EVALUATION OF GLUTATHIONE, TOTAL ANTIOXIDANT CAPACITY, TOTAL PLASMA PEROXIDES, OXIDATIVE STRESS INDEX IN CATARACT PATIENTS IN CALABAR
ISONG, IDONGESIT KOKOABASI
Department of Clinical Chemistry and Immunology, University of Calabar, P.M.B. 1115, Calabar, Cross River State, Nigeria.
AKPAN, UWEM OKON *
Department of Clinical Chemistry and Immunology, University of Calabar, P.M.B. 1115, Calabar, Cross River State, Nigeria.
BASSEY, IYA EZE
Department of Clinical Chemistry and Immunology, University of Calabar, P.M.B. 1115, Calabar, Cross River State, Nigeria.
ANA, AUGUSTA
Department of Ophthalmology, University of Calabar Teaching Hospital, Calabar, Cross River State, Nigeria.
OFEM, NTONGHA
Department of Clinical Chemistry and Immunology, University of Calabar, P.M.B. 1115, Calabar, Cross River State, Nigeria.
EMMANUEL KINGSLEY JOHN
Department of Clinical Chemistry and Immunology, University of Calabar, P.M.B. 1115, Calabar, Cross River State, Nigeria.
ISONG EKPENYONG
Department of Clinical Chemistry and Immunology, University of Calabar, P.M.B. 1115, Calabar, Cross River State, Nigeria.
*Author to whom correspondence should be addressed.
Abstract
Introduction: Cataract with prevalence of 15.4% is the leading cause of blindness among blinding eye diseases. The cause of cataracts is not fully understood and may be multifactorial, however oxidative damage to the lens proteins and lipids is suggested to be involved in the development of cataracts. This study aimed to determine the serum levels of glutathione (GSH), Total Antioxidant Capacity (TAC), Total Plasma Peroxides (TPP) and Oxidative Stress Index (OSI) in cataract patients in Calabar.
Materials and Methods: One hundred and seventeen subjects which comprise 75 diagnosed cataract patients and 42 controls were recruited. The cataract patients were sub-divided based on WHO criteria as: No visual impairment (n = 25), visually impaired (n = 25) and blind (n = 25). GSH, TAC and TPP were determined using verified colorimetric methods while OSI was calculated. Anthropometric indices, blood pressure and sociodemographic information were obtained using standard methods. Data were analyzed using Student’s t-test, analysis of variance (ANOVA), LSD post hoc and Pearson’s correlation at P < .05.
Results: The TPP and OSI were significantly higher while GSH and TAC were significantly lower (P < .05) in cataract patients compared to the control subjects. GSH and TAC were significantly lower (P < .05) in cataract patients with blindness and visually impaired compared to those without visual impairment. Oxidative stress index correlated negatively with TAC (r = -0.607, P < .05) and positively with diastolic blood pressure (r = 0.296, P = .01) in cataract patients.
Conclusion: It can be concluded that increased oxidative stress may be associated with the formation of cataracts and further depletion of GSH and TAC may cause the progression of cataracts to blindness.
Keywords: Cataract, glutathione, oxidative stress, antioxidants