Etiopathogenesis of cataract: An appraisal

Abstract

Natural eye lens is a crystalline substance to produce a clear passage for light. Cataract is opacity within the clear lens of the eye and is the dominant cause of socio-medical problem i.e., blindness worldwide. The only available treatment of cataract is surgery. However, insufficient surgical facilities in poor and developing countries and post-operative complications inspire researchers to find out other modes of treatment for cataract. In this review, an attempt has been made to appraise various etiological factors of cataract to make their perception clear to build up counterpart treatment. Present study is an assortment of various available literatures and electronic information in view of cataract etiopathogenesis. Various risk factors have been identified in development of cataracts. They can be classified in to genetic factors, ageing (systemic diseases, nutritional and trace metals deficiencies, smoking, oxidative stress etc.), traumatic, complicated (inflammatory and degenerative diseases of eye), metabolic (diabetes, galactosemia etc.), toxic substances including drugs abuses, alcohol etc., radiation (ultraviolet, electromagnetic waves etc.) are implicated as significant risk factors in the development of cataract.

Possible mechanisms of development of carcinoma of breast in patients with early-onset cataract

“…2,3 Carcinogenesis is similarly related to oxidative stress and oxidative damage. 4 This anti-oxidative insufficiency may occur as a result of faulty anti-oxidative and/or deoxyribonucleic acid (DNA) repair or due to overproduction of reactive oxygen species (ROS) which leads to oxidative damage to cellular macromolecules, genomic instability and uncontrolled cell proliferation.…”

“…1 Age related/senile cataract is defined as cataract occurring in people >50 years of age, unrelated to known mechanical, chemical, or radiation trauma. 2 But cataract may present in younger patients referred to as early-onset cataract (EOC). No definitive relationship was reported between cataract and breast cancer.…”

“…However, in a recent nation-wide population based retrospective cohort study from Taiwan by Chiang et al, an increased incidence of BC was observed in patients presenting with EOC. 2 One such young nonobese female presented to us who had bilateral progressive vision loss due to cataract for five years and subsequently she developed carcinoma of the right breast (Stage IIIB at presentation) ( Figure 1). Patient had no history of trauma to eyes, watering, glares, floaters or redness of eyes; nor did she have diabetes mellitus or any other metabolic abnormality.…”

Investigating Risk Factors for Cataract Using the Cerner Health Facts® Database

“…The proposed mechanism of aspirin mediated protection against cataract formation is not known, however studies have shown that lowering plasma tryptophan levels and reduced aldose reductase activity may be involved [39]. Further, the use of allopurinol suggested that it may be a risk factor for cataract formation [40]. A proposed mechanism for allopurinol reducing the odds of cataract formation is through the inhibition of the antioxidant xanthine oxidase.…”

An Epha4/Sipa1l3/Wnt pathway regulates eye development and lens maturation

“…nucleus, ER, mitochondria), disturbed cell adhesion or disorganized cytoskeleton. There are specific gene mutations known to cause congenital cataracts (Gupta et al, 2014), such as mutations in the Ephrin receptor tyrosine kinase, EPH receptor A2 (EPHA2), and its ligand Ephrin A5 (EFNA5). Both play a crucial role in lens development and Epha2 or Efna5 knockout mice develop cataracts (Shi et al, 2012;Jun et al, 2009;Cooper et al, 2008).…”