Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Prevention of Refractive Defects of Vision by Means of Evolutionary Medicine Libertini G. (M.D., Independent Researcher) 1 2 Evolutionary Medicine is not an Alternative Medicine (like homeopathy, iridology, ayurvedic medicine, naturopathy, traditional Chinese medicine, energy medicine, etc.) but a Medicine that is more thoroughly scientific in that it involves the concepts of Evolutionism. What is Evolutionary Medicine? Evolutionary or Darwinian Medicine [1-6] comes into being in 1991 [1], but there are some known forerunners [7] (e.g. [8]) and others not generally cited as forerunners [9,10]. A medicine that ignored the principles of chemistry, for example, would be partially scientific. [1] Williams GC, Nesse RM (1991) The dawn of Darwinian medicine. Quart. Rev. Biol. 66, 1-22. [2] Nesse RM, Williams GC (1994) Why we get sick. New York (USA), Times Books. [3] Stearns SC (ed) (1999) Evolution in health and disease (1st ed.). Oxford (UK), Oxford University Press. [4] Trevathan WR, Smith EO, McKenna JJ (eds) (1999) Evolutionary Medicine. New York (USA), Oxford University Press. [5] Trevathan WR, Smith EO, McKenna JJ (eds) (2008) Evolutionary Medicine: new perspectives. New York (USA), Oxford University Press. [6] Stearns SC, Koella JC (eds) (2008) Evolution in health and disease (2nd ed.). Oxford (UK), Oxford University Press. [7] Trevathan WR, Smith EO, McKenna JJ (2008) Introduction and overview of Evolutionary Medicine. In: Trevathan WR, Smith EO, McKenna JJ (eds) Evolutionary Medicine: new perspectives. New York (USA), Oxford University Press. [8] Eaton SB, Shostak M, Konner M (1988) The paleolithic prescription: a program of diet & exercise and a design for living. New York (USA), Harper & Row. [9] Price WA (1939) Nutrition and Physical Degeneration. New York – London, Paul B. Hoeber. [10] Libertini G (1983) Ragionamenti Evoluzionistici. Naples (Italy), Società Editrice Napoletana; English Edition (2011): Evolutionary Arguments, Crownsville (USA), Azinet Press. Similarly, a medicine that ignores the principles of evolution is partially scientific. Is this difference only a theoretical / verbal nicety? or Does this difference have strong and significant implications for the structure of medical studies and for health organization? Refractive defects (myopia, astigmatism and hyperopia) are a group of related diseases with frequency: - very common [1-3] - varying greatly from population to population (e.g.: “The prevalence of myopia in Asia is as high as 70-90%, in Europe and America 30-40%, and in Africa 10-20 %” [1]) … 6 Data from Step 1 and Step 2 indicate that refractive defects are surely a group of diseases caused by environmental factors, i.e. by presumable mismatch phenomena. [1] Cordain, L, Eaton, SB, Miller, JB, Lindeberg, S, Jensen, C (2002) An evolutionary analysis of the aetiology and pathogenesis of juvenileonset myopia. Acta Ophthalmol. Scand. 80, 125–35. The study of primitive peoples shows that these defects are very rare or nonexistent among them. As regards Australian Aborigenes: “The marvelous vision of these primitive people is illustrated by the fact that they can see many stars that our race cannot see. In this connection it is authoritatively recorded regarding the Maori of New Zealand that they can see the satellites of Jupiter which are only visible to the white man's eye with the aid of telescopes. These people prove that they can see the satellites by telling the man at the telescope when the eclipse of one of the stars occurs. It is said of these primitive Aborigines of Australia that they can see animals moving at a distance of a mile which ordinary white people can not see at all.” [1] As regards Yakuts (a Siberian people): “Many travelers observed what some of them call ‘telescopic’ eyesight among these peoples. A Yakut distinguished with the naked eye stars in the Pleiades not usually seen without a telescope. The Yakuts say there are many stars in this group, but only seven large ones” [2] … [1] Rose KA , Morgan IG, Smith W, Burlutsky G, Mitchell P, Saw S-M (2008) Myopia, lifestyle, and schooling in students of Chinese ethnicity in Singapore and Sydney. Arch. Ophthalmol. 126, 527-30. [2] Cordain, L, Eaton, SB, Miller, JB, Lindeberg, S, Jensen, C (2002) An evolutionary analysis of the aetiology and pathogenesis of juvenileonset myopia. Acta Ophthalmol. Scand. 80, 125–35. [3] Garner LF, Owens H, Kinnear RF, Frith MJ. (1999) Prevalence of myopia in Sherpa and Tibetan children in Nepal. Optom. Vis. Sci. 76, 282-5. [4] Edwards MH, Lam CS (2004). The epidemiology of myopia in Hong Kong. Ann. Acad. Med. Singapore. 33, 34-8. [5] Morgan, RW, Munro, M (1973) Refractive problems in northern natives. Can. J. Ophthalmol. 8,: 226–8. 8 “a number of lines of evidence strongly reject the notion that [a] recent (in evolutionary terms) relaxation of natural selection pressures could be responsible for the high incidence of myopia in modern, technological societies.” [1] Step 2 - Comparison between the frequency of a disease in modern populations and the frequency of the same disease in populations in primitive conditions (From [2]:) Figure 1. Moderate myopia (1.00– 5.00 D) by age in Indians and Eskimos of the Yukon and NorthWest territories. Adapted from Morgan & Munro (1973) ([5]) [1] Fredrick DR (2002) Myopia. BMJ. 324, 1195-9. [2] Dirani M et al. (2010) Prevalence of refractive error in Singaporean Chinese children: the strabismus, amblyopia, and refractive error in young Singaporean Children (STARS) study. Invest. Ophthalmol. Vis. Sci. 51, 1348-55. [3] Chow YC, Dhillon B, Chew PT, Chew SJ (1990) Refractive errors in Singapore medical students. Singapore Med. J. 31, 472–3. … As regards two hunter-gatherer populations: “Using a retinoscope and cycloplegia, Holm (1937) refracted 2364 members (aged 20–65 years) of several hunter-gatherer tribes in Gabon (formerly French Equatorial Africa) in 1936. Of the 3624 eyes examined, only 14 were classified as myopic (nine eyes from − 0.50 to 1.00 D; five eyes from − 3.00 to − 9.00 D), thereby yielding a myopia incidence rate of 0.4%. Similar low rates for myopia were reported by Skeller (1954), who refracted the eyes of 775 Angmagssalik Eskimos as part of a comprehensive anthropological study carried out in 1954. Retinoscopy in conjunction with cycloplegia demonstrated that of the 1123 eyes examined, only 13 (1.2%) were classified as myopic (nine eyes =− 1.00 D; four eyes =− 1.25 D).” [1] [1] Eaton SB, Shostak M, Konner M (1988) The paleolithic prescription: a program of diet & exercise and a design for living. New York (USA), Harper & Row. [2] Libertini G (2009) Prospects of a Longer Life Span beyond the Beneficial Effects of a Healthy Lifestyle, in: Bentely JV, Keller MA (eds) Handbook on Longevity: Genetics, Diet & Disease, New York (USA), Nova Science Publishers Inc. … - varying greatly within the same population with changing conditions [1-3] - varying greatly within a population over a short time [2,4,5] (see Figure) Step 1 - Epidemiological study of modern populations 7 Here, I develop a practical application of a simple concept, the “mismatch” [1,2], to the genesis of refractive defects of vision. If a species is adapted to a certain range of conditions (including diet, environmental conditions, interrelations with other living beings, etc.), called for brevity “ecological niche”, any change in the ecological niche potentially is a source of disfunctions (diseases), because there is no adaptation to the new conditions. This is defined as "mismatch”. So, the contrast is not between current medicine and alternative medicines but between current medicine (which in most cases ignores Evolutionism) and Evolutionary Medicine (which is a more thoroughly scientific medicine) Refractive Defects of Vision in the Context of Evolutionary Medicine Evolutionary Medicine involves many concepts and applicative consequences. The concept of “mismatch” is simple but with huge implications: 5 4 3 [1] Price, WA (1939) Nutrition and Physical Degeneration. New York – London, Paul B. Hoeber. [2] De Hutorowicz H, Adler BF (1911) Maps of Primitive Peoples. Bull. Amer. Geogr. Soc. 43, 669-79. 9 Step 3 - Hypotheses on the possible changes in the ecological niche underlying the disease and on possible pathogenetical mechanisms Excessive near work, especially using artificial lighting, an improbable condition in the ecological niche to which we are adapted, is a common hypothesis regarding the causes of refractive defects, in particular myopia [1,2]. Against this hypothesis: “In an earlier study of 977 school children (6–17 years of age) on the remote South Pacific island of Vanuatu, Garner et al. (1985) found that only 1.3% of subjects had myopia greater than − 0.25 D, despite engaging in about 8 hrs of school work per day.” [3] Another hypothesis ascribes the epidemic of myopia incidence to dietary alterations, in particular the “increase in high glycaemicload foods” [3]. But, in two homogeneous populations with no detectable difference in dietary habits, incidence of myopia was very different [4]. … [1] Zylbermann R, Landau D, Berson D (1993): The influence of study habits on myopia in Jewish teenagers. J. Pediatr. Ophthalmol. Strabismus 30, 319–22. [2] McBrien NA, Adams DW (1997): A longitudinal investigation of adult-onset and adult-progression of myopia in an occupational group. Refractive and biometric findings. Invest Ophthalmol. 38, 321–33. [3] Cordain L, Eaton SB, Miller JB, Lindeberg S, Jensen C (2002) An evolutionary analysis of the aetiology and pathogenesis of juvenileonset myopia. Acta Ophthalmol. Scand. 80, 125–35. [4] Rose KA , Morgan IG, Smith W, Burlutsky G, Mitchell P, Saw S-M (2008) Myopia, lifestyle, and schooling in students of Chinese ethnicity in Singapore and Sydney. Arch. Ophthalmol. 126, 527-30. … A study was made of two homogeneous groups of 6-7-years old children of Chinese ethnicity, living in Singapore and in Sidney, respectively, with the same frequency of myopia in their parents: “Children in Sidney read more books per week (P < .001) and did more near-work activity (P = .002). Children in Sidney spent more time on outdoor activities (13.75 vs 3.05 hours per week) (P < .001)”. The prevalence of myopia was 3.3% in Sidney and 29.1% in Singapore [1]. This suggests that the critical factor is the outdoor activity, alias the exposition to natural light, a hypothesis confirmed by other studies [2,3]. In particular “Higher levels of total time spent outdoors, rather than sport per se, were associated with less myopia” [2]. In these studies, near-work activities appeared to be an independent aggravating factor, but not the main cause of myopia [2,3]. [1] Rose KA, Morgan IG, Smith W, Burlutsky G, Mitchell P, Saw SM (2008) Myopia, lifestyle, and schooling in students of Chinese ethnicity in Singapore and Sydney. Arch. Ophthalmol. 126, 527-30. [2] Rose KA, Morgan IG, Ip J, Kifley A, Huynh S, Smith W, Mitchell P. (2008) Outdoor activity reduces the prevalence of myopia in children. Ophthalmol. 115, 1279-85. [3] Dirani M, Tong L, Gazzard G, Zhang X, Chia A, Young TL, Rose KA, Mitchell P, Saw SM. (2009) Outdoor activity and myopia in Singapore teenage children. Br. J. Ophthalmol. 93, 997-1000.