Continuous Transitional Focus (CTF): A New Concept in Ophthalmic Surgery.
Ontology highlight
ABSTRACT:
SUBMITTER: Mesa RR
PROVIDER: S-EPMC6258586 | biostudies-literature | 2018 Dec
REPOSITORIES: biostudies-literature
Publications
Continuous Transitional Focus (CTF): A New Concept in Ophthalmic Surgery.
Mesa Ramón Ruiz RR Monteiro Tiago T
Ophthalmology and therapy 20180618 2
Presbyopia is a condition that affects many as the lens ages, and is a secondary effect of cataract surgery. Multifocal lenses for the treatment of presbyopia have been undergoing cycles of development and improvement over the past two decades. The latest advancements have yielded lenses with a continuous range of optical powers, otherwise known as continuous transitional focus (CTF) lenses. Modern CTF lenses provide a more natural experience for patients while minimizing unwanted optical side e ...[more]
Similar Datasets
Project description:Surgery of the skull base has evolved over the past 100 years. This anatomical area has been approached by neurosurgeons, otologists, maxillofacial surgeons and plastic surgeons from different angles. Presently, the combined skills of these surgeons are utilized in treating lesions of this area once considered a 'bony no man's land'. Modern microsurgical techniques are based on the principle that removal of adequate bone from the cranial base could provide sufficient access without the necessity to retract dura. Accurate preoperative assessment by imaging, the use of microsurgical techniques, preservation of vital structures such as nerves by intraoperative monitoring, and modern anaesthetic and postoperative management have all contributed to the reduction in mortality and morbidity to acceptable levels. In the future, with refinements in imaging, stereotactic radiosurgery and chemotherapy, the above management protocol would be tailored to suit each individual patient and decided by a team of experts.
| S-EPMC5530769 | biostudies-other
Project description:"Molecular neurosurgery" is emerging as a new medical concept, and is the combination of two partners: (i) a molecular neurosurgery agent, and (ii) the cognate receptor whose activation results in the selective elimination of a specific subset of neurons in which this receptor is endogenously expressed. In general, a molecular surgery agent is a selective and potent ligand, and the target is a specific cell type whose elimination is desired through the molecular surgery procedure. These target cells have the highest innate sensitivity to the molecular surgery agent usually due to the highest receptor density being in their plasma membrane. The interaction between the ligand and its receptor evokes an overactivity of the receptor. If the receptor is a ligand-activated non-selective cation channel, the overactivity of receptor leads to excess Ca2+ and Na+ influx into the cell and finally cell death. One of the best known examples of such an interaction is the effect of ultrapotent vanilloids on TRPV1-expressing pain-sensing neurons. One intrathecal resiniferatoxin (RTX) dose allows for the receptor-mediated removal of TRPV1+ neurons from the peripheral nervous system. The TRPV1 receptor-mediated ion influx induces necrotic processes, but only in pain-sensing neurons, and usually within an hour. Besides that, target-specific apoptotic processes are also induced. Thus, as a nano-surgery scalpel, RTX removes the neurons responsible for generating pain and inflammation from the peripheral nervous system providing an option in clinical management for the treatment of morphine-insensitive pain conditions. In the future, the molecular surgery concept can also be exploited in cancer research for selectively targeting the specific tumor cell.
| S-EPMC5455100 | biostudies-literature
Project description:BackgroundOphthalmic viscoelastic devices (OVDs) used during small-incision cataract surgery have numerous advantages. However, OVDs have longer retention time in an eye after surgery resulting in intraocular pressure (IOP) spikes. The purpose of this study is to analyze and quantify the effect of various OVDs on both IOP and best corrected visual acuity (BCVA) by systematically reviewing the literature and performing meta-analysis.MethodsNumerous databases from January 1, 1985, to present were systematically searched. Thirty-six (3893 subjects) of 3313 studies identified were included for analysis. Standardized mean difference (SMD) was computed, and meta-analysis was performed.ResultsA total of 3313 records were retrieved including 1114 from database search and 2199 from grey literature search. Significant increase in postoperative IOP in 1-day follow-up with Healon (SMD = 0.37, CI: [0.07, 0.67]), Viscoat (SMD = 0.29, CI: [0.13, 0.45]), Provisc (SMD = 0.46, CI: [0.17, 0.76]), and Soft Shell (SMD = 0.58, CI: [0.30, 0.86]) was computed. On the other hand, results implied a nonsignificant increase in postoperative IOP with Healon GV (SMD = 0.07, CI: [-0.28, 0.41]), Healon5 (SMD = 0.15, CI: [-0.33, 0.64]), 2% HPMC (SMD = 0.32, CI: [-0.0, 0.64]), and OcuCoat (SMD = 0.26, CI: [-0.37, 0.9]). Additionally, a nonsignificant reduction in postoperative IOP was inferred with Viscoat + Provisc (SMD = -0.28, CI: [-2.23, 1.68]).ConclusionImprovement in IOP was shown with Viscoat + Provisc. Additionally, IOP nonsignificant upsurge was observed with Healon GV, Healon5, 2% HPMC, and OcuCoat compared to significant upsurge with Healon, Viscoat, and Soft Shell.
| S-EPMC7593745 | biostudies-literature
Project description: Not available
| S-EPMC7539939 | biostudies-literature
Project description:BackgroundWe have developed a new compact lightweight 8K ultra-high-definition (UHD; 7,680×4,320 pixels) camera and started medical application with an ophthalmic surgical microscope which is interchangeable with the conventional high-definition (1,920×1,080 pixels)/4K UHD (3,840×2,160 pixels) microscopic camera.MethodsWe did a feasibility study to apply our 8K UHD microscope in cataract surgery, glaucoma surgery and vitreous surgery using pig cadaver eyes. The 8K UHD microscope comprises a surgical microscope, a camera adaptor with relay lenses, an 8K UHD camera and an 8K UHD LCD to share the 8K UHD images with all surgical staff in real time.ResultsIn ophthalmic surgeries, higher resolution images than conventional microscopic cameras were obtained with 8K UHD LCD equivalent to the observation through the microscopic eye pieces.ConclusionBased on the results of this feasibility study, clinical trials on human ophthalmic surgery using the new 8K UHD microscopic camera should be conducted in the near future.
| S-EPMC6157988 | biostudies-literature
Project description:Image formation in bright field electron microscopy can be described with the help of the contrast transfer function (CTF). In this work the authors describe the "CTF Estimation Challenge", called by the Madrid Instruct Image Processing Center (I2PC) in collaboration with the National Center for Macromolecular Imaging (NCMI) at Houston. Correcting for the effects of the CTF requires accurate knowledge of the CTF parameters, but these have often been difficult to determine. In this challenge, researchers have had the opportunity to test their ability in estimating some of the key parameters of the electron microscope CTF on a large micrograph data set produced by well-known laboratories on a wide set of experimental conditions. This work presents the first analysis of the results of the CTF Estimation Challenge, including an assessment of the performance of the different software packages under different conditions, so as to identify those areas of research where further developments would be desirable in order to achieve high-resolution structural information.
| S-EPMC4672951 | biostudies-literature
Project description:NFI/CTF is a family of polypeptides involved in stimulating the initiation of adenovirus DNA replication and the activation of transcription driven by RNA polymerase II. Several naturally occurring NFI/CTF variants display distinctive transactivation activities in vivo. To define more precisely the role of the NFI/CTF family in regulating gene expression, we cloned the splice variant CTF5, analyzed transcriptional activation patterns in a yeast transcription assay, and compared it with other CTF proteins. CTF5, which lacks exons 9 and 10 including a CTD-like motif essential for transcriptional activation by full-length CTF1, enhances transcription to a greater extent than CTF1. In addition, CTF5 is even more active than CTF7, which lacks exons 7-9. These findings indicate that CTF proteins formed by differential splicing display a much broader range of transcriptional activities as observed previously.
| S-EPMC145930 | biostudies-other
Project description:ObjectivesTo determine the baseline risk factors for elective ophthalmic surgery cancellations and characterise the reasons for cancellation.MethodsThis is a retrospective, non-randomised study performed at a large tertiary ophthalmic centre. It included a consecutive sample of patients above the age of 18 who had an ophthalmic surgery scheduled at Cole Eye Institute, Cleveland Clinic, OH between January 2012 and December 2019. An automated search pull identified 75,908 scheduled surgeries (63,987 completed and 11,921 cancelled surgeries). Statistical analysis was performed using R (version 3.5.1). Main outcome measures were baseline factors that impact risk for surgery cancellation and reasons for surgery cancellation.ResultsAnalysis was performed on 69,963 scheduled surgeries (57.37% Female, 42.63% Male; Mean age of 62.72 years; 59,959 completed and 10,004 cancelled surgeries). Of the 2384 cancelled surgeries with reasons provided, the most common causes of cancellation were patient refusal (38.42%), patient health condition (18.79%), and rescheduling of surgery (15.27%). Female sex, black race, patient age less than 50 years, non-cataract surgeries, regional mean household income greater than $82,900, Medicare insurance, and geographical distance of less than 10 miles from home to the surgery site were each associated with a significantly increased risk of surgery cancellation (p < 0.01).ConclusionsThis study successfully identified several baseline factors predicting elective ophthalmic surgery cancellation. The clinical insights gained from these lines of enquiry may be used to construct models that not only identify patients at greater risk for cancellation but also highlight which interventions have greatest efficacy in preventing ophthalmic surgery cancellations.
| S-EPMC10482885 | biostudies-literature
Project description:There have been significant changes in the management of out of hours services in ophthalmology recently. The European Working Time Directive (EWTD) and economic measures have anecdotally reduced the availability of staff and facilities outside normal working hours, and there have been various responses to the provision of emergency surgical care. There are disparate attitudes to the optimum management of the emergency surgical case. We sought to establish a nationwide picture of the management of out of hours surgery.A questionnaire was distributed to every consultant ophthalmologist working in the NHS and registered with the Royal College of Ophthalmologists (n=947). Information was requested regarding departmental and personal policies, local facilities, and personal beliefs regarding emergency surgery.A total of 440 (46.5%) questionnaires were returned from 155 units; 18.7% of the units had no out of hours services or no operating facilities. Sixty-three percent of units reported a local policy regarding a time after which patients should not be taken to theatre. For 57%, this time began between 2100 hours and midnight. The most common reasons for not operating after a certain time were 'belief that delay does not significantly affect the outcome' (41.6%), 'delayed access to theatre due to competition with other surgical specialities' (40%), and 'no specialist ophthalmic-theatre nursing input' (32.7%).We report the first nationwide study on out of hours ophthalmological surgical working practices. This demonstrates variation in work patterns. It is significant to patients and ophthalmologists that there should be units in United Kingdom without full local facilities and staff.
| S-EPMC3597882 | biostudies-other
Project description:PurposeTo evaluate the rheological properties of the ophthalmic viscoelastic device (OVD) PRO-149, its preclinical safety, and its effectiveness when used during cataract surgery in patients with age-related cataract.Material and methodsControl (HEC) and test (PRO-149) OVDs were compared through rheological measures, by two preclinical safety studies in rabbits, and under normal-use conditions during cataract removal and lens implantation in a parallel randomized clinical trial.ResultsRheological properties were determined. Preclinical studies did not find any evidence of safety issues or toxicity. In the clinical trial, 36 subjects were included. After 29 days, there were no statistically significant differences in mean percentage of endothelial cell count change or in the postoperative intraocular pressure between groups. There were no significant differences between OVDs for any safety parameter studied. Finally, PRO-149 showed a statistically significant improvement in surgeon rating for ease of use during extraction (p < 0.05).ConclusionPRO-149 is a dispersive OVD. The rabbit models did not find evidence of clinical alterations or toxicity. The results of the clinical study support that the two studied OVDs were clinically similar in terms of safety and effectiveness for cataract surgery.Trial registrationThe trial is registered at Clinical Trials.gov at NCT04702802 (21-01-11).
| S-EPMC9421612 | biostudies-literature