conclusion, bevacizumab was released from BMM, and the use of this innovative mixture yielded good results following DS with no complications. Further studies are required to determine its efficacy prior to establishing BMM as an adjunct treatment for penetrating and non-penetrating glaucoma surgeries.

RESUMO O bevacizumabe (um agente anti-fator de crescimento endotelial vascular) tem sido sugerido como potencial modulador cicatricial na cirurgia do glaucoma. Este estudo objetivou melhorar a biodisponibilidade do bevacizumabe, investigando a viabilidade de uma nova mistura de bevacizumabe-metilcelulose (BMM) como terapia adjuvante para a esclerectomia profunda não-penetrante (DS). Dez olhos sem cirurgias prévias de 10 pacientes com glaucoma primário de ângulo aberto foram submetidos à DS associada à uma injeção subconjuntival de 0,3 ml da mistura de bevacizumabe-metilcelulose (bevacizumabe 3,75 mg incorporado em metilcelulose 4%) no sítio cirúrgico. A liberação de bevacizumabe foi avaliada in vitro através de cromatografia líquida de alta performance por exclusão de tamanho (HPLC). A pressão intraocular (PIO), a morfologia da ampola de filtração, a contagem de células endoteliais da córnea (CECC) e as complicações foram estudadas aos seis meses de seguimento. O bevacizumabe foi detectado a partir da mistura de bevacizumabe-metilcelulose por meio do HPLC até 72 horas. Além disso, todas as ampolas cirúrgicas permaneceram expandidas com material hialino durante a primeira semana. Uma redução significativa da pressão intraocular (média ± DP= -10,3 ± 5,4 mmHg, P<0,001) e ampolas difusas foram observadas ao final do período de seguimento. Embora a contagem de células endoteliais da córnea se mostrou discretamente diminuída (-7,4%), nenhuma complicação foi observada. Neste estudo, o bevacizumabe foi liberado da mistura de bevacizumabe-metilcelulose e o uso desta nova mistura se associou com bons resultados cirúrgicos e nenhuma complicação. Estudos futuros serão necessários para determinar sua eficácia, antes de se estabelecer a mistura de bevacizumabe-metilcelulose como um tratamento adjuvante às cirurgias penetrantes e não-penetrantes para o glaucoma.

Modulatory effect of different riboflavin compositions on the central corneal thickness of African keratoconus corneas during collagen crosslinking.

PURPOSE: A pilot investigation to transfer the established corneal collagen crosslinking (CXL) procedure in European eyes into clinically affected African eyes and to optimize the treatment by adapting the riboflavin composition. MATERIALS AND METHODS: CXL was performed in 15 eyes (11 patients) with advanced stages of keratoconus in the Eye Clinic of Bafoussam in the West Region of Cameroon. The following six riboflavin compositions with different portions of active swelling additives were applied: Solution 1 (0.5% methylhydroxypropylcellulose [MHPC]), solution 2 (1.0% MHPC), solution 3 (1.7% MHPC), solution 4 (5% dextran), solution 5 (10% dextran) and solution 6 (no active swelling ingredient). The central corneal thickness (CCT) was measured by ultrasound pachymetry before and after de-epithelialization and at least every 10 min during CXL. RESULTS: THE APPLICATION OF THE RIBOFLAVIN SOLUTIONS RESULTED IN THE FOLLOWING MEAN FINAL CCT VALUES: 172 ± 15% using solution 1 (60 min/n = 5); 183 ± 8% using solution 2 (60 min/n = 5); 170% using solution 3 (60 min/n = 1); 80% using solution 4 (45 min/n = 1); 99% using solution 5 (45 min/n = 1) and 150 ± 13% using solution 6 (50 min/n = 2). CONCLUSIONS: The combination of riboflavin compositions with swelling and stabilizing effects on the corneal stroma seems necessary in African eyes with advanced keratoconus. Further studies are required to confirm these primary results.

Biopolymeric film containing bioactive naphthoquinone (shikonin) in combined therapy of inflammatory destructive lesions in the buccal mucosa.

Clinical morphological efficiency of local application of a new biopolymeric film was studied. The film was based on methylcellulose derivatives and contained shikonin (preparation of plant origin) and its esters isolated from Lithospermum erythrorhizon L. cell culture. Combined therapy of 30 patients (34-72 years) with erosive ulcerative lichen planus and leukoplakia of the buccal mucosa was carried out. Local application of the new drug led to more rapid pain relief, epithelialization of the inflammatory destructive foci in the buccal mucosa, and reduced the intensity of morphological signs of lesions in the studied patient population.

Completion rates of anterior and posterior continuous curvilinear capsulorrhexis in pediatric cataract surgery for surgery performed by trainee surgeons with the use of a low-cost viscoelastic.

CONTEXT: Pediatric cataract surgery is traditionally done with the aid of high-molecular-weight viscoelastics which are expensive. It needs to be determined if low-cost substitutes are just as successful. AIMS: The study aims to determine the success rates for anterior and posterior capsulorrhexis and intraocular lens (IOL) implantation in the bag for pediatric cataract surgery performed with the aid of a low-molecular-weight viscoelastic. SETTINGS AND DESIGN: Nonrandomized observational study. MATERIALS AND METHODS: Children less than 6 years of age who underwent cataract surgery with IOL implantation in the period May 2008-May 2009 were included. The surgeries were done by pediatric ophthalmology fellows. A standard procedure of anterior capsulorrhexis, lens aspiration with primary posterior capsulorrhexis, anterior vitrectomy, and IOL implantation was followed. Three parameters were studied: successful completion of anterior and posterior capsulorrhexis and IOL implantation in the bag. RESULTS: 33 eyes of 28 children were studied. The success rate for completion was 66.7% and 88.2 % for anterior and posterior capsulorrhexis, respectively. IOL implantation in the bag was successful in 87.9%. CONCLUSIONS: 2% hydroxypropylmethylcellulose is a viable low-cost alternative to more expensive options similar to high-molecular-weight viscoelastics. This is of great relevance to hospitals in developing countries.

Viscocannula-assisted reinversion of implantable collamer lens: comparison of postoperative outcomes with the fellow eyes.

PURPOSE: To analyze and compare the postoperative outcomes of eyes with accidental intraoperative inversion of implantable collamer lens (ICL) and viscocannula-assisted reinversion in high myopia. DESIGN: Retrospective observational case comparison. SETTING: Institutional practice. PATIENTS: Consecutive eyes with accidental intraoperative inversion of ICL and viscocannula-assisted reinversion from January 2007 to September 2010 were analyzed retrospectively. They were compared with the fellow eyes with normal ICL implantation at 1 month, 6 months, and 2 years. MAIN OUTCOME MEASURES: Uncorrected visual acuity (UCVA), best-corrected visual acuity (BCVA), corneal pachymetry, endothelial cell loss, intraocular pressure, lens transparency, anterior chamber depth, and postoperative uveitis. RESULTS: A total of 206 myopic eyes had ICL implantation. Eight eyes (3.8%) of 8 patients had accidental intraoperative reinversion. Their fellow eyes had normal ICL implantation. There was no significant change (P = .611) in UCVA (reinverted and fellow eyes) at 2 years. There was no significant difference in postoperative UCVA (P = .611) and BCVA (P = .854) between the reinverted and the fellow eyes. The mean endothelial loss at 1 month, 6 months, and 2 years was 0.96% ± 0.5%, 0.92% ± 0.63%, and 0.89% ± 0.52% respectively in the reinverted eyes. There was no significant difference in the endothelial loss between the 2 groups at 1 month (P = .753), 6 months (P = .834), and 2 years (P = .916). One out of 8 eyes with reinversion had postoperative corneal edema, which resolved at 48 hours. None of the eyes reported uveitis or glaucoma. There was no loss of lens transparency. CONCLUSION: Intraoperative inversion can occur during insertion of ICL and viscocannula-assisted reinversion can be performed without significant complications.

Poly(ethylene glycol) modification enhances penetration of fibroblast growth factor 2 to injured spinal cord tissue from an intrathecal delivery system.

There is no effective treatment for spinal cord injury and clinical drug delivery techniques are limited by the blood-spinal cord barrier. Our lab has developed an injectable drug delivery system consisting of a biopolymer blend of hyaluronan and methylcellulose (HAMC) that can sustain drug release for up to 24h in the intrathecal space. Fibroblast growth factor 2 (FGF2) has great potential for treatment of spinal cord injury due to its angiogenic and trophic effects, but previous studies showed no penetration into spinal cord tissue when delivered locally. Conjugation to poly(ethylene glycol) (PEG) is known to improve penetration of proteins into tissue by reducing clearance and providing immunogenic shielding. We investigated conjugation of PEG to FGF2 and compared its distribution relative to unmodified FGF2 in injured spinal cord tissue when delivered intrathecally from HAMC. Importantly, PEG conjugation nearly doubled the concentration of FGF2 in the injured spinal cord when delivered locally and, contrary to previous reports, we show that some FGF2 penetrated into the injured spinal cord using a more sensitive detection technique. Our results suggest that PEGylation of FGF2 enhanced tissue penetration by reducing its rate of elimination.

Development of photocrosslinked methylcellulose hydrogels for soft tissue reconstruction.

A variety of materials have been used as fillers for soft tissue augmentation. In this study, methylcellulose (MC), a water-soluble derivative of the polysaccharide cellulose, was modified with functional methacrylate groups and photocrosslinked to produce hydrogels for potential application in plastic and reconstructive surgery. Purified macromer (5% theoretical modification, 2.3% actual) was resuspended in 0.05wt.% of the photoinitiator, 2-methyl-1-[4-(hydroxyethoxy)phenyl]-2-methyl-1-propanone, cast into custom molds, and exposed to long-wavelength UV light for 10min to form gels. Photocrosslinked MC hydrogels at varying weight/volume percentages displayed equilibrium weight swelling ratios (wet weight/dry weight) and elastic moduli of 30+/-3 to 17+/-2 and 8.48+/-0.25kPa to 23.21+/-1.55kPa, respectively, demonstrating the formation of stable gels with tunable properties. Human dermal fibroblasts grown in the presence of MC hydrogels in vitro exhibited no significant changes in cell viability after 5days of co-culture, indicating that the materials are non-cytotoxic. Higher weight percentage MC hydrogels (6%) implanted subcutaneously in CD-1 mice maintained their integrity and original dimensions after 80days in vivo, eliciting a mild inflammatory response with no observed inflammatory exudate, minimal vascular infiltration and thin translucent fibrous capsule formation of approximately 50microm in thickness. Taken together, the material and biological properties of photocrosslinked MC hydrogels suggest that they may be of use in soft tissue reconstruction.

Different solutions used for submucosal injection influenced early healing of gastric endoscopic mucosal resection in a preclinical study in experimental pigs.

BACKGROUND: We hypothesised that different solutions for submucosal injection may influence early healing of endoscopic mucosal resection (EMR). The aim of this study was to evaluate histological and immunological changes after EMR in experimental pigs. MATERIALS AND METHODS: Two parallel EMRs on the anterior and posterior wall of the gastric body were performed by means of the cap technique in 21 female pigs. A glycerol-based solution (anterior EMR) and hydroxypropyl methylcellulose solution (posterior EMR) were applied for submucosal injection. The animals were sacrificed 7 days later, and tissue sections of all EMRs were stained using combined trichrome. Computer image analysis was used for objective evaluation of elastic and collagen fibres content. Two-colour indirect immunophenotyping of blood and gastric samples were performed using mouse anti-pig monoclonal antibodies. RESULTS: The values of collagen fibre content 7 days after EMR were significantly higher in lesions after the use of solution A in comparison with solution B (2.10 +/- 0.25% versus 1.57 +/- 0.25%, p = 0.009). Concordant results were found in elastic fibres (3.23 +/- 0.49% versus 2.93 +/- 0.61%, p = 0.018). No systemic changes in major leukocyte subpopulations were found. In gastric tissue, lymphocyte subsets exhibited only minor changes. CD4(+) T-lymphocytes were increased in the healing tissue after EMR using solution A (17.08 +/- 9.24% versus 9.76 +/- 7.97%, p = 0.011). Significant increase of SWC3(+) leukocytes was observed after EMR using solution B (47.70 +/- 25.41% versus 18.70 +/- 12.16%, p = 0.001). CONCLUSIONS: The use of glycerol-based solution for submucosal injection was associated with more pronounced histological signs of early healing of EMRs compared with hydroxypropyl methylcellulose.

In vitro neural injury model for optimization of tissue-engineered constructs.

Stem cell transplantation is a promising approach for the treatment of traumatic brain injury, although the therapeutic benefits are limited by a high degree of donor cell death. Tissue engineering is a strategy to improve donor cell survival by providing structural and adhesive support. However, optimization prior to clinical implementation requires expensive and time-consuming in vivo studies. Accordingly, we have developed a three-dimensional (3-D) in vitro model of the injured host-transplant interface that can be used as a test bed for high-throughput evaluation of tissue-engineered strategies. The neuronal-astrocytic cocultures in 3-D were subjected to mechanical loading (inducing cell death and specific astrogliotic alterations) or to treatment with transforming growth factor-beta1 (TGF-beta1), inducing astrogliosis without affecting viability. Neural stem cells (NSCs) were then delivered to the cocultures. A sharp increase in the number of TUNEL(+) donor cells was observed in the injured cocultures compared to that in the TGF-beta1-treated and control cocultures, suggesting that factors related to mechanical injury, but not strictly astrogliosis, were detrimental to donor cell survival. We then utilized the mechanically injured cocultures to evaluate a methylcellulose-laminin (MC-LN) scaffold designed to reduce apoptosis. When NSCs were co-delivered with MC alone or MC-LN to the injured cocultures, the number of caspase(+) donor cells significantly decreased compared to that with vehicle delivery (medium). Collectively, these results demonstrate the utility of an in vitro model as a pre-animal test bed and support further investigation of a tissue-engineering approach for chaperoned NSC delivery targeted to improve donor cell survival in neural transplantation.

The influence of viscoelastic substances on the corneal endothelial cell population during cataract surgery: a prospective study of cohesive and dispersive viscoelastics.

PURPOSE: To compare the ability of cohesive and dispersive ophthalmic viscoelastic devices (OVDs) to protect the corneal endothelium following in-the-bag phacoemulsification with implantation of a foldable posterior chamber intraocular lens (IOL). METHODS: In a prospective single-masked randomized study, 60 eyes of 60 cataract patients were assigned to three groups of 20 patients each, according to which OVD was used: Celoftal, Vitrax or Healon. The corneal response to surgery was evaluated by measuring the endothelial cell loss, the variation in mean cell area of the endothelial cells (CV), the frequency of hexagonal cells, and the central corneal thickness. Data were recorded preoperatively and 3 months postoperatively. RESULTS: Preoperatively, no significant difference was observed in cell count, CV, hexagonal pattern or pachymetry among groups. Postoperatively, all three groups had a significant decrease in cell count, but the decrease was significantly less in the Vitrax group (6.97%) than in the Celoftal (18.03%) and Healon groups (18.46%). No changes in CV, hexagonality or corneal thickness were observed within any of the three groups or among the groups. There was an equal and significant increase in visual acuity. CONCLUSIONS: Phacoemulsification with implantation of a posterior chamber lens is known to affect the density and morphology of corneal endothelial cells. Viscoelastics facilitate cataract surgery and protect the corneal endothelium during the procedure. Choosing a dispersive hyaluronate OVD during the phaco procedure may allow for protection of the endothelial cells while suppressing the formation of free radicals. This may be the reason for the superior protective effect on the corneal endothelial cells of Vitrax compared with Celoftal and Healon.

Effect of an oil-in-water emulsion on the tear physiology of patients with mild to moderate dry eye.

PURPOSE: To determine the effect of an oil-in-water emulsion eye drop compared with a conventional dry eye supplement (hypromellose) on tear physiology in dry eye. METHODS: A randomized parallel, longitudinal, and investigator-masked study of the efficacy of 1.25% castor oil emulsion and 0.32% hypromellose solution was carried out. A total of 53 patients with mild to moderate dry eye (27 in emulsion group and 26 in hypromellose group) were recruited for the study. Patients were enrolled if they reported at least 2 symptoms on a McMonnies Dry Eye Questionnaire together with 1 of the following screening tests: noninvasive tear breakup time (5-10 seconds) and Schirmer test without anesthesia (2-5 mm in 5 minutes). Patients were instructed to use the test solutions 3 times a day for 30 days. Tear production, evaporation, lipid layer structure, and osmolality were measured before and 30 days after use of the drops. RESULTS: A statistically significant decrease was seen after 1 month in tear evaporation rates with both emulsion (7.25 +/- 5.43 g/m2/h) and hypromellose (2.02 +/- 4.75 g/m2/h). However, the decrease with emulsion was significantly greater than with hypromellose (P < 0.001). Lipid layer structure improved from day 1 to day 30 of the study with the emulsion but not with the hypermellose. No significant changes were seen in tear production and osmolality with either of the drops. CONCLUSIONS: The oil-water emulsion was more effective in reducing tear evaporation than hypromellose after repeated application over a 1-month period. This finding signifies the potential of the emulsion in the management of evaporative dry eye.

Artificial tear gel as a gonioscopic and contact lens ophthalmoscopy fluid.

An easy and convenient method of using a commercially available clear lubricant eye gel for diagnostic and therapeutic contact lens applications at the slit lamp is described. The authors used hydroxypropyl methylcellulose 0.3% as a medium for contact lens applications and compared it to the traditional hydroxypropyl methylcellulose 2.5%. Hydroxypropyl methylcellulose 0.3% as a contact lens solution is clear, viscous, and easy to apply; does not require irrigation after use; and has levels of convenience, safety, and visual recovery superior to the standard 2.5% solution characteristics. The 0.3% gel could be used as an effective and convenient gonioscopic and ophthalmoscopic contact medium.

Change in intraocular pressure within 1 week of phacoemulsification and intraocular lens implantation using Adatocel.

PURPOSE: To examine the change in intraocular pressure (IOP) within 1 week of phacoemulsification and foldable posterior chamber intraocular lens (PC IOL) implantation using Adatocel (hydroxypropyl methylcellulose 2% [HPMC]). SETTING: Department of Ophthalmology, University of Sciences, Faculty of Medicine, Pécs, Hungary. METHODS: In this prospective study, the IOP in 118 eyes of 118 patients (57 men, 61 women, mean age 68 years +/- 7.8 [SD]) with no history of glaucoma was assessed by Goldmann applanation tonometry 2 to 3, 6 to 8, and 22 to 24 hours and 1 week after uneventful phacoemulsification and PC IOL implantation. The effect of the removal of Adatocel ("partial removal" from the anterior chamber [AC] only versus "complete removal" from behind of the IOL as well), the lens type (Medicontur 601 HP versus Bausch & Lomb Hydroview), and the type of anesthesia (topical versus parabulbar) were compared. Statistical analysis was performed using the Student t test, and P< or =.05 was considered statistically significant. RESULTS: The mean preoperative IOP was 13.83 +/- 2.5 mmHg. There were no significant differences at any time in postoperative IOP measurements between the 2 IOL types and the 2 modes of anesthesia. At 2 to 3 hours, 6 to 8 hours, and 22 to 24 hours, the IOP was significantly higher in the 30 eyes in which the Adatocel was partially removed (from the AC only) than in the 88 eyes in which it was completely removed (from behind the PC IOL as well) (P< or =.05, P< or =.01, and P< or =.001, respectively). CONCLUSION: Severe postoperative IOP spikes in nonglaucomatous patients after uneventful phacoemulsification cataract surgery are rare. The type of implanted PC IOL and the mode of anesthesia had no significant effect on postoperative IOP. Total removal of the ophthalmic viscosurgical device, even when using HPMCs such as Adatocel, is necessary to prevent postoperative IOP spikes.

Methyl cellulose gel obstructed bone formation by GBR: an experimental study in rats.

AIM: To evaluate whether bone formation under Teflon capsules may be enhanced by concomitant implantation of recombinant human platelet-derived growth factor-BB/insulin-like growth factor-I (rhPDGF-BB/IGF-I) incorporated into a methyl cellulose gel. MATERIALS AND METHODS: Fifty-five male 6-month-old albino rats of the Wistar strain were used in the study. The lateral aspect of the mandibular ramus was exposed on both sides of the jaw. In 70 sites, the periosteum was removed from the ramus, leaving the bone denuded, while in 35 sites, it was preserved. On 10 non-periosteal (P-) sites and five periosteal (P+) sites, an empty rigid teflon capsule (d=7 mm), serving as control, was placed on the ramus. In the 40 test animals, the capsule placed on the one side of the jaw was filled at random with one of three different concentrations (1,200, 600, 150 microg/ml) of rhPDGF-BB/IGF-I gel. The capsules placed on the contralateral side of the jaw contained a placebo methyl cellulose gel. Each growth factor group, defined according to the gel concentration, and the placebo group contained 10 capsules placed on the P- side and five capsules placed on the P+ side. Two months after surgery, all animals were sacrificed. RESULTS: Histologic analysis revealed that in the non-filled control capsules, the amount of new bone including the bone marrow was 29.9% and 39.7% of the capsule area on the P- and P+ sides, respectively. In the test capsules with the growth factor gel and placed on the P-sides, the amounts of new bone ranged from 5.6% to 6.3%, which were similar (p>0.05) to that formed in the capsules filled with the methyl cellulose gel (5.5%). New bone formation was larger in the capsules on the P+ sides than in those on the P- sides but was similar in the capsules with different growth factor concentrations (range 17.9-19.6%) and in those with placebo gel (21.0%). In all groups, the carrier gel was poorly absorbed and occupied most of the capsules. CONCLUSION: Local application of a methyl cellulose gel obstructed bone formation under Teflon capsules placed adjacent to uninjured cortical bone in the mandibular ramus of rats. These data suggest that another material should be utilized to deliver growth factors under Teflon membranes for guided bone regeneration.