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Preterm birth and visual development.

Visual impairment, oculomotor abnormalities, and refractive error are prevalent among children with a history of preterm birth. These conditions may result from exposure of the immature visual system to early visual stimulation, from nutritional deficits that occur following the abrupt loss of placental maternal-to-fetal transfer of essential nutrients, and as secondary effects of systemic disease or complications associated with preterm birth. This chapter provides an overview of the structural and functional maturation of the visual system of the healthy preterm infant and of several forms of visual impairment that are prevalent in the low birth weight population.

Electroretinography↗

Age-related vision loss in the older adult: the role of the nurse practitioner in prevention and early detection.

Vision loss is a common problem in older adults and may result in functional impairment and accidental injury. The four most common causes of vision loss in this age group are age-related macular degeneration, cataracts, glaucoma, and diabetic retinopathy. The nurse practitioner has an important role in the prevention and early detection of these conditions. This article reviews scientific evidence on risk factors and preventative interventions for the causes of age-related vision loss. It also describes the important role of the nurse practitioner in assessment of eye health, so that conditions that may be damaging to vision may be detected early and monitored in the primary care setting.

Aged↗

The Pulfrich phenomenon in a large population of young healthy subjects.

BACKGROUND: To determine whether the Pulfrich phenomenon, an optical illusion occurring in many ophthalmological diseases, is perceived equally in both eyes in a large group of healthy medical students. SUBJECTS AND METHODS: A pendulum bob swinging perpendicular to the direction of observation was observed with either the right or the left eye covered with neutral density filters (50, 80 or 90 % absorption) and the apparent elliptical pendulum movement measured in depth. Interocular time delay was calculated from depth. Data from 65 individuals were included based on having: completed all 7 determinations of depth, a visual acuity of >/= 20/20 on both eyes and an intact stereoscopic perception (Titmus stereotest, acuity of >/= 20/25). RESULTS: All subjects perceived the phenomenon. Depth perception was not significantly different (p > 0.05; MANOVA) between the two eyes (depth in [mm]; mean +/- sem): OD: 8.5 +/- 0.38, 23.7 +/- 0.53, 36.3 +/- 0.81; OS 9.4 +/- 0.50, 24.1 +/- 0.69, 35.6 +/- 0.92; for 50, 80 and 90 % absorption of the filter respectively. At 0 % absorption the pendulum was seen in average at positive values (0.9 +/- 0.23 mm; p > 0.05). Calculated interocular time delay (ms) was: OD: 8.0 +/- 0.18, 5.1 +/- 0.12, 1.8 +/- 0.08; OS: 7.46 +/- 0.15, 5.0 +/- 0.11, 1.9 +/- 0.10. The average depth perceived without filter corresponded to a time delay for the right eye of 0.2 +/- 0.05 ms. Correction for the depth perception perceived without filter did not alter statistical significance. CONCLUSIONS: The Pulfrich phenomenon is perceived equally in both eyes. Depth perception without filters was not significantly different from zero. The illusion has clinical utility, since in normal subjects reliability of measurements is good and size of the illusion (without filters) small.

Adult↗

[Congenital ptosis: amblyogenic refractive errors, amblyopia, manifest strabismus and stereopsis related to the types of ptosis. Data on 77 patients and review of the literature].

BACKGROUND: Former reports on amblyogenic refractive errors, amblyopia and binocular vision in congenital ptosis usually comprise all forms of ptosis without any differentiation. This study is an analysis of different kinds of ptosis. PATIENTS AND METHODS: 154 eyes (98 ptotic eyes) of 77 patients with congenital ptosis aged > or = 1 year (56 unilateral ptoses: 45 simple, 1 with rectus superior paresis, 7 with Marcus Gunn's syndrome, 2 congenital oculomotor palsies, 1 unilateral fibrosis syndrome; 21 bilateral ptoses: 10 simple, 2 with bilateral double elevator paresis, 7 blepharophimosis syndromes and 2 bilateral fibrosis syndromes) were investigated concerning visual acuity, refractive error (94 % in cycloplegy), strabismus and stereo acuity. As amblyogenic refractive errors were defined: astigmatism > or = ldpt, anisometropia > or = 1 dpt (spherical equivalent) and hyperopia > or = 3 dpt; amblyopia was defined as visual acuity less than 1.0 or a difference between both eyes of at least 0.2. RESULTS: Altogether were found: Hyperopia > or = 3 dpt in 28.6 % (n = 28); astigmatism > or = 1 dpt in 63.3 % (n = 62), anisometropia in 27.3 % (n = 21), amblyopia in 65.3 % (n = 64), strabismus in 29.9 % (n = 23) and stereopsis in 76.6 % (n = 59). In unilateral simple ptosis, astigmatism of the fellow eye was found in 26.8 % (n = 14). In unilateral ptosis, esotropia was 21.4 % (n = 12), in bilateral ptosis, exotropia 19 % (n = 4), as well as astigmatism > or = 3 dpt 26.2 % (n = 11). As was to be expected, ptosis groups with motility disorders were associated with higher rates of strabismus and amblyopia. The blepharophimosis syndrome could be differentiated by the typical lid anomalies. CONCLUSION: The subgroups of congenital ptosis differ in frequency of amblyogenic factors. In unilateral ptosis these are also frequent in the fellow eye.

Adolescent↗

[The physical examination within the scope of The Child and Adolescent Health Survey].

The National Health Survey for Children and Adolescents intends a comprehensive description of the health status of children and adolescents. In this context physical examination of children and adolescents permits collection of objective data concerning physical development, certain body functions and selected performance parameters. Most important are indicators pointing towards increasing developmental and health problems in children and adolescents, which are partly predictive for the health status as an adult. Body measurements including stages of puberty will be taken, the blood pressure measured, vision tests carried out, coordination skills and endurance tested. Besides, if acute symptoms are detected, severity of atopic dermatitis is recorded. The methods and instruments have been tested in a pilot study over a period of one year and were optimised for the main study.

Adolescent↗

[Computerized perimetry in infants treated with ethambutol (author's transl)].

Computerized perimetry of the central visual field (Competer) was utilized in 12 eyes of children treated with Ethambutol because of tuberculosis to verify potential visual hazards of the drug. Visual acuity, visual field and the mean retinal threshold of the central field revealed no significant changes with increasing cumulative Ethambutol dose up to 166.5 g. The visual field was re-checked five times with a consecutive time lapse of 7 weeks. It can be concluded that the critical total dose of 150 g that is considered to be potential dangerous in adults does not affect the optic nerve of the infant either. Since this total dose can be exceeded in the continued treatment of the disease parents should be aware of the necessity of repeated visual field examinations or color vision testing. This concern is especially valid in infants suffering from renal tuberculosis because of higher plasma levels of the drug when excretion is prolonged.

Adolescent↗

[Preoperative assessment of intraocular lens corrected vision].

BACKGROUND: At present, preoperative estimation of the influence of intra-ocular lenses (IOL) on visual performance, that is not only based on visual acuity but on the whole contrast sensitivity function (CSF), is only possible with high efforts. METHODS: We describe a method to evaluate the CSF of a patient after IOL implantation. The method is based on the knowledge of a normal subject's CSF, and the modulation transfer function of the IOL that can be measured or computed. RESULTS AND DISCUSSION: Comparison of computed and measured CSF with monofocal and multifocal IOL shows that the method allows prediction of visual performance after implantation of the IOL.

Contrast Sensitivity↗

[Contrast enhancement in the public environment--improvement in orienting capacity of visually handicapped patients].

BACKGROUND: Partially sighted often experience problems in orientation in public areas. Individual visual aids can only be used with limitations. Improving light intensity and colour contrasts of timetables, information signs, direction symbols, etc. can provide remedies. Experimentally substantiated directives do not yet exist. PATIENTS AND METHODS: Experiments were conducted in 231 partially sighted subjects (binocular vision < 0.3) diagnosed as experiencing dullness when watching the media, having maculopathies, glaucomas, or dystrophic alterations of the retina or choroid, and in 43 normal subjects to determine the subjective assessment of colour and light-intensity contrasts. The presented contrast patterns were Hartmann-characters as infield (3.3 degrees) with a rectangular surround (19.5 degrees x 14.3 degrees). Three experimental series were carried out in which subjects assigned 14 non-coloured/non-coloured contrasts, 35 non-coloured/colour contrasts and 30 colour/colour contrasts to any of the five assessment classes of extremely poor, poor, optimal, sharp, extremely sharp. The colour contrasts consisted of combinations of yellow, green, red, purple, blue, and non-coloured. RESULTS: For non-coloured/non-coloured, the subjects preferred positive contrasts (bright infield, dark surround). Preferred contrast levels were 0.91 to 0.99 for positive contrasts and -0.96 to -0.99 for negative contrasts. For colour/non-coloured contrasts, 90% of the partially sighted preferred yellow as the foreground colour with a contrast level above 0.89. For colour/colour contrasts, optimal assessments of 90% of all partially sighted were yellow/purple and yellow/blue with contrast levels above 0.90. The determined results are applicable for the exact experimental contrast settings only. A field manual was prepared for planning and design of contrasts suited for the partially sighted in public areas. CONCLUSIONS: Partially sighted, in subjective contrasts assessment, prefer bright characters of signs on a dark background for both non-coloured and colour contrasts with contrast levels above 0.9. Yellow was the preferred infield colour.

Adolescent↗

[Changes in subjective cyclodeviation and objective cycloposition after modified Harada-Ito operation in acquired trochlear paralysis].

BACKGROUND: After recently published own investigations on subjective and objective cyclorotatory changes following inferior oblique recession for inferior oblique overaction, it was our aim to determine and to compare subjective and objective cyclorotatory changes following a modified Harada-Ito procedure for acquired trochlear palsy. PATIENTS AND METHODS: Eight patients suffering from acquired uni-(n = 3) or bilateral (n = 5) trochlear palsy were investigated before surgery and 1 day, 3 days and 4 months after surgery. Subjective cyclodeviation was assessed by Harms' tangent scale. Objective cycloposition was measured by means of fundus cyclometry using an infrared Scanning Laser Ophthalmoscope. RESULTS: The immediate postoperative incyclorotatory effect was 12 degrees in the unilateral group and 18 degrees in the bilateral group. Subjective and objective changes were nearly equal in both groups, with a subjective over-effect of 1 degree. After two days of binocular stimulation a marked regression of the surgical effect was found which still increased after four months. The long term incyclorotatory effect was subjectively and objectively nearly equal in the unilateral group which showed a relaps of subjective excyclodeviation of 5 degrees: in the bilateral group, the subjective effect was more pronounced than the objective effect, the immediate postoperative over-effect being disappeared. CONCLUSIONS: In contrast to our results concerning inferior oblique muscle recession for strabismus sursoadductorius, subjective and objective cyclorotatory changes did not differ grossly following a modified Harada-Ito procedure. Subjective and objective short and long term regression was confirmed which objectively exceeded the amount of over-correction. As the underlying cause mechanical and sensory mechanisms are discussed.

Adult↗

[Comparison of five methods for subjective assessment of ocular cyclodeviation].

METHODS: 1. simple Maddox rod (Franceschetti) 2. set of scaled large diameter Maddox rods 3. synoptophore 4. synoptometer (Cüppers) 5. dark red glass in front of the Harms tangent scale (Kolling). Whereas the first two methods allow to measure in primary position only, the other three also permit secondary and tertiary position measurements. Thirty normal subjects underwent comparative measurements by means of the above techniques in monocular and binocular condition. The median values indicate that all these methods are reliable but that certain specific differences influence the results. For this reason, pre- and postoperative measurements of ocular torsion should always be performed by the same method. The most appropriate techniques have shown to be: the set of scaled Maddox rods for measurements in primary position only, the dark red glass in front of the Harms tangent screen for measuring also in secondary and tertiary positions.

Convergence, Ocular↗

[Results of full binocular correction versus conventional methods].

UNLABELLED: 163 patients suffering from different serious troubles were treated with binocular full correction (BFC) i.e. examination by Polatest and prismatic correction. Before, they all had seen other ophthalmologists. The former diagnose and therapy are listed and compared with those of the author. RESULTS: After a 2 2/3 years average follow-up period 68% of the patients were complaintless, 23% felt better. All patients reached at least binocular single vision, although initially 13% had no binocular vision and 1% complained about diplopia. 70% got ideal binocular vision (initially 0%). In the beginning 50 patients suffered from reduced visual acuity. It improved in all cases with differences of v.a. from 2-4/10 to 10/10. From the shown results the author concludes that conventional binocular diagnostic and therapeutic methods do no longer meet the state of the art. It is postulated that BFC should be accepted by school-medicine and that ophthalmologists and orthoptists should be trained in BFC. Only in this way ophthalmologists may fulfil their task to free patients from the many complaints caused by binocular troubles. The used terminology about BFC is explained in the appendix.

Adolescent↗

[Vertical accommodative vergence].

Five patients showed vertical accommodative vergence during which the strabismic eye deviated either up- or downwards. Additional components of strabismus included intermittent or constant exotropia, dissociated vertical divergence, and various incomitancies. There were no signs of misdirected regeneration after oculomotor palsy. We interpret vertical accommodative vergence as a supranuclear abnormality, most likely congenital.

Adult↗

[Visual evoked potentials, contrast sensitivity and color perception in patients with optic nerve neuritis and multiple sclerosis].

Forty-nine patients with acute optic neuritis (in 21 cases associated with MS) and 26 patients known to have MS but with no history of optic nerve disease underwent visual evoked potential, contrast sensitivity and color vision tests. In patients with optic neuritis the contrast sensitivity was shown to detect optic nerve lesions better than the VEP an often permitted a distinction between acute and past optic neuritis. Combined testing with contrast sensitivity and VEP was superior to the single tests and detected 100% of the acute optic nerve lesions, although in many cases damage was selective and only involved some of the information channels. Desaturated color tests were abnormal in 3/4 of the patients, disturbances of blue-yellow discrimination being commoner than those of red-green. In cases with clinically unilateral optic neuritis the apparently normal partner eye was affected in 61% of the patients; complete recovery of optic nerve function without some residual deficit is rare. Approximately 3/4 of the eyes of patients known to have MS but with no history of past visual disturbances showed bilateral optic nerve involvement. The frequency of subclinical optic nerve lesions rose to 91% at a follow-up examination one year later. the literature is reviewed and our results are compared with the previously published data.

Adolescent↗

The Gollin incomplete figures test: a flexible, computerised version.

The Gollin incomplete figures test has been used as a measure of visual development, as a clinical test for parietal cortex dysfunction, and to examine long-term memory in amnesic patients. It has traditionally been administered by using a series of three or five stimulus cards, successive cards containing progressively more information. A study is reported in which digitised outline drawings of familiar objects were presented via a computer, the percentage of the figure on the screen slowly increasing from 0 to 100. The original findings of Gollin were successfully replicated; children's performance on the task improved markedly over the age range 2-5 years, and performance improved dramatically over three tests in all subjects. Computerisation of the Gollin task provides a precise and versatile alternative to the original card version.

Child Development↗

The minimum temporal thresholds for motion detection of grating patterns.

The minimum temporal thresholds for absolute motion detection were measured for sinusoidal grating patterns in foveal vision. Test patterns of relatively low temporal frequencies and low velocities were examined. The thresholds clearly decreased with test velocities rather than with test temporal frequencies. Modified velocity-time reciprocity was observed (i.e. the relationship between test velocity and temporal thresholds was described by a simple equation including two constants which indicate temporal and spatial limits). The temporal constant was about 35 ms and the spatial constant was about 1 min of arc. These constants are thought to provide the basic constraints on motion detection.

Humans↗

Associations of performance-based and self-reported measures of visual function. The Beaver Dam Eye Study.

OBJECTIVE: To describe and compare performance-based and self-reported measures of visual function and to evaluate how each varied with age and how the performance-based measures were associated with the responses to self-reported questions about visual function. DESIGN: Population-based epidemiologic study. PARTICIPANTS: Adults participating in the first follow-up of the Beaver Dam Eye Study (n = 3,722). MAIN OUTCOME MEASURES: Performance-based measures of vision including current binocular, best-corrected and near visual acuities, sensitivity to light as measured by an automated perimeter, contrast sensitivity, and self-reported measures from a standardized interview. RESULTS: All performance-based and self-reported visual functions decreased with increasing age (p < 0.0001 for each). On average, women did more poorly than men on all the performance-based measures (p < 0.0001 for each), and on some of the self-reported measures. For both genders, correlations among the performance-based measures ranged from 0.38 to 0.67. In general, individuals reporting good visual function or little difficulty with visual tasks scored better on performance-based measures compared to individuals whose questionnaire responses reflected limited visual function. Overall, about 39% of drivers reported that their vision caused them to limit their night driving. Correlations of performance-based with self-reported measures of visual function were greater for best-corrected, binocular and near visual acuity compared to correlations of visual sensitivity to light and contrast sensitivity. There were 1,285 persons whose best-corrected acuity was better than their current binocular acuity and there were 97 people with visual impairment considering only current binocular acuity whose vision improved to better than 20/40 after refraction. CONCLUSIONS: Performance-based and self-reported measures of visual function were consistently and inversely related to age. Performance-based measures were, in general, more highly correlated between themselves than were self-reported measures. Self-reported visual functions were significantly positively correlated with all performance-based measures, but correlations were moderate. While high contrast measures are usually used in clinical settings and in many studies, the data suggest that in assessing function it is appropriate to measure several different aspects of vision, both performance-based and self-assessed. Our data give some indication of the impact these visual functions have on daily life as reflected by night driving and on near and distant visual acuity. New refractive corrections would likely improve the visual acuity in many older adults.

Adult↗