Prevalence and Causes of Blindness, Low Vision and Status of Cataract in 50 Years and Older Citizen of Qatar—A Community Based Survey

Abstract

Background: Rapid Assessment for the Avoidable Blindness (RAAB) was conducted in Qatar during 2009. We present the prevalence and determinants of visual disabilities and status of cataract among citizens aged 50 years and older.

Methods: Residents of randomly selected houses and clusters participated in the survey. Opticians noted the presenting and the best corrected vision of participants from 49 clusters. Ophthalmologists examined participants with additional instruments like bio-microscope, digital camera, auto-perimeter and auto-refractor in a mobile van. World Health Organization recommended principal cause of blindness (Visual acuity [VA] < 3/60 in better eye), Severe visual impairment (SVI) (<6/60), low vision (VA < 6/18) and unilateral blindness (VA < 3/60) were designated. Persons with VA < 6/18 and cataract were interviewed to calculate coverage and barriers for cataract surgeries. Age sex adjusted prevalence of visual disabilities and their 95% Confidence Intervals (CI) were estimated.

Results: We examined 2,433 (97.3%) participants. The age sex adjusted prevalence of bilateral blindness was 1.28% [95% CI 1.22–1.35], SVI (1.67%), low vision (3.66%) and unilateral blindness (3.61%) in 50 years and older population. Female and older age groups were significant risk factors of visual disabilities. Cataract and glaucoma were the main causes of visual disabilities. The coverage of cataract services was 68.2%. Believing that cataract as an aging process (25) and adequate vision in the fellow eye (15) were the reasons for delay in surgery.

Conclusions: To reduce avoidable blindness, un-operated cataract should be addressed. Primary and secondary eye care systems should be strengthened to improve the care of blinding eye diseases in Qatar.

KEYWORDS::

• blindness
• epidemiology
• low vision
• public health
• VISION 2020

ACKNOWLEDGMENTS

We thank the administrators and the staff of Hamad Medical Corporation, especially Dr. Abdulla Al Naimi, Dr. Al Hareth M. Al Kater and other staff and members of the research committee and the department. We would like to extend our thanks to Dr. Mariam A. Malik the primary health care president, Mr. Nasser Al Mahdi and Mr. Mansour Al Malki from the statistics authority and the members of the National committee for Prevention of Blindness in the state of Qatar. We also thank all the staff who assisted and contributed in the patients’ care in our study. We appreciate the efforts and cooperation of all participants and community to make this survey a success.

Declaration of Interest: The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.