Near Vision Research Articles

Body mass index, lifestyles, physical performance and cognitive decline: the "Treviso Longeva (TRELONG)" study.

The relative contributions of risk factors, as body mass index (BMI), depression, chronic diseases, smoking, and lifestyles (as physical and performance activity, social contacts and reading habit) to cognitive decline in the elderly are unclear. We explored these variables in relation to 7-year cognitive decline in long-lived Italian elderly. Secondary data analysis of a longitudinal study of a representative, age-stratified, population sample. The TREVISO LONGEVA (TRELONG) Study, in Treviso, Italy. 120 men and 189 women, age 77 years and older (mean age 80.2 ± 6.9 years) survivors after seven years of follow up. Cognitive decline measured as difference between Mini-Mental State Examination (MMSE) score in 2003 and in 2010; Body mass index (BMI), handgrip, Short Physical Performance Battery (SPPB) score, social contacts, reading habit, sight, hearing, schooling, mediterranean diet and multiple clinical and survey data recorded at baseline in 2003. In separate univariate analyses, age, SPPB score < 5, depressive symptoms (GDS) and more comorbidities (CCI) were associated with greater cognitive decline. Otherwise higher BMI, higher handgrip, reading habit, non-deteriorated sight and hearing, and schooling were protective. In a final multivariate model, age and higher BMI were associated with greater cognitive decline while reading habits was protective. SPPB score < 5 tends, though weakly, to be associated with greater cognitive decline. These associations remained with multivariate adjustment for gender, schooling, Charlson co-morbidity index (CCI) and baseline MMSE. Age and higher baseline BMI, independent of gender, and other confounding factors, are risk factors for cognitive decline. Reading habit plays a protective role seven years later among northern Italian adults aged 70 years or older. Low physical performance tends, though weakly, to be associated with greater cognitive decline.

Shedding light on night myopia

First described during the 18th century, the cause of night myopia remains a controversial topic. Whereas several explanations have been suggested in the literature, particularly related with accommodation or chromatic shift in scotopic light conditions, no definitive explanation for its aetiology has been provided. We describe an experiment in which ocular refractive state was objectively and subjectively measured while viewing two kind of stimulus: letters on a bright background and a punctual source of light in a dark background. We found that under photopic conditions the optimum refractive state of the accommodating eye is significantly more myopic when maximizing perceived quality of a point source on a dark background compared to a conventional letter chart with black letters on a white background. Optical modeling suggested this difference in refractive state is due to spherical aberration. Since isolated point sources are more likely encountered at night, whereas extended objects are more likely encountered in the daytime, our results suggest that a significant part of the night myopia phenomenon is determined by the nature of the visual stimulus and the visual task used to assess ocular refractive state.

Sine wave mesopic contrast sensitivity – defining the normal range in a young population

Limited information is available regarding the normal range of mesopic sine wave contrast sensitivity (CS). The aim of this study was therefore to define a reference range and in addition to identify factors related to mesopic CS in a young population. Individuals with normal visual acuity (VA) were included from a population of air crew members visiting the Institute of Aviation Medicine for routine medical examinations. CS was measured using the Optec 6500/FACT and evaluated by (i) the CS curve with five frequencies and (ii) the index of contrast sensitivity (ICS). ICS was defined as the sum of the weighted differences from the median CS value for each frequency. Multivariate analyses were performed to identify factors related to CS. In a total of 197 subjects included, the mean mesopic CS score was significantly lower compared to the corresponding photopic measurements for all five frequencies tested. Median CS score for frequencies 1.5, 3, 6, 12 and 18 cycles per degree was 50, 114, 180, 60 and 33 for photopic and 71, 80, 90, 22 and 12 for mesopic (- glare) conditions, respectively. Better binocular VA was positively associated, while the use of corrective lenses was negatively associated with CS performance. We have provided reference values for mesopic CS and identified factors important for CS. The difference between mesopic and photopic measurements highlights the need for separate population norms. The new ICS score may be a useful collective descriptor of the traditional CS curve with five frequencies.

How an analysis of reviewers' reports can enhance the quality of submissions to a journal of education

Not only has the number of scholarly journals worldwide increased substantially in recent years but also the number of articles published in them. However, closer examination reveals that the percentage of articles actually published has remained in the region of 25%. This implies that much of researchers’ time and energy has been wasted because of failure to have their research findings published. This has been occurring despite the availability of a surfeit of publications on the theme of ‘How to write and publish a scientific article’. Analysis of the process of article writing and publishing reveals that it consists of four phases: writing and submitting an article, processes followed by the editor, actual review process by the reviewers, and how authors deal with the feedback. A literature survey shows that the last phase has not been discussed in the same detail as the other three. The authors contend that if prospective authors gave greater attention to this phase and learned from the findings outlined in this article, it would lead to an improvement in the quality of future submissions to a journal, of education in this particular case. ‘We have read your manuscript with boundless delight. If we are to publish your paper, it would be impossible for us to publish any work of lower standard. And, as it is unthinkable that, in the next thousand years, we shall see its equal, we are, to our regret, compelled to return your divine composition, and to beg you a thousand times to overlook our short sight and timidity.’ Reputedly a rejection slip from a Chinese economics journal (Day, 1983:90).

Familial Patterns and Biological Markers of Dyslexia

Dyslexia is one of the most common learning disability. Though dyslexia is a major educational problem, studies on biological aspects of dyslexia are very limited in India. Here we report prevalence, inheritance patterns and biological markers of dyslexia in 179 selected families from South India. Families were ascertained through probands attending special schools for dyslexic students as well as from regular schools from Karnataka state, South India. Prevalence and types of inheritance patterns were recorded. A questionnaire concerning allergies, asthma, arthritis, migraine etc. was used to assess the prevalence of immune disorders. Occurrence of chicken pox, measles, mumps, delayed milestones, birth complications, motor coordination problems, short sight and left handedness, fatty acid deficiency signs were recorded in the dyslexic probands. Among school children, prevalence of dyslexia is found to be 9.87% and in the selected families the prevalence is 28.32%. Based on the affectedness, dyslexia phenotypes were classified as severe and mild deficits. Mild deficits were better compensated than the severe deficits. Among the selected families autosomal dominant mode of inheritance was found to be more prevalent. Consanguinity plays a major role in familial aggregation of dyslexia. Allergy, migraine, delayed milestones, low level of blood cholesterol and certain fatty acid deficiency signs were found to be associated with dyslexia. Since complex array of symptoms are associated with dyslexia an integrated research approach is needed for effective diagnosis and remediation of dyslexia.

Stereoacuity before and after operation of parks shift of neutral zone in congenital nystagmus combined with paralytic strabismus in modified Kestenbaum

Objective To evaluate thestereoacuity before and after operation of Parks shift of neutral zone in congenital nystagmus combined with paralytic strabismus. Methods Using stereograms and near stereo-acuity chart, preoperative measurement of distance and near stereoacuity in primary gaze position and neutral zone were qualitatively and quantitatively determined in 27 congenital nystagmus combined with paralytic stra-bismus. After parks shift of neutral zone, streroacuity measurement was evaluated by the similar method. The grade of stereoacuity before and after operation was analyzed Rusults Nystagmus was disappeared or obviously re-lieved in the primary gaze position, vision was improved 2-5 lines, and compensatory head posture was eliminated or improved after operation in 27 cases. The stereoacuity was gradually improved from 800 to 60 seconds of arc, peripheral to macular stereoacuity, and even foveal stereoacuity. Conclusion Congenital nystagmus combined with paralytic strabismus may partly have stereoscopic vision. The stereoscopic vision in neutral zone may be bet-ter than in non-neutral zone. The nystagmus, compensatory head posture, and distance and near stereoscopic vi-sion were improved after operation of Parks shift of neutral zone. Key words: Congenital nystagmus; Paralytic strabismus; Stereoacuity

Relationship between night myopia and night‐time motor vehicle accidents

To investigate the relationship between night myopia and the occurrence of night-time motor vehicle accidents in a group of professional drivers. We examined 136 professional drivers. Refraction was determined in full illumination (100 cd/m2) and after sitting in darkness for 5 mins. The change in refraction, indicative of night myopia, was correlated with the number of motor vehicle accidents in which each driver was involved (detailed in their personal files) and with the results of a visual complaints questionnaire. The mean age of the study group was 21.0 years. Mean spherical refraction changed from + 0.11 dioptres (D) in light to -0.17 D after dark adaptation for 5 mins. Night myopia was found in 34 drivers (25%), at a mean of -1.2 D (range -0.75 D to -3.50 D). There was no statistically significant difference between these drivers and the rest of the group in the results of the visual complaints questionnaire, or in the number of accidents occurring during the day. However, drivers with a myopic shift > 0.75 D were involved in more accidents at night than the rest of the group (p = 0.044). In this study population, drivers with night myopia of > 0.75 D were more likely to be involved in night-time accidents. This may imply that selected groups of drivers should be examined for night myopia.

Keratorefractive approaches to achieving pseudoaccommodation.

Although presbyopia is ostensibly an age-related disease of the lens, ciliary body, and zonular apparatus, surgeons have nonetheless persevered in their attempts to create a solution to the problem of diminished near vision by performing keratorefractive procedures. This article discusses two approaches of varying technological sophistication, beginning with surgically induced astigmatism and continuing through enhanced monovision. Sometimes simple solutions are the best, and the technological innovation in cataract and refractive surgery has met with unrivalled success in the last three decades.

Il capolavoro del Boccaccio e due diverse redazioni by Maurizio Vitale , Vittore Branca (review)

518 Reviews the brochures that come with a new PC. This latest single-volume survey, a confident three-hander, swims bravely against the tide. It stands up for permanence, the craft of writing, and the pleasures of reading. Despite preliminary hesitations, the tradi? tional canon suffersonly minor adjustments and the implications of the remark that in the communication of personal experience the balance of power has now 'shifted decisively from literature to film' (p. 311) are left hanging tantalizingly. Anxieties about the usefulness of the division by centuries are also quickly resolved by the adoption of the tripartite structure which Caesar once applied to ancient Gaul. One concern?'the masculine bias of literaryculture' (p. 26)?is identified at an early stage and kept sternly at bay throughout, firstin the Middle Ages (to 1470), then during the early modern period (1470-1789), and finally the modern era (1789-2000). Each section is prefaced by a summary of the period's main features before the forward thrust, halted at intervals by sketches and vignettes of major topics and writers, is resumed. Of course, authors of histories of literature invariably sin by omission and commission, and have short sight and hidden agendas. Bricks are certainly dropped here?what is said on p. 214 about Restif and his 'zany charm' is not arguable, just wrong?but grounds for such quibbles are remarkably rare. It is, however, disconcerting to findsuch sparse coverage of critical theory,which was deliberately omitted. It is also a disappointment that the story after about 1970 falters and that, despite its newly proclaimed significance, just three brief paragraphs are given to the whole of cinema as against the three splendid pages on Valery. Denying any suggestion that French literature 'has been in retreat in the later years of the French Republic' (p. 312), this welcome volume sets its face against the values of popular culture and offersa sturdy defence and illustration of quality writing in all the traditional genres. Leeds David Coward //capolavoro del Boccaccio e due diverse redazioni. By Maurizio Vitale and Vittore Branca. (Memorie dell' Istituto Veneto di Scienze, Lettere ed Arti, Classe di scienze morali, lettere ed arti, ioo) Venice: Istituto Veneto. 2002. 2 vols: ix + 571 pp.; 220 pp. ?60 (the set). ISBN 88-88143-13-0. In two volumes, Maurizio Vitale and the late Vittore Branca each set out to analyse the relationship between two differentredactions of Boccaccio's Decameron; in the first volume, La riscrittura del 'Decameron': i mutamenti linguistici, Vitale examines the two texts from a historical-linguistic perspective, while in the shorter second volume, Variazionistilistichee narrative, Branca considers the narrative and stylisticvariations that characterize the two redactions. Both volumes, therefore, take as their starting point the proposal, firstmooted by Branca in the early 1980s, that a non-autograph manuscript known as P (Paris, Bibliotheque Nationale, MS Ital. 482) is witness to a redaction ofthe Decameron dating fromc. 1349-5 2. This redaction was compiled some twenty years earlier than the redaction conserved in the autograph B (Berlin, StaatsbibliothekPreu6ischerKulturbesitz ,MS Hamilton 90), which is dated toc. 1370-72, and which Branca was also instrumental in authenticating. Since his hypothesis was first raised, Branca has published further evidence in support of his claim, which remains, as yet, unchallenged. These two volumes are the latest contributions to the ongoing process of reconstructing the textual tradition of the Decameron. In the firstvolume Vitale carries out a lengthy and extremely detailed analysis of the grammatical parts of the variants between P and B, using other vernacular works by Boccaccio in both prose and verse as points of comparison, as well as almost sixty thirteenth- and fourteenth-century vernacular texts by other authors, including Dante and Petrarch. Although the selection of texts is impressive and the 'Tavola MLR, 100.2, 2005 519 degli auctores citati' placed towards the beginning of the volume usefully includes references to electronic repositories of texts where appropriate, the number of au? tograph manuscripts is necessarily limited and Vitale does not indicate his selection criteria for non-Boccaccian texts. The results of this dense evaluation lead Vitale to anticipate his conclusion in the introduction ('I preliminari') that 'tale studio non solo ha confortato [.. .] dal punto...

Modeling Accident Occurrence at Signalized Tee Intersections with Special Emphasis on Excess Zeros

In implementing effective remedial treatments at hazardous intersections, it often is necessary to identify the geometric and traffic factors that lead to accident occurrence. However, one particular problem frequently encountered in accident studies is how to distinguish virtually safe intersections with little likelihood of accident occurrence from those that have happened to have no accident due to the random process. To deal with this problem, the "excess" records of zero accident, the zero-inflated negative binomial was used to assign the probability to the accident outcome. Accident data at 104 signalized tee intersections in Singapore over a period of 9 years were employed for model development. The model indicates that uncontrolled left-turn slip road, permissive right-turn phase, existence of a horizontal curve, short sight distances, large number of signal phases, total approach volume, and left-turn volume may increase accident occurrence. On the other hand, right-turn channelization, acceleration section on the left-turn lane, median railings, and more than 5% approach gradient may reduce accident occurrence. Moreover, there is a trend of reducing accidents over the years.

Does accommodation inaccuracy matter in children with Down syndrome?

Purpose: Almost 57% of children with Down syndrome have significant refractive error (hypermetropia ≥+3.00 D, myopia ≥−1.00 D) (Woodhouse et al., 1997); they are 17 times more likely to have significant long or short sight than their typically developing peers. Also, for the age range 4.5 months to 11.1 years, 34% of children with Down syndrome have strabismus, compared with 4–7.5% of control children (British College of Optometrists, 1991–94). In addition, 82% of our cohort of children with Down syndrome (n = 100) have reduced accommodation at near. In order to investigate the influence of accommodation accuracy on refractive error and strabismus, this study compared the above parameters in children with Down syndrome who accommodated accurately with those who did not.Methods: Accommodation was measured using dynamic retinoscopy technique at testing distances of 25, 16.6 and 10 cm. An accommodative lag of plano to 0.75 D is normal for typically developing children (Rouse et al., 1984). Accurate accommodation for our cohort was therefore defined as ≤0.75 D lag of accommodation (at a minimum of two of three testing distances). Children with Down syndrome who accommodated accurately were age matched with a child with inaccurate accommodation, based on their most recent visit for which a full data set was available.Results: Chi‐square analysis of the data for the two groups revealed that there was a greater number of children with significant hypermetropia (p = 0.003) and strabismus (p = 0.003, Fisher's exact test) in the under‐accommodating group.Conclusion: Children with Down syndrome who under‐accommodate are more likely to be strabismic and have significant hypermetropia.

Simulation of Night Myopia in Pseudophakic Eyes

Purpose: Eyes with an intraocular lens (IOL) implanted that have no accommodative ability are likely to have night myopia caused by Purkinje's shift and chromatic aberration. We evaluated the changes in retinal images caused by night myopia in various IOL-implanted eyes by simulation using model eyes. Methods: A polymethylmethacrylate (PMMA) IOL, soft acrylic IOLs, and high-refractive-index silicone IOLs were prepared, and inserted into the model eye. The image plane of the model eye was determined as the line image at which a slit light of 560 nm was best focused, which was regarded as emmetropic condition under photopic vision. A slit light of 505 nm was then directed into the model eye. Its line image on the image plane was blurred, which was regarded as myopic condition under scotopic vision. Under each condition. The modulation transfer functions (MTF) were calculated and the line images were photographed. Results: The degree of reduction of MTF and blurring of the line image under the night myopic condition was in the order of PMMA<soft acrylic<high refractive index silicone IOL. Conclusion: Eyes with a soft acrylic or high-refractive-index silicone IOL may have more intense night myopia caused by chromatic aberration.

Accommodation and acuity under night-driving illumination levels

Laboratory experiments are described in which the monocular changes in the refractive error and acuity of six young, normal, adult subjects were measured as the field luminance was reduced from approximately 100 to 10(-3) cd/m2. It was found that, at luminance levels equal to those recommended for road lighting (about 1 cd/m2), acuity fell from its photopic value of > or = 6/6 to about 6/9, with little change in the measured refraction. Marked changes in refraction, i.e. night myopia, only started to become manifest when the luminance was further reduced to below about 0.03 cd/m2, much less than that applying under normal night-driving conditions. Direct experiments under street-lighting conditions confirmed the absence of any significant night myopia. It is concluded, therefore, that neural changes, rather than night myopia, normally are responsible for the acuity loss suffered by drivers at night.

Night myopia and driving

Current knowledge of the refractive shifts (twilight myopia, night myopia, dark focus) that occur as the luminance is progressively lowered from photopic levels is reviewed. In complete darkness, myopic changes of the order of 1 dioptre are typical in young adult subjects. These gradually diminish as presbyopia is approached. The possible role of these refractive changes in causing visual difficulties for young drivers on the road at night is considered. It is concluded that high mesopic levels (about 1 cd/m2) of road luminance produced by street and vehicle lighting are normally too great to allow significant refractive shifts to occur, although acuity will be reduced due to light-dependent neural changes. Under these circumstances it appears unlikely that specific night-driving prescriptions will be beneficial: the accurate correction of normal refractive errors is, however, more important during night than day driving due to the greater blur associated with the larger night-time pupil. Suggestions are made for further experimental work in this area.

Night myopia and driving

Current knowledge of the refractive shifts (twilight myopia, night myopia, dark focus) that occur as the luminance is progressively lowered from photopic levels is reviewed. In complete darkness, myopic changes of the order of 1 dioptre are typical in young adult subjects. These gradually diminish as presbyopia is approached. The possible role of these refractive changes in causing visual difficulties for young drivers on the road at night is considered. It is concluded that high mesopic levels (about 1 cd/m2) of road luminance produced by street and vehicle lighting are normally too great to allow significant refractive shifts to occur, although acuity will be reduced due to light-dependent neural changes. Under these circumstances it appears unlikely that specific night-driving prescriptions will be beneficial: the accurate correction of normal refractive errors is, however, more important during night than day driving due to the greater blur associated with the larger night-time pupil. Suggestions are made for further experimental work in this area.

The symbiosis between basic and applied research.

To illustrate the interdependence between the solution of practical problems and the search for fundamental mechanisms, their relationship within the contexts of the history of night myopia and the problem of nighttime traffic accidents is discussed. Night myopia, or nearsightedness at night, which has been a problem since the late 18th century, was shown to be the result of a recently discovered oculomotor mechanism, the intermediate resting position of accommodation. With this knowledge, the handicap of nearsightedness at night ( a major problem in nighttime viewing such as driving and military operations) is readily amenable to solution. Recent developments in our knowledge of the functional significance of the nervous system has led to an increased understanding of the cause and to amelioration of nighttime traffic accidents. These developments illustrate the symbiotic relationship between basic and applied research and the benefits to be gained by consideration of both objectives.

A REJECTION SLIP WITH CLASS

"We have read your manuscript with boundless delight. If we were to publish your paper it would be impossible for us to publish any work of a lower standard. As it is unthinkable that, in the next thousand years, we shall see its equal, we are, to our regret, compelled to return your divine composition, and to beg you a thousand times to overlook our short sight and timidity."

Education, reading, and familial tendency as risk factors for myopia in Hong Kong fishermen.

The aim was to assess the influence of childhood reading on the development of myopia after allowance for familial differences in susceptibility. The study was a cross sectional survey. Four fishing harbours in Hong Kong in 1989. Participants were 408 men and women aged 15-39 years old from 159 families. Histories of school attendance and reading habits in childhood were obtained at interview. Myopia was assessed by retinoscopy. Associations between myopia (defined as a refractive error of at least -1.0D in one or both eyes) and indices of reading in childhood were explored. Myopia was more common in subjects who had attended school (odds ratio = 1.7, 95% CI 1.0-3.0), with the highest risks in those who had started school at the earliest ages and who had spent the most time reading and writing while at primary school. Allowance for familial tendency to myopia produced no diminution in the risks associated with reading. These data support the hypothesis that reading in childhood is a cause of short sight.

Correction: surgery for short sight? photorefractive keratectomy (19 August, page 65)

The depth of ablation with each laser application should be 0.25μm not 0.25mm which was a misprint.

Surgery for short sight?

People with short sight may learn of surgical procedures which enable them to see clearly without spectacles or contact lenses, often from articles in the press. These may present a somewhat rosy view of the subject; complications can follow any surgical procedure and surgery for myopia is no exception. The potential demand for such surgery is huge; about 5% of people in Britain have myopia in the range from −2 to −8 dioptres. Two procedures are used to correct myopia in these patients: radial keratotomy and laser photorefractive keratectomy.