BCLA CLEAR presbyopia: Management with intraocular lenses

Cataract surgery including intraocular lens (IOL) insertion, has been refined extensively since the first such procedure by Sir Harold Ridley in 1949. The intentional creation of monovision with IOLs using monofocal IOL designs has been reported since 1984. The first reported implantation of multifocal IOLs was published in 1987. Since then, various refractive and or diffractive multifocal IOLs have been commercialised. Most are concentric, but segmented IOLs are also available. The most popular are trifocal designs (overlaying two diffractive patterns to achieve additional focal planes at intermediate and near distances) and extended depth of focus designs which leave the patient largely spectacle independent with the reduced risk of bothersome contrast reduction and glare. As well as mini-monovision, surgical strategies to minimise the impact of presbyopia with IOLs includes mixing and matching lenses between the eyes and using IOLs whose power can be adjusted post-implantation. Various IOL designs to mimic the accommodative process have been tried including hinge optics, dual optics, lateral shifts lenses with cubic-type surfaces, lens refilling and curvature changing approaches, but issues in maintaining the active mechanism with post-surgical fibrosis, without causing ocular inflammation, remain a challenge. With careful patient selection, satisfaction rates with IOLs to manage presbyopia are high and anatomical or physiological complications rates are no higher than with monofocal IOLs

Glare prediction and mechanism of adaptation following implantation of hydrophilic and hydrophobic intraocular lenses

Purpose: Glare is a known side effect of intraocular lens (IOL) implantation, affected principally by IOL material and optics, although it is reported subjectively to decrease in impact with time. However, little objective data have been published on changes over time, how these relate to subjective reports, and whether those who will report greater glare symptoms can be predicted prior to IOL implantation. Methods: A total of 32 patients (aged 72.4 ± 8.0 years) with healthy eyes were implanted bilaterally with hydrophilic 600s (Rayner, Worthing, UK) or hydrophobic Acrysof (Alcon, Texas, USA) acrylic IOLs (n = 16 each, randomly assigned). Each patient reported their dysphotopsia symptoms subjectively using the validated forced choice photographic questionnaire for photic phenomena, and halo size resulting from a bright light in a dark environment was quantified objectively in eight orientations using the Aston Halometer. Assessment was performed binocularly pre-operatively and at 1, 2, 3, and 4 weeks after IOL implantation. Setting: The study was carried out at the National Health Service Ophthalmology Department, Queen Elizabeth Hospital, Birmingham, UK. Results: Visual acuity (average 0.37 ± 0.26 logMAR) did not correlate with subjective glare (r = 0.184, p = 0.494) or objective glare (r = 0.294, p = 0.270) pre-surgery. Objective halo size (F = 112.781, p 0.05). It was not possible to predict post-surgery dysphotopsia from symptoms or a ratio of symptoms to halo size pre-surgery (p > 0.05). Conclusions: Subjective dysphotopsia and objective halos caused by cataracts are greatly reduced by implantation of IOL after cataract removal causing few perceivable symptoms. However, objective measures are able to quantify a further reduction in light scatter over the first month post-IOL implantation, suggesting that any subjective effects over this period are due to the healing process and not due to neuroadaptation

Translational Learning with Orange Data Mining

Abstract for the e-NATCONPH 2021 (International Conference) TRANSLATIONAL LEARNING WITH ORANGE DATA MINING Raqib F 1, Dunne MCM 1*, Gurney JC2, Harle DE 3, Sivapalan T 2, Sabokbar N 2, Bhogal-Bhamra GK 1 1 Ophthalmic Research Group, Optometry School, Aston University, Birmingham, UK 2 Acute Primary Care Ophthalmology Service, West Kent CCG, Aylesford, UK 3 Acute Primary Care Ophthalmology Service, West Kent CCG, Tonbridge, UK *Corresponding author’s email ID: [email protected] BACKGROUND. Health Education England’s Topol Review has recommended preparation of clinicians for a digital future. Orange Data Mining software enables hands-on exposure of machine learning to practitioners that traditionally lack this training. PURPOSE. This case study presents a translational learning approach, used for teaching undergraduate optometrists, that includes (a) gathering clinical evidence (b) learning from the clinical evidence and (c) translation to evidence-based teaching and practice. METHODOLOGY In this approach, students are taught about research ethics before creating an Orange Data Mining canvas containing widgets to upload clinical data (File), remove missing data (Impute), assign variables (Select columns), carry out machine learning (Naïve Bayes and Logistic Regression), master cross validation and hyperparameter tuning (Test and score) before gaining new knowledge and clinical decision support (Nomogram). This is demonstrated with 1351 real clinical cases for determining the relative importance of clinical data, recommended by the College of Optometrists’ Clinical Management Guidelines, for investigating an anterior eye disease (uveitis). RESULTS. Students discover that Naive Bayes has higher informedness (96%) than tuned Logistic Regression (90%). The Naïve Bayes nomogram reveals the relative importance of the clinical symptoms and signs while the Logistic regression nomogram indicates possible redundancy. A presentation of acute unilateral discomfort and visual disturbance with mild red eye and anterior chamber inflammation results in 90% and 68% probabilities of uveitis according, respectively, to Naïve Bayes’ and Logistic Regression nomograms. CONCLUSION. Our students enjoy this translational learning approach and we ask if it might also be useful for training other health scientists. Key Words: Education, Health Sciences, Translational learnin

Best technique for upper lid eversion

Aim: Lid eversion is an essential component of contact lens aftercare. Hence, this study determined the best method of lid eversion based on three criteria: comfort, speed of administration and the area of the palpebral conjunctiva exposed. Method: Twenty-five participants (aged 20–34) had 6 different techniques applied in random order by the same clinician on two separate occasions: three involving a cotton bud placed on the extended upper eyelid either centrally, at the top of the tarsal plate or off-centre; one using the wooden end of the bud placed at the top of the tarsal plate; one using the clinician's index finger to evert the lid; and one using a silicone rubber, finger-shaped substitute. The participants judged the degree of discomfort of each technique on a visual analogue scale. The time to complete the task was timed with a stop-watch and the area of exposed palpebral conjunctiva was captured with a digital slit lamp and assessed using image analysis. Results: There was no difference between the initial lid eversion or subsequent repeat in terms of comfort (F = 0.304, p = 0.586), time to complete (F = 3.075, p = 0.092) or area exposed (F = 2.311, p = 0.142). Lid eversion using fingers alone or the silicone substitute everter were similar in comfort (p = 0.312), being the most comfortable methods, with off-centre cotton bud eversion or the wooden end of the cotton bud the least comfortable techniques (F = 17.480, p < 0.001). The quickest method to perform was the wooden end of the cotton bud, followed by the silicone everter (F = 17.522, p < 0.001). The area of exposed palpebral conjunctiva was greatest using the silicone everter (F = 28.199, p < 0.001). Conclusions: Lid eversion had repeatable results, with the silicone everter placed at the top of the tarsal plate the most comfortable for the patient, quick to perform and exposed a greater area of tarsal plate than other techniques and therefore is recommended to clinicians

Patterns of somatic mutation in human cancer genomes

Cancers arise owing to mutations in a subset of genes that confer growth advantage. The availability of the human genome sequence led us to propose that systematic resequencing of cancer genomes for mutations would lead to the discovery of many additional cancer genes. Here we report more than 1,000 somatic mutations found in 274 megabases (Mb) of DNA corresponding to the coding exons of 518 protein kinase genes in 210 diverse human cancers. There was substantial variation in the number and pattern of mutations in individual cancers reflecting different exposures, DNA repair defects and cellular origins. Most somatic mutations are likely to be 'passengers' that do not contribute to oncogenesis. However, there was evidence for 'driver' mutations contributing to the development of the cancers studied in approximately 120 genes. Systematic sequencing of cancer genomes therefore reveals the evolutionary diversity of cancers and implicates a larger repertoire of cancer genes than previously anticipated. ©2007 Nature Publishing Group.link_to_subscribed_fulltex