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Effects of Ocular Carteolol and Timolol on Plasma High-density Lipoprotein Cholesterol Level
Correspondence
Vol. 117, No. 5
potential macular phototoxicity caused by in traocular illumination. Dr. Teichmann has pro posed an internal occlusion device that could protect the macula during vitreoretinal sur gery.1 This device consists of opaque or tinted heavy liquids (such as perfluorocarbons) that could shield the macula or posterior pole from the harmful wavelengths of light while the sur geon works in the retinal periphery. This is an interesting approach to preventing macular phototoxicity, but it has several associated problems. It is widely believed that macular phototoxicity occurs only during prolonged di rect illumination of the macula by the light, source, and is virtually never seen when the vitreoretinal surgery has involved working outside of the macula. Reports of macular light toxicity occurring after epiretinal dissection and macular hole surgery support this notion. 2 The phototoxic effect of indirect scattered light on the macula has not been studied, but it is generally believed to be low, obviating the need to protect the macula while working in the periphery. Opaque, or even moderately tinted, heavy liquids would impair the sur geon's view as well as the ability to manipu late the tissue beneath them during macular surgery, rendering them useless for the very procedures in which they would be the most useful. Heavy liquids are currently investigational, and their potential toxicities have not been fully elucidated. We believe that the solution to the problem of macular phototoxicity is safer light sources rather than temporary intraocular occluding devices, and we have shown that our multiport illumination system may be among the safest. F. H. J. KOCH, M.D. H. P. SCHMIDT, M.D. T. MONKS, M.D. S. H. BLUMENRÖDER, Ph.D. A. HALLER, B.S Bonn, Germany R. L. STEINMETZ, M.D. Tallahassee, Florida
References 1. Teichmann, K. D.: Proposed internal occlusion device for vitreoretinal surgery. Saudi J. Ophthalmol. 6:141, 1992. 2. Michels, M., Lewis, H. Abrams, G. W., Han, D. P., Mieler, W. F., and Neitz, J.: Macular phototoxi city caused by fiberoptic endoillumination during pars plana vitrectomy. Am. J. Ophthalmol. 114:287, 1992.
683
Effects of Ocular Carteolol and Timolol on Plasma High-density Lipoprotein Cholesterol Level EDITOR: We read with interest the article, "Effects of ocular carteolol and timolol on plasma highdensity lipoprotein cholesterol level," by S. F. Freedman, N. J. Freedman, M. B. Shields, B. Lobaugh, G. P. Samsa, E. U. Keates, and A. Ollie (Am. J. Ophthalmol. 116:600, November 1993). The results included the observation that, in healthy subjects, ocular treatment with timolol decreased high-density lipoprotein cholesterol levels by 8.0%, and raised the ratio of total to high-density lipoprotein cholesterol by 10.0%, with no marked change in triglyc érides. These findings are similar to those of our own study, published six months previously. 1 Our study, however, involved eight subjects suffering from glaucoma. After receiving timo lol 0.5%, one drop twice daily in each eye for three months, plasma high-density lipoprotein cholesterol levels were decreased by 11.4% (P = .035), and the ratio of low to high-density lipoprotein cholesterol was increased by 24.2% (P = .012), whereas no marked change was found in triglycéride levels. The agreement between the results of our data and those of Freedman and associates fur ther emphasizes the need to monitor changes in high-density lipoprotein cholesterol levels in patients at high risk with coronary heart disease, who are receiving ocular treatment with timolol. AVINOAM B. SAFRAN, M.D. FILIPO SIMONA, M.D. ALESSANDRA SANSONETTI, M.D. DANIEL POMETTA, M.D. RICHARD JAMES, Ph.D. Geneva, Switzerland
Reference 1. Safran, A. B., Simona, F., Sansonetti, A., Pometta, D., and James, R.: Topical timolol maleate might adversely affect serum lipoproteins. Int. Oph thalmol. 17:109, 1993.
Vol. 117, No. 5
potential macular phototoxicity caused by in traocular illumination. Dr. Teichmann has pro posed an internal occlusion device that could protect the macula during vitreoretinal sur gery.1 This device consists of opaque or tinted heavy liquids (such as perfluorocarbons) that could shield the macula or posterior pole from the harmful wavelengths of light while the sur geon works in the retinal periphery. This is an interesting approach to preventing macular phototoxicity, but it has several associated problems. It is widely believed that macular phototoxicity occurs only during prolonged di rect illumination of the macula by the light, source, and is virtually never seen when the vitreoretinal surgery has involved working outside of the macula. Reports of macular light toxicity occurring after epiretinal dissection and macular hole surgery support this notion. 2 The phototoxic effect of indirect scattered light on the macula has not been studied, but it is generally believed to be low, obviating the need to protect the macula while working in the periphery. Opaque, or even moderately tinted, heavy liquids would impair the sur geon's view as well as the ability to manipu late the tissue beneath them during macular surgery, rendering them useless for the very procedures in which they would be the most useful. Heavy liquids are currently investigational, and their potential toxicities have not been fully elucidated. We believe that the solution to the problem of macular phototoxicity is safer light sources rather than temporary intraocular occluding devices, and we have shown that our multiport illumination system may be among the safest. F. H. J. KOCH, M.D. H. P. SCHMIDT, M.D. T. MONKS, M.D. S. H. BLUMENRÖDER, Ph.D. A. HALLER, B.S Bonn, Germany R. L. STEINMETZ, M.D. Tallahassee, Florida
References 1. Teichmann, K. D.: Proposed internal occlusion device for vitreoretinal surgery. Saudi J. Ophthalmol. 6:141, 1992. 2. Michels, M., Lewis, H. Abrams, G. W., Han, D. P., Mieler, W. F., and Neitz, J.: Macular phototoxi city caused by fiberoptic endoillumination during pars plana vitrectomy. Am. J. Ophthalmol. 114:287, 1992.
683
Effects of Ocular Carteolol and Timolol on Plasma High-density Lipoprotein Cholesterol Level EDITOR: We read with interest the article, "Effects of ocular carteolol and timolol on plasma highdensity lipoprotein cholesterol level," by S. F. Freedman, N. J. Freedman, M. B. Shields, B. Lobaugh, G. P. Samsa, E. U. Keates, and A. Ollie (Am. J. Ophthalmol. 116:600, November 1993). The results included the observation that, in healthy subjects, ocular treatment with timolol decreased high-density lipoprotein cholesterol levels by 8.0%, and raised the ratio of total to high-density lipoprotein cholesterol by 10.0%, with no marked change in triglyc érides. These findings are similar to those of our own study, published six months previously. 1 Our study, however, involved eight subjects suffering from glaucoma. After receiving timo lol 0.5%, one drop twice daily in each eye for three months, plasma high-density lipoprotein cholesterol levels were decreased by 11.4% (P = .035), and the ratio of low to high-density lipoprotein cholesterol was increased by 24.2% (P = .012), whereas no marked change was found in triglycéride levels. The agreement between the results of our data and those of Freedman and associates fur ther emphasizes the need to monitor changes in high-density lipoprotein cholesterol levels in patients at high risk with coronary heart disease, who are receiving ocular treatment with timolol. AVINOAM B. SAFRAN, M.D. FILIPO SIMONA, M.D. ALESSANDRA SANSONETTI, M.D. DANIEL POMETTA, M.D. RICHARD JAMES, Ph.D. Geneva, Switzerland
Reference 1. Safran, A. B., Simona, F., Sansonetti, A., Pometta, D., and James, R.: Topical timolol maleate might adversely affect serum lipoproteins. Int. Oph thalmol. 17:109, 1993.