1. World Health Organisation. Global Initiative for the Elimination of Avoidable Blindness: An Informal Consultation. Geneva: WHO; 1997. Available from: https://www.who.int/blindness/Vision2020_report.pdf. [Last accessed on 2021 Oct 20].
2. National Program for Control of Blindness. Quarterly Oct-Dec 2011. Available from: https://www.who.int/blindness/Newsletter_3.pdf. [Last accessed on 2021 Oct 20].
3. Preoperative posterior segment evaluation by ultrasonography in dense cataract;Shaikh;Pak J Ophthalmol,2009
4. Is ultrasonography essential before surgery in eyes with advanced cataracts?;Salman;J Postgrad Med,2006
5. Role of B-scan ultrasonography in pre-operative cataract patients;Qureshi;Int J Health Sci (Qassim),2010