Participants: 49 subjects (76 affected eyes) with an average age of 65.3 ± 7.0 years with a diagnosis of senile cataract with minimum to advanced opacification in various lens layers.
Methods: 26 patients (41 eyes)were allocated to topicalNAC 1% eyedrops twice daily. The control group consisted of 13 patients (21 eyes) who received placebo eyedrops and 10 patients (14 eyes) who did not receive eyedrops.
Main outcome measures: All patients were evaluated at entry and followed up every 2 months for a 6-month period (trial 1), or at 6-month intervals for a 2-year period (trial 2), for best-corrected visual acuity and glare testing. In addition, cataract was measured using stereocinematographic slit-images and retro-illumination examination of the lens. Digital analysis of lens images displayed light scattering and absorbing centres in two- and three-dimensional scales.
Results: The overall intra-reader reproducibility of cataract measurements (image analysis) was 0.830, and glare testing 0.998. After 6 months, 90% of NAC-treated eyes showed improvement in best corrected visual acuity (7 to 100%) and 88.9% showed a 27 to 100% improvement in glare sensitivity. Topographic studies indicated fewer areas of posterior subcapsular lens opacity and 41.5% of treated eyes had improvement in image analysis characteristics. The overall ratios of image analysis characteristics at 6 months compared with baseline measures were 1.04 and 0.86 for the control and NAC-treated group, respectively (p < 0.001). The apparent benefits of treatment were sustained after 24 months’ treatment. No treated eyes demonstrated worsening of vision. The overall visual outcome in the control group showed significant worsening after 24 months in comparison with both baseline and the 6-month follow-up examination. The overall clinical results observed in the NAC-treated group by the 24-month period of examination differed significantly (p < 0.001) from the control group in the eyes with cortical, posterior subcapsular, nuclear or combined lens opacities.
Tolerability of NAC eyedrops was good in almost all patients, with no reports of ocular or systemic adverse effects.
Conclusion: Topical NAC shows potential for the treatment and prevention of cataracts.
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This work was organised, conducted and supported by Innovative Vision Products, Inc, County of New Castle, Delaware, USA.
World Health Organization. Management of cataract in primary health care services. Geneva, 1990: WHOGoogle Scholar
Kupfer C, Underwood B, Gillen T. Leading causes of visual impairment worldwide. In: Albert DM, Jakobiec FA, editors. Principles and practice of ophthalmology. Basic Sci. Philadelphia: W.B. Saunders & Co, 1994: 1249–1255Google Scholar
Vision Research, ANational Plan 1999–2002. Report of the National Advisory Council, National Eye Institute, 1998: 59Google Scholar
Stark WJ, Sommer A, Smith RE. Changing trends in intraocular lens implantation. Arch Ophthalmol 1989; 107: 1441–4PubMedCrossRefGoogle Scholar
Kupfer C. The conquest of cataract, a global challenge. Trans Ophthalmol Soc UK 1984; 104: 1–10Google Scholar
Dische Z, Zil H. Studies on the oxidation of cysteine and cystine in lens proteins during cataract formation. Am J Ophthalmol 1951; 34: 104–13PubMedGoogle Scholar
Spector A, Roy D. Disulfide-linked high molecular weight protein associated with human cataract. Proc Natl Acad Sci USA 1978; 75: 3244–8PubMedCrossRefGoogle Scholar
Garner MH, Spector A. Selective oxidation of cysteine and methionine in normal and senile cataractous lenses. Proc Natl Acad Sci USA 1980; 77: 1274–7PubMedCrossRefGoogle Scholar
Augusteyn RC. Protein modification in cataract: possible oxidative mechanisms. In: Duncan G, editor. Mechanisms of cataract formation in human lens. New York: Academic Press, 1981: 72–115Google Scholar
Varma SD, Chand D, Sharma YR, et al. Oxidative stress on lens and cataract formation: role of light and oxygen. Curr Eye Res 1984; 3: 35–57PubMedCrossRefGoogle Scholar
Bhuyan KC, Bhuyan DK. Molecular mechanism of cataractogenesis: III. Toxic metabolites of oxygen as mediators of lipid peroxidation and cataract. Curr Eye Res 1984; 3: 67–81PubMedCrossRefGoogle Scholar
Babizhayev MA, Deyev AI, Linberg LP. Lipid peroxidation as a possible cause of cataract. Mech Ageing Dev 1988; 44: 69–89PubMedCrossRefGoogle Scholar
Zigman S. Photochemical mechanisms in cataract formation. In: Duncan G, editor. Mechanisms of cataract formation in human lens. London: Academic Press, 1981: 117–149Google Scholar
Varma SD. Superoxide and lens of the eye: a new theory of cataractogenesis. Int J Quantum Chem 1981; 20: 479–84CrossRefGoogle Scholar
Babizhayev MA, Deyev AI. Lens opacity induced by lipid peroxidation products as a model of cataract associated with retinal disease. Biochim Biophys Acta 1989; 1004: 124–33PubMedCrossRefGoogle Scholar
Babizhayev MA, Bozzo Costa E. Lipid peroxide and reactive oxygen species generating systems of the crystalline lens. Biochim Biophys Acta 1994; 1225: 326–37PubMedCrossRefGoogle Scholar
Robertson JM, Donner AP, Trevithick JR. A possible role for vitamins C and E in cataract prevention. Am J Clin Nutr 1991; 53: 346S–51SPubMedGoogle Scholar
Borchman D, Paterson CA, Delamere NA. Oxidative inhibition of Ca2+-ATPase in the rabbit lens. Invest Ophthalmol Vis Sci 1989; 30: 1633–7PubMedGoogle Scholar
Babizhayev MA, Deyev AI. Free radical oxidation of lipids and thiol groups in genesis of cataract. Biophysics 1986; 31: 119–25Google Scholar
Babizhayev MA. Lipid fluorophores of the human crystalline lens with cataract. Graefes Arch Clin Exp Ophthalmol 1989; 227: 384–91PubMedCrossRefGoogle Scholar
Babizhayev MA, Seguin M-C, Gueyne J, et al. L-Carnosine (β-alanyl-L-histidine) and carcinine (β-alanylhistamine) act as natural antioxidantswith hydroxyl radicals scavenging and lipid peroxidase activities. Biochem J 1994; 304: 509–16PubMedGoogle Scholar
Dahl TA, Midden WR, Hartman PE. Some prevalent biomolecules as defenses against singlet oxygen damage. Photochem Photobiol 1988; 47: 357–62PubMedCrossRefGoogle Scholar
Boldyrev AA, Dupin AM, Bunin AYa, et al. The antioxidative properties of carnosine, a natural histidine containing dipeptide. Biochem Int 1987; 15: 1105–13PubMedGoogle Scholar
Babizhayev MA. Antioxidant activity of L-carnosine, a natural histidine-containing dipeptide in crystalline lens. Biochim Biophys Acta 1989; 1004: 363–71PubMedCrossRefGoogle Scholar
Jackson MC, Kucera CM, Lenney JF. Purification and properties of human serum carnosinase. Clin Chim Acta 1991; 196: 193–206PubMedCrossRefGoogle Scholar
O’Dowd JJ, Robins DJ, Miller DJ. Detection, characterization, and quantification of carnosine and other histidyl derivatives in cardiac and skeletal muscle. Biochim Biophys Acta, 1988; 967: 241–9PubMedCrossRefGoogle Scholar
Okabe S, Ainehara T, Sato M, et al. Pharmaceuticals containing N-acetylcarnosine aluminium salt for treatment of gastric ulcer. Japanese Patent Nippon Chemiphar Co. Ltd. Jpn Kokai Tokkyo Koho JP 62 84, 063 [87,84,063] (Cl. C07D 233/64) 17 Apr. 1987, Appl. 86/215,196 12 Sept 1986, 7 pp. Chem Abstr 1987; 107: 223–279Google Scholar
Anderson JA, Davis WL, Wei C. Site of ocular hydrolysis of a prodrug, dipivefrin, and a comparison of its ocular metabolism with that of the parent compound, epinephrine. Invest Ophthalmol Vis Sci 1980; 19: 817–23PubMedGoogle Scholar
Babizhayev MA, Yermakova VN, Sakina NL, et al. NAcetylcarnosine is a prodrug of L-carnosine in ophthalmic application as antioxidant. Clin Chim Acta 1996; 254: 1–21PubMedCrossRefGoogle Scholar
Babizhayev MA, Bozzo Costa E. Composizioni farmaceutiche contenentiN-acetilcarnosina per il trattamento della cataratta. Italian Patent A61K gruppo 37/00 20122 MI, Priority Oct 15 1993Google Scholar
Babizhayev MA, Bozzo Costa E. Pharmaceutical compositions containing N-acetylcarnosine for the treatment of cataract. Patent PCT/EP 94/03340 SCB 238 PCT, Oct 10 1994Google Scholar
Babizhayev MA, Yermakova VN, Deyev AI, et al. Imidazolecontaining peptidomimetic NACA as a potent drug for the medicinal treatment of age-related cataract in humans. JAnti-Aging Med 2000; 3: 43–62PubMedCrossRefGoogle Scholar
Babizhayev MA, Deyev AI, Yermakova VN, et al. N-Acetylcarnosine, a natural histidine-containing dipeptide, as a potent ophthalmic drug in treatment of human cataracts. Peptides 2001; 22: (6): 979–94PubMedCrossRefGoogle Scholar
Babizhayev MA, Zhukotskii AV, Sologub AA. Image analysis of the lens opacities induced in developing chick embryo by glucocorticoid. Exp Eye Res 1992; 55: 521–37PubMedCrossRefGoogle Scholar
Babizhayev MA, Deyev AI, Derevyagin VI. Morphometric evaluation of human lens opacification. J Microsc 1989; 154: 115–27PubMedCrossRefGoogle Scholar
Yager D, Yuan R, Mathews S. What is the utility of the psychophysical “light scattering factor”? Invest Ophthalmol Vis Sci 1992; 33: 688–90PubMedGoogle Scholar
Babizhayev MA. Failure to withstand oxidative stress induced by phospholipid hydroperoxides as a possible cause of the lens opacities in systemic diseases and ageing. Biochim Biophys Acta 1996; 1315: 87–99PubMedCrossRefGoogle Scholar
Babizhayev MA, Yermakova VN, Semiletov YA, et al. The natural histidine-containing dipeptide N-acetylcarnosine as an antioxidant for ophthalmic use. Biochemistry (Moscow) 2000; 65:588–98Google Scholar