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At least 19 recordsLinked to original sources
PubMed1979

A laser retinoscope.

A retinoscope that uses a He-Ne laser as its light source has been designed. By this means it is possible to improve the performance of the conventional retinoscope. In particular the contrast of the fundus reflex has been enhanced and the retinoscope can be used at a greater working distance than usual. By using a polarized laser the specular reflections from the eye are completely suppressed. The retinoscope lends itself to refractions under normal room illumination. Patients find the light from the laser retinoscope less bothersome than that of the usual tungsten filament lamp. Advantages and disadvantages of the unit are discussed.

Helium↗
PubMedDate not supplied

An ophthalmoscope is not a retinoscope. The difference is in the red reflex.

Both the retinoscope and the ophthalmoscope allow observation of the fundus and of the "red reflex." Retinoscopy, however, requires an effective light source that may be quickly moved off the visual axis. The ophthalmoscope is unable to provide this type of illumination. On the other hand, the retinoscope is unable to provide sufficient illumination of the retina to make it useful for ophthalmoscopy . Ophthalmoscopy requires the examiner's retina to be conjugate to the retina being examined, whereas the examiner's retina becomes conjugate to the peephole of the retinoscope in retinoscopy. The "red reflex" seen with either the retinoscope or the ophthalmoscope may be clear or blurred. The clear red reflex is more useful for ophthalmoscopy , while the blurred red reflex is primarily used for retinoscopy.

Humans↗
PubMedDate not supplied

Does a tilted retina cause astigmatism? The ocular imagery and the retinoscopic reflex resulting from a tilted retina.

An astigmatic dial viewed by a tilted retina will have only one line in focus, simulating astigmatic blur. We compare and contrast this optical situation to actual astigmatism. Photographs were taken of an astigmatic dial blurred with a cylindrical lens, and also of the same astigmatic dial tilted, simulating tilted retinal imagery. A model eye for retinoscopy practice was provided with a retina tilted 30 degrees and was retinoscoped repeatedly with and without added confounding cylinder by five skilled retinoscopists. Photographs of the astigmatically blurred and tilted astigmatic dials were similar but not identical, as expected. The model eye with tilted retina showed no astigmatism by retinoscopy in 14/15 measurements and 0.25 D of astigmatism in one measurement. When confounding cylinder was present, the retinoscopic measurement was always within 0.25 D of the added cylinder. The ocular imagery resulting from a tilted retina can simulate astigmatic blur, but this is actually due to a type of curvature of field. Only a minute area of the tilted retina is viewed during retinoscopy, so the tilt has essentially no influence on the retinoscopic reflex.

Adult↗
PubMed1987

Television retinoscopy with a slit-aperture retinoscope and a highly sensitive camera.

The low light level of the retinoscopic reflex and the small aperture required to obtain the customary shape of the reflex make it difficult to photograph the actual reflex for teaching or permanent recording. We describe the design and application of a television retinoscopy system that solves this problem. The system uses a standard streak retinoscope modified to gather more light, a highly sensitive television camera, and an image processor. The system can be used for live demonstration of retinoscopic techniques or for videotape recordings for teaching or research.

Equipment Design↗
PubMed1988

Simple retinoscopic screening.

A simplified retinoscopic technique to screen for refractive errors in children is presented. The technique described was assessed in 98 children and the results correlated with full retinoscopic refractions. All tests were done with cycloplegia. Orthoptists' results using the simple retinoscopy compared well with the full retinoscopic findings of the ophthalmologists, with an overall sensitivity of 90% and specificity of 74%. These results compare favourably with more technical refractive screening methods. This technique may be suitable as an adjunct to vision screening in pre-school children.

Child↗
PubMed1992

[Further development of a streak retinoscope with calibrated collimator].

Development and rationale of a new streak retinoscope have been discussed in an earlier paper. In contrast to classical retinoscopy this retinoscope determines the refraction by forming the narrowest streak in the test person's pupil with a calibrated collimator. In addition to the first prototype the extension of the lamp according to variation of the refraction is measured electronically and the data are transposed into a computer. This allows to freely choose a working distance in a range from about 30 to 120 cm and therefore it is possible to examine restless patients. Accuracy of the measurement was less than or equal to 0.25 D for Ametropia from -0.5 to 5.0 D in a working distance of 30 cm or from -4.0 to -1.5 D in 100 cm. In most persons it is not necessary to use additional glasses during refraction by choosing the adequate distance. Therefore this method can help to refract kids and other persons which could not be refracted by use of glasses. In addition this method excludes the accommodation of the patient as apposed to regular refractometers.

Calibration↗
PubMed1978

The discrepancy between retinoscopic and subjective measurements: Effect of age.

Comparison of the retinoscopic and subjective measurements of 1078 eyes of all ages showed that the discrepancy (retinoscopy--subjective) was positive and equal to 0.3--0.4 D in young eyes. The discrepancy diminished with age, eventually becoming negative in the 6th decade of life. The results are explained by postulating that retinoscopic light is reflected from the internal limiting membrane in young eyes and from a layer posterior to the photoreceptors in older eyes.

Accommodation, Ocular↗
PubMed1978

The discrepancy between retinoscopic and subjective refraction: effect of light polarization.

To identify the surface from which the retinoscopic reflex originates, retinoscopy was performed on 305 eyes of various ages with polarized and depolarized light. The discrepancy between retinoscopic and subjective refraction measures in the two conditions shows that two fundus reflective layers contribute to retinoscopy: a specularly reflecting layer presumably at the retina/vitreous interface and a diffusely reflecting layer near the pigment epithelium. In young eyes the retina/vitreous interface predominates; the other predominates in older eyes.

Adolescent↗
PubMed1987

Simple pointspread retinoscope suitable for vision screening.

A simple pointspread retinoscope and method of retinoscopy are described which use optical principles similar to those of photoretinoscopy or static photographic skiascopy. In this instrument the degree of defocus of an eye is estimated from the disappearance of the bright fundal reflex or "crescent" in the eye of the subject when the distance between the light source and the eye of the observer is increased systematically. The instrument is particularly suitable for large scale screening efforts because it is easy to use and can be constructed from inexpensive materials. The pointspread retinoscope was calibrated against an artificial eye of known defocus. Additionally, results from pointspread retinoscopy were compared against meridional photorefractive data from a sample of infants and young children, and a significant correlation was found to exist between measurements made by the two methods.

Child↗
PubMed1981

A retinoscopic method of assessing accommodative performance of young human infants.

A retinoscopic method of assessing changes of the accommodative status of the young human infant with changes of the stimulus viewing distance id described. This method utilized dynamic retinoscopy and a series of patterned visual stimuli. Vertical, above-threshold, squarewave gratings presented at viewing distances of from 10 through 50 centimeters were utilized as fixation and accommodation stimuli. During fixation of the stimuli by the infants, the refractive state of the eyes was determined by location of the conjugate retinal focus. Comparison of the refractive state of the eye to the magnitude of the accommodative stimulus at a particular viewing distance can be utilized as an index of the accuracy of the accommodative response. The applicability of this retinoscopic method to private clinical practice is discussed.

Accommodation, Ocular↗
PubMed1996

Retinoscopic reflexes: theoretical basis and effects of monochromatic aberrations.

BACKGROUND: Current literature describing retinoscopy does not provide a full description of the pupil reflexes observed in retinoscopy or of the effects of monochromatic aberrations. The intent of the study was to develop a geometrical model of retinoscopy that provides a more complete analysis. The model can take specific aberrations and predict the succession of reflexes observed in retinoscopy for an eye with these aberrations. METHODS: Theoretical predictions were compared with observations using a hand-held streak retinoscope. CCD-based retinoscopy was performed on subjects with known aberrations. RESULTS: Reflexes observed in retinoscopy can be computed by modeling a light source whose eccentricity from the retinoscope sight-hole is varying in position. Results from study calculations show that the succession of reflexes observed in retinoscopy can be thought of as a measure of the transverse aberration of the eye. Both qualitative and quantitative measures showed agreement between theoretical and experimental results. Transverse aberration of the eye can be observed and measured using retinoscopy. CONCLUSIONS: Monochromatic aberrations have significant and predictable effects on retinoscopy. The best way for a retinoscopist to avoid such aberrations and provide a proper refraction is to neutralize the reflex across the largest visual zone possible and ignore the reflex motion at the edges of the pupil.

Humans↗
PubMed1977

A personality profile of "Gold Retinoscope" winners: 1961-1975.

Fifteen Gold Retinoscope winners, each judged the most outstanding student in his/her graduating class of the School of Optometry, University of California at Berkeley, were compared with samples of optometry students, Academy Fellows, and non-Academy optometrists. Although most Gold Retinoscope winners had entered optometry school with low to average grades, their grades and clinical performance in optometry school were outstanding. When compared with other optometry students and optometrists in practice, these outstanding students were distinguished by greater self-confidence, initiative, and motivation to achieve. It is suggested that these personality traits were important contributors to their superior achievement.

Achievement↗
PubMed1979

Infrared recording retinoscope for monitoring accomodation.

An optometer (infrared recording retinoscope) that provides high resolution measurements of accommodative changes of the eye has been developed. The instrument employs the principle of retinoscopy to monitor changes in the refractive state of the eye. Infrared radiation is scanned across the eye to provide a moving retinal source as in retinoscopy. An electro-optical system replaces the observer in determining the direction and amount of apparent motion in the pupil of the patient. The optometer is sensitive to accommodative changes of 0.12 D over a range of 12 D. The response of the instrument is faster than the most rapid changes of accommodation, and measurements are unaffected by pupil changes or by small eye movements.

Accommodation, Ocular↗
PubMed1980

The effectiveness of a retinoscope beam as an accommodative stimulus.

Two experiments with adult subjects and one with infant subjects showed that the beam of a retinoscope, when viewed monocularly in a dark surround, does not stimulate accommodation. In this situation, the eye assumes an intermediate focus that is correlated with the individual's intermediate dark focus or resting state of accommodation. These results provide further evidence that near retinoscopy is a useful method of refraction which controls accommodation by minimizing effective stimulation. The technique is particularly valuable for refracting infants or young children who would otherwise require cycloplegia, and it may be an effective clinical method for the correction of night myopia and related anomalies in adults.

Accommodation, Ocular↗
PubMed1992

Retinoscopic measurement of the refractive state of the rat.

Using retinoscopy, we measured the refractive state of 96 eyes of three different strains of rats: albino Sprague-Dawley, Royal College of Surgeons (RCS) with and without inherited retinal dystrophy, and lean and obese varieties of Zucker rats. Contrary to previous reports, we do not find consistent high hyperopia in the rat, but rather refractions that range from near emmetropia (-0.12 D) to extreme hyperopia (+18.95 D). This range of refractive errors suggests a poorly developed emmetropization mechanism in the rat, and that individual refractions should be performed on animals utilized in experiments where refractive state is critical.

Albinism, Ocular↗