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Some Improved Methods of Anterior Segment Fluorescein Angiography
SOME I M P R O V E D M E T H O D S O F A N T E R I O R SEGMENT FLUORESCEIN ANGIOGRAPHY 1. BASIC SYSTEM
Mizuo
MATSUI,
M.D.,
J E A N - M A R I E PAREL, ING.
ETS-G,
H A N S J U R G WEDER, A N D J O H N N Y JUSTICE, JR.
Miami, Florida 1
In 1960, Novotny and Alvis reported the use of fluorescein for fundus angiography. In 1968, Jensen and Lundbaek 2 · 3 utilized this technique to study the iris and conjunctival vessels in diabetic patients. Using a Zeiss-Robot fundus camera, they magnified the image by adding a +200 mm lens in front of the standard aspherical objective. In 1970, Rosen and Lyons 4 reported fluorescein angiographs of microhemangiomas at the pu pillary border, using a standard Zeiss fundus camera adjusted for anterior segment pho tography. Mapstone5'6 also used this system for his studies. Mitsui, Matsubara and Kanagawa7 reported iridocorneal angiography using modified Nikon and Zeiss photo-slit lamps. Baggesen's8 report of iris angiog raphy by means of a Zeiss photo-slit lamp powered by a high-speed power supply was followed by others9-20 who used the same technique. Koh 21 studied conjunctival angiography using a low-power binocular microscope and the light source of an Olympus fundus camera. Craandijk22 reported anterior segment an giography using a standard single-lens re flex camera coupled to a macrophotographic objective with a standard Zeiss fundus cam era as an illumination device. Using the same technique, Cobb, Shilling, and Chisholm23 studied vascular tufts at the pupillary margin· From the Bascom Palmer Eye Institute, Depart ment of Ophthalmology, University of Miami School of Medicine, Miami, Florida. This investiga tion was supported in part by Public Health Service Grant EY00338 from the National Eye Institute, and by Research to Prevent Blindness, Inc. Reprint Requests to Mr. Jean-Marie Parel, Bas com Palmer Eye Institute, P.O. Box 875, Biscayne Annex, Miami, Florida 33152.
Four basically different methods for ante rior segment fluorescein angiography have been reported. Each technique utilizes a dif ferent instrument: a fundus camera, a photo-slit lamp, a binocular microscope, or a combination of single-lens reflex camera with a fundus camera as an illuminator. Each of these methods presents certain dis advantages : The fundus camera is designed for a spe cial purpose. It is not suitable for anterior segment photography because of low magni fication, severe peripheral aberrations, inad equate depth of field, and obscured frame margins. The addition of a +200 mm lens only increases the magnification at the ex pense of the depth of field. A photo-slit lamp provides angiograms of good quality but obscured frame margins oc cur because of the limited field angle of the slit illuminator. Also, forced-developed high speed films must be used because of insuf ficient lighting. An operating binocular microscope, being vertically mounted, cannot be used effec tively in the clinic without extensive modifi cations. The usual single lens reflex camera pro vides optimal use of the 35 mm frame. When a standard fundus camera is used as an illuminator, the system becomes bulky and optical efficiency is low. A 75% loss of light is estimated to occur because of Fresnel reflections at each optical interface, due to the inherent ring-shaped diaphragm and due to the limited span of the aperture of the il lumination system. If good quality angiograms are to be ob tained, all four methods require extensive modifications to the basic instrument. For
1075
1076
AMERICAN JOURNAL OF OPHTHALMOLOGY
Fig. 1 (Matsui, Parel, Weder, and Justice). Front view of equipment (chin rest removed). this reason, we specifically designed an appa ratus for anterior segment fluorescein angiography. It consists of a specially developed illuminator and a medical Nikkor objective, coupled to a motor-driven Nikon F camera body. Both sections are mounted on a stan dard Haag-Streit slitlamp table (Fig. 1). A modified 250 joules Zeiss fundus camera power supply provides the necessary electri cal energy. We selected a 200 mm Nikkor lens that is designed specifically for close-up medical photography. Its diaphragm is auto matic, permitting sharp focusing during angiography. The long focal length of this lens provides ample working distance. Magnifica tion up to X3 are obtained simply by chang ing the complementary objectives, which is advantageous if linear measurements are to be made on the angiograms. This system provides an optimal image size of 24 X 35 mm without marginal obscurity or aberra tion.
DECEMBER, 1972
The illuminator is built around two light sources. A tungsten lamp provides the obser vation beam, and a high-power xenon tube provides the photographic beam (Fig. 2). For simplicity, we chose two commercially available light sources. The 6V/30W tung sten bulb has a compact filament, giving a bright and uniform illumination. It is nor mally used in the Zeiss operating micro scope. The xenon flash tube, made of quartz, has a large inner bore and well-designed electrodes. The plasma discharge is very bright and uniform. This flash tube is nor mally used in the Zeiss fundus camera and in the Zeiss photo-slit lamp. The plasma discharge of the glass tube is optimally imaged on the subject's eye by a two-element condensing system of large ap erture, thus making best use of the available light. A heat filter is provided to cut off the infrared portion of the discharge. The tung sten filament is in turn imaged in front of the flash tube envelope with another con densing system consisting of two aspheric el ements. Thus, a blurred image of the fila ment is projected on the subject. This per mits the photographer to focus sharply, but
Fig. 2 (Matsui, Parel, Weder, and Justice). Opti cal diagram of system : W = tungsten lamp, Xe = xenon tube, S = subject, L = Nikkor lens, C = motor driven Nikon F, T = trigger module, B4 and BS = interference niters, a = filament, ai = inter mediate image offilament,a2 = final image of fila ment, b = plasma, bi = image of plasma, h = infra red filter, d = diaphragm, f = film plane.
VOL. 74, NO. 6
ANTERIOR SEGMENT ANGIOGRAPHY
does not interfere with the photographic pro cess because the plasma intensity is much higher. The camera and the illuminating device are mounted on the slit-lamp table in order to have the foci of both photographing and illuminating systems at the same point. The joy stick simultaneously controls the il luminating and photographing systems very easily. We use a pair of interference fluorescein filters (Baird Atomic B4 and B5). Because of the high intensity of the observation light, we can select the desired area to be photo graphed and bring it into focus without re moving any of these filters. The xenon tube, the tungsten bulb and the motor are powered by a modified Zeiss fundus camera power supply (240 Joules, pos. I V ) . We also used a fast-charge unit so that we could photograph up to one frame per second. The entire system is controlled by a single foot switch. TECHNIQUE
Kodak Tri-X film is used and developed in Kodak D - l l diluted 1:3 for eight and one-half minutes at 74°F. Forced develop ment is not necessary because enough light is provided by the illuminating system. Usually, we used an aperture of 1:22 and a flash intensity of 120 joules (pos. I I I ) .
1077
Fig. 4. (Matsui, Parel, Weder, and Justice). Angiograph of 73-year-old man with untreated angleclosure glaucoma of several years' duration. Photo graph shows corneal neovascularization in fully filled phase. Sometimes, a flash intensity of 60 joules (pos. I I ) was selected for late phase conjunctival studies because of the intense scierai fluorescence. Color photographs were always taken with a Donaldson stereo camera. Five ml of 10% fluorescein sodium solu tion was injected into the antecubital vein as rapidly as possible. Usually, 20 pictures were taken continuously at one-second intervals, and several more pictures at five- and 15minute intervals. RESULTS
This method was studied in over 100 sub jects. Some were patients with various eye diseases, and others were normal subjects of various ages. Some examples of our results are illustrated and described in Figures 3-5. DISCUSSION
Fig. 3 (Matsui, Parel, Weder, and Justice). Angiograph of normal 32-year-old man. Fine structure of the limbal vessel arcades can be seen on the temporal side. Enough resolution for anterior seg ment angiography was easily obtained with the technique described. Measurements show that the fine capillaries are in the order of 8 μ in diameter (X30).
There are a number of advantages to this system. One can obtain a full image of 24 X 35 mm size without obscuring the margins. Enough magnification ( X 2 or X 3 on the film) for iris or conjunctival angiography is easily achieved. The angle between the axis of the photographing system and that of the illuminating system is easily changed in or der to move the reflex image on the cornea or the conjunctiva out of the desired area. The large depth of field gives critical focus
1078
AMERICAN JOURNAL OF OPHTHALMOLOGY
DECEMBER, 1972
focusing, enabled us to obtain excellent pho tographic results. Resolution in the order of 10 μπι was obtained. ACKNOWLEDGMENTS
We thank E. W. D. Norton, M.D., for his in valuable encouragement and support. We are also indebted to Drs. J. G. Hirschberg and H. R. Gor don for their scientific assistance. N. Hecklinski, D. Clark, K. Peterson, J. Goren and B. French were responsible for the photography. We are grateful to R. Hurtes for her editorial assistance and we ap preciate the secretarial help provided by C. D. Rowlette and Y. Karrenberg. We also thank Drs. S. Takizawa, Topcon Optical Co., Tokyo, E. Stern, Zeiss Oberkochen, and D. Schmidheini, Wild Herbrugg, for their technical advice. Fig. S (Matsui, Parel, Weder, and Justice). Angiograph of seven-month-old black child, born pre maturely. Note clarity of pupillary membrane. Iris vessels show marked fluorescence, due to immatur ity of the iris pigmentation in the external limiting membrane. With maturation of the iris pigmenta tion, this fluorescence decreased. This infant was tranquilized, but not anesthetized, before this photo graph was made, illustrating that this technique can be performed easily in very small children. over the entire anterior chamber. A motordriven system controlled by a foot switch permits serial angiography at the rate of one frame per second. The xenon flash tube pro vides enough light so that forced develop ment is not necessary. Fine grain negatives result and details as small as 10 μ, can be eas ily resolved. No forced cooling is necessary and a relatively small power supply is used. A disadvantage of this technique is its in ability to record simultaneous stereo photo graphs. A simultaneous stereo system for anterior segment fluorescein angiography is being developed and will be reported in the near future. SUMMARY
An improved method for anterior segment fluorescein angiography was achieved by us ing a 200 mm lens with an automatic dia phragm, coupled to a motor-driven camera body. A special lighting system, providing high intensity illumination, coupled with an automatic diaphragm which allows critical
REFERENCES
1. Novotny, H. R., and Alvis, D. L. : A method of photographing flourescence in circulating blood of the human eye. Aero. Med. 60:82, 1960. 2. Jensen, V. A., and Lundbaek, K. : Fluorescence angiography of the iris in recent and long-term dia betes. Acta Ophth. 46:584, 1968. 3. Jensen, V. A., and Lundbaek, K. : Florescence angiography of the iris in recent and long-term di abetes. Diabetologica 4:161, 1968. 4. Rosen, E., and Lyons, D. : Microhemangiomas at the pupillary border demonstrated by fluorescein photography. Am. J. Ophth. 67:846, 1969. 5. Mapstone, R. : Ischaemia in vein occlusions. Brit. J. Ophth. 54:312, 1970. 6. : Fluorescein iridography. Brit. J. Ophth. 55:400, 1971. 7. Mitsui, Y., Matsubara, M., and Kanagawa, M. : Fluorescence iridocorneal photography. Brit. J. Ophth.53 :505, 1969. 8. Baggesen, L. H. : Fluorescence angiography of the iris in diabetics and non-diabetics. Acta Ophth. 47:449, 1969. 9. Bruun-Jensen, J. : Fluorescein angiography of the anterior segment. Am. J. Ophth. 67:842, 1969. 10. Brancato, R., and Frosini, R. : Fluorescein microangiography of the anterior segment of the eye. Ann. Ott. Clin. Ocul. 11:543, 1970. 11. Raitta, C, and Vannas, S. : Fluorescein angi ographie features of the limbus and perilimbal ves sels. EENT Monthly 50:20.1971. 12. : Fluoresceinangiographie der Irisgefasse nach Zentralvenenverschluss. von Graefe's Arch. klin. exp. Ophth. 177:33, 1969. 13. Vannas, A. : Fluorescein angiography of the vessels of the iris in pseudoexfoliation of the lens capsule, capsular glaucoma and some other forms of glaucoma. Acta Ophth. 105 (Suppl.) : 75, 1969. 14. Déodati, F., Bec, P., Labro, J. B., and Camezind, M. : Angiographie fluorescéinique du segment antérieur. Premiers résultats cliniques. Bull. Soc. Opht. Franc. 69:1099, 1969. 15. : Angiographie fluorescéinique du seg-
VOL. 74. NO. 6
ANTERIOR SEGMENT ANGIOGRAPHY
ment antérieur dans les hypertensions oculaires. Bull. Soc. Opht. 83 :561, 1970. 16. : L'angiographie fluorescéinique du segment antérieur son intérêt, ses possibilities. Bull. Soc. Opht. Franc. 70:33, 1970. 17. Amalric, P., Rebière, P.. and Jourdes, J. C. : Noucelles indications de l'angiographie fluorescéi nique du segment antérieur de l'oeil Ann. Ocul. 204:455, 1971. 18. Amalric, P., and Rebière, P . : Nouvelles in dications de l'angiographie fluorescéinique du seg ment antérieur de l'oeil : Les veines aqueuses. Ann. Ocul. 204:469, 1971. 19. : Nouvelles indications de l'angio graphie fluorescéinique du segment antérieur de
1079
l'oeil. III Chapitre: Altérations des vaissaux conjonctivaux. Am. Ocul. 204:595,1971. 20. : Nouvelles indications de l'angio graphie fluorescéinique du segment antérieur de l'oeil. Ann. Ocul. 204:731, 1971. 21. Koh, K. : Studies on the fluorescence photogra phy of the bulbar conjunctiva! vessels, on the tech niques of photography. Nich. Igaku Zash. 27:386, 1969. 22. Craandijk, A., and Aan de Kerk, A, L. : Flu orescence angiography of the iris. Brit. J. Ophth. 54:229, 1970. 23. Cobb, B., Shilling, J. S., and Chisholm, I. H. : Vascular tufts at the pupillary margin in myotonic dystrophy. Am. J. Ophth. 69:573, 1970.
O P H T H A L M I C MINIATURE
T h e r e is a sandhopper on the seashore which stays on the belt of wet sand above the wash of the sea. W h e n the hoppers are put on the dry sand higher up the shore, they make their way straight to the wet area which they prefer. Apparently they guide themselves by the light from the sky. H o p p e r s from the west coast of Italy transported and set free on the eastern shores still hopped westward in their endeavour to reach the sea, though in their new locality this was quite the wrong way to go. Hoppers in a bowl will j u m p in the direction of the sea, but they alter their direction when a polarised light filter over the bowl changes the pat tern presented to their eyes. J. D. Carthy Animal Navigation Allen & Unwin" 1956
Mizuo
MATSUI,
M.D.,
J E A N - M A R I E PAREL, ING.
ETS-G,
H A N S J U R G WEDER, A N D J O H N N Y JUSTICE, JR.
Miami, Florida 1
In 1960, Novotny and Alvis reported the use of fluorescein for fundus angiography. In 1968, Jensen and Lundbaek 2 · 3 utilized this technique to study the iris and conjunctival vessels in diabetic patients. Using a Zeiss-Robot fundus camera, they magnified the image by adding a +200 mm lens in front of the standard aspherical objective. In 1970, Rosen and Lyons 4 reported fluorescein angiographs of microhemangiomas at the pu pillary border, using a standard Zeiss fundus camera adjusted for anterior segment pho tography. Mapstone5'6 also used this system for his studies. Mitsui, Matsubara and Kanagawa7 reported iridocorneal angiography using modified Nikon and Zeiss photo-slit lamps. Baggesen's8 report of iris angiog raphy by means of a Zeiss photo-slit lamp powered by a high-speed power supply was followed by others9-20 who used the same technique. Koh 21 studied conjunctival angiography using a low-power binocular microscope and the light source of an Olympus fundus camera. Craandijk22 reported anterior segment an giography using a standard single-lens re flex camera coupled to a macrophotographic objective with a standard Zeiss fundus cam era as an illumination device. Using the same technique, Cobb, Shilling, and Chisholm23 studied vascular tufts at the pupillary margin· From the Bascom Palmer Eye Institute, Depart ment of Ophthalmology, University of Miami School of Medicine, Miami, Florida. This investiga tion was supported in part by Public Health Service Grant EY00338 from the National Eye Institute, and by Research to Prevent Blindness, Inc. Reprint Requests to Mr. Jean-Marie Parel, Bas com Palmer Eye Institute, P.O. Box 875, Biscayne Annex, Miami, Florida 33152.
Four basically different methods for ante rior segment fluorescein angiography have been reported. Each technique utilizes a dif ferent instrument: a fundus camera, a photo-slit lamp, a binocular microscope, or a combination of single-lens reflex camera with a fundus camera as an illuminator. Each of these methods presents certain dis advantages : The fundus camera is designed for a spe cial purpose. It is not suitable for anterior segment photography because of low magni fication, severe peripheral aberrations, inad equate depth of field, and obscured frame margins. The addition of a +200 mm lens only increases the magnification at the ex pense of the depth of field. A photo-slit lamp provides angiograms of good quality but obscured frame margins oc cur because of the limited field angle of the slit illuminator. Also, forced-developed high speed films must be used because of insuf ficient lighting. An operating binocular microscope, being vertically mounted, cannot be used effec tively in the clinic without extensive modifi cations. The usual single lens reflex camera pro vides optimal use of the 35 mm frame. When a standard fundus camera is used as an illuminator, the system becomes bulky and optical efficiency is low. A 75% loss of light is estimated to occur because of Fresnel reflections at each optical interface, due to the inherent ring-shaped diaphragm and due to the limited span of the aperture of the il lumination system. If good quality angiograms are to be ob tained, all four methods require extensive modifications to the basic instrument. For
1075
1076
AMERICAN JOURNAL OF OPHTHALMOLOGY
Fig. 1 (Matsui, Parel, Weder, and Justice). Front view of equipment (chin rest removed). this reason, we specifically designed an appa ratus for anterior segment fluorescein angiography. It consists of a specially developed illuminator and a medical Nikkor objective, coupled to a motor-driven Nikon F camera body. Both sections are mounted on a stan dard Haag-Streit slitlamp table (Fig. 1). A modified 250 joules Zeiss fundus camera power supply provides the necessary electri cal energy. We selected a 200 mm Nikkor lens that is designed specifically for close-up medical photography. Its diaphragm is auto matic, permitting sharp focusing during angiography. The long focal length of this lens provides ample working distance. Magnifica tion up to X3 are obtained simply by chang ing the complementary objectives, which is advantageous if linear measurements are to be made on the angiograms. This system provides an optimal image size of 24 X 35 mm without marginal obscurity or aberra tion.
DECEMBER, 1972
The illuminator is built around two light sources. A tungsten lamp provides the obser vation beam, and a high-power xenon tube provides the photographic beam (Fig. 2). For simplicity, we chose two commercially available light sources. The 6V/30W tung sten bulb has a compact filament, giving a bright and uniform illumination. It is nor mally used in the Zeiss operating micro scope. The xenon flash tube, made of quartz, has a large inner bore and well-designed electrodes. The plasma discharge is very bright and uniform. This flash tube is nor mally used in the Zeiss fundus camera and in the Zeiss photo-slit lamp. The plasma discharge of the glass tube is optimally imaged on the subject's eye by a two-element condensing system of large ap erture, thus making best use of the available light. A heat filter is provided to cut off the infrared portion of the discharge. The tung sten filament is in turn imaged in front of the flash tube envelope with another con densing system consisting of two aspheric el ements. Thus, a blurred image of the fila ment is projected on the subject. This per mits the photographer to focus sharply, but
Fig. 2 (Matsui, Parel, Weder, and Justice). Opti cal diagram of system : W = tungsten lamp, Xe = xenon tube, S = subject, L = Nikkor lens, C = motor driven Nikon F, T = trigger module, B4 and BS = interference niters, a = filament, ai = inter mediate image offilament,a2 = final image of fila ment, b = plasma, bi = image of plasma, h = infra red filter, d = diaphragm, f = film plane.
VOL. 74, NO. 6
ANTERIOR SEGMENT ANGIOGRAPHY
does not interfere with the photographic pro cess because the plasma intensity is much higher. The camera and the illuminating device are mounted on the slit-lamp table in order to have the foci of both photographing and illuminating systems at the same point. The joy stick simultaneously controls the il luminating and photographing systems very easily. We use a pair of interference fluorescein filters (Baird Atomic B4 and B5). Because of the high intensity of the observation light, we can select the desired area to be photo graphed and bring it into focus without re moving any of these filters. The xenon tube, the tungsten bulb and the motor are powered by a modified Zeiss fundus camera power supply (240 Joules, pos. I V ) . We also used a fast-charge unit so that we could photograph up to one frame per second. The entire system is controlled by a single foot switch. TECHNIQUE
Kodak Tri-X film is used and developed in Kodak D - l l diluted 1:3 for eight and one-half minutes at 74°F. Forced develop ment is not necessary because enough light is provided by the illuminating system. Usually, we used an aperture of 1:22 and a flash intensity of 120 joules (pos. I I I ) .
1077
Fig. 4. (Matsui, Parel, Weder, and Justice). Angiograph of 73-year-old man with untreated angleclosure glaucoma of several years' duration. Photo graph shows corneal neovascularization in fully filled phase. Sometimes, a flash intensity of 60 joules (pos. I I ) was selected for late phase conjunctival studies because of the intense scierai fluorescence. Color photographs were always taken with a Donaldson stereo camera. Five ml of 10% fluorescein sodium solu tion was injected into the antecubital vein as rapidly as possible. Usually, 20 pictures were taken continuously at one-second intervals, and several more pictures at five- and 15minute intervals. RESULTS
This method was studied in over 100 sub jects. Some were patients with various eye diseases, and others were normal subjects of various ages. Some examples of our results are illustrated and described in Figures 3-5. DISCUSSION
Fig. 3 (Matsui, Parel, Weder, and Justice). Angiograph of normal 32-year-old man. Fine structure of the limbal vessel arcades can be seen on the temporal side. Enough resolution for anterior seg ment angiography was easily obtained with the technique described. Measurements show that the fine capillaries are in the order of 8 μ in diameter (X30).
There are a number of advantages to this system. One can obtain a full image of 24 X 35 mm size without obscuring the margins. Enough magnification ( X 2 or X 3 on the film) for iris or conjunctival angiography is easily achieved. The angle between the axis of the photographing system and that of the illuminating system is easily changed in or der to move the reflex image on the cornea or the conjunctiva out of the desired area. The large depth of field gives critical focus
1078
AMERICAN JOURNAL OF OPHTHALMOLOGY
DECEMBER, 1972
focusing, enabled us to obtain excellent pho tographic results. Resolution in the order of 10 μπι was obtained. ACKNOWLEDGMENTS
We thank E. W. D. Norton, M.D., for his in valuable encouragement and support. We are also indebted to Drs. J. G. Hirschberg and H. R. Gor don for their scientific assistance. N. Hecklinski, D. Clark, K. Peterson, J. Goren and B. French were responsible for the photography. We are grateful to R. Hurtes for her editorial assistance and we ap preciate the secretarial help provided by C. D. Rowlette and Y. Karrenberg. We also thank Drs. S. Takizawa, Topcon Optical Co., Tokyo, E. Stern, Zeiss Oberkochen, and D. Schmidheini, Wild Herbrugg, for their technical advice. Fig. S (Matsui, Parel, Weder, and Justice). Angiograph of seven-month-old black child, born pre maturely. Note clarity of pupillary membrane. Iris vessels show marked fluorescence, due to immatur ity of the iris pigmentation in the external limiting membrane. With maturation of the iris pigmenta tion, this fluorescence decreased. This infant was tranquilized, but not anesthetized, before this photo graph was made, illustrating that this technique can be performed easily in very small children. over the entire anterior chamber. A motordriven system controlled by a foot switch permits serial angiography at the rate of one frame per second. The xenon flash tube pro vides enough light so that forced develop ment is not necessary. Fine grain negatives result and details as small as 10 μ, can be eas ily resolved. No forced cooling is necessary and a relatively small power supply is used. A disadvantage of this technique is its in ability to record simultaneous stereo photo graphs. A simultaneous stereo system for anterior segment fluorescein angiography is being developed and will be reported in the near future. SUMMARY
An improved method for anterior segment fluorescein angiography was achieved by us ing a 200 mm lens with an automatic dia phragm, coupled to a motor-driven camera body. A special lighting system, providing high intensity illumination, coupled with an automatic diaphragm which allows critical
REFERENCES
1. Novotny, H. R., and Alvis, D. L. : A method of photographing flourescence in circulating blood of the human eye. Aero. Med. 60:82, 1960. 2. Jensen, V. A., and Lundbaek, K. : Fluorescence angiography of the iris in recent and long-term dia betes. Acta Ophth. 46:584, 1968. 3. Jensen, V. A., and Lundbaek, K. : Florescence angiography of the iris in recent and long-term di abetes. Diabetologica 4:161, 1968. 4. Rosen, E., and Lyons, D. : Microhemangiomas at the pupillary border demonstrated by fluorescein photography. Am. J. Ophth. 67:846, 1969. 5. Mapstone, R. : Ischaemia in vein occlusions. Brit. J. Ophth. 54:312, 1970. 6. : Fluorescein iridography. Brit. J. Ophth. 55:400, 1971. 7. Mitsui, Y., Matsubara, M., and Kanagawa, M. : Fluorescence iridocorneal photography. Brit. J. Ophth.53 :505, 1969. 8. Baggesen, L. H. : Fluorescence angiography of the iris in diabetics and non-diabetics. Acta Ophth. 47:449, 1969. 9. Bruun-Jensen, J. : Fluorescein angiography of the anterior segment. Am. J. Ophth. 67:842, 1969. 10. Brancato, R., and Frosini, R. : Fluorescein microangiography of the anterior segment of the eye. Ann. Ott. Clin. Ocul. 11:543, 1970. 11. Raitta, C, and Vannas, S. : Fluorescein angi ographie features of the limbus and perilimbal ves sels. EENT Monthly 50:20.1971. 12. : Fluoresceinangiographie der Irisgefasse nach Zentralvenenverschluss. von Graefe's Arch. klin. exp. Ophth. 177:33, 1969. 13. Vannas, A. : Fluorescein angiography of the vessels of the iris in pseudoexfoliation of the lens capsule, capsular glaucoma and some other forms of glaucoma. Acta Ophth. 105 (Suppl.) : 75, 1969. 14. Déodati, F., Bec, P., Labro, J. B., and Camezind, M. : Angiographie fluorescéinique du segment antérieur. Premiers résultats cliniques. Bull. Soc. Opht. Franc. 69:1099, 1969. 15. : Angiographie fluorescéinique du seg-
VOL. 74. NO. 6
ANTERIOR SEGMENT ANGIOGRAPHY
ment antérieur dans les hypertensions oculaires. Bull. Soc. Opht. 83 :561, 1970. 16. : L'angiographie fluorescéinique du segment antérieur son intérêt, ses possibilities. Bull. Soc. Opht. Franc. 70:33, 1970. 17. Amalric, P., Rebière, P.. and Jourdes, J. C. : Noucelles indications de l'angiographie fluorescéi nique du segment antérieur de l'oeil Ann. Ocul. 204:455, 1971. 18. Amalric, P., and Rebière, P . : Nouvelles in dications de l'angiographie fluorescéinique du seg ment antérieur de l'oeil : Les veines aqueuses. Ann. Ocul. 204:469, 1971. 19. : Nouvelles indications de l'angio graphie fluorescéinique du segment antérieur de
1079
l'oeil. III Chapitre: Altérations des vaissaux conjonctivaux. Am. Ocul. 204:595,1971. 20. : Nouvelles indications de l'angio graphie fluorescéinique du segment antérieur de l'oeil. Ann. Ocul. 204:731, 1971. 21. Koh, K. : Studies on the fluorescence photogra phy of the bulbar conjunctiva! vessels, on the tech niques of photography. Nich. Igaku Zash. 27:386, 1969. 22. Craandijk, A., and Aan de Kerk, A, L. : Flu orescence angiography of the iris. Brit. J. Ophth. 54:229, 1970. 23. Cobb, B., Shilling, J. S., and Chisholm, I. H. : Vascular tufts at the pupillary margin in myotonic dystrophy. Am. J. Ophth. 69:573, 1970.
O P H T H A L M I C MINIATURE
T h e r e is a sandhopper on the seashore which stays on the belt of wet sand above the wash of the sea. W h e n the hoppers are put on the dry sand higher up the shore, they make their way straight to the wet area which they prefer. Apparently they guide themselves by the light from the sky. H o p p e r s from the west coast of Italy transported and set free on the eastern shores still hopped westward in their endeavour to reach the sea, though in their new locality this was quite the wrong way to go. Hoppers in a bowl will j u m p in the direction of the sea, but they alter their direction when a polarised light filter over the bowl changes the pat tern presented to their eyes. J. D. Carthy Animal Navigation Allen & Unwin" 1956