Cataract Blindness in Armenia: The Results of Nationwide Rapid Assessment of Avoidable Blindness (RAAB)

ABSTRACT Purpose This study assessed the prevalence of cataract blindness, cataract surgical coverage (CSC), effective CSC, visual outcome after cataract surgery, and barriers to cataract surgery in a population aged 50 years and older in Armenia using Rapid Assessment of Avoidable Blindness (RAAB) methodology. Methods The study sample included 2258 individuals aged 50 years and older who were randomly selected from 11 provinces of Armenia in 2019 following the RAAB methodology. The study team randomly selected 50 clusters, 50 people in each. The RAAB survey form was used to collect information on cataract blindness, visual outcome after cataract surgery, and barriers to cataract surgery. Results The mean age of the participants was 65.3 (SD = 9.9) ranging from 50 to 99. The majority of participants were women (65.6%). Age- and sex-adjusted prevalence of blindness due to all causes was 1.5%; of which 36.4% was bilaterally blind due to cataract. The CSC and effective CSC at a cataract surgical threshold of <6/12 were 55.1% and 24.4%, respectively. Good outcome was reported in 43.7% of eyes after cataract surgery, borderline in 37.2% of eyes, and poor outcome in 19.1%. The main barriers to cataract surgery included “cost,” “need not felt,” or “fear.” Conclusion The prevalence of cataract blindness in our study was higher compared to high-income regions and lower than estimates from South/Southeast Asia. This study suggests the urgent need to update the National Strategic Plan to prevent blindness in Armenia with a focus on improving the quality and coverage of cataract surgery.


Introduction
From 1990 to 2020, the age-standardized prevalence of global blindness decreased by 28.5% among people aged 50 years and older, while the number of blind people increased by 50.6%. 1According to the Global Burden of Disease (GBD) study, cataract was the first leading cause of blindness with 15.2 million cases, and the second leading cause of moderate and severe visual impairment (MSVI) with 78.8 million cases globally among people aged 50 years and older in 2020. 2 Cataract was the main cause of blindness in all regions except for high-income regions.Globally, 45.4% of all age-standardized blindness are due to cataract, while in central Europe, eastern Europe, and central Asia, this number was 22.4%. 2 In high-income regions, cataract was the second leading cause of blindness (17.5% of cases), followed by glaucoma (28.2%). 2 The prevalence of cataract worldwide varies by region and age groups, and most of the cases are aged over 50 years.A systematic review of the global and regional prevalence of age-related cataract reported that the age-standardized prevalence of any type of cataract was 17.2%, cortical cataract 8.0%, nuclear cataract 8.2%, and posterior subcapsular cataract 2.2%. 3 The prevalence of age-related cataract increases with population aging, and the health and economic burden of cataract will grow, especially in low-and middleincome countries (LMIC), where access to cataract surgery is limited. 3ataract surgery is the most common surgical intervention and is very cost-effective. 4Visual acuity (VA) is the most common clinical indicator used for measuring the outcomes of cataract surgery.Global data on visual outcome after cataract surgery in 2020 reported that the median prevalence of good visual outcome (presenting visual acuity (PVA) of 6/18 or better) and poor visual outcome (PVA of worse than 6/60) after cataract surgery were 48% and 30% in Sub-Saharan Africa, 62% and 23% in central Europe, eastern Europe, and central Asia, and 76% and 9% in high-income countries, respectively. 4

Situation in Armenia
Armenia has a population of about 2.93 million in 2022. 5The country is divided into 10 administrative provinces: Ararat, Armavir, Aragatsotn, Gegharkunik, Kotayk, Lori, Shirak, Syunik, Tavush, and Vayots Dzor, and the capital Yerevan, where one-third of the population resides. 5There are two specialized eye hospitals and three ophthalmic departments in general hospitals providing secondary and tertiary ophthalmic services in Yerevan. 6Accessibility to secondary and tertiary levels of eye care is limited in the provinces of Armenia.Secondary eye care is available in four towns outside of Yerevan (regional ophthalmic departments/units (ROU) in Gegharkunik, Tavush, Lori, and Shirak provinces), while tertiary eye care is available only in Yerevan.Overall, there are 332 ophthalmologists in the country; two-thirds of them work in Yerevan. 6rimary health care is available at no charge for the general population, including eye care services in primary health-care facilities covering visual acuity measurement, eye fundus examination, and intraocular pressure measurement, if needed.Spectacles are not subsidized. 7The Basic Benefit Package (BBP) does not cover cataract surgeries for the general population.A limited group of people (socially vulnerable and disabled and others) may receive free medical care. 8Even people eligible for free cataract surgery, have to pay for the lens, which may not be affordable for many. 9The price of cataract surgery ranges from 200 to 400 thousand Armenian dram ($500 -$1,000), depending on the type of surgery and the facility. 10here are no nationally representative data on the epidemiology of eye diseases in Armenia. 11In 2003-4, a survey was conducted among the population aged 50 years and older in Gegharkunik Province of Armenia using the Rapid Assessment of Cataract Surgical Services methodology. 12Untreated cataract contributed to 71.9% of all blindness cases.Good, borderline, and poor visual outcomes after cataract surgery by PVA were in 64.6%, 15.0%, and 20.4% of eyes, respectively.Uncorrected aphakia was the main cause of a poor outcome. 12 nationwide survey with support from the Lions Club International Foundation was conducted in Armenia in 2019 to estimate the prevalence and main causes of blindness and VI in a population aged 50 years and older using the Rapid Assessment of Avoidable Blindness (RAAB) methodology.13 The present report from the RAAB survey focuses on cataract and aims to assess the rate of cataract blindness, CSC, effective CSC, visual outcome after cataract surgery, and barriers to cataract surgery in the population aged 50 years and older in Armenia.

Sample size, sampling, and study population
This study included 2,500 individuals aged 50 years and older who were randomly selected from 11 provinces in Armenia in 2019 using a multi-stage cluster sampling methodology.We compiled a list of all 10 provinces in Armenia, including the capital city Yerevan, along with the total population over the age of 50 in each province.Then, we calculated the number of eligible individuals in proportion to the population size of each province and Yerevan.The study team selected 50 clusters, each consisting of 50 residents aged 50 years or older.The distribution of these clusters was as follows: 19 clusters (950 people) from Yerevan, four clusters (200 people) from each of the provinces Ararat, Armavir, Gegharkunik, Lori, Kotayk, and Shirak, two clusters (100 people) from each of the provinces Aragatsotn, Tavush, and Syunik, and one cluster (50 people) from Vayots Dzor.During the initial stage of sampling, we utilized a simple random sampling technique to select the starting points for the clusters.These starting points, also referred to as starting point households, were chosen from the sampling frame of the 2018 Republic of Armenia Parliamentary Election lists, which provided a comprehensive collection of names and addresses of citizens aged 18 and above from each province.Moving on to the second stage of sampling, within each cluster, we employed the RAAB manual to select 50 eligible individuals.More details of the study sampling are described elsewhere. 13Sample size was calculated based on the assumed prevalence of blindness in this population of 4.0% and a relative precision of 25% at the highest, with a required confidence of 95%, a nonresponse rate of 10%, and the design effect of 1.5 using the RAAB software tool.

Data collection and ophthalmic examination
The data collection phase of the RAAB survey took place during the spring and summer of 2019.The Armenian translation of the RAAB survey form was used to collect data.The ophthalmic nurse measured the participant's PVA using a simplified "E" chart at a six-meter distance.If PVA was less than 6/12, the patient was also examined for VA with a pinhole.The ophthalmologist provided a standard lens examination by torch and by distant direct ophthalmoscopy at 20-30 cm in a semi-dark area.The ophthalmologist conducted a detailed lens examination with a short-acting mydriatic if VA was <6/12 and did not improve with a pinhole.The study team provided a leaflet with information regarding the nearest available ophthalmic facilities for further diagnosis and/or treatment as needed.

Survey team
Four survey teams with experienced professionals were selected for the RAAB survey.Each team consisted of an ophthalmologist, an ophthalmic nurse, and an interviewer.Before conducting the survey, all teams participated in trainings, where they learned how to conduct the RAAB survey.The survey teams had high inter-observer reliability with a kappa value of at least 0.75.

Data analysis
The RAAB data entry was conducted simultaneously with the RAAB data collection.All data were recorded in the RAAB survey record forms.The RAAB 6 software provided automatic data analysis and generated reports, including the prevalence of cataract blindness, the prevalence of aphakia and pseudophakia, visual outcome after cataract surgery, barriers to cataract surgery, age at the time of surgery, place of surgery, and type of surgery.
The research team calculated the Cataract Surgical Coverage (CSC) and effective CSC (eCSC) values utilizing the recently updated definitions of CSC and eCSC endorsed by the World Health Organization (WHO) during a technical meeting held in July 2022. 14The CSC calculates the proportion of individuals who have undergone cataract surgery (either aphakia or pseudophakia) in relation to the combined number of individuals with operated cataract and those who have a best corrected visual acuity (BCVA) below a specific surgical threshold in both eyes with cataract as the main cause of visual impairment in one or both eyes.The eCSC calculates the proportion of people with operated cataract attaining a defined level of PVA after the surgery as a proportion of the same denominator used in CSC calculation. 14The research team calculated effective refractive error coverage (eREC) using the alternative PVA-based definition 15 at a threshold of 6/12 according to the recently updated WHO definitions.The WHO recommended reporting eCSC against a cataract surgical threshold of mild vision impairment (worse than 6/ 12) and revised the definition of a good outcome after cataract surgery, changing the criteria from a visual acuity of 6/18 or better to a visual acuity of 6/12 or better. 14 two-proportion Z-test was used to assess any difference between the two groups at the significance level of p < .05using Stata-13 statistical software package.

Ethical consideration
The American University of Armenia Institutional Review Board approved the study protocol.An informed oral consent was obtained from all study participants.

Cataract blindness and VI
Age-and sex-adjusted prevalence of severe, moderate, and early VI was 1.6% (95% CI: 1.0-2.2),6.6 (95% CI: 5.5-7.7), and 16.0% (95% CI: 12.4-19.6),respectively. 13ge-and sex-adjusted prevalence of blindness due to all causes was estimated to be 1.5% (CIs: 1.0-2.1)(extrapolated 13,900 people).Of which 36.4% (extrapolated 5,062 people) were estimated to be bilaterally blind due to cataract.A total of 38,788 eyes were estimated to be blind due to cataract (Table 1).Bilateral and unilateral pseudophakia/aphakia were higher among men compared to women.However, the differences were not statistically significant.Supplementary Table S1 presents the estimates on the crude prevalence of blindness due to all causes and cataract.
The eCSC at a cataract surgical threshold <6/12 was 24.4% (30.8% in men vs. 21.1% in women), at a cataract surgical threshold <6/18 was 27.6% (34.5% in men vs. 23.9% in women), at a cataract surgical threshold <6/60 was 37.7% (39.7% in men vs. 36.5% in women), and at a cataract surgical threshold <3/60 was 43.7% (47.8% in men vs. 41.3% in women) (Table 2).Thus, eCSC was also higher in men compared to women, which means that coverage, corrected for the quality post-operative outcome, was better in men than women.However, these differences were not statistically significant.
A total of 96.4% of the eyes had cataract surgery with an intraocular lens (IOL).The majority of the operations were performed either in governmental/municipal (40.1%) or private (46.2%) hospitals, and 12.7% were either in eye camps or in a charitable hospital.A total of 73.5% (216) had unilateral cataract surgery; 73.7% (84) in men and 73.3% (132) in women, while 26.5% (78) had bilateral cataract surgery; 26.3% (30) in men and 26.7% (48) in women.A total of 11.2% of eyes were operated at the age of "50-59," 31.0%at the age of "60-69," 37.5% at the age of "70-79," and 12.6% at the age of over 80.

Main barriers to cataract surgery
The main barriers to cataract surgery among the population with bilateral PinVA <6/60 due to cataract included "cost" (35.3%), "need not felt" (23.5%), or "fear" (23.5%).There were notable gender differences in reported barriers to cataract surgery.Female participants with bilateral PinVA <6/60 due to cataract mentioned "need not felt" (30.4%) and "fear" (26.1%) as the main barriers, while the vast majority of male participants (63.6%) mentioned "cost" as the main barrier to receiving cataract surgery (Figure 1).

Discussion
This is the first nationwide epidemiological study in Armenia, which assessed the prevalence of cataract blindness, CSC, eCSC, and visual outcome of cataract surgery among people aged 50 years and older.It reported that the age-and sex-adjusted prevalence of blindness due to all causes was 1.5% (95% CIs: 1.0-2.1); of which 36.4% was bilaterally blind due to cataract.The findings on blindness due to all causes in our study were comparable with the rates reported in Turkmenistan (2002) (1.3% (95% CIs: 1.0 to 1.7)) and 16 Moldova (2014) (1.6% (95% CI 1.1% to 2.0%)), 17 and higher than the estimates from Hungary (2018) (0.9% (95% CI: 0.6-1.2)). 18The findings on cataract blindness in our study were lower compared to the worldwide estimate (45.4%) and the estimates from Southeast/East Asia and Oceania (48.3%), and higher compared to the estimates from Eastern/Central Europe and Central Asia (22.4%). 2 In Armenia 96.4% of the eyes had cataract surgery with IOL, while in Moldova 85.5%, 17 and in Kyrgyzstan 92%, 19 which are countries with a similar background.RAAB survey in Armenia reported that the sample prevalence of CSC at a cataract surgical threshold of <6/ 18 was 63.0% (69.0% in men and 59.7% in women).The estimates on CSC in Armenia were higher than the estimates from LMICs such as Kyrgyzstan (54.7%; 57.5% in men and 52.5% in women), 19 Turkmenistan (15.9%; 20.1% in men and 12.8% in women), 16 and lower compared to high-income countries such as Hungary (84.0%; 82.6% in men and 84.6% in women). 18The estimates on CSC in Armenia were fairly good compared to other LMICs.
The eCSC at a cataract surgical threshold of <6/18, <6/ 60, and <3/60 were 27.6%, 37.7%, and 43.7% in our study, respectively.However, eCSC at a cataract surgical threshold <6/12 was 24.4% in our study, which means about onequarter of people met the threshold of visual acuity ≥6/12 after cataract surgery among those who have been operated on or had operable cataract at least in one eye.
The data on eCSC at the 6/12 visual acuity threshold are available in 19 countries, and no country had eCSC over 50%.Among these countries, Hungary (2015) reported the highest results for eCSC at the surgical threshold <6/12 around 50%, India (2017) reported about 33%, and Kyrgyzstan (2017-19) about 25%. 14he relative quality gap at a cataract surgical threshold <6/12 was 55.7% (CSC: 55.1%, eCSC: 24.4%) in our study.The lowest relative quality gap of cataract surgery was reported in Argentina (2013) 10.8% (CSC: 65.7%, eCSC: 58.6%) and the highest in Guinea-Bissau (2010) 70.3% (CSC: 14.3%, eCSC: 3.8%).The median estimate on eCSC is higher in high-income countries (60.5%) and lower in low-income countries (14.8%).The 74 th World Health Assembly endorsed to have a 30%-point increase in a global target for eCSC by 2030. 14Strategic plans with a focus on improving the quality and coverage of cataract surgery might decrease the rates of blindness and visual impairment due to cataract in Armenia.The Ministry of Health (MOH) in Armenia with technical assistance from the Garo Meghrigian Institute for Preventive Ophthalmology developed a 5-year National Strategic Plan for Prevention of Blindness in Armenia in 2004-2005.The National Strategy on blindness prevention in Armenia has not been updated since then.
The CSC at a cataract surgical threshold of <6/12 was higher in men compared to women in Armenia; however, the difference was not statistically significant.It means that women were operated at a later stage than men.The majority of women in Armenia reported "need not felt" as a barrier for cataract surgery.Fear of surgery, low access to accurate eye health-related information, cultural beliefs, and overloaded household duties might be potential reasons for a late application for cataract surgery by women. 12Eye health education and promotion in communities targeting women specifically might improve knowledge and utilization of ophthalmic services.The investigation of the reasons that keep women from receiving cataract surgery at an earlier stage in Armenia would be helpful.
In Armenia, good visual outcome with available correction ≥6/12 was reported in 43.7% of eyes after cataract surgery, borderline (≥6/60) in 37.2% of eyes, and poor (<6/60) in 19.1%, which is below the WHO recommendation. 20The findings on visual outcomes after cataract surgery in Armenia are comparable with other LMIC data and worse than reported in highincome countries.In Kyrgyzstan, a good visual outcome was reported in 44.4% of eyes, borderline in 32.6%, and poor visual outcome in 23%, 19 while in Turkmenistan, a visual outcome with available correction ≥6/18 was reported in 30.6% of eyes, ≥6/60 in 34.9%, and <6/60 in 34.5%. 16n Armenia, poor visual outcome after cataract surgery was due to posterior segment diseases (66.0%), postoperative complications (18.9%), and surgery-related complications (11.3%).In Turkmenistan, the poor outcome was mostly due to uncorrected aphakia (43%), followed by posterior segment diseases (38%), and surgery-related complications (19%), 16 while in Hungary, the poor outcome was mainly attributable to posterior segment diseases (78.1%), followed by postoperative complications (17.2%), uncorrected aphakia (3.1%). 21Hospitalbased studies reported that regular monitoring of visual outcomes after cataract surgery and providing appropriate feedback to the surgeons will improve the quality of cataract surgical outcome. 22Regular control and timely intervention could be able to reduce poor visual outcome after cataract surgery due to posterior segment diseases such as age-related macular degeneration, glaucoma, and diabetic retinopathy. 18Quality post-operative follow-up could help to avoid complications, some of which can lead to permanent damage to the eye and poor visual outcome after cataract surgery. 19Good surgical outcomes might reduce people's fear of surgery and inspire more people in need to have cataract surgery. 19n our study, the main barriers to cataract surgery among the population with bilateral PinVA <6/60 due to cataract included "cost" (35.3%), "need not felt" (23.5%), or "fear" (23.5%).However, "cost" was the major barrier for men, while "need not felt" and "fear" were more reported by women than men.Reducing the cataract surgery cost and providing the expenses for transportation significantly increased the rate of cataract surgery in India. 23Reporting no need or fear of cataract surgery might be explained by a lack of awareness/understanding about cataract treatment by patients, especially by women.In Turkmenistan, the main barriers to cataract surgery were "old age, no need for surgery" and "waiting for cataract to mature." 16"Cost" was the main barrier to cataract surgery following "poor access to ophthalmic services" and "need not felt" in Nigeria. 24In Kyrgyzstan, "fear" was the main barrier to cataract surgery, followed by "waiting for cataract to mature," "unaware treatment is possible," and "cost." 19he strengths of the study included the use of standard methodology that makes our data comparable to other countries.The limitation of the study was the absence of specialized diagnostic equipment (except for direct ophthalmoscopy) for detailed examination of eye conditions, but this was mandated by the RAAB methodology.
In conclusion, the nationwide study in Armenia confirmed that the rate of cataract blindness was higher compared to high-income regions and lower than estimates from South/Southeast Asia and Oceania.CSC was higher compared to countries with similar socio-economic backgrounds, and the "cost" was one of the main barriers to cataract surgery.The rates on eCSC were lower compared to the rates from high-income countries and higher compared to low-income countries.The estimates of visual outcome after cataract surgery in our study were comparable with estimates from LMICs, and worse than the WHO recommendations.
This study suggests the urgent need to update the National Strategic Plan to prevent blindness in Armenia, focusing on improving the quality and coverage of cataract surgery.Educational and training programs on the quality of cataract surgery among physicians might improve the quality of cataract surgery and increase the number of qualified surgeons in the country.This study also suggests including cataract surgery as part of the basic package of health services covered by universal health coverage planned to be improved in 2024 to increase the CSC.Increasing awareness of cataract treatment and the introduction of relevant follow-up mechanisms after cataract surgery might address the main barriers to cataract surgery in the Armenian population.
This study provided important information about cataract in the region and can be used as baseline information for planning future eye care projects to improve cataract care in the country.The findings of this study can be used by other countries with a similar background where the epidemiological data are limited.

Figure 1 .
Figure 1.Barriers to cataract surgery as reported by female versus male participants.

Table 3 .
Visual acuity in operated eyes in sample.