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Photocoagulation in Toxoplasmic Retinochoroiditis
CORRESPONDENCE
VOL. 91, NO. 3
Reply Editor: We appreciate Dr. Thompson's re marks about false clinical localization in our series of patients with Homer's syn drome. We rewrote the first draft of the paper in an attempt to explain these paradoxical responses, and we agree with Dr. Thompson's theory of multiple neuromal involvement in at least several of these cases. BRIAN R. YOUNGE,
Rochester,
M.D.
Minnesota
Photocoagulation in Toxoplasmic Retinochoroiditis Editor: I was greatly interested in the article, "Photocoagulation in active toxoplasmic retinochoroiditis" (Am. J. Ophthalmol. 89:858, 1980), by K. N. Ghartey and R. J. Brockhurst. In September 1964, at the VII Pan American Congress of Ophthalmology in Montreal, I presented a report on xenon photocoagulation treatment of 25 cases of retinochoroiditis, performed either dur ing an active primary attack or during an active recurrent episode. This report, along with a review of other studies, was published in Spain. 1 Spalter and associ ates 2 published a report the next year. My comments on their article appeared in 1966. 3 At that time, photocoagulation was used to treat toxoplasmic retinochoroidi tis in my country for the following rea sons: (1) the high incidence of the disor der; (2) the social and economic factors that made it difficult for many people to obtain medical treatment; (3) the system ic complication and unproven efficacy, particularly in regard to cysts, of the many drugs used to treat the disease; (4) photocoagulation's ability to shorten the active phase of the attacks; (5) the possibility of avoiding satellite recur rences by destroying nearby cysts; and
417
(6) the possibility of avoiding secondary complications (including glaucoma and cataract) produced by the inflammation. During the 1960s, I studied 60 cases treated by this method. By the 1970s, however, I came to believe that active cases did not need photocoagulation for a number of reasons. Active foci seem to heal spontaneously, although the amount of time required varies. Routine examinations disclose many instances of healed retinochoroidi tis scars in patients unaware of ever having had the disease. The disease can still recur, despite photocoagulation, near the treated area or in other parts of the retina, because all the cysts near the retinochoroiditis were not destroyed or because the cysts occurred far from the primary focus (D. Nicholson, personal communication, June 1980). For this reason, I have aban doned photocoagulation of inactive foci, something I originally recommended. Two of the 60 cases became worse after photocoagulation, and the possibility of spreading the Toxoplasma organisms was raised. In some cases, macular or extramacular tractional epiretinal membranes devel oped or worsened after photocoagulation. Vitreoretinal membrane contraction can lead to retinal holes and retinal detach ment. In eight cases, an iatrogenic hemorrhagic retinal vasculitis developed near the areas that underwent photocoagulation. 4 At the present time, I rarely treat active retinochoroiditis with photocoagu lation. I use this method no more than three or four times a year and only in cases where there is a danger of foveolar involvement or when the disease is ex tremely protracted. Although xenon photocoagulation is still used, argon-laser photocoagulation and crycoagulation 5 have also been used in some cases.
418
AMERICAN JOURNAL OF OPHTHALMOLOGY
I agree with the other findings of Drs. Ghartey and Brockhurst and congratulate them on their article. ALVARO RODRIGUEZ,
Bogota,
M.D.
Colombia
REFERENCES 1. Rodriguez, A.: Fotocoagulacion en las retinocoroiditis récidivantes. Arch. Soc. Oftalmol. Hispano-Americana 25:197, 1965. 2. Splater, H. F., Cambell, C. J., Noyori, K. S., Ritter, M. D., and Koester, C. J.: Prophylactic photocoagulation of recurrent toxoplasmic retinochoroiditis. A preliminary report. Arch. Ophthalmol. 75:21, 1966. 3. Rodriguez, A.: Toxoplasmic retinochoroiditis, correspondence, Arch. Ophthalmol. 76:309, 1966. 4. : Vascular obstructive alterations related to chorioretinitis. Mod. Probl. Ophthalmol. 20:127, 1979. 5. Dobbie, J. G. : Cryotherapy in the management of toxoplasmic retinochoroiditis. Trans. Am. Acad. Ophthalmol. Otolaryngol. 72:364, 1968.
Reply Editor: First, I must state that I was unaware of Dr. Rodriguez's presentation at the Pan American Congress of Ophthalmology in 1964 regarding photocoagulation in toxo plasmic retinitis. Second, I am well aware of Dr. Spalters work concerning prophy lactic photocoagulation, a technique that proved to be ineffective in my hands. Third, I agree with Dr. Rodriguez that photocoagulation in active toxoplasmic retinitis is indicated only in protracted cases, refractory to conventional forms of therapy, and wish to congratulate him on his work. ROBERT J. BROCKHURST,
Boston,
M.D.
Massachusetts
Senile Lens and Senile Macular Changes Editor: In their article, "Senile lens and senile macular changes in a population-based sample" (Am. J. Ophthalmol. 90:86, 1980), R. D. Sperduto and D. Seigel failed to find an association between senile lens changes and senile macular degeneration. When two diseases are so
MARCH, 1981
prevalent (with senile lens changes found in 42% to 9 1 % of the sample and senile macular degeneration in 35% to 50%) but show no association, the presumption that senility causes both must be doubt ed. It is likely that macular degeneration is a disease of senility, whereas lenticular changes may be the result of prolonged exposure to harmful environmental fac tors. Environmental factors have been shown to play a significant role in cata ract. 1,2 This hypothesis suggests that fur ther investigation into the identity of environmental risk factors is needed if we are to prevent these lenticular changes. S. P. D H I R ,
M.D.
Chanigarh,
India
REFERENCES 1. Dhir, S. P., Detels, R., and Alexander, E. R.: The role of environmental factors in cataract, pterygium and trachoma. Am. J. Ophthalmol. 64:128, 1967. 2. Fuchs, A.: Geographic distribution of senile cataract. Am. J. Ophthalmol. 49:1039, 1960.
Reply Editor: Both senile macular and senile lens changes are increasingly prevalent at older ages. Analysis of our data indicated that they occurred independently, which implied separate causative mechanisms to us. Our data did not permit us to distinguish between environmental fac tors and those that are part of biological aging. Finally, the relationships between the various subgroups which make up these two broad groups of "senile" changes remain largely unexplored. ROBERT D. SPERDUTO, DANIEL SEIGEL,
Bethesda,
M.D. Sc.D.
Maryland
BOOK REVIEWS Cataract Surgery and its Complications, 3rd. ed. By Norman S. Jaffe. St. Louis, C. V. Mosby Co., 1981. Hardcover,
VOL. 91, NO. 3
Reply Editor: We appreciate Dr. Thompson's re marks about false clinical localization in our series of patients with Homer's syn drome. We rewrote the first draft of the paper in an attempt to explain these paradoxical responses, and we agree with Dr. Thompson's theory of multiple neuromal involvement in at least several of these cases. BRIAN R. YOUNGE,
Rochester,
M.D.
Minnesota
Photocoagulation in Toxoplasmic Retinochoroiditis Editor: I was greatly interested in the article, "Photocoagulation in active toxoplasmic retinochoroiditis" (Am. J. Ophthalmol. 89:858, 1980), by K. N. Ghartey and R. J. Brockhurst. In September 1964, at the VII Pan American Congress of Ophthalmology in Montreal, I presented a report on xenon photocoagulation treatment of 25 cases of retinochoroiditis, performed either dur ing an active primary attack or during an active recurrent episode. This report, along with a review of other studies, was published in Spain. 1 Spalter and associ ates 2 published a report the next year. My comments on their article appeared in 1966. 3 At that time, photocoagulation was used to treat toxoplasmic retinochoroidi tis in my country for the following rea sons: (1) the high incidence of the disor der; (2) the social and economic factors that made it difficult for many people to obtain medical treatment; (3) the system ic complication and unproven efficacy, particularly in regard to cysts, of the many drugs used to treat the disease; (4) photocoagulation's ability to shorten the active phase of the attacks; (5) the possibility of avoiding satellite recur rences by destroying nearby cysts; and
417
(6) the possibility of avoiding secondary complications (including glaucoma and cataract) produced by the inflammation. During the 1960s, I studied 60 cases treated by this method. By the 1970s, however, I came to believe that active cases did not need photocoagulation for a number of reasons. Active foci seem to heal spontaneously, although the amount of time required varies. Routine examinations disclose many instances of healed retinochoroidi tis scars in patients unaware of ever having had the disease. The disease can still recur, despite photocoagulation, near the treated area or in other parts of the retina, because all the cysts near the retinochoroiditis were not destroyed or because the cysts occurred far from the primary focus (D. Nicholson, personal communication, June 1980). For this reason, I have aban doned photocoagulation of inactive foci, something I originally recommended. Two of the 60 cases became worse after photocoagulation, and the possibility of spreading the Toxoplasma organisms was raised. In some cases, macular or extramacular tractional epiretinal membranes devel oped or worsened after photocoagulation. Vitreoretinal membrane contraction can lead to retinal holes and retinal detach ment. In eight cases, an iatrogenic hemorrhagic retinal vasculitis developed near the areas that underwent photocoagulation. 4 At the present time, I rarely treat active retinochoroiditis with photocoagu lation. I use this method no more than three or four times a year and only in cases where there is a danger of foveolar involvement or when the disease is ex tremely protracted. Although xenon photocoagulation is still used, argon-laser photocoagulation and crycoagulation 5 have also been used in some cases.
418
AMERICAN JOURNAL OF OPHTHALMOLOGY
I agree with the other findings of Drs. Ghartey and Brockhurst and congratulate them on their article. ALVARO RODRIGUEZ,
Bogota,
M.D.
Colombia
REFERENCES 1. Rodriguez, A.: Fotocoagulacion en las retinocoroiditis récidivantes. Arch. Soc. Oftalmol. Hispano-Americana 25:197, 1965. 2. Splater, H. F., Cambell, C. J., Noyori, K. S., Ritter, M. D., and Koester, C. J.: Prophylactic photocoagulation of recurrent toxoplasmic retinochoroiditis. A preliminary report. Arch. Ophthalmol. 75:21, 1966. 3. Rodriguez, A.: Toxoplasmic retinochoroiditis, correspondence, Arch. Ophthalmol. 76:309, 1966. 4. : Vascular obstructive alterations related to chorioretinitis. Mod. Probl. Ophthalmol. 20:127, 1979. 5. Dobbie, J. G. : Cryotherapy in the management of toxoplasmic retinochoroiditis. Trans. Am. Acad. Ophthalmol. Otolaryngol. 72:364, 1968.
Reply Editor: First, I must state that I was unaware of Dr. Rodriguez's presentation at the Pan American Congress of Ophthalmology in 1964 regarding photocoagulation in toxo plasmic retinitis. Second, I am well aware of Dr. Spalters work concerning prophy lactic photocoagulation, a technique that proved to be ineffective in my hands. Third, I agree with Dr. Rodriguez that photocoagulation in active toxoplasmic retinitis is indicated only in protracted cases, refractory to conventional forms of therapy, and wish to congratulate him on his work. ROBERT J. BROCKHURST,
Boston,
M.D.
Massachusetts
Senile Lens and Senile Macular Changes Editor: In their article, "Senile lens and senile macular changes in a population-based sample" (Am. J. Ophthalmol. 90:86, 1980), R. D. Sperduto and D. Seigel failed to find an association between senile lens changes and senile macular degeneration. When two diseases are so
MARCH, 1981
prevalent (with senile lens changes found in 42% to 9 1 % of the sample and senile macular degeneration in 35% to 50%) but show no association, the presumption that senility causes both must be doubt ed. It is likely that macular degeneration is a disease of senility, whereas lenticular changes may be the result of prolonged exposure to harmful environmental fac tors. Environmental factors have been shown to play a significant role in cata ract. 1,2 This hypothesis suggests that fur ther investigation into the identity of environmental risk factors is needed if we are to prevent these lenticular changes. S. P. D H I R ,
M.D.
Chanigarh,
India
REFERENCES 1. Dhir, S. P., Detels, R., and Alexander, E. R.: The role of environmental factors in cataract, pterygium and trachoma. Am. J. Ophthalmol. 64:128, 1967. 2. Fuchs, A.: Geographic distribution of senile cataract. Am. J. Ophthalmol. 49:1039, 1960.
Reply Editor: Both senile macular and senile lens changes are increasingly prevalent at older ages. Analysis of our data indicated that they occurred independently, which implied separate causative mechanisms to us. Our data did not permit us to distinguish between environmental fac tors and those that are part of biological aging. Finally, the relationships between the various subgroups which make up these two broad groups of "senile" changes remain largely unexplored. ROBERT D. SPERDUTO, DANIEL SEIGEL,
Bethesda,
M.D. Sc.D.
Maryland
BOOK REVIEWS Cataract Surgery and its Complications, 3rd. ed. By Norman S. Jaffe. St. Louis, C. V. Mosby Co., 1981. Hardcover,