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Retinal Damage after Argon Laser Iridotomy
668
AMERICAN JOURNAL OF OPHTHALMOLOGY
November, 1986
syndrome. A new malformation syndrome of postnatal dwarfism, mental retardation, unusual face, and protruding ears. J. Pediatr. 101:417, 1982. 3. Ondo, S., Madokoro, H., Sonoda, T., Nishiguchi, T., Kawaguchi, K., and Hayakawa, K.: Kabuki make-up syndrome (Niikawa-Kuorki syndrome) associated with congenital heart disease. J. Med. Genet. 22:126, 1985. 4. Shiekh, T. M., Qazi, Q. H., and Beller, E.: Niikawa-Kuroki syndrome (Kabuki make-up syndrome) in a hispanic child. Pediatr. Res. 20:340A, 1986. 5. Duke-Elder, S.: Normal and Abnormal Development. Congenital Deformities. In System of Ophthalmology, vo!' 3, pt2. St. Louis, C. V. Mosby, 1964, p. 841.
Correspondence Correspondence concerning recent articles or other material published in THE JOURNAL should be submitted within six weeks of publication. Correspondence must be typed double-spaced, on 8'12 x Ll-inch bond paper with 1V2-inch margins on all four sides and should be no more than two typewritten pages in length. Every effort will be made to resolve controversies between the correspondents and the authors of the article before formal publication.
Figure (Kaiser-Kupfer and associates). Full face, with mild blepharoptosis, lateral ectropion of lateral one third of the lower eyelids, and sparse lateral eyebrows.
Retinal Damage after Argon Laser Iridotomy EDITOR:
short stature and highly arched eyebrows, and the negroid nasal structure may have obscured expression of nasal findings seen in previous cases. This note emphasizes the syndrome's striking ocular findings, which may require cosmetic surgery and should facilitate prompt diagnosis to guide management. Identification of additional cases is necessary for further characterization of this syndrome in various populations.
References 1. Braun, O.H., and Schmid, E.: Kabuki make-up syndrome (Niikawa-Kuroki syndrome) in Europe. J. Pediatr. 105:849, 1984. 2. Koutras, A., and Fisher, S.: Niikawa-Kuroki
In their article, "Retinal damage after argon laser iridotomy" (Am. J. Ophthalmol. 101:554, May 1986), G. Karmom and H. Savir reported focal retinal damage after laser iridotomy. Their argon laser iridotomy technique varies markedly from commonly accepted techniques. No corneal contact lens was used. The Abraham lens is considered an indespensable aid for the efficient production of laser iridectorny.! This lens facilitates penetration by increasing power density at the iris. Most importantly, it also decreases power density at the retina by nearly one third," Peak laser energies up to 2,000 mW were used. These power levels are significantly higher than those commonly associated with laser iridectomy. 3 The energy levels were progressively in-
Vol. 102, No. 5
669
Correspondence
creased to enlarge the iridectomy. This would be expected to increase the amount of laser energy reaching the retina. . An average of 171 burns were used for heavily pigmented irides and an average of 128 burns were necessary for lighter irides. Common clinical experience suggests that these are unusually high burn totals. The above considerations seriously qualify the authors' findings. Their statement that "peripheral retinal damage exists after laser iridectomy" should, in the absence of data to the contrary, pertain only to the results of this less than optimal technique. CHARLES M. LEDERER, JR., M.D.
Kansas City, Missouri
References 1. Lederer, C. M., and Belcher, C. D.: Laserinstrumentation. In Belcher, C. D., Thomas, J. V., and Simmons, R. J. (eds.): Photocoagulation in Glaucoma
and Anterior Segment Disease. Baltimore, Williams & Wilkins, 1984, p. 46. 2. Wise, J. B., Munnerlyn, C. R., and Erickson, P. J.: A high-efficiency laser iridotomy-sphincterotomy lens. Am. J. Ophthalmol. 101:546, 1986. 3. Belcher, C. D.: Laser iridectomy. In Belcher, C. D., Thomas, J. V., and Simmons, R. J. (eds.): Photocoagulation in Glaucoma and Anterior Segment Disease. Baltimore, Williams & Wilkins, 1984, pp. 87-110.
EDITOR: G. Karmon and H. Savir demonstrated focal retinal damage by static perimetry and fluorescein angiography in up to 96% of the treated eyes. Although retinal damage has been reported;' the high incidence of complications in this study is of concern. There are some aspects of the study that deserve further comment and investigation. In the performance of the laser iridotomy Karmon and Savir did not use a contact lens. Additionally, a patent iridotomy required a mean of 128 spots in lightly pigmented irides and 171 in heavily pigmented irides. These factors may have had some effect on the number of retinal complications. An iridotomy contact lens such as the Abraham lens provides more precise focusing and attenuation of the laser energy while reducing energy density at the cornea
and retina," Consequently, the procedure usually requires less energy. A prospective study should be undertaken to determine if the frequency of retinal complications is reduced when an iridotomy lens is used. J RICHARD A. LEWIS, M.D.
Sacramento, California
References 1. Berger, B. B.: Foveal photocoagulation from laser iridotomy. Ophthalmology 91:1029,1984. 2. Abraham, R. K., and Munnerly, c.: Laser iridotomy. Improved methodology with a new iridotomy lens. Ophthalmology 86(suppl.):126, 1979.
_ _ _ _ _ _ _ Reply
_
EDITOR: We wish to comment on the letters of C. M. Lederer, Ir., and R. A. Lewis concerning our article. At the time we performed the argon laser iridotomies, no contact lens was used in our department and not widely used elsewhere. Since 1982 we have used an Abraham lens and have studied our results with the Abraham lens performing static perimetry and fluorescein angiography. Peak laser energies up to 2,000 mW were sometimes required by us as well as by others.! We agree that, in our experience, the use of the Abraham lens has considerably lowered the peak laser energies needed to penetrate the iris. We find even now with the Abraham lens that the energy level should be small at the beginning and gradually increased if necessary. We would like to point out that merely citing the number of burns used does not reflect the reality or the spirit of our article. We calculated in each case the amount of energy used to obtain a patent coloboma of approximately 200 um.. A careful review of some papers previously published demonstrated that the amount of energy was not calculated and it is precisely this figure that truly reflects the optimum technique while performing a laser iridotomy. Our first clinical observations of retinal damage following argon laser iridotomy were implied in our paper published in 19822; a long follow-up was necessary before we published the present study. We are now studying our results with the Abraham lens.
AMERICAN JOURNAL OF OPHTHALMOLOGY
November, 1986
syndrome. A new malformation syndrome of postnatal dwarfism, mental retardation, unusual face, and protruding ears. J. Pediatr. 101:417, 1982. 3. Ondo, S., Madokoro, H., Sonoda, T., Nishiguchi, T., Kawaguchi, K., and Hayakawa, K.: Kabuki make-up syndrome (Niikawa-Kuorki syndrome) associated with congenital heart disease. J. Med. Genet. 22:126, 1985. 4. Shiekh, T. M., Qazi, Q. H., and Beller, E.: Niikawa-Kuroki syndrome (Kabuki make-up syndrome) in a hispanic child. Pediatr. Res. 20:340A, 1986. 5. Duke-Elder, S.: Normal and Abnormal Development. Congenital Deformities. In System of Ophthalmology, vo!' 3, pt2. St. Louis, C. V. Mosby, 1964, p. 841.
Correspondence Correspondence concerning recent articles or other material published in THE JOURNAL should be submitted within six weeks of publication. Correspondence must be typed double-spaced, on 8'12 x Ll-inch bond paper with 1V2-inch margins on all four sides and should be no more than two typewritten pages in length. Every effort will be made to resolve controversies between the correspondents and the authors of the article before formal publication.
Figure (Kaiser-Kupfer and associates). Full face, with mild blepharoptosis, lateral ectropion of lateral one third of the lower eyelids, and sparse lateral eyebrows.
Retinal Damage after Argon Laser Iridotomy EDITOR:
short stature and highly arched eyebrows, and the negroid nasal structure may have obscured expression of nasal findings seen in previous cases. This note emphasizes the syndrome's striking ocular findings, which may require cosmetic surgery and should facilitate prompt diagnosis to guide management. Identification of additional cases is necessary for further characterization of this syndrome in various populations.
References 1. Braun, O.H., and Schmid, E.: Kabuki make-up syndrome (Niikawa-Kuroki syndrome) in Europe. J. Pediatr. 105:849, 1984. 2. Koutras, A., and Fisher, S.: Niikawa-Kuroki
In their article, "Retinal damage after argon laser iridotomy" (Am. J. Ophthalmol. 101:554, May 1986), G. Karmom and H. Savir reported focal retinal damage after laser iridotomy. Their argon laser iridotomy technique varies markedly from commonly accepted techniques. No corneal contact lens was used. The Abraham lens is considered an indespensable aid for the efficient production of laser iridectorny.! This lens facilitates penetration by increasing power density at the iris. Most importantly, it also decreases power density at the retina by nearly one third," Peak laser energies up to 2,000 mW were used. These power levels are significantly higher than those commonly associated with laser iridectomy. 3 The energy levels were progressively in-
Vol. 102, No. 5
669
Correspondence
creased to enlarge the iridectomy. This would be expected to increase the amount of laser energy reaching the retina. . An average of 171 burns were used for heavily pigmented irides and an average of 128 burns were necessary for lighter irides. Common clinical experience suggests that these are unusually high burn totals. The above considerations seriously qualify the authors' findings. Their statement that "peripheral retinal damage exists after laser iridectomy" should, in the absence of data to the contrary, pertain only to the results of this less than optimal technique. CHARLES M. LEDERER, JR., M.D.
Kansas City, Missouri
References 1. Lederer, C. M., and Belcher, C. D.: Laserinstrumentation. In Belcher, C. D., Thomas, J. V., and Simmons, R. J. (eds.): Photocoagulation in Glaucoma
and Anterior Segment Disease. Baltimore, Williams & Wilkins, 1984, p. 46. 2. Wise, J. B., Munnerlyn, C. R., and Erickson, P. J.: A high-efficiency laser iridotomy-sphincterotomy lens. Am. J. Ophthalmol. 101:546, 1986. 3. Belcher, C. D.: Laser iridectomy. In Belcher, C. D., Thomas, J. V., and Simmons, R. J. (eds.): Photocoagulation in Glaucoma and Anterior Segment Disease. Baltimore, Williams & Wilkins, 1984, pp. 87-110.
EDITOR: G. Karmon and H. Savir demonstrated focal retinal damage by static perimetry and fluorescein angiography in up to 96% of the treated eyes. Although retinal damage has been reported;' the high incidence of complications in this study is of concern. There are some aspects of the study that deserve further comment and investigation. In the performance of the laser iridotomy Karmon and Savir did not use a contact lens. Additionally, a patent iridotomy required a mean of 128 spots in lightly pigmented irides and 171 in heavily pigmented irides. These factors may have had some effect on the number of retinal complications. An iridotomy contact lens such as the Abraham lens provides more precise focusing and attenuation of the laser energy while reducing energy density at the cornea
and retina," Consequently, the procedure usually requires less energy. A prospective study should be undertaken to determine if the frequency of retinal complications is reduced when an iridotomy lens is used. J RICHARD A. LEWIS, M.D.
Sacramento, California
References 1. Berger, B. B.: Foveal photocoagulation from laser iridotomy. Ophthalmology 91:1029,1984. 2. Abraham, R. K., and Munnerly, c.: Laser iridotomy. Improved methodology with a new iridotomy lens. Ophthalmology 86(suppl.):126, 1979.
_ _ _ _ _ _ _ Reply
_
EDITOR: We wish to comment on the letters of C. M. Lederer, Ir., and R. A. Lewis concerning our article. At the time we performed the argon laser iridotomies, no contact lens was used in our department and not widely used elsewhere. Since 1982 we have used an Abraham lens and have studied our results with the Abraham lens performing static perimetry and fluorescein angiography. Peak laser energies up to 2,000 mW were sometimes required by us as well as by others.! We agree that, in our experience, the use of the Abraham lens has considerably lowered the peak laser energies needed to penetrate the iris. We find even now with the Abraham lens that the energy level should be small at the beginning and gradually increased if necessary. We would like to point out that merely citing the number of burns used does not reflect the reality or the spirit of our article. We calculated in each case the amount of energy used to obtain a patent coloboma of approximately 200 um.. A careful review of some papers previously published demonstrated that the amount of energy was not calculated and it is precisely this figure that truly reflects the optimum technique while performing a laser iridotomy. Our first clinical observations of retinal damage following argon laser iridotomy were implied in our paper published in 19822; a long follow-up was necessary before we published the present study. We are now studying our results with the Abraham lens.