Global estimates on the number of people blind or visually impaired by cataract: a meta-analysis from 2000 to 2020
Authors:   Vision Loss Expert Group of the Global Burden of Disease Study, Pesudovs Konrad , Lansingh Van Charles , Kempen John H. , Tapply Ian , Fernandes Arthur G. , Cicinelli Maria Vittoria , Arrigo Alessandro , Leveziel Nicolas , Resnikoff Serge , Taylor Hugh R. , Sedighi Tabassom , Flaxman Seth , Bikbov Mukkharram M. , Braithwaite Tasanee , Bron Alain , Cheng Ching-Yu , Del Monte Monte A. , Ehrlich Joshua R. , Ellwein Leon B. , Friedman David , Furtado João M. , Gazzard Gus , George Ronnie , Hartnett M. Elizabeth , Jonas Jost B. , Kahloun Rim , Khairallah Moncef , Khanna Rohit C. , Leasher Janet , Little Julie-Anne , Nangia Vinay , Nowak Michal , Peto Tunde , Ramulu Pradeep , Topouzis Fotis , Tsilimbaris Mitiadis , Wang Ya Xing , Wang Ningli , Bourne Rupert ,   GBD 2019 Blindness and Vision Impairment Collaborators, Pesudovs Konrad , Lansingh Van Charles , Kempen John H. , Tapply Ian , Fernandes Arthur G. , Cicinelli Maria Vittoria , Arrigo Alessandro , Leveziel Nicolas , Briant Paul Svitil , Vos Theo , Resnikoff Serge , Flaxman Seth , Abate Yohannes Habtegiorgis , Abdollahi Mohammad , Abdollahi Mozhan , Abebe Ayele Mamo , Abiodun Olumide , Aboagye Richard Gyan , Abrha Woldu Aberhe , Abualruz Hasan , Ali Hiwa Abubaker , Abu-Gharbieh Eman , Aburuz Salahdein , Adal Tadele Girum Girum , Adane Mesafint Molla , Addo Isaac Yeboah , Adnani Qorinah Estiningtyas Sakilah , Afzal Muhammad Sohail , Aghamiri Shahin , Ahinkorah Bright Opoku , Ahmad Aqeel , Ahmad Sajjad , Ahmadi Ali , Ahmed Ayman , Ahmed Haroon , Alfaar Ahmad Samir , Ali Abid , Ali Syed Shujait Shujait , Altaf Awais , Amu Hubert , Androudi Sofia , Anguita Rodrigo , Anil Abhishek , Anvari Saeid , Anyasodor Anayochukwu Edward , Appiah Francis , Arabloo Jalal , Arafat Mosab , Areda Damelash , Arefnezhad Reza , Aregawi Brhane Berhe , Asgedom Akeza Awealom , Ashraf Tahira , Athari Seyyed Shamsadin , Atinafu Bantalem Tilaye Tilaye , Atout Maha Moh’d Wahbi , Atreya Alok , Ayatollahi Haleh , Azzam Ahmed Y. , Babamohamadi Hassan , Bagherieh Sara , Bahurupi Yogesh , Baig Atif Amin , Banik Biswajit , Bardhan Mainak , Basu Saurav , Batra Kavita , Bayileyegn Nebiyou Simegnew , Bazvand Fatemeh , Beyene Addisu Shunu , Bhagat Devidas S. , Bhagavathula Akshaya Srikanth , Bhardwaj Pankaj , Bhaskar Sonu , Bhatti Jasvinder Singh , Bikbov Mukharram , Bineshfar Niloufar , Birck Marina G. , Bitra Veera R. , Braithwaite Tasanee , Burkart Katrin , Bustanji Yasser , Butt Zahid A. , dos Santos Florentino Luciano Caetano , Cámera Luis Alberto , Carneiro Vera L. A. , Cenderadewi Muthia , Chandrasekar Eeshwar K. , Chattu Vijay Kumar , Chitranshi Nitin , Chopra Hitesh , Chu Dinh-Toi , Coberly Kaleb , Coelho João M. , Cruz-Martins Natália , Dadras Omid , Dai Xiaochen , Das Subasish , Dascalu Ana Maria , Dashti Mohsen , Dastmardi Maedeh , Demessa Berecha Hundessa , Demisse Biniyam , Dereje Diriba , Derese Awoke Masrie Asrat , Dervenis Nikolaos , Devanbu Vinoth Gnana Chellaiyan , Do Thanh Chi , Do Thao Huynh Phuong , dos Santos Figueiredo Francisco Winter , Dziedzic Arkadiusz Marian , Edinur Hisham Atan , Efendi Ferry , Ehrlich Joshua R. , Ekholuenetale Michael , Ekundayo Temitope Cyrus , Sayed Iman El , Elhadi Muhammed , Emamian Mohammad Hassan , Emamverdi Mehdi , Etemadimanesh Azin , Fagbamigbe Adeniyi Francis , Fahim Ayesha , Farrokhpour Hossein , Fatehizadeh Ali , Feizkhah Alireza , Desideri Lorenzo Ferro , Fetensa Getahun , Fischer Florian , Forouhari Ali , Foschi Matteo , Fowobaje Kayode Raphael , Gaidhane Abhay Motiramji , Gandhi Aravind P. , Gebregergis Miglas W. W. , Gebrehiwot Mesfin , Gebremariam Brhane , Gerema Urge , Ghassemi Fariba , Ghozy Sherief , Golechha Mahaveer , Goleij Pouya , Goulart Bárbara Niegia Garcia , Guan Shi-Yang , Gudisa Zewdie , Gupta Sapna , Gupta Veer Bala , Gupta Vivek Kumar , Haj-Mirzaian Arvin , Halimi Aram , Hallaj Shahin , Hamidi Samer , Harorani Mehdi , Hasani Hamidreza , Heyi Demisu Zenbaba , Hoan Nguyen Quoc , Holla Ramesh , Hong Sung Hwi , Hosseinzadeh Mehdi , Hu Chengxi , Huang John J. , Huynh Hong-Han , Ibitoye Segun Emmanuel , Ilic Irena M. , Immurana Mustapha , Islam Md. Rabiul , Islam Sheikh Mohammed Shariful , Iwu Chidozie C. D. , Jacob Louis , Jairoun Ammar Abdulrahman , Janodia Manthan Dilipkumar , Jayaram Shubha , Jindal Har Ashish , Jokar Mohammad , Joseph Nitin , Joshua Charity Ehimwenma , Kadashetti Vidya , Kalankesh Laleh R. , Kalhor Rohollah , Kamath Sagarika , Kandel Himal , Kantar Rami S. , Karaye Ibraheem M. , Kasraei Hengameh , Kaup Soujanya , Kaur Navjot , Kaur Rimple Jeet , Kayode Gbenga A. , Khader Yousef Saleh , Khajuria Himanshu , Khalilov Rovshan , Khatib Mahalaqua Nazli , Kisa Adnan , Kosen Soewarta , Koyanagi Ai , Krishan Kewal , Kulimbet Mukhtar , Kumar Nithin , Kurmi Om P. , Lahariya Chandrakant , Lan Tuo , Landires Iván , Leasher Janet L. , Lee Munjae , Lee Seung Won , Lee Wei-Chen , Lim Stephen S. , Little Julie-Anne , Mahajan Preetam Bhalchandra , Maharaj Sandeep B. , Mahmoudi Alireza , Mahmoudi Razzagh , Malhotra Kashish , Mallhi Tauqeer Hussain , Mansouri Vahid , Manu Emmanuel , Marzo Roy Rillera , Maugeri Andrea , McAlinden Colm , Mebratu Wondwosen , Meto Tesfahun Mekene , Meng Yang , Mersha Abera M. , Mestrovic Tomislav , Minh Le Huu Nhat , Misganaw Awoke , Mishra Manish , Misra Sanjeev , Mohamed Nouh Saad , Mohammadi Soheil , Mohammed Mustapha , Mojiri-forushani Hoda , Mokdad Ali H. , Vardanjani Hossein Molavi , Moni Mohammad Ali , Montazeri Fateme , Moradi Maryam , Motappa Rohith , Mousavi Parsa , Mulita Admir , Murray Christopher J. L. , Naik Ganesh R. , Naik Gurudatta , Nargus Shumaila , Natto Zuhair S. , Nayak Biswa Prakash , Negaresh Mohammad , Negash Hadush , Nguyen Dang H. , Nguyen Phat Tuan , Nguyen Van Thanh , Niazi Robina Khan , Okonji Osaretin Christabel , Olagunju Andrew T. , Olatubi Matthew Idowu , Ordak Michal , Osuagwu Uchechukwu Levi , Otstavnov Nikita , Owolabi Mayowa O. , Padubidri Jagadish Rao , Pandey Ashok , Panos Georgios D. , Pardhan Shahina , Park Seoyeon , Patel Jay , Pawar Shrikant , Peprah Prince , Petcu Ionela-Roxana , Peyman Alireza , Pham Hoang Tran , Pourazizi Mohsen , Quan Nguyen Khoi , Rahim Fakher , Rahimi-Movaghar Vafa , Rahman Mohammad Hifz Ur , Rajaa Sathish , Ramasamy Shakthi Kumaran , Ramasubramani Premkumar , Ranjan Shubham , Rashidi Mohammad-Mahdi , Rath Rama Shankar , Rauf Annisa Utami , Rawaf Salman , Damavandi Amirmasoud Rayati , Redwan Elrashdy Moustafa Mohamed , Roy Priyanka , Pramanik Koushik Roy , Saadatian Zahra , Sabour Siamak , Saddik Basema , Saeed Umar , Safi Sare , Safi Sher Zaman , Saghazadeh Amene , Sharif-Askari Fatemeh Saheb , Sahebkar Amirhossein , Sahraian Mohammad Ali , Sakshaug Joseph W. , Saleh Mohamed A. , Samadzadeh Sara , Samodra Yoseph Leonardo , Samuel Vijaya Paul , Samy Abdallah M. , Saravanan Aswini , Selvaraj Siddharthan , Semnani Farbod , Senapati Sabyasachi , Sethi Yashendra , Seyedi Seyed Arsalan , Seylani Allen , Shaheen Amira A. , Shahid Samiah , Shahwan Moyad Jamal , Shaikh Masood Ali , Sham Sunder , Shamim Muhammad Aaqib , Shannawaz Mohammed , Shashamo Bereket Beyene , Shayan Maryam , Shittu Aminu , Shiue Ivy , Shivakumar K. M. , Shorofi Seyed Afshin , Sibhat Migbar Mekonnen , Siddig Emmanuel Edwar , Silva Juan Carlos , Singh Jasvinder A. , Singh Paramdeep , Skiadaresi Eirini , Solomon Yonatan , Sousa Raúl A. R. C. , Sreeramareddy Chandrashekhar T. , Starodubov Vladimir I. , Subramaniam Mohana Devi , Susanty Sri , Tabatabaei Seyyed Mohammad , Taye Birhan Tsegaw , Teklay Gebrehiwot , Temsah Mohamad-Hani , Terefa Dufera Rikitu , Ticoalu Jansje Henny Vera , Toma Temesgen Mohammed , Tsatsakis Aristidis , Tsegay Guesh Mebrahtom , Tumurkhuu Munkhtuya , Tusa Biruk Shalmeno , Ty Sree Sudha , Ubah Chukwudi S. , Umair Muhammad , Umar Tungki Pratama , Valizadeh Rohollah , Van den Eynde Jef , Watson Stephanie Louise Watson , Wonde Tewodros Eshete , Wondimagegn Guadie Sharew , Xiao Hong , Yao Yao , Nia Iman Yazdani , Yiğit Arzu , Yismaw Yazachew , Yon Dong Keon , Yonemoto Naohiro , You Yuyi , Yu Chuanhua , Zastrozhin Mikhail Sergeevich , Zhao Hanqing , Ziafati Makan , Zielińska Magdalena , Zikarg Yossef Teshome , Zoladl Mohammad , Steinmetz Jaimie D. 
Published: March 2024

Abstract
Background
To estimate global and regional trends from 2000 to 2020 of the number of persons visually impaired by cataract and their proportion of the total number of vision-impaired individuals.

Methods
A systematic review and meta-analysis of published population studies and gray literature from 2000 to 2020 was carried out to estimate global and regional trends. We developed prevalence estimates based on modeled distance visual impairment and blindness due to cataract, producing location-, year-, age-, and sex-specific estimates of moderate to severe vision impairment (MSVI presenting visual acuity <6/18, ≥3/60) and blindness (presenting visual acuity <3/60). Estimates are age-standardized using the GBD standard population.

Results
In 2020, among overall (all ages) 43.3 million blind and 295 million with MSVI, 17.0 million (39.6%) people were blind and 83.5 million (28.3%) had MSVI due to cataract blind 60% female, MSVI 59% female. From 1990 to 2020, the count of persons blind (MSVI) due to cataract increased by 29.7%(93.1%) whereas the age-standardized global prevalence of cataract-related blindness improved by −27.5% and MSVI increased by 7.2%. The contribution of cataract to the age-standardized prevalence of blindness exceeded the global figure only in South Asia (62.9%) and Southeast Asia and Oceania (47.9%).

Conclusions
The number of people blind and with MSVI due to cataract has risen over the past 30 years, despite a decrease in the age-standardized prevalence of cataract. This indicates that cataract treatment programs have been beneficial, but population growth and aging have outpaced their impact. Growing numbers of cataract blind indicate that more, better-directed, resources are needed to increase global capacity for cataract surgery.