9 results on '"Ezra, Daniel G."'
Search Results
2. Characterizing the Occluded Lacrimal Punctum Using Anterior Segment Optical Coherence Tomography.
- Author
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Timlin HM, Keane PA, Rose GE, and Ezra DG
- Subjects
- Adult, Aged, Eyelids surgery, Female, Humans, Lacrimal Apparatus surgery, Lacrimal Apparatus Diseases diagnosis, Male, Margins of Excision, Middle Aged, Prospective Studies, Dacryocystorhinostomy methods, Eyelids diagnostic imaging, Lacrimal Apparatus diagnostic imaging, Lacrimal Apparatus Diseases surgery, Tomography, Optical Coherence methods
- Abstract
Purpose: Epiphora is sometimes associated with an absent or occluded lacrimal drainage punctum (or puncta). This study uses noninvasive "enhanced depth" anterior segment optical coherence tomography (OCT) to give improved characterization and understanding of absent or fully occluded puncta and the underlying canaliculus., Methods: Anterior segment spectral domain OCT images were collected prospectively from 9 lower puncta of 6 patients with epiphora and absent or fully occluded puncta, not amenable to dilation in clinic, to see if a canaliculus was visible on OCT imaging below the occluded punctum., Results: An epithelial lined canalicular lumen was visible on OCT in 4 lower eyelid puncta from 2 patients and OCT identified 80% (4/5) of the canaliculi that were located on microscope-assisted punctal exploration. These lumens were seen within 580 μm depth from the eyelid margin surface. A half of the eyes in which a canaliculus was identified on OCT (the 2 eyes in a single patient) had resolution of epiphora following punctoplasty, and the other patient was found to have coexisting nasolacrimal duct stenosis and required later dacryocystorhinostomy. The positive predictive value for identifying a canaliculus on lower eyelid punctal exploration in acquired complete punctal occlusion (excluding the congenital case) was 1, with a negative predictive value of 1., Conclusions: This study demonstrates that canaliculi can be imaged with OCT where formal access is precluded by an occluded punctum. This noninvasive investigation might help predict the likelihood of successful retrieval of a canaliculus at surgical exploration.
- Published
- 2018
- Full Text
- View/download PDF
3. The Application of Infrared Imaging and Optical Coherence Tomography of the Lacrimal Punctum in Patients Undergoing Punctoplasty for Epiphora.
- Author
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Timlin HM, Keane PA, Rose GE, and Ezra DG
- Subjects
- Adult, Aged, Aged, 80 and over, Case-Control Studies, Eyelids surgery, Female, Humans, Lacrimal Apparatus surgery, Lacrimal Apparatus Diseases surgery, Male, Middle Aged, Pilot Projects, Prospective Studies, Eyelids diagnostic imaging, Infrared Rays, Lacrimal Apparatus diagnostic imaging, Lacrimal Apparatus Diseases diagnostic imaging, Ophthalmologic Surgical Procedures, Tomography, Optical Coherence
- Abstract
Purpose: To determine the application of imaging the stenotic lacrimal punctum with infrared photographs and optical coherence tomography (OCT) and to identify characteristics of the lacrimal punctum in patients who benefit from punctoplasty., Design: Case-control study., Participants: Twenty patients with epiphora who were listed for punctoplasty and 20 healthy controls., Methods: Prospectively, 20 patients listed for punctoplasty were asked to rate their epiphora, using the Munk score, before and after punctoplasty. They also underwent preoperative OCT and infrared imaging of the affected punctum. They were divided into 2 groups, depending on whether the epiphora improved, and were compared with 20 healthy controls., Main Outcome Measures: Measurements of puncta from infrared and OCT images were obtained along with Munk scores of patient epiphora., Results: The infrared image measurements were significantly smaller in those patients whose epiphora improved compared with those whose did not in both the area of the punctal aperture and in the maximum punctal diameter. Additionally, those patients with improvement in epiphora had a significantly smaller preoperative punctal diameter at 100 μm depth on OCT compared with healthy controls; this was not observed in patients whose epiphora failed to improve. There was no significant difference in the punctum diameter among the 3 groups at the punctum surface entrance or at 500 μm depth. Patients with epiphora had a higher tear meniscus within the punctum compared with healthy controls., Conclusions: Lacrimal punctum infrared and OCT imaging may be helpful in predicting patients more likely to benefit symptomatically from punctoplasty, with patients with smaller puncta having greater symptomatic improvement. However, the results suggest that inner punctum diameter (not readily measurable by slit-lamp examination), rather than the surface diameter, is correlated with outcome. Additionally, OCT measurements of the tear meniscus height within the punctum may be related to the degree of epiphora., (Copyright © 2017 American Academy of Ophthalmology. All rights reserved.)
- Published
- 2017
- Full Text
- View/download PDF
4. The Mechanics of Brow-Suspension Ptosis Repair: A Comparative Study of Fox Pentagon and Crawford Triangle Techniques.
- Author
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Kwon KA, Shipley RJ, Edirisinghe M, Best SM, Cameron RE, Poitelea C, Rose GE, and Ezra DG
- Subjects
- Adult, Aged, Blinking physiology, Female, Forehead surgery, Humans, Male, Middle Aged, Blepharoptosis surgery, Eyelids surgery, Suture Techniques
- Abstract
Purpose: To perform quantitative analysis of the most commonly used brow-suspension configurations., Methods: The inflection positions for Fox pentagon and Crawford triangle configurations were marked on 49 healthy volunteers (male and female) and photographs taken in 3 states: "normal," "closed," and "raised." The skin marks were measured vectorially with respect to the medial canthus, and displacement changes were evaluated for "normal-to-closed" ("blinking") and from "closed-to-raised" ("eye-opening") states. The distance between a pair of inflection marks, representing the approximate path of sling configurations, were also measured and analyzed in relation to the mechanical properties of a variety of synthetic brow-suspension materials., Results: "Blinking" resulted in the greatest displacement in the medial eyelid incision, resulting in the greatest strain on the line connecting the medial eyelid and medial brow inflections. No significant differences in the strains for individual lines were found between the Fox and Crawford techniques, although the former shows a significantly lower overall strain in the whole loop than the latter. The displacements of some inflections and of the strains of a few lines differed significantly in men and women., Conclusions: Within the scope of this study, the blinking action was shown to result in the maximum strain of ~40%, which lies within the elastic region of stress-strain curves for some commonly used synthetic brow-suspension materials. No one method was statistically superior, although the Fox pentagon gave a significantly lower overall strain when the sling material was assumed to move somewhat around the inflections within a closed loop.
- Published
- 2017
- Full Text
- View/download PDF
5. Analysis of blink dynamics in patients with blepharoptosis.
- Author
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Mak FH, Harker A, Kwon KA, Edirisinghe M, Rose GE, Murta F, and Ezra DG
- Subjects
- Adult, Aged, Aged, 80 and over, Blepharoptosis pathology, Blepharoptosis surgery, Eyelids pathology, Eyelids surgery, Female, Humans, Male, Middle Aged, Blepharoptosis physiopathology, Blinking, Eyelids physiopathology
- Abstract
Owing to the rapid movements of the human upper eyelid, a high-speed camera was used to record and characterize voluntary blinking and the blink dynamics of blepharoptosis patients were compared to a control group. Twenty-six blepharoptosis patients prior to surgery and 45 control subjects were studied and the vertical height of the palpebral aperture (PA) was measured manually at 2 ms intervals during each blink cycle. The PA and blinking speed were plotted with respect to time and a predictive model was generated. The blink dynamic was analysed in closing and opening phases, and revealed a reduced speed of the initial opening phase in ptotic patients, suggesting intrinsic muscle function change in ptosis pathogenesis. The PA versus time curve for each subject was reconstructed using custom-built parameters; however, there were significant differences between the two groups. Those parameters used included the rate of closure, the delay between opening and closing, rate of initial opening, rate of slow opening (nonlinear function) and the 'switch point' between those two rates of opening. The model was tested against a new group of subjects and was able to discriminate ptosis patients from controls with 80% accuracy., (© 2016 The Author(s).)
- Published
- 2016
- Full Text
- View/download PDF
6. Characterizing the lacrimal punctal region using anterior segment optical coherence tomography.
- Author
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Timlin HM, Keane PA, Day AC, Salam T, Abdullah M, Rose GE, and Ezra DG
- Subjects
- Adult, Female, Healthy Volunteers, Humans, Male, Middle Aged, Prospective Studies, Tears physiology, Eyelids anatomy & histology, Lacrimal Apparatus anatomy & histology, Tomography, Optical Coherence
- Abstract
Purpose: Abnormalities of lacrimal punctum size and morphology probably contribute to excess tearing, with significant effects on quality-of-life for affected individuals. Our current understanding of normal punctal morphology originates from ex vivo studies, which are unlikely to capture the true nature of the living punctum. This study used enhanced depth anterior segment optical coherence tomography (OCT) to give improved characterization and understanding of lacrimal punctal structure., Methods: Qualitative and quantitative assessments were performed on spectral domain OCT images collected prospectively from 40 lower puncta of 20 healthy volunteers., Results: The average external lower lid punctal diameter was 0.646 mm (SD 150 μm) on OCT imaging, measured at the largest diameter, which was in parallel to the mucocutaneous junction. Fifty-five per cent of puncta appeared closed, whilst the eyelids were open. Fluid menisci were visible within 73% of puncta. A postpunctal 'ampulla' was visible within three systems, one of which was imaged through the conjunctival surface. Ampullary dilatation occurred laterally, rather than at the medial wall., Conclusion: Optical coherence tomography provides quick and non-invasive assessment of the lacrimal punctum and its neighbouring tissue layers. This assessment of punctal size and morphology has the potential for further investigation of punctal physiology, for aiding diagnosis, and for monitoring the results of treatment. The average external diameter of the punctal opening measured in this study is greater than that recorded in anatomical textbooks., (© 2015 Acta Ophthalmologica Scandinavica Foundation. Published by John Wiley & Sons Ltd.)
- Published
- 2016
- Full Text
- View/download PDF
7. Stress-relaxation and fatigue behaviour of synthetic brow-suspension materials.
- Author
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Kwon KA, Shipley RJ, Edirisinghe M, Rayment AW, Best SM, Cameron RE, Salam T, Rose GE, and Ezra DG
- Subjects
- Muscles physiology, Eyelids physiology, Materials Testing, Prostheses and Implants, Stress, Mechanical
- Abstract
Ptosis describes a low position of the upper eyelid. When this condition is due to poor function of the levator palpebrae superioris muscle, responsible for raising the lid, "brow-suspension" ptosis correction is usually performed, which involves internally attaching the malpositioned eyelid to the forehead musculature using brow-suspension materials. In service, such materials are exposed to both rapid tensile loading and unloading sequences during blinking, and a more sustained tensile strain during extended periods of closure. In this study, various mechanical tests were conducted to characterise and compare some of commonly-used synthetic brow-suspension materials (Prolene(®), Supramid Extra(®) II, Silicone rods (Visitec(®) Seiff frontalis suspension set) and Mersilene(®) mesh) for their time-dependent response. At a given constant tensile strain or load, all of the brow-suspension materials exhibited stress-relaxation or creep, with Prolene(®) having a statistically different relaxation or creep ratio as compared with those of others. Uniaxial tensile cyclic tests through preconditioning and fatigue tests demonstrated drastically different time-dependent response amongst the various materials. Although the tests generated hysteresis force-strain loops for all materials, the mechanical properties such as the number of cycles required to reach the steady-state, the reduction in the peak force, and the cyclic energy dissipation varied considerably. To reach the steady-state, Prolene(®) and the silicone rod required the greatest and the least number of cycles, respectively. Furthermore, the fatigue tests at physiologically relevant conditions (15% strain controlled at 6.5 Hz) demonstrated that the reduction in the peak force during 100,000 cycles ranged from 15% to 58%, with Prolene(®) and the silicone rod exhibiting the greatest and the least value, respectively. Many factors need to be considered to select the most suitable brow-suspension material for ptosis correction. These novel data on the mechanical time-dependent performance could therefore help to guide clinicians in their decision-making process for optimal surgical outcome., (Copyright © 2014 Elsevier Ltd. All rights reserved.)
- Published
- 2015
- Full Text
- View/download PDF
8. Animated ophthalmology
- Author
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Ezra, Daniel G, Rose, Geoff, Coombes, Andrew, and Plant, Gordon
- Published
- 2009
9. The Mechanics of Brow-Suspension Ptosis Repair: A Comparative Study of Fox Pentagon and Crawford Triangle Techniques
- Author
-
Kwon, Kyung-Ah, Shipley, Rebecca J, Edirisinghe, Mohan, Best, Serena M, Cameron, Ruth E, Poitelea, Cornelia, Rose, Geoffrey E, Ezra, Daniel G, Best, Serena [0000-0001-7866-8607], Cameron, Ruth [0000-0003-1573-4923], and Apollo - University of Cambridge Repository
- Subjects
Adult ,Male ,Blinking ,Suture Techniques ,Blepharoptosis ,Eyelids ,Humans ,Female ,Forehead ,Middle Aged ,eye diseases ,Aged - Abstract
PURPOSE: To perform quantitative analysis of the most commonly used brow-suspension configurations. METHODS: The inflection positions for Fox pentagon and Crawford triangle configurations were marked on 49 healthy volunteers (male and female) and photographs taken in 3 states: "normal," "closed," and "raised." The skin marks were measured vectorially with respect to the medial canthus, and displacement changes were evaluated for "normal-to-closed" ("blinking") and from "closed-to-raised" ("eye-opening") states. The distance between a pair of inflection marks, representing the approximate path of sling configurations, were also measured and analyzed in relation to the mechanical properties of a variety of synthetic brow-suspension materials. RESULTS: "Blinking" resulted in the greatest displacement in the medial eyelid incision, resulting in the greatest strain on the line connecting the medial eyelid and medial brow inflections. No significant differences in the strains for individual lines were found between the Fox and Crawford techniques, although the former shows a significantly lower overall strain in the whole loop than the latter. The displacements of some inflections and of the strains of a few lines differed significantly in men and women. CONCLUSIONS: Within the scope of this study, the blinking action was shown to result in the maximum strain of ~40%, which lies within the elastic region of stress-strain curves for some commonly used synthetic brow-suspension materials. No one method was statistically superior, although the Fox pentagon gave a significantly lower overall strain when the sling material was assumed to move somewhat around the inflections within a closed loop.
- Published
- 2017
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