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[Modernization of ophthalmoscopic techniques].

The great principles of ophthalmoscopy have been known for many decades. This paper intends show the new possibilities allowed by modern technology, especially in two fields. First of all, it is possible, even in keeping basic principles, to improve previous machines with, for example, better magnification, new ophthalmoscopic lens, or to create new materials as telescopes for clinical practice or intra-ocular surgery, wide angle or high magnification fundus cameras for posterior pole examination. Secondary, by revolutionary principles, it is possible to introduce laser in the ophthalmoscopic field and to imagine new ophthalmoscopes: SLO i.e. Scanning Laser Ophthalmoscope or SLM i.e. Scanning Laser Microscope, which opens a window on the future.

Humans↗

[Vital capillary microscopy and with ophthalmoscope-detected findings in progressive systemic scleroderma].

Nineteen patients suffering from scleroderma (average age 56.6 years; 18 women, 1 man) were examined by in vivo capillary microscopy of the nail fold. The possibility of achieving results with the ophthalmoscope was examined. The correspondence between ophthalmoscopic and television microscopic results was evaluated. With the ophthalmoscope hemorrhages were found in 68% of the patients, reduction in the number of capillaries in 79%, avascular areas in 79%, and dilated capillaries in 84%. The correspondence between the findings of the two methods was 80% and more, so that examination of the nail fold capillaries with an ophthalmoscope can help to verify the diagnosis of scleroderma. This method should be employed whenever scleroderma is suspected and microscopical equipment is not available.

Adult↗

[Correlation between visual acuity and ophthalmoscopic findings in presenile and senile macular degeneration].

The exisiting studies in macular degeneration reveal discrepancies between the ophthalmoscopic signs and the degree in reduction in vision. In this study the results of 156 ophthalmoscopic investigations are presented in order to clarify this correlation between the clinical findings and the loss of vision. The patients are divided into four groups, slight macular degenerations, representing group I, being at one of the scala, and very severe forms, representing group IV, being at the other end. Especially in the group I and II with slight macular degenerations very marked discrepancies were observed between the sligns having been obtained through the ophthalmoscope and the vision. In those cases the visual function was more impaired than to the expected from the ophthalmoscopic signs.

Adult↗

Sesquicentennial of the ophthalmoscope.

The year 2000 coincides with the 150th anniversary of the invention of the ophthalmoscope. In 1850, Hermann von Helmholtz (1821-1894) inaugurated the modern era in ophthalmology with his magnificent instrument, which has done more to revolutionize the development of ophthalmology than any other invention or discovery. Before Helmholtz's invention, it was not possible to visualize the posterior pole of the eye in a living subject. The ophthalmoscope permitted the clinical correlation of signs and symptoms with findings in the retina, vitreous, and optic nerve. The ophthalmoscope became the model for all forms of endoscopy that followed. It is often compared in importance with 2 earlier inventions, the telescope (17th century) and the stethoscope (early 19th century). All of these instruments made dramatic new information available to the human mind.

Germany↗

Scotoma and fixation patterns using scanning laser ophthalmoscope microperimetry in patients with macular dystrophy.

PURPOSE: We used scanning laser ophthalmoscope microperimetry to evaluate the retinal scotoma and the fixation points in the patients with macular dystrophy. METHODS: We studied 10 eyes of five patients with macular dystrophy (three patients with cone dystrophy and two patients with Stargardt disease). The mean patient age was 37 years (range, 13 to 64 years). An estimation of scotoma and fixation points on the retina was performed using scanning laser ophthalmoscope microperimetry. RESULTS: All 10 eyes (100%) had one of two types of dense scotoma: type one was a dense ring scotoma (five eyes, 50%), and type two was a dense central scotoma (five eyes, 50%) that included the center of the fovea. In all eyes with a dense ring scotoma, the fixation points were stable and did not shift. In all eyes with a dense central scotoma, the fixation shifted. The logarithm of minimal angle of resolution of the visual acuity in the eyes with the dense central scotoma was significantly worse than that of eyes with the dense ring scotoma type (P =.005). CONCLUSIONS: Scanning laser ophthalmoscope microperimetry findings demonstrate two types of dense scotoma (dense ring scotoma and dense central scotoma) in the patients with macular dystrophy. The two types of dense scotoma affect the shifting of the fixation points and the stability of fixation and may result in the difference in visual acuity in the patients with macular dystrophy.

Adolescent↗

Fluorescent dots in fluorescein angiography and fluorescein leukocyte angiography using a scanning laser ophthalmoscope in humans.

PURPOSE: The purpose of the study is to disclose the nature of fluorescent dots and segments traditionally observed with fluorescein angiography (FA) using a scanning laser ophthalmoscope (SLO 101; Rodenstock, München, Germany). The authors developed a new method, called fluorescein leukocyte angiography (FLA), to display directly the movement of leukocytes in human retinal vessels. METHODS: Fluorescein angiography was performed on two normal volunteers using a scanning laser ophthalmoscope and fluorescent dots and segments were observed. Fluorescein leukocyte angiography, using an injection of fluorescent buffy coat layer from which the fluorescent plasma and nonfluorescent erythrocytes have been removed externally, was performed on seven normal volunteers. Injection fluid smears were examined through a fluorescent microscope. Peripheral blood smears taken during midphase of FA and FLA also were examined. In addition, 15 early-phase FAs of central serous chorioretinitis (CSC) were studied retrospectively. RESULTS: In the FAs of normal volunteers, fluorescent dots were detected only in perimacular capillaries at early phase. Eight of the 15 CSC FAs examined showed both fluorescent dots and segments. In the FLAs, fluorescent dots were detected in whole retinal vessels for more than 30 minutes. Fluorescent segments were observed in FA but not in FLA. Injected fluid smears from one FLA showed fluorescent leukocytes and small platelets. However, in peripheral blood smears of the FLA, leukocytes and platelets were more visible and exhibited higher contrast than those of an FA due to background plasma fluorescence. The mean velocity of 21 flowing leukocytes in perifoveal capillaries was 1.37 +/- 0.35 mm/second in 2 FAs and that of 89 flowing leukocytes was 1.41 +/- 0.29 mm/second in 7 FLAs. CONCLUSIONS: The authors' observations suggest that fluorescent dots in scanning laser ophthalmoscope imaging are fluorescein-stained leukocytes, whereas fluorescent segments are the hyperfluorescent plasma that is located between rouleaux formations of erythrocytes. The velocity of the fluorescent dots could be measured in the perimacular capillaries by either FA or FLA; however, only FLA can display the flow of fluorescent leukocytes in large vessels.

Adult↗

[Kinetic fundus controlled perimetry with the scanning laser ophthalmoscope].

BACKGROUND: The detection of circumscribed visual field defects due to pathologic macular findings may be difficult even when modern conventional perimetry procedures are used. Using conventional clinical methods there exists no reliable correlation between morphology and function for follow-up and documentation. The Laser Scanning Ophthalmoscope enables a fundus-based examination and therefore allows exact comparison between morphologic appearance and corresponding function. PATIENTS AND METHODS: 50 eyes with pathologic macular findings were examined using a newly developed kinetic perimetry method based on the Scanning Laser Ophthalmoscope. The results were compared to those obtained with other clinical examinations such as Goldmann or Octopus visual field and Amsler-chart. RESULTS: Fundus-based examination with the SLO is preferable for detection especially when small pathologic findings at the posterior pole like macular holes or small serous detachments are combined with reduced stability of fixation. The detection of sharp borders of the scotomas is much better than with conventional perimetry. CONCLUSION: The Scanning Laser Ophthalmoscope allows several different types of fundus-based examinations. Concerning kinetic perimetry we were able to find the borders of scotomas within very short examination times. This method therefore is of valuable help in patients with circumscribed scotomas at the posterior pole combined with deterioration of the stability of fixation and allows documentation for follow-up and further comparison with other clinical findings.

Adult↗

A modified combined indirect ophthalmoscope and illuminated magnifying loupes.

A modified combined indirect ophthalmoscope and magnifying loupes with illumination was made by mounting a pair of Zeiss loupes below the SOLA indirect ophthalmoscope eye-piece. A beam-splitter, which was made of a piece of ordinary microscopic glass slide, splits a secondary light beam off from the original light source of the indirect ophthalmoscope at an angle of approximately 15 degrees to provide additional illumination for the magnifying loupes. The optics involved was discussed.

Audiovisual Aids↗

Manufacture and use of home made ophthalmoscopes: a 150th anniversary tribute to Helmholtz.

OBJECTIVE: To produce a simple, effective, and inexpensive training ophthalmoscope. DESIGN: Case study. SETTING: A coffee table in a sitting room and an eye clinic. PARTICIPANTS: 10 friends and relatives, several patients, and a cooperative Persian cat. INTERVENTIONS: Direct ophthalmoscopy with instrument made with easily available material and tools from art and office equipment shops. MAIN OUTCOME MEASURES: Efficiency, clarity of view, and price of ophthalmoscope. RESULTS: The instrument was readily made; of the 50 manufactured two thirds gave a good view; and each cost less than pound1 to make. CONCLUSION: The ophthalmoscope is fun to make, works well, and anyone can make one.

Equipment Design↗

Comparison of eccentric fixation measurements using the streak target of an ophthalmoscope and a traditional visuoscopy target.

PURPOSE: To compare measurements of eccentric fixation using two different targets for fixation, a traditional visuoscope target and the streak target of an ophthalmoscope. PATIENTS AND METHODS: Monocular fixation was evaluated using visuoscopy in 47 patients ranging in age from 4 months to 22 years. Visuoscopy measurements were compared using both the traditional visuoscope target and the streak target of a Welch Allyn ophthalmoscope. The streak light was rotated both horizontally and vertically to detect both horizontal and vertical eccentric fixation. RESULTS: The streak target improved testability of eccentric fixation in children younger than 3 years compared to the traditional visuoscope target (75% versus 30%). All of the patients older than 3 years were testable using both targets, with both methods yielding the same results. All of the patients with a visual acuity of at least 20/20 also demonstrated central fixation using both techniques. CONCLUSIONS: Using the streak of a Welch Allyn ophthalmoscope as a visuoscope target allows for testing of eccentric fixation in children younger than 3 years.

Adolescent↗

Enlarged diode laser spot using indirect ophthalmoscope delivery in conjunction with indocyanine green to treat large choroidal neovascularizations.

BACKGROUND AND OBJECTIVE: To evaluate the effectiveness of a new method of delivering diode laser (810 nm) spots through an indirect ophthalmoscope in conjunction with intravenous indocyanine green to treat choroidal neovascularizations (CNVs) larger than 5,400 microm. PATIENTS AND METHODS: A prospective, non-comparative, interventional case series study was conducted with 8 patients with CNV secondary to age-related macular degeneration. Laser pulses were applied to the CNV within 5 minutes of an intravenous injection of 25 mg of indocyanine green. The laser spot was enlarged up to one disc diameter by shortening the distance between the indirect ophthalmoscope and the 20-diopter viewing lens. The follow-up period was 3 months. RESULTS: Three eyes had an improvement in visual acuity of more than 2 lines, and fluorescein angiography showed stabilization of the membrane and reduction of the hemorrhages and subretinal fluid at the last follow-up. Three other eyes maintained the same visual acuity and two had a decrease in visual acuity of more than 2 lines at the 3-month follow-up examination. CONCLUSION: Laser treatment delivered through an indirect ophthalmoscope system may be used as a palliative treatment for CNVs larger than 5,400 microm.

Aged↗

Retinal light exposure from ophthalmoscopes, slit lamps, and overhead surgical lamps. An analysis of potential hazards.

The projected beam radiance of several common ophthalmologic instruments was measured, and potential hazard to the patient from light exposure was analyzed with reference to safety standards for coherent light. The indirect ophthalmoscopes tested appear to be "safe" under moderate voltage settings, provided exposure is reasonably brief. Slit-lamp biomicroscopy of the fundus, however, merits caution. It produces a three-times-higher retinal irradiance than the indirect ophthalmoscope. Overhead surgical lamps produce a retinal irradiance about one-third that of the indirect ophthalmoscope (for clear media and dilated pupil). This could be dangerous, since an operation may take long enough to exceed the maximal permissible exposure by several orders of magnitude. Major design changes are indicated for surgical illuminators to extend the "safe time" to the 40 to 60 min range.

Animals↗

Colored focal visual evoked potentials by cathode ray tube versus scanning laser ophthalmoscope.

We compared the focal visual evoked potentials obtained in 52 young subjects with normal vision, evoked by means of three alternating black/color checkerboards generated by a trichromic cathode ray tube (dominant wavelength, 514 nm; colorimetric purity, 0.45) and by means of a scanning laser ophthalmoscope (argon laser beam, 514 nm; colorimetric purity, approximately 1). These three checkerboards, with an area of 3.5 degrees x 3.5 degrees (stimulating the fovea), then with an area of 3.5 degrees x 3.5 degrees with a central exclusion of 1.5 degrees x 1.5 degrees (stimulating the perifoveola) and finally with an area of 1.5 degrees x 1.5 degrees (stimulating the foveola) were presented within a field (8 degrees x 8 degrees) of homogeneous luminance of 170 cd/m2 and 1500 cd/m2, respectively. Their check sizes were 30', with a reversal temporal frequency of 0.75 Hz. The transient focal visual evoked potentials recorded with these three stimuli generated by the two types of stimulators were clearly detected for at least 85% of subjects. Their characteristics (waveform, amplitude and culmination times of the different waves) were comparable, regardless of the stimulator used (cathode ray tube or scanning laser ophthalmoscope). These results suggest that, under these various conditions of luminance and colorimetric purity, the neurophysiologic circuits tested function in identical ways. The focal visual evoked potential signs, now clearly defined by means of stimuli generated by cathode ray tubes, therefore apparently can be applied to the focal visual evoked potential evoked by stimuli generated by the scanning laser ophthalmoscope.

Adult↗

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↗

Ophthalmoscopic detectability of the parafoveal annular reflex in the evaluation of the optic nerve: an experimental study in rhesus monkeys.

OBJECTIVE: To evaluate whether assessment of the ophthalmoscopic visibility of the parafoveal annular reflex is helpful in the detection of optic nerve fiber and optic nerve damage. DESIGN: Experimental animal study. ANIMALS: The study was performed in rhesus monkeys, divided into four study groups, with no significant difference in ages of the animals in the various groups. Three of these groups had (1) experimental chronic high-pressure glaucoma (n = 37 monkeys), (2) experimental temporary occlusion of the central retinal artery (n = 19 monkeys), and (3) systemic atherosclerosis and arterial hypertension (n = 13 monkeys). The fourth group was the normal control group (n = 10 monkeys). METHODS: In 60-degree color fundus photographs, taken at baseline and at the end of the study, the ophthalmoscopic detectability of the parafoveal annular reflex was graded, the visibility of the retinal nerve fiber layer was assessed, and neuroretinal rim and parapapillary atrophy were measured. MAIN OUTCOME MEASURES: Ophthalmoscopic detectability of the parafoveal annular reflex; visibility of the retinal nerve fiber layer; neuroretinal rim area; size of parapapillary atrophy. RESULTS: The parafoveal annular reflex was significantly (P < 0.0001) better detectable at baseline of the study than at the end of the study. In all study groups, detectability of the parafoveal annular reflex decreased significantly (P < 0.0001) with decreasing visibility of the retinal nerve fiber layer. In the glaucoma group, parafoveal annular reflex detectability additionally decreased significantly (P < 0.001) with increasing area of beta zone of parapapillary atrophy and with decreasing neuroretinal rim area. In the normal group, the parafoveal annular reflex detectability decreased with increasing age, parallel to a loss in the visibility of the retinal nerve fiber layer. In 23 of 25 (92%) eyes with a complete loss of the visibility of the retinal nerve fiber layer at the end of the study, the parafoveal annular reflex was no longer detectable. CONCLUSIONS: The findings suggest that evaluation of the detectability of the parafoveal annular reflex in routine ophthalmoscopy is a useful additional tool in the qualitative assessment of the retinal nerve fiber layer and optic nerve.

Animals↗

Ophthalmoscopic measurement of the optic disc.

PURPOSE: The authors evaluated whether the optic disc dimensions can be measured directly by ophthalmoscopy without the use of a fundus camera or special ophthalmoscope. MATERIALS AND METHODS: The horizontal and vertical disc diameters were measured ophthalmoscopically in 158 eyes of 95 subjects using a standard Goldmann three-mirror contact lens and a commercial slit lamp with adjustable length of the beam. The refractive error ranged from -7.25 to 3.5 diopters. Based on these direct measurements, the authors calculated the disc area by applying a modified formula for an ellipse, where area = pi/4 x the horizontal diameter x the vertical diameter. Additionally, the authors determined by planimetry the diameters and area of the disc on color photographs after correcting the ocular and photographic magnification. RESULTS: The values of the disc diameters as determined by photography were x1.27 larger than those measured with the Goldmann contact lens. Taking into account this constant correction factor of 1.27 for all eyes examined, the disc diameters, as measured by the Goldmann lens, varied by 0.11 +/- 0.06 mm or 5.8% +/- 3.5% from the values measured on the photographs. This error decreased slightly (P = 0.04) with increasing disc size. It was independent of the refractive error. The calculated disc area based on the ophthalmoscopically determined disc diameters differed by 9.4% +/- 6.6% from the disc area as measured by planimetry on the photographs. CONCLUSIONS: For clinical purposes, the optic disc and other structures of the posterior fundus can be measured by ophthalmoscopy using a Goldmann contact lens and a slit lamp with adjustable beam length. The optic disc area can be calculated by the formula: horizontal disc diameter x vertical disc diameter x pi/4.

Adult↗

Colloidal carbon as a combined ophthalmoscopic and microscopic probe of retinal and choroidal vascular integrity.

While studying an experimental retinal immunopathy, we searched for a vascular tracer that would permit us to test the anatomical and functional status of retinal and choroidal vessels by ophthalmoscopy, light microscopy, and electron microscopy in the same eye. We found that colloidal carbon, administered intravenously, can be seen ophthalmoscopically in the choroidal and retinal circulations, and abnormal deposits of it can be visualized in vivo. The ophthalmoscopic findings can be corroborated and extended by stereomicroscopy, and later the same specimens can be used for light and transmission electron microscopical studies. This tracer, thus, would allow the correlation of the ophthalmoscopic appearance of a clinical lesion with its histological and ultrastructural substrata.

Animals↗

[Ophthalmoscopic observations of ocular fundus in colony-born cynomolgus monkeys aged from 0 day to 90 days].

Apparently healthy 242 colony-born cynomolgus monkeys (Macaca fascicularis) aged from 0 day to 90 days were examined for the findings of ocular fundus by using ophthalmoscope. One drop of mixed solution of 0.5% tropicamide and 0.5% phenylephrine hydrochloride was instilled into each eye of the monkey. Then, those monkeys were anesthetized with ketamine-HC1 at the dose level of 10mg/kg B. W. Regular and fluorescein photographs were taken with Kowa RC-II ophthalmoscope-camera by using daylight typed color film. Following findings were obtained in each age class: Retinal color was salmon pink with 0 to 3-days-old neonates, salmon pink and blue to green with 7 days to 14-days-old animals and blue to green with 60-days to 90-days-old monkeys. As regards optic disc, 0- to 14-days-old animals were observed to be light orange in color, and the infant aged more than 28-days showed orange color. Retinal arteries and veins were lightly reddish in color with every age class. Macular color was salmon pink in 0-day-old cases, slightly dark in 3-days-old neonates and very dark after 14-days of age. Lightly retinal reflex was noted in 0- and 7-days-old animals. The reflex was observable in 14-days-old animals without any case of exception. Retinal hemorrhages were recorded in 22 (67%) of 36 neonates born in natural condition and 10 (33%) of 30 neonates born by cesarean section. These findings will be useful as the criteria for ophthalmoscopic observations of the cynomolgus monkeys as laboratory use.

Animals↗