The pupillary light reflex in migraine

The literature suggests that there may be pupil size and response abnormalities in migraine headache sufferers. We used an infra-red pupillometer to measure dynamic pupil responses to light in 20 migraine sufferers (during non-headache periods) and 16 non-migraine age and gender matched controls. There was a significant increase in the absolute inter-ocular difference of the latency of the pupil light response in the migraine group compared with the controls (0.062 s vs 0.025 s, p = 0.014). There was also a significant correlation between anisocoria and lateralisation of headache such that migraine sufferers with a habitual head pain side have more anisocoria (r= 0.59, p < 0.01), but this was not related to headache laterally. The pupil changes were not correlated with the interval since the last migraine headache, the severity of migraine headache or the number of migraine headaches per annum. We conclude that subtle sympathetic and parasympathetic pupil abnormalities persist in the inter-ictal phase of migraine. © 2005 The College of Optometrists.

Normative contrast sensitivity values for the back-lit Melbourne Edge Test and the effect of visual impairment

Background: The Melbourne Edge Test (MET) is a portable forced-choice edge detection contrast sensitivity (CS) test. The original externally illuminated paper test has been superseded by a backlit version. The aim of this study was to establish normative values for age and to assess change with visual impairment. Method: The MET was administered to 168 people with normal vision (18-93 years old) and 93 patients with visual impairment (39-97 years old). Distance visual acuity (VA) was measured with a log MAR chart. Results: In those eyes without disease, MET CS was stable until the age of 50 years (23.8 ± .7 dB) after which it decreased at a rate of ≈1.5 dB per decade. Compared with normative values, people with low vision were found to have significantly reduced CS, which could not be totally accounted for by reduced VA. Conclusions: The MET provides a quick and easy measure of CS, which highlights a reduction in visual function that may not be detectable using VA measurements. © 2004 The College of Optometrists.

Simultaneous continuous recording of accommodation and pupil size using the modified Shin-Nippon SRW-5000 autorefractor

The internal optics of the recent models of the Shin-Nippon SRW-5000 autorefractor (also marketed as the Grand Seiko WV-500) have been modified by the manufacturer so that the infrared measurement ring has been replaced by pairs of horizontal and vertical infrared bars, on either side of fixation. The binocular, open field-of-view, allowing the accommodative state to be objectively monitored while a natural environment is viewed, has made the SRW-5000 a valuable tool in further understanding the nature of the oculomotor response. It is shown that the root-mean-square of model eye measures was least (0.017 ± 0.002D) when the separation of the horizontal measurement bars were averaged twice. The separation of the horizontal bars changes by 3.59 pixels/dioptre (r2 = 0.99), allowing continuous on-line analysis of the refractive state at up to 60 Hz temporal resolution to an accuracy of <0.001D, with pupils >3 mm. The pupil edge is not obscured in the diagonal axis by the measurement bars, unlike the ring of the original optics, so in the newer model pupil size can be measured simultaneously at the same rate with a resolution of <0.001 mm. The measurements of accommodation and pupil size are relatively unaffected by eccentricity of viewing up to ±10° from the visual axis and instrument focusing inaccuracies over a range of 10 mm towards the eye and 5 mm away from the eye. The resolution and temporal properties of the analysis are therefore ideal for the simultaneous measurement of dynamic accommodation and pupil responses. © 2004 The College of Optometrists.

A review of current knowledge on Electronic Vision Enhancement Systems for the visually impaired

Magnification can be provided to assist those with visual impairment to make the best use of remaining vision. Electronic transverse magnification of an object was first conceived for use in low vision in the late 1950s, but has developed slowly and is not extensively prescribed because of its relatively high cost and lack of portability. Electronic devices providing transverse magnification have been termed closed-circuit televisions (CCTVs) because of the direct cable link between the camera imaging system and monitor viewing system, but this description generally refers to surveillance devices and does not indicate the provision of features such as magnification and contrast enhancement. Therefore, the term Electronic Vision Enhancement Systems (EVES) is proposed to better distinguish and describe such devices. This paper reviews current knowledge on EVES for the visually impaired in terms of: classification; hardware and software (development of technology, magnification and field-of-view, contrast and image enhancement); user aspects (users and usage, reading speed and duration, and training); and potential future development of EVES. © 2003 The College of Optometrists.

Drug-induced bilateral transient myopia with the sulphonamide sulphasalazine

Whereas there are numerous reported ocular side effects from systemic sulpha medication, most are rare and reversible, with myopia being the most common reaction observed. A case report is presented of sudden bilateral onset of -1.0 DS of myopia (from -3.0 to -4.0 DS) in a young adult female following the addition of a sulphonamide (sulphasalazine) to oral non-steroidal anti-inflammatory treatment (meloxicam) for rheumatoid arthritis. The myopia regressed to -3.50 DS after 2 weeks when all medication was withdrawn and stabilised at this level when subsequent treatment was resumed after 8 weeks with the non-steroidal anti-inflammatory drug celecoxib. The case indicates that account needs to be taken of the possibility that relatively modest myopic shifts encountered in young adult contact lens wearers may be associated with concomitant systemic medication. © 2003 The College of Optometrists.

Benefit of coloured lenses for age-related macular degeneration

Purpose: To evaluate and compare the functional and perceived benefits of wearing coloured lenses by patients with age-related macular degeneration (ARMD). Method: Ten subjects with early ARMD and five elderly controls wore a selection of NoIR wrap-around coloured lenses (yellow 29.7% light transmission, orange 22.9%, red 16.8% and grey 10.3%), each for a duration of 7 days. Contrast sensitivity, colour vision, visual acuity, the effect of glare and peripheral sensitivity were measured for each lens and compared with a control (no lens) condition. Subjective ratings of visual performance were also scored. Results: Compared with the no filter condition, red and grey lenses reduced contrast sensitivity whereas yellow and orange lenses increased contrast sensitivity. These objective changes were supported by subjective ratings in subjects with ARMD. Grey lenses reduced the loss of contrast sensitivity usually suffered in the presence of glare, whereas visual acuity and peripheral sensitivity decreased with red lenses. Colour vision became distorted with red lenses in control subjects, but was relatively unaffected by the use of coloured lenses in subjects with ARMD. Conclusions: The subjective benefit of coloured lenses appears to be due to a minor enhancement of contrast sensitivity. © 2002 The College of Optometrists.

Sympathetic control of accommodation:evidence for inter-subject variation

Autonomic innervation of ciliary smooth muscle is mediated principally by the parasympathetic nervous system and is supplemented by the sympathetic nervous system. Previous drug and nerve stimulation experiments on humans and animals have demonstrated that sympathetic innervation is inhibitory (via β-2 adrenoceptors), relatively small, slow and augmented by concurrent levels of background parasympathetic activity. These characteristics are pertinent to the sympathetic system having a specific role in our ability to adapt successfully to sustained near vision tasks and, given the clear association between near vision and the onset and development of myopia, to a putative aetiological role in myopia development in pre-disposed individuals. A fifth characteristic, namely the variation between individuals in access to an inhibitory sympathetic facility is therefore of particular interest. A novel method for continuous recording of accommodation, currently employed in a large sample longitudinal study of myopia in young adults, was used following topical instillation of non-selective (timolol) and selective (betaxolol) sympathetic β-adrenoceptor antagonists. Measures of post-task accommodative hysteresis were taken with reference to the time-course of regression of accommodation when open-loop (Difference of Gaussian) conditions were immediately imposed following short (10 s) and long (3 min) duration far (0D) and near (3D above tonic level) tasks viewed through a Badal system. Data confirm earlier informal experimental observations that only one in three individuals are likely to have access to a sympathetic inhibitory facility during sustained near vision. © 2002 The College of Optometrists.

Continuous recording of accommodation and pupil size using the Shin-Nippon SRW-5000 autorefractor

A newly released commercial autorefractor, the Shin-Nippon SRW-5000 (Japan), has been found to be valid compared to subjective refraction and repeatable over a wide prescription range. Its binocular open field-of-view allows the accommodative state to be monitored while a natural environment is viewed. In conventional static mode, the device can take up to 45 readings in 1min using digital image analysis of the reflected retinal image of a measurement ring. Continuous on-line analysis of the ring provides high (up to 60Hz) temporal resolution of the refractive state to an accuracy of <0.001D. Pupil size can also be analysed to a resolution of <0.001mm. The measurement of accommodation and pupil size was relatively unaffected by eccentricity of viewing up to ±10° and instrument focusing inaccuracies of ±5mm. The resolution properties of the analysis are shown to be ideal for measurement of dynamic accommodation and pupil responses. Copyright © 2001 The College of Optometrists.

Improving the description of the retinal vasculature and patient history taking for monitoring systemic hypertension

Systemic hypertension is an important public health concern. If optometrists are to perform a more active role in the detection and monitoring of high blood pressure (BP), there is a need to improve the consistency of describing the retinal vasculature and to assess patient's ability to correctly report the diagnosis of hypertension, its control and medication. One hundred and one patients aged >40 years were dilated and had fundus photography performed. BP was measured and a self-reported history of general health and current medication was compared with the records of their general practitioner (GP). The status of the retinal vasculature was quantified using a numeric scale by five clinicians and this was compared to the same evaluation performed with the aid of a basic pictorial grading scale. Image analysis was used to objectively measure the artery-to-vein (A/V) ratio and arterial reflex. Arteriolar tortuosity and calibre changes were found to be the most sensitive retinal signs of high BP. Using the grading scale to describe the retinal vasculature significantly improved inter- and intra-observer repeatability. Almost half the patients examined were on medication for high BP or cardiovascular disease. Patients' ability to give their complete medical history was poor, as was their ability to recall what medication they had been prescribed. GPs indicated it was useful to receive details of their patient's BP when it was >140/90 mmHg. The use of improved description of the retinal vasculature and stronger links between optometrists and GPs may enhance future patient care. © 2001 The College of Optometrists. Published by Elsevier Science Ltd. All rights reserved.

Ocular signs of systemic hypertension:a review

Cardiovascular disease and stroke continue to be the chief causes of death in developed countries and one of the leading causes of visual impairment. The individual with systemic hypertension may remain asymptomatic for many years. Systemic mortality and morbidity are markedly higher for hypertensives than normotensives, but can be significantly reduced by early diagnosis and then efficient management. However, the ability of Optometrists to detect and appropriately refer systemic hypertensives remains generally poor. This review examines the disease, its effects and detection by observation of the retinal signs, particularly those considered to be pre-malignant. Previous methods of classifying retinal hypertensive signs are discussed along with more recent image analysis techniques. The role of the optometrist in detecting, monitoring and appropriate referral of systemic hypertensives is discussed in relation to current research. (C) 2001 The College of Optometrists. Published by Elsevier Science Ltd. All rights reserved.

Exploring attitudes towards dietary modification and nutritional supplementation in people with and without age-related macular degeneration

Age-related macular degeneration (AMD) is the leading cause for visual impairment and blindness registration in the developed world. Due to the large amounts of conflicting AMD research on the role of nutrition and antioxidant intake, it is difficult for patients and practitioners to determine which measures can be taken to slow down the disease progression. The aim of this research was to determine the beliefs and knowledge that patients with AMD have about nutrition, to identify whether their condition is preventing them from eating a healthy diet, and to discover what their diet consists of. For the initial study, 158 participants with AMD (mean age 79 ± 7.8 years) and 50 participants without AMD (mean age 67 ± 8 years) were recruited from the Macular Society helpline, or from optometric practice. Participants had a 25 minute telephone interview where a 36-question survey was completed. The survey elicited demographic information, and questions covered the knowledge that participants had on nutrition and their current diet. The results from this survey uncovered three major findings: 1) 100% of AMD participants felt that they do not have enough information and support from eye-care practitioners regarding nutrition, 2) AMD patients are confused over, and display a lack of knowledge of, which foods are beneficial for eye health and when and what nutritional supplements to take, evidenced by 65% of participants not taking the correct dosage 3) AMD patients are not eating enough nutrients that would be beneficial for their condition - consuming an average of 1.4mg of lutein and zeaxanthin rather than the recommended 10mg. A clinical decision-making aid was created as an intervention based upon these findings. The aim of the aid was to help eye-care practitioners give the correct nutritional advice to their patients. Founded on the AREDS 2 inclusion and exclusion criteria, practitioners are able to identify which patients could benefit from a nutritional supplement, and which patients could benefit from dietary modification. An evaluation of the aid with 72 qualified eye-care practitioners exhibited a statistically significant increase in confidence after using the aid for two weeks. An evaluation using 51 student optometrists showed a statistically significant increase in confidence and a statistically significant increase in appropriate management of patients after using the aid. This project has elicited findings that are significant for AMD patient education. It is hoped that through these studies, patients will receive consistent advice about the risk factors for AMD, the link between AMD and nutrition, and the importance of maintaining a healthy, well-balanced diet.

Visual signs and symptoms of multiple system atrophy

Multiple system atrophy (MSA) is a rare movement disorder and a member of the 'parkinsonian syndromes', which also include Parkinson's disease (PD), progressive supranuclear palsy (PSP), dementia with Lewy bodies (DLB) and corticobasal degeneration (CBD). Multiple system atrophy is a complex syndrome, in which patients exhibit a variety of signs and symptoms, including parkinsonism, ataxia and autonomic dysfunction. It can be difficult to separate MSA from the other parkinsonian syndromes but if ocular signs and symptoms are present, they may aid differential diagnosis. Typical ocular features of MSA include blepharospasm, excessive square-wave jerks, mild to moderate hypometria of saccades, impaired vestibular-ocular reflex (VOR), nystagmus and impaired event-related evoked potentials. Less typical features include slowing of saccadic eye movements, the presence of vertical gaze palsy, visual hallucinations and an impaired electroretinogram (ERG). Aspects of primary vision such as visual acuity, colour vision or visual fields are usually unaffected. Management of the disease to deal with problems of walking, movement, daily tasks and speech problems is important in MSA. Optometrists can work in collaboration with the patient and health-care providers to identify and manage the patient's visual deficits. A more specific role for the optometrist is to correct vision to prevent falls and to monitor the anterior eye to prevent dry eye and control blepharospasm.

Changes at the BCLA

As we welcome 2014 we say goodbye to 2013 and I must start with an apology to authors who have submitted papers to CLAE and seen a delay in either the review process or the hard copy publication of their proofed article. The delays were caused by a major hike in the number of submissions to the journal in 2012 that increased further in 2013. In the 12 months leading to the end of October 2011 we had 94 new paper submissions, and for the same period to the end of 2012 the journal had 116 new papers. In 2012 we were awarded an impact factor for the first time and following that the next 12 month period to the end of October 2013 saw a massive increase in submissions with 171 new manuscripts being submitted. This is nearly twice as many papers as 2 years ago and 3 times as many as when I took over as Editor-in-Chief. In addition to this the UK academics will know that 2014 is a REF year (Research Excellence Framework) where universities are judged on their research and one of the major components of this measure remains to be published papers so there is a push to publishing before the REF deadline for counting. The rejection rate at CLAE has gone up too and currently is around 50% (more than double the rejection rate when I took over as Editor-in-Chief). At CLAE the number of pages that we publish each year has remained the same since 2007. When compiling issue 1 for 2014 I chose the papers to be included from the papers that were proofed and ready to go and there were around 200 proofed pages ready, which is enough to fill 3½ issues! At present Elsevier and the BCLA are preparing to increase the number the pages published per issue so that we can clear some of this backlog and remain up to date with the papers published in CLAE. I should add that on line publishing of papers is still available and there may have been review delays but there are no publishing online so authors can still get an epub on line final version of their paper with a DOI (digital object identifier) number enabling the paper to be cited. There are two awards that were made in 2013 that I would like to make special mention of. One was for my good friend Jan Bergmanson, who was awarded an honorary life fellowship of the College of Optometrists. Jan has served on the editorial board of CLAE for many years and in 2013 also celebrated 30 years of his annual ‘Texan Corneal and contact lens meeting’. The other award I wish to mention is Judith Morris, who was the BCLA Gold Medal Award winner in 2013. Judith has had many roles in her career and worked at Moorfields Eye Hospital, the Institute of Optometry and currently at City University. She has been the Europe Middle East and Africa President of IACLE (International Association of Contact Lens Educators) for many years and I think I am correct in saying that Judith is the only person who was President of both the BCLA (1983) and a few years later she was the President College of Optometrists (1989). Judith was also instrumental in introducing Vivien Freeman to the BCLA as they had been friends and Judith suggested that Vivien apply for an administrative job at the BCLA. Fast forward 29 years and in December 2013 Vivien stepped down as Secretary General of the BCLA. I would like to offer my own personal thanks to Vivien for her support of CLAE and of me over the years. The BCLA will not be the same and I wish you well in your future plans. But 2014 brings in a new position to the BCLA – Cheryl Donnelly has been given the new role of Chief Executive Officer. Cheryl was President of the BCLA in 2000 and has previously served on council. I look forward to working with Cheryl and envisage a bright future for the BCLA and CLAE. In this issue we have some great papers including some from authors who have not published with CLAE before. There is a nice paper on contact lens compliance in Nepal which brings home some familiar messages from an emerging market. A paper on how corneal curvature is affected by the use of hydrogel lenses is useful when advising patients how long they should leave their contact lenses out for to avoid seeing changes in refraction or curvature. This is useful information when refracting these patients or pre-laser surgery. There is a useful paper offering tips on fitting bitoric gas permeable lenses post corneal graft and a paper detailing surgery to implant piggyback multifocal intraocular lenses. One fact that I noted from the selection of papers in the current issue is where they were from. In this issue none of the corresponding authors are from the United Kingdom. There are two papers each from the United States, Spain and Iran, and one each from the Netherlands, Ireland, Republic of Korea, Australia and Hong Kong. This is an obvious reflection of the widening interest in CLAE and the BCLA and indicates the new research groups emerging in the field.

Optical quality and visual performance with customised soft contact lenses for keratoconus

Purpose: This study investigated how aberration-controlling, customised soft contact lenses corrected higher-order ocular aberrations and visual performance in keratoconic patients compared to other forms of refractive correction (spectacles and rigid gas-permeable lenses). Methods: Twenty-two patients (16 rigid gas-permeable contact lens wearers and six spectacle wearers) were fitted with standard toric soft lenses and customised lenses (designed to correct 3rd-order coma aberrations). In the rigid gas-permeable lens-wearing patients, ocular aberrations were measured without lenses, with the patient's habitual lenses and with the study lenses (Hartmann-Shack aberrometry). In the spectacle-wearing patients, ocular aberrations were measured both with and without the study lenses. LogMAR visual acuity (high-contrast and low-contrast) was evaluated with the patient wearing their habitual correction (of either spectacles or rigid gas-permeable contact lenses) and with the study lenses. Results: In the contact lens wearers, the habitual rigid gas-permeable lenses and customised lenses provided significant reductions in 3rd-order coma root-mean-square (RMS) error, 3rd-order RMS and higher-order RMS error (p ≤ 0.004). In the spectacle wearers, the standard toric lenses and customised lenses significantly reduced 3rd-order RMS and higher-order RMS errors (p ≤ 0.005). The spectacle wearers showed no significant differences in visual performance measured between their habitual spectacles and the study lenses. However, in the contact lens wearers, the habitual rigid gas-permeable lenses and standard toric lenses provided significantly better high-contrast acuities compared to the customised lenses (p ≤ 0.006). Conclusions: The customised lenses provided substantial reductions in ocular aberrations in these keratoconic patients; however, the poor visual performances achieved with these lenses are most likely to be due to small, on-eye lens decentrations. © 2014 The College of Optometrists.

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.