Health

How climate and temperature have been affecting eye diseases in India in general

Introduction

The sudden impact on climate change due to global warming is causing an array of health-related problems (McMichael, et al, 2003; Hales, et al,2003). Due to the ozone depletion in the stratospheric level, the exposure to UVR is increasing inducing the global climate change (McKenzie, et al, 2011).

Cataracts

According to the previous epidemiological studies, cataracts can occur due to the high level of exposure to UVR and it is a serious public health issue because it is one of the preventable blindness throughout the world. The increased exposure to sunlight is responsible for cortical cataract. The risk of the disease due to the increased level of ozone depletion is estimated to be within 5 – 20%. The findings indicated that the rate of cortical cataract would rise to 1.3 – 6.9 % within the year of 2050 (Liu, et al, 2009; Katoh, et al, 2001; Schein, et al, 1994).

Refractive Error

Nuclear cataracts occur due to extreme nuclear sclerosis. Moreover, enhanced exposure to UVR results in premature ageing of the lens which in turn may contribute to nuclear sclerosis and myopia (Saito, et al, 1999).

Presbyopia

Apart from the several eye defects linked with climate change, research-based evidence have shown that the refractive condition presbyopia and the anterior lens capsule are considerably linked with increased exposure to sunlight and UV-B. It is a condition where the lens of the eye loses its capability to adjust the focal length and the focusing on the near objects becomes difficult (Stevens, et al, 1989; Johnson, et al,1989).

Eyelid Lesions

The chronic exposure to the UVA and UV-B radiation induces damage in the skin of the eyelids by making it more susceptible to the changes in the production of melanin, certain histopathological conditions, and erythema. Based on the study findings conducted by Neff et al. (1999), nearly 5 -10% of the variety of skin cancers of the eyelid and the surrounding areas of the eyes such as the lid margins, eyebrows, canthi may occur due to the more susceptibility to harmful solar UVR. The most common types of cancers that occur due to the increased solar radiation exposure are squamous cell, basal cell, sebaceous cell carcinoma and malignant melanoma (Jaggernath, et al, 2013).

Conjunctiva and Corneal Lesions

The chronic exposure to UVR may result in acute pain and other inflammatory changes in the exposed cornea or conjunctiva of the eye [12]. The associated eye disease includes dryness of the eye, squamous metaplasia, pterygium and carcinoma related to the epithelial lining of the eye. Photokeratitis and photo conjunctivitis may also result due to the acute solar radiation exposure (Oliva, 2005; Kennedy, et al, 1997).

Retinal Lesions and Damage

The human retina is extremely delicate and susceptible to damage such as photochemical damage, mechanical and thermal damage (Miller, et al, 1999).

Macular Degeneration

The macula is considered to be the most sensitive region of the retina and constant exposure to sunlight may cause damage to the outer retina. The incident rate of central melanomas is higher in those regions that receive the highest solar exposure (Oliva, 2005).

Temperature-induced Eye damages

The high temperature causes dryness in the eye and also triggers the risk of cataract. The frozen temperature can cause sting in the eye and even freeze the cornea (Heussner, et al, 2014).

Conclusion

The Vision 2020, Right to sight is a global initiative by WHO and IAPB was built with a series of plans. In 2006 the stakeholders of the organisation had developed an action plan for 2006 – 11 to focus on the cause of avoidable blindness and visual impairment due to impaired refractive error. Thus all the possible eye damages due to the climate changes have been discussed above.

References:

• McMichael, A.J., Campbell-Lendrum, D.H., Corvalan, C.F., Ebi, K.L., Githeko, A.K., Scheraga, J.D. and Woodward, A., 2003. Climate change and human health (pp. 145-186). Geneva, World Health Organization.
• Hales, S., Edwards, S.J. and Kovats, R.S., 2003. Impacts on health of climate extremes. Climate change and human health: Risks and responses, pp.79-102.
• extremes. Climate change and human health: Risks and responses, pp.79-102. McKenzie, R.L., Aucamp, P.J., Bais, A.F., Björn, L.O., Ilyas, M. and Madronich, S., 2011. Ozone depletion and climate change: impacts on UV radiation. Photochemical & Photobiological Sciences, 10(2), pp.182-198.
• Liu, B., Xu, L., Wang, Y.X. and Jonas, J.B., 2009. Prevalence of cataract surgery and postoperative visual outcome in Greater Beijing: the Beijing Eye Study. Ophthalmology, 116(7), pp.1322-1331.
• Katoh, N., Jonasson, F., Sasaki, H., Kojima, M., Ono, M., Takahashi, N., Sasaki, K. and Reykjavik Eye Study Group, 2001. Cortical lens opacification in Iceland: Risk Factor Analysis–Reykjavik Eye Study. Acta Ophthalmologica Scandinavica, 79(2), pp.154-159.
• Schein, O.D., Steinberg, E.P., Javitt, J.C., Cassard, S.D., Tielsch, J.M., Steinwachs, D.M., Legro, M.W., Diener-West, M. and Sommer, A., 1994. Variation in cataract surgery practice and clinical outcomes. Ophthalmology, 101(6), pp.1142-1152.
• Saito, Y., Lewis, J.M., Park, I., Ikuno, Y., Hayashi, A., Ohji, M. and Tano, Y., 1999. Nonvitrectomizing vitreous surgery: a strategy to prevent postoperative nuclear sclerosis. Ophthalmology, 106(8), pp.1541-1545.
• Stevens, M.A. and Bergmanson, J.P., 1989. Does sunlight cause premature aging of the crystalline lens?. Journal of the American Optometric Association, 60(9), pp.660-663.
• Johnson, G., Minassian, D. and Franken, S., 1989. Alterations of the anterior lens capsule associated with climatic keratopathy. British journal of ophthalmology, 73(3), pp.229-234.
• Jaggernath, J., Haslam, D. and Naidoo, K.S., 2013. Climate change: Impact of increased ultraviolet radiation and water changes on eye health.
• Oliva, M.S. and Taylor, H., 2005. Ultraviolet radiation and the eye. International ophthalmology clinics, 45(1), pp.1-17.
• Kennedy, M., Kim, K.H., Harten, B., Brown, J., Planck, S., Meshul, C., Edelhauser, H., Rosenbaum, J.T., Armstrong, C.A. and Ansel, J.C., 1997. Ultraviolet irradiation induces the production of multiple cytokines by human corneal cells. Investigative ophthalmology & visual science, 38(12), pp.2483-2491.
• Miller, D.A.V.I.D. and Scott, C.A., 1999. Light Damage to the eye. Ophthamology. London: Mosby, 2, pp.1-2.
• Heussner, N., Holl, L., Nowak, T., Beuth, T., Spitzer, M.S. and Stork, W., 2014. Prediction of temperature and damage in an irradiated human eye—Utilization of a detailed computer model which includes a vectorial blood stream in the choroid. Computers in biology and medicine, 51, pp.35-43.