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Neovascularization after Argon Laser Photocoagulation of Macular Lesions
NEOVASCULARIZATION A F T E R ARGON LASER PHOTOCOAGULATION O F MACULAR LESIONS J. FRANÇOIS, M.D.,
J. J. D E LAEY, M.D., and
E. CAMME, M.D.,
V. VICTORIA-TRONCOSO,
M. HANSSENS,
M.D.,
M.D.
Ghent, Belgium
Since photocoagulation has been used for the treatment or prevention of macular de generation a number of reports of success have been published, but only a few authors have called attention to possible complica tions. Gass1 mentioned the following: acci dental photocoagulation of the fovea; macu lar distortion secondary to a contraction of a preretinal vitreous membrane ; macular distortion secondary to excessive paracentral photocoagulation ; large paracentral scotoma ; excessive photocoagulation in the papillomacular bundle area; subretinal and intravitreous hemorrhages ; possible rupture of Bruch's membrane ; and possible stimulation of a subretinal neovascular membrane. We should like to call attention to the last two complications. Laser photocoagulation can not only stimulate the growth of a pre existing subretinal neovascular membrane, but can also produce neovascularization, par ticularly when Bruch's membrane is dis eased. In two of our three patients described below neovascularization occurred in Groenblad-Strandberg disease. To prevent disciform macular degeneration photocoagulation was used along the angioid streaks jeopar dizing the macular area, as described by Offret, Coscas, and Orsoni-Dupont.2
Fig. 1 (François, De Laey, Cambie, Hanssens, and Victoria-Troncoso). Case 1, left eye. Fluoroangiographic appearance before argon laser photo coagulation. Slight fluorescence of the angioid streaks.
CASE REPORTS Case 1—A 48-year-old man with GroenbladStrandberg disease presented with disciform macu lar degeneration of the right eye. Typical angioid streaks were observed in the macular area of the left eye although visual acuity was 10/10 (Fig. 1). These streaks were photocoagulated with the argon laser (12 points of 250 m W ; 100 μ; 0.2 sec). Three weeks later an area of late fluoresFrom the Ophthalmological Clinic, University of Ghent, Ghent, Belgium. Read before the International Laser Symposium, Albi, France, May 21, 1974. Reprint requests to J. Francois, M.D., Director, Ophthalmological Clinic, University of Ghent, De Pintelaan, 135, B-9000, Ghent, Belgium. 206
Fig. 2 (François, De and Victoria-Troncoso). angiographic appearance laser photocoagulation of
Laey, Cambie, Hanssens, Case 1, left eye. Fluorothree weeks after argon the angioid streaks.
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Fig. 3 (François, De Laey, Cambie, Hanssens, and Victoria-Troncoso). Case 1, left eye. Fluoroangiographic appearance six weeks after treatment. Neovascular tuft at the level of the photocoagulation. cence was observed at one coagulation site (Fig. 2). Six weeks after treatment this spot showed a typical neovascular tuft surrounded by localized detachment (Fig. 3). Visual acuity was 7/10. Case 2—In this SS-year-old man central visual acuity of the left eye was already lost following disciform macular degeneration with angioid streaks. In his right eye angioid streaks were photocoagulated with the argon laser (27 points of 300 mW; 100 μ; 0.2 sec). One month later visual acuity was still 10/10. Two months after the treatment, however, a new rupture of Bruch's membrane was observed together with neovascu-
larization at one of the coagulation sites. The new streak was in connection with the neovascularization. Case 3—A bilateral filtering operation had been performed for open-angle glaucoma in this 48year-old man. Useful vision of the left eye was lost following disciform macular degeneration. The patient complained of decreased visual acuity of the right eye. There was an infrafoveal disci form lesion without visible vessels. As visual acuity was 3/10 and the late fluorescence did not include the fovea (Fig. 4), argon laser photocoagulation was employed (3 points of 250 mW,
Fig. 4 (Francois, De Laey, Cambie, Hanssens, and Victoria-Troncoso). Case 3, right eye. Fluoroangiographic appearance before treatment. Left, venous time; right, ten minutes after the fluorescein injection.
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Fig. S (François, De Laey, Camhie, Hanssens, and Victoria-Troncoso). Case 3, right eye. Fluoroangìographic appearance two weeks after treatment. The three coagulation points and the proofpoint already show some scarring. Hyperfluorescence in the center of the treated area. 200 μ, 0.1 sec). Two weeks later visual acuity was 7/10. The perifoveal retina was flattened, al though control fluoroangiography still indicated a marked late fluorescence at the level of the central coagulation site (Fig. S). One month later a new serous detachment was ohserved with a marked neovascular tuft starting from the central photocoagulation scar (Fig. 6). COMMENT
These three cases show some similarities.
The light intensity used was relatively high (up to 300 m W ) . The spot-size was small (100 to 200 μ ) . The neovascular tuft ap peared six to eight weeks after the treat ment at a site that had initially an abnor mal fluorescence. In two of these cases Bruch's membrane was markedly abnormal. Choroidal neovascularization might have appeared even without treatment. It has been
Fig. 6 (Francois, De Laey, Cambie, Hanssens, and Victoria-Troncoso). Case 3, right eye. Fluoroangiographic appearance six weeks after treatment. Neovascular membrane in the center of the treated area.
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described early in the course of disciform macular degeneration.3"8 In our cases the close relationship be tween the treated area and the early ap pearance of neovascularization after treat ment proves the relationship with photoco agulation. Also, in Cases 1 and 2 there was no disciform degeneration and photocoagula tion was used to prevent this complication. We have also studied the effect of photocoagulation experimentally in pigmented rabbits, using the argon laser (spot-size 50 μ, 600 mW, 0.2 sec). One week after photocoagulation, the retina, choroid, and inner scierai layer formed a fibroglial pig mented and hemorrhagic mass with some microglial reaction. Fibrovascular tissue pen etrated into the vitreous cavity and spread along the inner surface of the normal retina near the photocoagulation site. Further from the photocoagulation site a small, strong chorioretinal synechia was observed. The inner retinal layers had small thin-walled vessels at their surface. Four weeks after treatment fibrous tissue was seen pen etrating through a hole in the retina and spreading on its surface (Fig. 7). This seemed to occur only when a hole was made in the retina and the choroid.
209
Fig. 7 (François, De Laey, Cambie, Hanssens, and Victoria-Troncoso). Experimental argon laser photocoagulation of the retina of pigmented rab bits. Fibrous tissue starting from the coagulation and growing over the retina (hematoxylin-eosin, X80).
We also studied the effect of argon laser photocoagulation in rabbits on flat prepara tions of the choroid. One month after treat ment the photocoagulation spots presented a scar with whitish and highly biréfringent collagen fibers (Fig. 8 ) , pigment clumps at the center, and larger interrupted vessels. The most important alterations were, never theless, seen after depigmentation of the preparations (Fig. 9). A proliferation of capillaries was seen around each spot, but was usually lacking in the center. Locally these capillaries were seen growing into the
Fig. 8 (François, De Laey, Cambie, Hanssens, and Victoria-Troncoso). Choroidal flat preparation of rabbit eyes treated by argon laser photocoagulation. Appearance at the level of the scar (polarization microscopy, Van Gieson's stain, X6.3).
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mal scarring. Excessive intensity might pro duce a localized defect of Bruch's mem brane and no cicatricial sealing of this de fect. SUMMARY
Fig. 9 (François, De Laey, Cambie, Hanssens, and Victoria-Troncoso). Same lesion as shown in Figure 8, after depigmentation of the preparation. Proliferation of capillaries especially around the coagulation scar, which is surrounded by mucopolysaccharides (Rinehart and Abul-Haj staining, X6.3). retina. Around each spot was a ring of mucopolysaccharides with endothelial tissue in growth. This neovascularized tissue did not show elastic fibers on orcein staining. In conclusion, it seems that a direct trau ma to the choroidal vessels can either pro duce new vessel formation or stimulate a preexisting vascular membrane. This trauma is more likely to occur in cases of diseased Bruch's membrane and especially in cases of angioid streaks, where photocoagulation may produce a defect instead of sealing it. Such complications occur perhaps more easily with laser photocoagulation than with xenon-arc photocoagulation. T h e limited dis persion of the laser light with its maximal energy at the coagulation site and its mini mal reaction in the vicinity produces mini
I n three patients treated for macular de generation with argon laser photocoagulation choroidal neovascularization occurred four to six weeks later at the photocoagulation site. T w o of the patients were treated for angioid streaks of the macular region, the third patient was treated for disciform macular degeneration. Argon laser photoco agulation also induced neovascularization ex perimentally in pigmented rabbits. REFERENCES
1. Gass, J. D. M.: Options in the treatment of macular diseases. Trans. Ophthalmol. Soc. U.K. 92:449, 1972. 2. Offret, G-, Coscas, G, and Orsoni-Dupont, C. : Photocoagulation des stries angioides après angiographie fluorescéinique. Arch. Ophtalniol. 30:419, 1970. 3. Gass, J. D. M. : Pathogenesis of disciform detachment of the neuro-epithelium. 4. Fluorescein angiographie study of senile disciform macular degeneration. Am. J. Ophthalmol. 63:64S, 1967. 4. Bird, A. C., and Teeters, V. W. : The evo lution of subpigment epithelial neovascularisation in senile disciform macular degeneration. Trans. Ophthalmol. Soc. U.K. 92:413, 1972. 5. Teeters, V. W., and Bird, A. C. : A clinical study of the vascularity of senile disciform macular degeneration. Am. J. Ophthalmol. 75: S3, 1973. 6. : The development of neovascularization of senile disciform macular degeneration. Am. J. Ophthalmol. 76:1, 1973.
J. J. D E LAEY, M.D., and
E. CAMME, M.D.,
V. VICTORIA-TRONCOSO,
M. HANSSENS,
M.D.,
M.D.
Ghent, Belgium
Since photocoagulation has been used for the treatment or prevention of macular de generation a number of reports of success have been published, but only a few authors have called attention to possible complica tions. Gass1 mentioned the following: acci dental photocoagulation of the fovea; macu lar distortion secondary to a contraction of a preretinal vitreous membrane ; macular distortion secondary to excessive paracentral photocoagulation ; large paracentral scotoma ; excessive photocoagulation in the papillomacular bundle area; subretinal and intravitreous hemorrhages ; possible rupture of Bruch's membrane ; and possible stimulation of a subretinal neovascular membrane. We should like to call attention to the last two complications. Laser photocoagulation can not only stimulate the growth of a pre existing subretinal neovascular membrane, but can also produce neovascularization, par ticularly when Bruch's membrane is dis eased. In two of our three patients described below neovascularization occurred in Groenblad-Strandberg disease. To prevent disciform macular degeneration photocoagulation was used along the angioid streaks jeopar dizing the macular area, as described by Offret, Coscas, and Orsoni-Dupont.2
Fig. 1 (François, De Laey, Cambie, Hanssens, and Victoria-Troncoso). Case 1, left eye. Fluoroangiographic appearance before argon laser photo coagulation. Slight fluorescence of the angioid streaks.
CASE REPORTS Case 1—A 48-year-old man with GroenbladStrandberg disease presented with disciform macu lar degeneration of the right eye. Typical angioid streaks were observed in the macular area of the left eye although visual acuity was 10/10 (Fig. 1). These streaks were photocoagulated with the argon laser (12 points of 250 m W ; 100 μ; 0.2 sec). Three weeks later an area of late fluoresFrom the Ophthalmological Clinic, University of Ghent, Ghent, Belgium. Read before the International Laser Symposium, Albi, France, May 21, 1974. Reprint requests to J. Francois, M.D., Director, Ophthalmological Clinic, University of Ghent, De Pintelaan, 135, B-9000, Ghent, Belgium. 206
Fig. 2 (François, De and Victoria-Troncoso). angiographic appearance laser photocoagulation of
Laey, Cambie, Hanssens, Case 1, left eye. Fluorothree weeks after argon the angioid streaks.
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Fig. 3 (François, De Laey, Cambie, Hanssens, and Victoria-Troncoso). Case 1, left eye. Fluoroangiographic appearance six weeks after treatment. Neovascular tuft at the level of the photocoagulation. cence was observed at one coagulation site (Fig. 2). Six weeks after treatment this spot showed a typical neovascular tuft surrounded by localized detachment (Fig. 3). Visual acuity was 7/10. Case 2—In this SS-year-old man central visual acuity of the left eye was already lost following disciform macular degeneration with angioid streaks. In his right eye angioid streaks were photocoagulated with the argon laser (27 points of 300 mW; 100 μ; 0.2 sec). One month later visual acuity was still 10/10. Two months after the treatment, however, a new rupture of Bruch's membrane was observed together with neovascu-
larization at one of the coagulation sites. The new streak was in connection with the neovascularization. Case 3—A bilateral filtering operation had been performed for open-angle glaucoma in this 48year-old man. Useful vision of the left eye was lost following disciform macular degeneration. The patient complained of decreased visual acuity of the right eye. There was an infrafoveal disci form lesion without visible vessels. As visual acuity was 3/10 and the late fluorescence did not include the fovea (Fig. 4), argon laser photocoagulation was employed (3 points of 250 mW,
Fig. 4 (Francois, De Laey, Cambie, Hanssens, and Victoria-Troncoso). Case 3, right eye. Fluoroangiographic appearance before treatment. Left, venous time; right, ten minutes after the fluorescein injection.
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Fig. S (François, De Laey, Camhie, Hanssens, and Victoria-Troncoso). Case 3, right eye. Fluoroangìographic appearance two weeks after treatment. The three coagulation points and the proofpoint already show some scarring. Hyperfluorescence in the center of the treated area. 200 μ, 0.1 sec). Two weeks later visual acuity was 7/10. The perifoveal retina was flattened, al though control fluoroangiography still indicated a marked late fluorescence at the level of the central coagulation site (Fig. S). One month later a new serous detachment was ohserved with a marked neovascular tuft starting from the central photocoagulation scar (Fig. 6). COMMENT
These three cases show some similarities.
The light intensity used was relatively high (up to 300 m W ) . The spot-size was small (100 to 200 μ ) . The neovascular tuft ap peared six to eight weeks after the treat ment at a site that had initially an abnor mal fluorescence. In two of these cases Bruch's membrane was markedly abnormal. Choroidal neovascularization might have appeared even without treatment. It has been
Fig. 6 (Francois, De Laey, Cambie, Hanssens, and Victoria-Troncoso). Case 3, right eye. Fluoroangiographic appearance six weeks after treatment. Neovascular membrane in the center of the treated area.
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described early in the course of disciform macular degeneration.3"8 In our cases the close relationship be tween the treated area and the early ap pearance of neovascularization after treat ment proves the relationship with photoco agulation. Also, in Cases 1 and 2 there was no disciform degeneration and photocoagula tion was used to prevent this complication. We have also studied the effect of photocoagulation experimentally in pigmented rabbits, using the argon laser (spot-size 50 μ, 600 mW, 0.2 sec). One week after photocoagulation, the retina, choroid, and inner scierai layer formed a fibroglial pig mented and hemorrhagic mass with some microglial reaction. Fibrovascular tissue pen etrated into the vitreous cavity and spread along the inner surface of the normal retina near the photocoagulation site. Further from the photocoagulation site a small, strong chorioretinal synechia was observed. The inner retinal layers had small thin-walled vessels at their surface. Four weeks after treatment fibrous tissue was seen pen etrating through a hole in the retina and spreading on its surface (Fig. 7). This seemed to occur only when a hole was made in the retina and the choroid.
209
Fig. 7 (François, De Laey, Cambie, Hanssens, and Victoria-Troncoso). Experimental argon laser photocoagulation of the retina of pigmented rab bits. Fibrous tissue starting from the coagulation and growing over the retina (hematoxylin-eosin, X80).
We also studied the effect of argon laser photocoagulation in rabbits on flat prepara tions of the choroid. One month after treat ment the photocoagulation spots presented a scar with whitish and highly biréfringent collagen fibers (Fig. 8 ) , pigment clumps at the center, and larger interrupted vessels. The most important alterations were, never theless, seen after depigmentation of the preparations (Fig. 9). A proliferation of capillaries was seen around each spot, but was usually lacking in the center. Locally these capillaries were seen growing into the
Fig. 8 (François, De Laey, Cambie, Hanssens, and Victoria-Troncoso). Choroidal flat preparation of rabbit eyes treated by argon laser photocoagulation. Appearance at the level of the scar (polarization microscopy, Van Gieson's stain, X6.3).
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mal scarring. Excessive intensity might pro duce a localized defect of Bruch's mem brane and no cicatricial sealing of this de fect. SUMMARY
Fig. 9 (François, De Laey, Cambie, Hanssens, and Victoria-Troncoso). Same lesion as shown in Figure 8, after depigmentation of the preparation. Proliferation of capillaries especially around the coagulation scar, which is surrounded by mucopolysaccharides (Rinehart and Abul-Haj staining, X6.3). retina. Around each spot was a ring of mucopolysaccharides with endothelial tissue in growth. This neovascularized tissue did not show elastic fibers on orcein staining. In conclusion, it seems that a direct trau ma to the choroidal vessels can either pro duce new vessel formation or stimulate a preexisting vascular membrane. This trauma is more likely to occur in cases of diseased Bruch's membrane and especially in cases of angioid streaks, where photocoagulation may produce a defect instead of sealing it. Such complications occur perhaps more easily with laser photocoagulation than with xenon-arc photocoagulation. T h e limited dis persion of the laser light with its maximal energy at the coagulation site and its mini mal reaction in the vicinity produces mini
I n three patients treated for macular de generation with argon laser photocoagulation choroidal neovascularization occurred four to six weeks later at the photocoagulation site. T w o of the patients were treated for angioid streaks of the macular region, the third patient was treated for disciform macular degeneration. Argon laser photoco agulation also induced neovascularization ex perimentally in pigmented rabbits. REFERENCES
1. Gass, J. D. M.: Options in the treatment of macular diseases. Trans. Ophthalmol. Soc. U.K. 92:449, 1972. 2. Offret, G-, Coscas, G, and Orsoni-Dupont, C. : Photocoagulation des stries angioides après angiographie fluorescéinique. Arch. Ophtalniol. 30:419, 1970. 3. Gass, J. D. M. : Pathogenesis of disciform detachment of the neuro-epithelium. 4. Fluorescein angiographie study of senile disciform macular degeneration. Am. J. Ophthalmol. 63:64S, 1967. 4. Bird, A. C., and Teeters, V. W. : The evo lution of subpigment epithelial neovascularisation in senile disciform macular degeneration. Trans. Ophthalmol. Soc. U.K. 92:413, 1972. 5. Teeters, V. W., and Bird, A. C. : A clinical study of the vascularity of senile disciform macular degeneration. Am. J. Ophthalmol. 75: S3, 1973. 6. : The development of neovascularization of senile disciform macular degeneration. Am. J. Ophthalmol. 76:1, 1973.