43 research outputs found
Intraocular Pressure, Axial Length, and Refractive Changes after Phacoemulsification and Trabeculectomy for Open-Angle Glaucoma
Purpose. To compare changes in intraocular pressure (IOP), axial eye length (AEL), and refractive outcome in primary open-angle glaucoma patients undergoing cataract surgery and trabeculectomy in dependence of the sequence of surgeries. Materials and Methods. We retrospectively analysed 48 eyes. The changes in refraction, intraocular pressure, and axial eye length were analysed after surgery. In group A (21 subjects), phacoemulsification was performed before trabeculectomy, and in group B (27 subjects), trabeculectomy was performed before phacoemulsification with a minimum time span between interventions of 6 months. Results. The reduction in IOP and the decrease in AEL after trabeculectomy were significant after 6 and 12 months postsurgery (p<0.001 each). The decrease in AEL was 0.42 ± 0.11% at 6 months after surgery and 0.40 ± 0.13% after 12 months from surgery; this decrease in AEL was comparable between the groups. The refractive outcome was significantly different between the groups (group A: 0.35 ± 0.75 dpt, group B: −0.05 ± 0.36 dpt, p=0.018); in group A, trabeculectomy caused a hyperopic shift of 0.34 ± 0.44 dpt (p=0.002) at 12 months postsurgery. Conclusion. IOP reduction after trabeculectomy causes AEL shortening. The effect on refractive outcome depends on the sequence of surgeries. Better refractive outcome is achieved if phacoemulsification is performed after trabeculectomy
Assessment of choroidal blood flow using laser speckle flowgraphy
Background/aims There is considerable interest in novel techniques to quantify choroidal blood flow (CBF) in humans. In the present study, we investigated a novel technique to measure CBF based on laser speckle flowgraphy (LSFG) in healthy subjects. Methods This study included 31 eyes of 31 healthy, non-smoking subjects aged between 19 and 74 years. A commercial LSFG instrument was used to measure choroidal vessel diameter (CVD) and relative flow volume (RFV) in choroidal vessels that were identified on fundus photos, an approach that was used previously only for retinal vessels. The reproducibility and the effect of isometric exercise on these parameters were investigated. The latter was compared with measurement of subfoveal CBF using laser Doppler flowmetry (LDF). Results Intraclass correlation coefficients for CVD and RFV were higher than 0.8 indicating excellent reproducibility. During isometric exercise, we observed an increase in ocular perfusion pressure of approximately 60% (P<0.001). The increase in RFV and CBF was lower, but also highly significant versus baseline (at minute 6 of isometric exercise: RFV 10.5%+/- 4.2%, CBF 8.3%+/- 3.6%;P< 0.001 each) indicating choroidal autoregulation. Conclusion LSFG may be a novel approach to study blood flow in choroidal vessels. Data are reproducible and show good agreement with LDF data
TNF-α Gene Polymorphisms and Primary Open Angle Glaucoma in Romanian Population / Polimorfisme ale genei TNF-α în populația română cu glaucom primar cu unghi deschis
Glaucomul primar cu unghi deschis (GPUD) este una dintre cele mai frecvente forme de glaucom și este una dintre principalele cauze de orbire la nivel mondial. Dereglări ale sistemului imun precum și terenul genetic reprezintă factori de risc importanți. Influența polimorfismelor mononucleotidice (SNP) ale TNF-α asupra susceptibilității la GPUD a fost intens studiată, cu precădere pe populația asiatică. În studiul nostru am investigat posibila asociere a SNP din pozițiile -308G/A și -857C/T din promotorul genei TNF-α cu susceptibilitatea la GPUD și caracteristicile sale clinice. Studiul este de tip caz-control și a fost efectuat pe 197 de pacienți cu GPUD, împărțiți în două subgrupuri: glaucom cu hipertensiune intraoculară și glaucom cu tensiune intraoculară normală (HTG/NTG) comparați cu un lot martor de 208 subiecți clinic sănătoși. Acesta este primul studiu realizat pe subiecți români. Nu s-au observat diferențe semnificative statistic în frecvențele alelelor minore, în distribuția genotipurilor studiate sau a haplotipurilor construite între lotul de pacienți cu GPUD și lotul martor. La analiza subgrupurilor, s-a observat o asociere între genotipul TT al SNP TNF-α -857C/T cu valori mai crescute ale grosimii centrale a corneei în grupul pacienților cu glaucom normotensiv (p-value 0.032). Aceste rezultate necesită confirmarea prin studii efectuate pe loturi lărgite și în populații diferite
Investigative Ophthalmology & Visual Science / Regulation of Choroidal Blood Flow During Isometric Exercise at Different Levels of Intraocular Pressure
Purpose: There is evidence that choroidal blood flow (ChBF) is regulated in a complex way during changes in ocular perfusion pressure (OPP). We hypothesized that ChBF regulates better in response to changes in mean arterial pressure (MAP) than in intraocular pressure (IOP).
Methods: Eighteen volunteers (mean age, 26 years) were recruited for a randomized, three-way crossover design. MAP was varied via isometric exercise. IOP was either kept normal or elevated by 10 or 20 mm Hg by using a suction cup. Subfoveal ChBF was measured continuously for 8 minutes with laser Doppler flowmetry and OPP was calculated as 2/3*MAP-IOP. For data analysis, values from all subjects were pooled according to either IOP or MAP values, and correlation analyses were done.
Results: When data were grouped according to IOP, no correlation was observed between ChBF and MAP, but ChBF was lower the higher the IOP (P < 0.001). When data were grouped according to MAP, a significant correlation was found between ChBF and IOP (P < 0.001). When data were pooled according to IOP, the correlation between ChBF and OPP was weaker (P < 0.05). The OPP at which ChBF significantly increased from baseline was 61.3% 4.9% without suction cup, 65.2% 3.5% when IOP was increased by 10 mm Hg, and slightly lower when IOP was increased by 20 mm Hg (56.3% 4.8%, P = 0.07), but this effect did not reach the level of significance.
Conclusions: The present study provides further evidence that the regulation of ChBF during changes in OPP is controlled by complex mechanisms in humans and has less capacity to adapt to IOP elevation than to MAP increase.(VLID)489618
Update on Myopia Risk Factors and Microenvironmental Changes
The focus of this update is to emphasize the recent advances in the pathogenesis and various molecular key approaches associated with myopia in order to reveal new potential therapeutic targets. We review the current evidence for its complex genetics and evaluate the known or candidate genes and loci. In addition, we discuss recent investigations regarding the role of environmental factors. This paper also covers current research aimed at elucidating the signaling pathways involved in the pathogenesis of myopia
Serum Neurofilaments and OCT Metrics Predict EDSS-Plus Score Progression in Early Relapse-Remitting Multiple Sclerosis
(1) Background: Early disability accrual in RRMS patients is frequent and is associated with worse long-term prognosis. Correctly identifying the patients that present a high risk of early disability progression is of utmost importance, and may be aided by the use of predictive biomarkers. (2) Methods: We performed a prospective cohort study that included newly diagnosed RRMS patients, with a minimum follow-up period of one year. Biomarker samples were collected at baseline, 3-, 6- and 12-month follow-ups. Disability progression was measured using the EDSS-plus score. (3) Results: A logistic regression model based on baseline and 6-month follow-up sNfL z-scores, RNFL and GCL-IPL thickness and BREMSO score was statistically significant, with χ2(4) = 19.542, p < 0.0001, R2 = 0.791. The model correctly classified 89.1% of cases, with a sensitivity of 80%, a specificity of 93.5%, a positive predictive value of 85.7% and a negative predictive value of 90.62%. (4) Conclusions: Serum biomarkers (adjusted sNfL z-scores at baseline and 6 months) combined with OCT metrics (RNFL and GCL-IPL layer thickness) and the clinical score BREMSO can accurately predict early disability progression using the EDSS-plus score for newly diagnosed RRMS patients
Optic nerve head blood flow autoregulation during changes in arterial blood pressure in healthy young subjects.
In the present study the response of optic nerve head blood flow to an increase in ocular perfusion pressure during isometric exercise was studied. Based on our previous studies we hypothesized that subjects with an abnormal blood flow response, defined as a decrease in blood flow of more than 10% during or after isometric exercise, could be identified.A total of 40 healthy subjects were included in this study. Three periods of isometric exercise were scheduled, each consisting of 2 minutes of handgripping. Optic nerve head blood flow was measured continuously before, during and after handgripping using laser Doppler flowmetry. Blood pressure was measured non-invasively in one-minute intervals. Intraocular pressure was measured at the beginning and the end of the measurements and ocular perfusion pressure was calculated as 2/3*mean arterial pressure -intraocular pressure.Isometric exercise was associated with an increase in ocular perfusion pressure during all handgripping periods (p < 0.001). By contrast no change in optic nerve head blood flow was seen. However, in a subgroup of three subjects blood flow showed a consistent decrease of more than 10% during isometric exercise although their blood pressure values increased. In addition, three other subjects showed a consistent decline of blood flow of more than 10% during the recovery periods.Our data confirm previous results indicating that optic nerve head blood flow is autoregulated during an increase in perfusion pressure. In addition, we observed a subgroup of 6 subjects (15%) that showed an abnormal response, which is in keeping with our previous data. The mechanisms underlying this abnormal response remain to be shown
Effect of hyaluronic acid/trehalose in two different formulations on signs and symptoms in patients with moderate to severe dry eye disease
Purpose. This randomized, observer-masked, crossover study investigated the effect of two hyaluronic acid/trehalose-based containing formulations, with different physical properties, on the signs and symptoms in patients with moderate to severe dry eye disease (DED). Methods. In one group, patients received a mixture of sodium hyaluronate and trehalose (HT, Thealoz Duo®) for use during the day. In the other group, patients received a more viscous formulation consisting of hyaluronic acid, trehalose, and carbomer (HTC-gel, Thealoz Duo Gel) to use pro re nata. Both groups used HTC-gel before going to bed. Clinical standard tests for DED were performed at the beginning and end of each one-week period. Further, patient satisfaction including quality of sleep was assessed using a visual analogue scale. Results. Corneal fluorescein and conjunctival lissamine green staining scores decreased, and tear breakup time (BUT) increased for both groups (p<0.001 each). Mean instillation frequency was 3.1 ± 2.6 drops/day when using HT and 1.9 ± 2.2 drops/day when using HTC-gel (p=0.02). A significant improvement in the quality of sleep was observed with both treatments (p=0.01). Conclusions. Our results show improvement in signs and symptoms of DED in both groups. While instillation of HTC-gel resulted in a lower instillation frequency, both formulations of trehalose showed good clinical efficacy. This trial is registered with NCT02980913.Published versio
Biocompatible materials for orbital wall reconstruction - an overview
The reconstruction of an orbit after complex craniofacial fractures can be extremely demanding. For satisfactory functional and aesthetic results, it is necessary to restore the orbital walls and the craniofacial skeleton using various types of materials. The reconstruction materials can be divided into autografts (bone or cartilage tissue) or allografts (metals, ceramics, or plastic materials, and combinations of these materials). Over time, different types of materials have been used, considering characteristics such as their stability, biocompatibility, cost, safety, and intraoperative flexibility. Although the ideal material for orbital reconstruction could not be unanimously identified, much progress has been achieved in recent years. In this article, we summarise the advantages and disadvantages of each category of reconstruction materials. We also provide an update on improvements in material properties through various modern processing techniques. Good results in reconstructive surgery of the orbit require both material and technological innovations.Nanyang Technological UniversityNational Medical Research Council (NMRC)National Research Foundation (NRF)Published versionThe study is funded by National Medical Research Council (grants CG/C010A/2017, OFIRG/0048/2017, OFLCG/004a/2018, and TA/MOH-000249-00/2018), the National Research Foundation Singapore, A*STAR (A20H4b0141), the Singapore Eye Research Institute & Nanyang Technological University (SERI-NTU Advanced Ocular Engineering (STANCE) Program), the DukeNUS Medical School (Duke-NUS-KP(Coll)/2018/0009A) and the SERI-Lee Foundation (LF1019-1)