color translation fundus photography

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COLOR TRANSLATION FUNDUS PHOTOGRAPHY J. TERRY ERNEST, M.D.* Chicago, Illinois White light directed into the ocular fun- dus is transmitted practically unchanged by the cornea, lens and vitreous and is in part absorbed and in part reflected by the visual pigments, retinal pigment epithelium, blood in the choroid and retinal vessels, and by the choroidal pigment. Short wavelengths of vis- ible light are absorbed by the visual pigment, retinal pigment epithelium and choriocapil- laris. Long wavelengths of visible light are transmitted by the neurosensory retina and blood and are to some degree absorbed by pigmented structures of the ocular fundus. Infrared light is transmitted by the neuro- sensory retina and blood and is markedly ab- sorbed by pigmented structures. Using monochromatic light, Potts 1 ' 2 has extended Kugelberg's 3 early observations to emphasize the spectral differences between areas of fundus abnormalities and the sur- rounding normal tissue. Permanent color rec- ords of the differential transmission of light are limited by the spectral sensitivity of the ordinary color film in common use. From the Eye Research Laboratories, The Uni- versity of Chicago. This investigation was supported in part by Public Health Research Grants NB- 033358 and FR 55 from the National Institutes of Health. ♦[Present address: Department of Experimental Psychophysiology, Forest Glen Section, Building 101, Walter Reed Army Medical Center, Washing- ton, D.C. (20012).] Kodak has developed a film for aerial photog- raphy which records both infrared and visi- ble red light in separate emulsions. These emulsions have different colors, permitting fundus photography with a permanent color record of sharply separated wavelengths of light. MATERIALS AND METHODS Kodak Ektachrome Infrared Aero Film, Type 8443* was used. It is a false-color pro- cess containing three superimposed emul- sions, each sensitive to a different region of the spectrum. The emulsion with a maxi- mum sensitivity at 550 millimicrons forms a yellow-positive image. The emulsion with a maximum sensitivity at 650 millimicrons forms a magenta-positive image and the emulsion with peak sensitivity in the in- frared wavelengths forms a cyan-positive image. 4 The film is developed by a reversal process so that no dye is formed in an emul- sion if it receives the wavelengths to which it is maximally sensitive. As an example, the normal fundus reflects both red and infrared light, exposing the magenta and cyan dye- forming layers. On reversal development, no dye forms in these layers but yellow dye is formed in the initially unexposed emulsion. * Special Sensitized Products Sales Division of the Eastern Kodak Company, 343 State Street, Rochester, New York. Fig. I (Ernest). Hemangioma arising from the temporal aspect of the disc. The pigment is secondary to photocoagulation. (A) Standard fundus photograph. The mass is seen poorly differentiated from the fundus structures. (B) Infrared Ektachrome photograph. The lesion is washed out with the retinal vessels and is poorly visualized. Fig. 2 (Ernest). A benign nevus, unchanged in size for several years. (A) Standard Technique fundus photograph. (B) Infrared Ektachrome fundus photograph demonstrating the improved contrast obtained. Fig. 3 (Ernest). Retinal detachment. (A) With standard technique the retinal elevation is dark because it is seen in reflected, diffused light. (B) Infrared Ektachrome film records the infrared wavelengths which penetrate the retina. Fig. 4 (Ernest). Malignant melanoma. (A) Standard color film poorly outlines the edges of the tumor. (B) Infrared Ektachrome film demonstrates the heavy pigmentation of the lesion and clearly outlines its boundaries. 170

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COLOR TRANSLATION FUNDUS PHOTOGRAPHY

J. TERRY ERNEST, M.D.* Chicago, Illinois

White light directed into the ocular fun­dus is transmitted practically unchanged by the cornea, lens and vitreous and is in part absorbed and in part reflected by the visual pigments, retinal pigment epithelium, blood in the choroid and retinal vessels, and by the choroidal pigment. Short wavelengths of vis­ible light are absorbed by the visual pigment, retinal pigment epithelium and choriocapil-laris. Long wavelengths of visible light are transmitted by the neurosensory retina and blood and are to some degree absorbed by pigmented structures of the ocular fundus. Infrared light is transmitted by the neuro­sensory retina and blood and is markedly ab­sorbed by pigmented structures.

Using monochromatic light, Potts1'2 has extended Kugelberg's3 early observations to emphasize the spectral differences between areas of fundus abnormalities and the sur­rounding normal tissue. Permanent color rec­ords of the differential transmission of light are limited by the spectral sensitivity of the ordinary color film in common use.

From the Eye Research Laboratories, The Uni­versity of Chicago. This investigation was supported in part by Public Health Research Grants NB-033358 and FR 55 from the National Institutes of Health.

♦[Present address: Department of Experimental Psychophysiology, Forest Glen Section, Building 101, Walter Reed Army Medical Center, Washing­ton, D.C. (20012).]

Kodak has developed a film for aerial photog­raphy which records both infrared and visi­ble red light in separate emulsions. These emulsions have different colors, permitting fundus photography with a permanent color record of sharply separated wavelengths of light.

MATERIALS AND METHODS

Kodak Ektachrome Infrared Aero Film, Type 8443* was used. It is a false-color pro­cess containing three superimposed emul­sions, each sensitive to a different region of the spectrum. The emulsion with a maxi­mum sensitivity at 550 millimicrons forms a yellow-positive image. The emulsion with a maximum sensitivity at 650 millimicrons forms a magenta-positive image and the emulsion with peak sensitivity in the in­frared wavelengths forms a cyan-positive image.4 The film is developed by a reversal process so that no dye is formed in an emul­sion if it receives the wavelengths to which it is maximally sensitive. As an example, the normal fundus reflects both red and infrared light, exposing the magenta and cyan dye-forming layers. On reversal development, no dye forms in these layers but yellow dye is formed in the initially unexposed emulsion.

* Special Sensitized Products Sales Division of the Eastern Kodak Company, 343 State Street, Rochester, New York.

Fig. I (Ernest). Hemangioma arising from the temporal aspect of the disc. The pigment is secondary to photocoagulation. (A) Standard fundus photograph. The mass is seen poorly differentiated from the fundus structures. (B) Infrared Ektachrome photograph. The lesion is washed out with the retinal vessels and is poorly visualized.

Fig. 2 (Ernest). A benign nevus, unchanged in size for several years. (A) Standard Technique fundus photograph. (B) Infrared Ektachrome fundus photograph demonstrating the improved contrast obtained.

Fig. 3 (Ernest). Retinal detachment. (A) With standard technique the retinal elevation is dark because it is seen in reflected, diffused light. (B) Infrared Ektachrome film records the infrared wavelengths which penetrate the retina.

Fig. 4 (Ernest). Malignant melanoma. (A) Standard color film poorly outlines the edges of the tumor. (B) Infrared Ektachrome film demonstrates the heavy pigmentation of the lesion and clearly outlines its boundaries.

170

VOL. 65, NO. 2 COLOR TRANSLATION FUNDUS PHOTOGRAPHY 173

The reversal processes are described in Evans'8 textbook on color photography.

All three emulsions react with blue light and it is thus necessary to exclude wave­lengths less then 520 millimicrons. This is done by placing a Kodak Wratten 1SG filter in front of the film.6 The film is pro­cessed in Kodak E-2 solution but infrared light inspection must not be done.

The Zeiss fundus camera can be used with this film. Its xenon flash lamp produces a high percentage of infrared light.7 The only modification necessary is the 15G filter in front of the film, the same filter recom­mended for use in front of the film in flu-orescein angiography.8 The color renditions are modified by the intensity of the elec­tronic flash illumination and the photographs in this paper were made with flash intensity setting II. The focusing light intensity was " 3 " and the aperture was "7" and contained a 6.0 mm central mask.9

RESULTS

Each patient was photographed with both Kodachrome II film and the Infrared Ekta-chrome film. The same equipment was em­ployed except that the Kodachrome II film was used at flash intensity III and without the 15G filter. Figure 1 shows two photo­graphs of a hemangioma. A barrier of pho-tocoagulation was placed along the margin of the lesion and the secondary pigment pro­liferation is evident. The vascular lesion is poorly visualized in both the Kodachrome II (A) and the Infrared Ektachrome (B) pho­tographs. The lesion blends in with the ret­ina in the infrared color photograph.

The pigment proliferation in Figure 1 is clearly demarcated with the Infrared Ekta­chrome technique, of advantage in the study of pigmented lesions. Figure 2 is a benign nevus photographed by the standard Koda­chrome II film (A) and the Infrared Ekta­chrome technique (B) . The high contrast be­tween pigment and normal retina makes pre­cise measurements of size and progression possible. Infrared wavelengths are little af­

fected by retinal elevation. Figure 3 is an idiopathic retinal detachment which appears dark with Kodachrome II film (A) while the Infrared technique (B) clearly indicates that there is no underlying pigmented mass. Fig­ure 4 is a lesion which histologic studies demonstrated to be a malignant melanoma. The lesion did not appear highly pigmented in standard color photographs (A) . The In­frared photographs demonstrate a deeply pigmented lesion and clearly demarcate its boundaries (B) .

COMMENT

A color film sensitive to both red and in­frared light recorded in separate emulsions is now available. The two wavelengths can be used to emphasize spectral differences in the structures of the ocular fundus. As pointed out, the normal fundus reflects both red and infrared light, resulting in a yellow translation color in the processed film. Pig­mented lesions, however, absorb infrared light and thus following reversal develop­ment, the cyan emulsion dye persists, result­ing in a red-brown record. It is this absorp­tion by pigment of the infrared wavelengths that makes possible the high contrast be­tween lesions and surrounding normal ret­ina. Serial photographs may be used to fol­low the course of melanotic lesions with change in size easily detected because of the high contrast between pigmented and non-pigmented areas. There is little contrast be­tween oxygenated and reduced blood, and vascular lesions are "washed out" just as are the retinal blood vessels. High contrasts are thus obtained between pigmented lesions and hemangiomas or hemorrhages. The Infrared Ektachrome technique, used in combination with fluorescein angiography, is a valuable adjuvant to fundus study.

SUMMARY

Kodak Ektachrome Infrared Aero Film has a high sensitivity in the red and infrared regions of the spectrum, and the xenon flash lamp in the Zeiss fundus camera is rich in

174 AMERICAN JOURNAL OF OPHTHALMOLOGY FEBRUARY, 1968

the infrared wavelengths. The Zeiss fundus camera can be used to photograph retinal disease with the film without major modifi­cations. The use of the infrared color system makes it possible to study melanotic lesions deep in the fundus.

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REFERENCES

1. Potts, A. M., West, S. S., and Shearer, J. R.: Application of television ophthalmoscope to some problems of clinical ophthalmology. Arch. Ophth. 62:48S, 1959.

2. Potts, A. M.: Monochromatic ophthalmoscopy. Tr. Am. Ophth. Soc. 63 :276, 1965.

3. Krugelberg, I.: Der Augenhintergrund in in-frarotem Licht. Acta Ophth. 12:179, 1934.

Deformity of the eyelids1 and hetero-chromia irides2 were reported long before Waardenburg3 studied 1,050 cases of congeni­tal deafness in Holland and described the full syndrome in 1951 as follows:

1. Lateral displacement of the medial can-thi, combined with dystopia of the lacrimal puncta and blepharophimosis

2. Prominent broad root of the nose 3. Growing together of the eyebrows,

with hypertrichosis of the medial portions 4. White forelock, a form of partial al­

binism (early graying of the hair begins soon after puberty). Defective pigmentation may occur in any part of the body.

5. Partial or complete heterochromia irides 6. Congenital deafness The complete syndrome is not present in

all patients, but more often presents with a combination of two or more of the above features. Fisch4 described cases with typical configuration of the skull with depressed nasal bridge, a metopic suture, and a massive

From the departments of Ophthalmology and Pe­diatrics, General Hospital.

4. Tarkington, R. G., and Sorem, A. L.: Color and false-color films for aerial photography. Photo-grammetric Eng. 28:88, 1963.

5. Evans, R. M.: Eye, Film, and Camera in Color Photography. New York and London, John Wiley and Sons, 1959, p. 190.

6. Gibson, H. L., Buckley, W. R., and Whitmore, K. E.: New vistas in infrared photography for bio­logical surveys. J. Biol. Phot. Assoc. 33:1, 1965.

7. Carlson, F. E., and Clark, C. N.: Light Sources for Optical Devices In: Kingslake, R.: Applied Optics and Optical Engineering. New York and London, Academic Press, 1965, p. 82.

8. Ferrer, O. M.: Serial fluorescein fundus pho­tography of retinal circulation. A description of technique. Am. J. Ophth. 60:587, 1965.

9. Allen, L.: Ocular fundus photography. Suggestions for achieving consistently good pic­tures and instructions for stereoscopic photography. Am. J. Ophth. 57:13, 1964.

jaw. Since then a number of other cases oc­curring in Danes,5 Scots,6 English7 and in Negroes8 have been described in the litera­ture. To our knowledge this paper is the first to report the syndrome in a Chinese family.

CASE REPORTS

The parents of the proband (N.A.T.) migrated to Singapore from South China at the beginning of the century. The proband was born in Singapore and has always lived in the rural area. His mother had no serious illness during this pregnancy and there was no consanguinity of the parents, who are now dead. No photographs are available. We were assured of the absence of congenital deafness and heterochromia in his ancestors. The family pedigree is shown in Figure 1. The proband's siblings cannot be traced, except for the eldest brother, who shows no signs of the syndrome, nor does anyone else in his family.

The proband (fig. 2) is a farmer, married to a local-born Chinese with no siblings. Her parents died in her early childhood. The pro-

A CHINESE FAMILY W I T H WAARDENBURG'S SYNDROME

CHEW KHENG LIAN, M.D., CHEN A I J U , M.D., AND TAN KWONG H O H , M.D. Singapore