Corneal pachymetry in normal and keratoconic eyes:Orbscan II versus ultrasound

Purpose: To compare corneal thickness measurements using Orbscan II (OII) and ultrasonic (US) pachymetry in normal and in keratoconic eyes. Setting: Eye Department, Heartlands and Solihull NHS Trust, Birmingham, United Kingdom. Methods: Central corneal thickness (CCT) was measured by means of OII and US pachymetry in 1 eye of 72 normal subjects and 36 keratoconus patients. The apical corneal thickness (ACT) in keratoconus patients was also evaluated using each method. The mean of the difference, standard deviation (SD), and 95% limits of agreement (LoA = mean ± 2 SD), with and without applying the default linear correction factor (LCF), were determined for each sample. The Student t test was used to identify significant differences between methods, and the correlation between methods was determined using the Pearson bivariate correlation. Bland-Altman analysis was performed to confirm that the results of the 2 instruments were clinically comparable. Results: In normal eyes, the mean difference (± 95% LoA) in CCT was 1.04 μm ± 68.52 (SD) (P>.05; r = 0.71) when the LCF was used and 46.73 ± 75.40 μm (P = .0001; r = 0.71) without the LCF. In keratoconus patients, the mean difference (± 95% LoA) in CCT between methods was 42.46 ± 66.56 μm (P<.0001: r = 0.85) with the LCF, and 2.51 ± 73.00 μm (P>.05: r = 0.85) without the LCF. The mean difference (± 95% LoA) in ACT for this group was 49.24 ± 60.88 μm (P<.0001: r = 0.89) with the LCF and 12.71 ± 68.14 μm (P = .0077; r = 0.89) when the LCF was not used. Conclusions: This study suggests that OII and US pachymetry provide similar readings for CCT in normal subjects when an LCF is used. In keratoconus patients, OII provides a valid clinical tool for the noninvasive assessment of CCT when the LCF is not applied. © 2004 ASCRS and ESCRS.

Nidek OPD-scan analysis of normal, keratoconic, and penetrating keratoplasty eyes

PURPOSE: To determine by wavefront analysis the difference between eyes considered normal, eyes diagnosed with keratoconus, and eyes that have undergone penetrating keratoplasty METHODS: The Nidek OPD-Scan wavefront aberrometer was used to measure ocular aberrations out to the sixth Zernike order. One hundred and thirty eyes that were free of ocular pathology, 41 eyes diagnosed with keratoconus, and 8 eyes that had undergone penetrating keratoplasty were compared for differences in root mean square value. Three and five millimeter root mean square values of the refractive power aberrometry maps of the three classes of eyes were compared. Radially symmetric and irregular higher order aberration values were compared for differences in magnitude. RESULTS: Root mean square values were lower in eyes free of ocular pathology compared to eyes with keratoconus and eyes that had undergone penetrating keratoplasty. The aberrations were larger with the 5-mm pupil. Coma and spherical aberration values were lower in normal eyes. CONCLUSION: Wavefront aberrometry of normal, pathological, and eyes after surgery may help to explain the visual distortions encountered by patients. The ability to measure highly aberrated eyes allows an objective assessment of the optical consequences of ocular pathology and surgery. The Nidek OPD-Scan can be used in areas other than refractive surgery.

Optical quality for keratoconic eyes with conventional RGP lens and simulated, customised contact lens corrections:a comparison

Purpose: To compare monochromatic aberrations of keratoconic eyes when uncorrected, corrected with spherically-powered RGP (rigid gas-permeable) contact lenses and corrected using simulations of customised soft contact lenses for different magnitudes of rotation (up to 15°) and translation (up to 1mm) from their ideal position. Methods: The ocular aberrations of examples of mild, moderate and severe keratoconic eyes were measured when uncorrected and when wearing their habitual RGP lenses. Residual aberrations and point-spread functions of each eye were simulated using an ideal, customised soft contact lens (designed to neutralise higher-order aberrations, HOA) were calculated as a function of the angle of rotation of the lens from its ideal orientation, and its horizontal and vertical translation. Results: In agreement with the results of other authors, the RGP lenses markedly reduced both lower-order aberrations and HOA for all three patients. When compared with the RGP lens corrections, the customised lens simulations only provided optical improvements if their movements were constrained within limits which appear to be difficult to achieve with current technologies. Conclusions: At the present time, customised contact lens corrections appear likely to offer, at best, only minor optical improvements over RGP lenses for patients with keratoconus. If made in soft materials, however, these lenses may be preferred by patients in term of comfort. © 2012 The College of Optometrists.

International session at the BCLA conference

Full text: It seems a long time ago now since we were at the BCLA conference. The excellent FIFA World Cup in Brazil kept us occupied over the summer as well as Formula 1, Wimbledon, Tour de France, Commonwealth Games and of course exam paper marking! The BCLA conference this year was held in Birmingham at the International Convention Centre which again proved to be a great venue. The number of attendees overall was up on previous years, and at a record high of 1500 people. Amongst the highlights at this year's annual conference was the live surgery link where Professor Sunil Shah demonstrated the differences in technique between traditional phacoemulsification cataract surgery and femtosecond assisted phacoemulsification cataract surgery. Dr. Raquel Gil Cazorla, a research optometrist at Aston University, assisted in the procedure including calibrating the femtosecond laser. Another highlight for me was the session that I chaired, which was the international session organised by IACLE (International Association of CL Educators). There was a talk by Mirjam van Tilborg about dry eye prevalence in the Netherlands and how it was managed by medical general practitioners (GPs) or optometrists. It was interesting to know that there are only 2 schools of optometry there and currently under 1000 registered optometrists there. It also seems that GPs were more likely to blame CL as the cause for dry eye whereas optometrists who had a fuller range of tests were better at solving the issue. The next part of the session included the presentation of 5 selected posters from around the world. The posters were also displayed in the main poster area but were selected to be presented here as they had international relevance. The posters were: 1. Motivators and Barriers for Contact Lens Recommendation and Wear by Nilesh Thite (India) 2. Contact lens hygiene among Saudi wearers by Dr. Ali Masmaly (Saudi) 3. Trends of contact lens prescribing and patterns of contact lens practice in Jordan by Dr. Mera Haddad (Jordan) 4. Contact Lens Behaviour in Greece by Dr. Dimitra Makrynioti (Greece) 5. How practitioners inform ametropes about the benefits of contact lenses and overcome the potential barriers: an Italian survey, by Dr. Fabrizio Zeri (Italy) It was interesting to learn about CL practice in different parts, for example the CL wearing population ration in Saudi Arabia is around 1:2 Male:Female (similar to other parts of the world) and although the sale of CL is restricted to registered practitioners there are many unregistered outlets, like clothing stores, that flout the rules. In Jordan some older practitioners will still advise patients to use tap water or even saliva! But thankfully the newer generation of practitioners have been educated not to advise this. In Greece one of the concerns was that some practitioners may advise patients to use disposable lenses for longer than they should and again it seems to be the practitioners with inadequate education that would do this. In India it was found that cost was one barrier to using contact lenses but also some practitioners felt that they shouldn’t offer CLs due to cost too. In Italy sensitive eyes and CL care and maintenance were the barriers to CL wear but the motivators were vision and comfort and aesthetics. Finally the international session ended with the IACLE travel award and educator awards presented by IACLE president Shehzad Naroo and BCLA President Andrew Yorke. The travel award went to Wang Ling, Jinling Institute of Technology, Nanjing, China. There were 3 regional Contact Lens Educator of the Year Awards sponsored by Coopervision and presented by Dr. J.C. Aragorn of Coopervision. 1. Asia Pacific Region – Dr. Rajeswari Mahadevan of Sankara Nethralaya Medical Research Foundation, Chennai, India 2. Americas Region – Dr. Sergio Garcia of University of La Salle, Bogotá and the University Santo Tomás, Bucaramanga, Colombia 3. Europe/Africa – Middle East Region: Dr. Eef van der Worp, affiliated with the University of Maastricht, the Netherlands The posters above were just a small selection of those displayed at this year's BCLA conference. If you missed the BCLA conference then you can see the abstracts for all posters and talks in a virtual issue of CLAE very soon. The poster competition was kindly sponsored by Elsevier. The poster winner this year was: Joan Gispets – Corneal and Anterior Chamber Parameters in Keratoconus The 3 runners up were: Debby Yeung – Scleral Lens Central Corneal Clearance Assessment with Biomicroscopy Sarah L. Smith – Subjective Grading of Lid Margin Staining Heiko Pult – Impact of Soft Contact Lenses on Lid Parallel Conjunctival Folds My final two highlights are a little more personal. Firstly, I was awarded Honorary Life Fellowship of the BCLA for my work with the Journal, and I would like to thank the BCLA, Elsevier, the editorial board of CLAE, the reviewers and the authors for their support of my role. My final highlight from the BCLA conference this year was the final presentation of the conference – the BCLA Gold Medal award. The recipient this year was Professor Philip Morgan with his talk ‘Changing the world with contact lenses’. Phil was the person who advised me to go to my first BCLA conference in 1994 (funnily he didn’t attend himself as he was busy getting married!) and now 20 years later he was being honoured with the accolade of being the BCLA Gold Medallist. The date of his BCLA medal addressed was shared with his father's birthday so a double celebration for Phil. Well done to outgoing BCLA President Andy Yorke and his team at the BCLA (including Nick Rumney, Cheryl Donnelly, Sarah Greenwood and Amir Khan) on an excellent conference. And finally welcome to new President Susan Bowers. Copyright © 2014 British Contact Lens Association. Published by Elsevier Ltd. All rights reserved.

Editorial

Full text: Welcome to issue 1 of 2012 and a belated Happy New Year to all CLAE readers and BCLA members. The hardest job I had for this issue was to decide which papers to include and which papers to hang on to and save for issue 2 of 2012. At the end of December when I was choosing the content for this issue there were additional 5 papers that could have been included. The final choice came down to various factors; such as first come first served – i.e. which papers had been ready and waiting the longest; secondly which papers had been submitted the earliest; are there similar papers so that it may be beneficial to publish them alongside this paper; and also was the content something which needed to be out there quicker than other papers as it was a current hot topic? But it should be noted that once papers are proofed and deemed ready by authors they are published in the epub version and put online for others to see in their final version. An epub version is given a DOI number (digital object identifier) so that it can be cited by other authors. Apart from being on line the only other difference is that an epub version is essentially waiting to be assigned to a particular issue. So those papers that are being held off for issue 2 of this year are actually already available for you to read (and cite) on line. In this issue there is a paper related to the cost of different contact lens replacement schedules – this may be a topic that is debated more in the future since as a society we are thinking more ‘green’ and all trying to help by reducing our carbon footprint, whether that be by recycling or using less in the first place. A timely review paper on the management of allergic eye disease may help us to better manage those patients we see in the spring with pollen allergies. We have two papers looking at different aspects in keratoconus patients, another looking at a modified fluoret strip and its application in measuring tear break up time and a review paper on corneal erosions. Another interesting paper comes from Professor Harminder Dua and his team. Professor Dua is the UK Royal College of Ophthalmologists’ president and has been interested in corneal anatomy and physiology for much of his research career. Finally, an unusual case of an ocular injury related to a snake bite. Overall I would say there is enough to sink your ‘fangs’ into! Finally, it gives me great pleasure in announcing the newest person to join our Editorial Board, Dr Florence Malet. Dr Malet is an Ophthalmologist and since September 2000 she has been at the Bordeaux Hospital in France developing the Contact Lens Unit of in the Ophthalmology University Department. She is ex-president of the French Contact Lens Society and president of the European Contact Lens Society of Ophthalmologists.

Transplantes de córneas no estado do Rio Grande do Norte: aspectos epidemiológicos e clínicos

This study aimed to characterize in a clinical and epidemiological way the patients who are on a waiting list for transplantation and the patients transplanted with corneal tissue in a corneal transplants reference service in the state of Rio Grande do Norte. It is an epidemiological study of a quantitative approach, with cross-sectional, descriptive and analytical cut including all patients on the waiting list for transplantation (population A) and the patients already transplanted with a corneal tissue (population B) in a reference service. In population A, there was a census conducted of patients on the waiting list for corneal transplantation (n=62 patients). In population B, the sample was non-probabilistic and corresponded to all corneal transplants performed in the service in the period from 2010 to 2014 (n=258). This study is approved by the Research Ethics Committee of the Federal University of Rio Grande do Norte, in Opinion 876 177 and CAAE 37533014.8.0000.5537. Data were collected in full in the period from January to April 2015, by two instruments built to systematize the necessary data collection. After being coded and tabulated, data were analyzed using the Statistical Package for Social Sciences software, version 20.0. The definition of variables and their distribution patterns were presented as frequencies and measures of central tendency while, for multivariate analysis, the effect of magnitude measures were applied (prevalence ratio) and measures of association (chi-square test or Fisher's exact test) for a 0.05 significance level. The results are shown in two scientific articles coming from the field survey data. It was found that the epidemiological profile of patients on the waiting list (n=62) showed a prevalence of individuals aged over 50 years old, female (54.84%) and residents of the middle region of East Rio Grande do Norte (66.13%). The clinical profile of patients with corneal transplantation (n=258) was characterized by being male (51.16%) with an average age of 49.33 years old and 57.75% were coming from East Rio Grande do Norte. The average time on the waiting list was 172.63 days in elective transplants and 9.03 days in urgent transplants. Keratoconus was the main indicator condition to perform the transplant. For patients on the waiting list, the variable “type of disorder of the cornea” showed statistically significant association with gender and age. For patients with corneal transplants, the variable "type of disorder of the cornea" was associated with the variables gender, age, previous surgery, failure of previous graft, classification of the eye and glaucoma. By characterizing the clinical and epidemiological profile of corneal transplants, it is possible to question the reality, pointing about the care that should be offered and develop targeted interventions to collective and individual needs intrinsic to patients who need this surgery as a treatment option.

Diagnóstico y características del queratocono mediante topografía corneal en el Hospital Santa Inés. Cuenca 2012-2014

Antecedentes: El Queratocono es un problema oftalmológico que se presenta en la edad adulta temprana, es generalmente bilateral y afecta indistintamente a ambos sexos. Representa la primera causa de trasplante corneal en países desarrollados. En el Ecuador existe escasa evidencia acerca de esta patología. Objetivo general: Establecer el diagnóstico y características del queratocono en pacientes con astigmatismo mayor a 1 dioptría (D) mediante topografía corneal en la consulta externa de oftalmología en el Hospital Santa Inés de Cuenca. Metodología: Se realizó un estudio retrospectivo, observacional y descriptivo. Se estudió las topografías corneales de pacientes con astigmatismo mayor a 1 Dioptría que asistieron a consulta externa de oftalmología en el Hospital Santa Inés de Cuenca entre enero del 2012 a diciembre del 2014. Los datos fueron recolectados del Topógrafo “Atlas 9000” y mediante el programa SPSS Statistics versión 20 se realizó el análisis de los datos. Para el diagnóstico se utilizaron los criterios de Rabinowitz y McDonnell modificados, y para su clasificación, se utilizaron los criterios queratométricos. Resultados: La frecuencia de queratocono fue 28,6%, el 53.1% fueron hombres y el 46.9% mujeres, fue bilateral en el 56.3% de los casos. El grupo de edad más afectado fue el de 20 a 39 años. El 75% de pacientes con queratocono presentó astigmatismo severo y el grado de queratocono incipiente fue el predominante con el 46,9%. Conclusiones: La alta frecuencia de queratocono, demuestra que nos encon-tramos frente a un grave problema de salud que muchas veces pasamos por alto y que compromete seriamente a la población joven

International flavours

It is an Olympic year and we have just witnessed the fantastic games hosted by Rio de Janeiro. Well done to team USA for winning the most medals overall but also well done to so many other nations and individuals who performed so well or were ambassadors in other ways. Teenage swimmer Yusra Mardini who swam for the refugee team and South Africa's Wayde van Niekerk who broke the longstanding 400 m record of Michael Johnson that has stood since 1999. Of course, we must mention sprinter Usain Bolt and swimmer Michael Phelps, who have now transcended superstar status and entered a new level of icon. My personal highlight was the sportsmanship witnessed in the 5000 m when American Abbey D’Agostino was accidentally felled by New Zealand runner Nikki Hamblin. D’Agostino helped Hamblin back to her feet but slumped to the track after realising her own injury. Hamblin helped her up and stayed with her so that both completed the race. The International Olympic Committee has awarded both with the prestigious Pierre de Coubertin award, also known as the International Fair Play Trophy. Fair play is of paramount importance in publishing in peer-reviewed papers. At CLAE we try and maintain, as do other journals, this by ensuring double blind peer review and allowing authors to select the most appropriate handling editor for their submission. Our handling editors are placed across the world (2 in Europe, 1 in the Americas, 1 in Australia and 1 in Asia) and part of their role is to encourage submissions from their region. Over the last decade we certainly have seen more and more papers from places that haven’t previously published in CLAE. In this issue of CLAE we have a true international blend of papers. We have papers from authors from the UK, USA, Iran, Jordan, France, Poland, Turkey, Nigeria, France, Spain and Brazil. I think it's a testament to the continued success of the journal that we are attracting new writers from so many parts of the world and retain papers from more established authors and research centres. We do continue to attract many weaker papers that are rejected early in the review process. Often these will be unexceptional case reports or papers describing a surgical technique. Case reports are published but only those that offer something original and especially those with interesting photographs. In this issue you will see Professor James Wolffsohn (UK) has an interesting paper around a lot of the focus of his recent research activity into clinical evaluation of methods of correcting presbyopia. In this paper he highlights predictors to aid success of presbyopic contact lenses. If you have been involved in any clinical work or research in the field of dry eye disease then you will know well the CLDEQ (Contact Lens Dry Eye Questionnaire) devised by Robin Chalmers and her colleagues (USA). This issue of CLAE details the latest research using the CLDEQ-8 (the 8 item version of the CLDEQ). The Shahroud Eye Cohort Study has produced many papers already and in this issue we see Fotouhi Akbar (Iran) looking at changes in central and peripheral corneal thickness over a five year period. These days we use a lot of new instrumentation, such as optical low-coherence reflectometry. In this issue Emre Güler (Turkey) compares that to a new optical biometry unit. Dry eye is more common and in this issue we see a study by Oluyemi Fasina (Nigeria) to investigate the disease in adults in South-West Nigeria. The TearLab™ is now commonly used to investigate osmolarity and Dorota Szczesna-Iskander (Poland) looks at measurement variability of this device. Following the theme of dry eyes and tear testing Renaud Laballe (France) looks at the use of scleral lenses as a reservoir-based ocular therapeutic system. In this issue we have a couple of papers looking at different aspects of keratoconus. Magdalena Popiela (UK) looks at demographics of older keratoconic patients in Wales, Faik Orucoglu (Turkey) reports a novel scoring system for distinguishing keratoconus from normal eyes, Gonzalo Carracedo (Spain) reports the effect of rigid gas permeable lens wear on dry eye in keratoconus and Hatice Nur Colak (Turkey) compares topographic and aberrations in keratoconus. Other interesting papers you will find are Mera Haddad (Jordan) investigates contact lens prescribing in Jordan, Camilla Fraga Amaral (Brazil) offers a report on the use of ocular prosthetics, Naveed Ahmed Khan (Malaysia) reports of the use of dimethyl sulfoxide in contact lens disinfectant and Michael Killpartrick (UK) offers a short piece with some useful advice on contamination risk factors that may occur from the posterior surface of disposable lenses. So for this issue I would say that the Gold Medal for biggest contribution in terms of papers has to go to Turkey. I could have awarded it to the UK too, but Turkey has three full papers and the UK has two plus one short communication. Turkey is also one of the countries that has shown the largest increase in submissions over the last decade. Finally, welcome aboard to our newest Editorial Board Member Nicole Carnt from Australia. Nicole has been an active researcher for many years and acted as a reviewer for CLAE many times in the past. We look forward to working with you.

Índice acumulativo de riesgo (nice) como prueba diagnóstica con base en tomografía corneal por elevación en la prevención de ectasia corneal post-lasik

Antecedentes La ectasia corneal post-lasik (ECPL) es una complicación infrecuente, pero devastadora en la cirugía lasik (queratomileusis asistida con éxcimer láser) para el tratamiento de la miopía con o sin astigmatismo. Con base en la tomografía corneal por elevación por imágenes de Scheimpflug (Sistema Pentacam HR, Oculus Wetzlar, Alemania), se propone un novedoso índice acumulativo de riesgo para ser utilizado como prueba diagnóstica de tamizaje y así prevenir esta complicación. Metodología Se realizó un estudio observacional analítico, de corte transversal tipo pruebas diagnósticas, con el fin de evaluar las características operativas del índice NICE teniendo como estándar de referencia el módulo de Belin-Ambrosio (Pentacam HR) utilizando un modelo de regresión logística binaria, tablas de contingencia y estimando el área bajo la curva ROC. Resultados Se evaluaron 361 ojos de los cuales el 59,3% provenían de pacientes de sexo femenino, la edad media global fue de 30 años (RIC 11,0). El modelo logístico binario aplicado se construyó con base en cuatro variables independientes cuantitativas (K2, PAQUI, EP e I-S) y una cualitativa (SEXO), y se determinó su relación con la variable dependiente, NICE (puntaje final). Las variables predictoras fueron estadísticamente significativas clasificando adecuadamente el 92,9% de los ojos evaluados según presencia o ausencia de riesgo. El coeficiente de Nagelkerke fue de 74,4%. Conclusiones El índice acumulativo de riesgo NICE es una herramienta diagnóstica novedosa en la evaluación de candidatos a cirugía refractiva lasik para prevenir la ectasia secundaria.