Outcomes of cataract surgery: a population‐based developing world study in the Bhaktapur district, Nepal

Abstract

Background:  To evaluate the visual outcome after cataract surgery in a population of Nepal.Design:  Population-based cross-sectional study.Participants:  Forty years and above residing in Bhaktapur district.Methods:  Subjects were selected from 30 clusters using cluster sampling procedure. All underwent a detailed examination at the base hospital, including logarithm of minimal angle of resolution visual acuity, refraction, applanation tonometry, cataract grading, retinal examination and perimetry when indicated.Main Outcome Measures:  Visual acuity after cataract surgery.Results:  Out of 4003 subjects examined, 151 had undergone cataract surgery. Pseudophakia was present in 142 (94.0%), aphakia in nine (6%). Presenting and best-corrected visual acuity ≥6/18 was achieved in 123 (54.4%) and 164 (72.4%) eyes, respectively. Among the pseudophakic eyes, at presentation 122 (57.5%), 72 (33.9%), 18 (8.5%) and after best correction 162 (76.2%), 33 (15.8%), 17 (8.0%) had visual acuity of ≥6/18, <6/18–≥6/60 and <6/60, respectively. Retinal disease (35.5%), surgical complications (27.4%) and posterior capsular opacification (14.5%) were the principle causes of visual impairment after best correction in all eyes. There was no significant association in visual outcome based on age, sex, literacy and the duration of surgery.Conclusion:  Correction of refractive errors, preoperative screening of coincidental diseases, reduction in surgical complication rates and monitoring of postoperative follow-up care has to be addressed seriously in order to improve the outcome of cataract surgery to meet standards proposed by the World Health Organization. In the future, longitudinal studies need to be undertaken to provide specific information on the outcomes of cataract surgery in this community.

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BHAKTAPUR GLAUCOMA STUDY
An epidemiological study on glaucoma in Nepal

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The studies presented in this thesis were performed at the Nepal Glaucoma Eye Clinic, Tilganga
Institute of Ophthalmology, Kathmandu, Nepal. Tilganga Institute of Ophthalmology is a
subspecialty referral eye hospital affiliated with the National Academy of Medical Sciences.
The study was conducted in collaboration with the municipality of Bhaktapur district.
Financial support for this study was provided by:
1.
2.
3.
4.
5.
Katholieke Stichting voor Blinden en Slechtzienden te Grave
Ronde tafel Croy 162 en 40+ clubs Helmond
Sint-Antoniusfonds Elkerliek ziekenhuis Helmond
Stichting Ontwikkelingssamenwerking VUmc (SOVUmc) Amsterdam
Stichting Indiahulp
Cover: Rohan S. Thapa
Copyright © 2011, Suman S. Thapa
Printed by: Garima Offset Printers
ISBN : 978-9937-2-3506-8

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VRIJE UNIVERSITEIT
BHAKTAPUR GLAUCOMA STUDY
An epidemiological study on glaucoma in Nepal
ACADEMISCH PROEFSCHRIFT
ter verkrijging van de graad Doctor aan
de Vrije Universiteit Amsterdam,
op gezag van de rector magnificus
prof.dr. L.M. Bouter,
in het openbaar te verdedigen
ten overstaan van de promotiecommissie
van de faculteit der Geneeskunde
op vrijdag 1 juli 2011 om 13.45 uur
in de aula van de universiteit,
De Boelelaan 1105
door
Suman Shumsher Thapa
geboren te Calcutta, India

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promotor: prof.dr. G.H.M.B. van Rens

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Contents
Chapter 1 General Introduction 7
Chapter 2

Rationale, Methods and Baseline Demographics of the
Bhaktapur Glaucoma Study
25
Chapter 3 A population based survey of the prevalence and types of
glaucoma in Nepal
43
Chapter 4

Central Corneal Thickness and Intraocular Pressure in a
Nepalese population
55
Chapter 5

Comparison of Axial Lengths in Occludable Angle and
Angle-Closure Glaucoma
69
Chapter 6

Prevalence of visual impairment, cataract surgery and awareness
of cataract and glaucoma in Bhaktapur district of Nepal
81
Chapter 7

Outcomes of cataract surgery: a population-based developing
world study in the Bhaktapur district, Nepal
99
Chapter 8

Hepatocyte Growth Factor is associated with Angle Closure
Glaucoma in Nepalese Population
113
Chapter 9 A novel approach to glaucoma screening and education in Nepal 125
Chapter 10 General discussion 137
Summary 157
Acknowledgement 161
Curriculum Vitae 162

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Preface
Prior to the commencement of this research, Prof. Dr. Ger van Rens and I had visited
Bhaktapur district in 2005. Mr. Sankha Twyana, a local resident and staff of Tilganga
Institute of Ophthalmology (TIO) facilitated meetings with the government officials of
Bhaktapur municipality. After several meetings, it was decided in 2006 that the research
could be undertaken formally. TIO and the municipality signed a contract and with the
initiation of the Bhaktapur Glaucoma Study (BGS), the Bhaktapur Community Eye Centre
was established. Since 2006, this community eye centre has served as a secondary level eye
care facility providing ophthalmic care to the people of Bhaktapur district.
The BGS is the first study in Nepal to report on the prevalence of glaucoma based on the
International Society for Geographic and Epidemiological Ophthalmology criteria and is
therefore comparable to other studies from the world that follows the same criteria. The
epidemiological field work and patient examination of the study began in 2007 and was
completed in 2010. The data analysis and reporting of research findings followed thereafter.

The main objective of this research was to estimate the prevalence of glaucoma among
subjects forty years and above residing in Bhaktapur district and to investigate the risk
factors associated with glaucoma. The prevalence of visual impairment, outcomes of cataract
surgery and awareness of cataract and glaucoma in this population have been reported in
this thesis.
Suman S. Thapa

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CHAPTER 1
General Introduction

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Chapter 1Chapter 1
8
Introduction of Nepal
Nepal extends along the southern slopes of the Himalayas in Central Asia. It is located
between 80° 4’ and 88° 12’ east longitude and between 26° 22’and 30° 27’ north latitude.
The total land area is 147,181 square kilometres and its borders are contiguous with India in
the west, south and east and with the Tibetan Autonomous Region of the People’s Republic
of China in the north. There are three geographical regions in Nepal, namely high Mountains,
Hills and Terai (plain) ranging from North to South. Administratively and politically the
whole country is divided into 5 regions (from east to west), 14 Zones, 75 Districts, 205
Electoral constituency and 3995 Village Development Committees (VDCs). Kathmandu is
the capital city of Nepal. The government of Nepal is a parliamentary democracy.
The current population of approximately 29 million people (2/3 of them live in
rural areas) is projected to increase by 71 % over the next 20 years. Population growth
is 1.9 % per year.1 Life expectancy at birth is low at 59 years but there are considerable
regional disparities. It is reported to be 74.4 years in Kathmandu valley where the elderly
population is expected to rise more than threefold increasing demand for the treatment of
non-communicable diseases.2 The major ethnic castes in Nepal comprise of the Brahmans,
Chettris, Newars and other Indigenous groups while the religions are Hindu (88%), Buddhist
(7%), Muslim (3%) and Christianity (2%).
Nepal has an annual per capita income of US $ 473 per year. Agriculture is the mainstay
of the economy, providing a livelihood for over 80% of the population and accounting for
40% of Gross Domestic Product. Forty percent of its population live below the poverty line.
Industrial activity mainly involves the processing of agricultural produce including jute,
sugarcane, tobacco, and grain.
National Health Policies, Plan and System
I. National Health Policies and Plan
1. National Health Policy (NHP) was adopted in the year 1991 to bring about improvement
in the health condition of the people of Nepal. The primary objective of the NHP was to
extend the primary health care system to the rural population so that they benefit from the
modern medical facilities and trained health care providers.3

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General Introduction General Introduction
9
2. Second Long Term Health Plan (SLTHP): This is a 20 year long (1997-2017) health
plan of the government the goal of which is to guide the health sector development for
the improvement of the health of the population, particularly those whose health needs
are not often met… and to develop the appropriate strategies programs and action plans
that reflect mutual health priorities; that are affordable and consistent with available
resources; and to establish co-ordination among public, private and NGO sectors and
development partners.
3. Medium Term Strategic Plan (MTSSP): A strategic analysis of the health sector
jointly conducted by the ministry if health and EDP in 1999 showed that despite the policy
commitment, equity on access to health care remained elusive and concern was raised
about the low rate of achievements when compared with the investments made.3 The MTSP
was the result of that strategic analysis. The key aims developed from this analysis were
incorporated into the Tenth Five Year Health Plan.
4. Tenth Five Year Health Plan: This covers the period between 2002 - 20074, and also
incorporates the key principles contained in the document Nepal Health Sector Strategy: an
Agenda for Reform.
5. Millennium Development Goals (MDGs) focussed on Health: In addition to the above
mentioned national policy the government of Nepal has also pledged its commitment towards
the accomplishment of MDGs, a UN led initiative endorsed by almost all the countries of
the world, including Nepal.
II. National Health System
The National Health System can be divided into two broad categories:
1. Central level institutions
In addition to 5 tertiary care level Hospitals (excluding the army and police Hospitals) in
Kathmandu (having the total bed capacity of 1100+) providing speciality and subspecialty
services, there are several other central level units/ bodies with a specialised function and is
directly under the Ministry of Health (MOH). These bodies include, National Tuberculosis
Centre, National Centre for AIDS and STD control; or, National Health Education,

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Chapter 1Chapter 1
10
Information and Communication Centre and various high level policy and management
units within the complex of MOH.
2. Department of Health Services (DOHS)
The main responsibility of the DOHS is to deliver preventive and curative health care
services throughout the country. The DOHS primarily does this through a network of
specialised units focussing on major public health problems. Of the state owned health care
institutions located outside the capital, there are 5 Regional Health Directorates (which also
includes five regional hospitals and are directly under the MOH rather than that of DOHS),
11 Zonal Hospitals, 62 District Hospitals,188 Primary Health Care Centres (PHCC; one for
each electoral constituency, has 5 beds and is managed by a non-specialist physician), 697
Health Posts and 3129 Sub-Health Posts (HP and SHP; one for each VDCs, has no inpatient
facility and is managed by paramedical personnel).
At the district level, in addition to the DH, there are also District (Public) Health Offices,
which has a responsibility to implement preventive health activities and supervise/ support
the PHCC, HP and SHP.
Regional and Zonal Hospitals are expected to provide the major clinical specialty
(Medical, Surgical, Paediatric and Obstetrical/Gynaecologic) services; the SHP, HP, PHCC
and DH are supposed to provide what is called Essential Health Care Services (EHCS).
The SHP could be conceptualised as the first contact point between the health care
delivery system and the population seeking health care services’ in reality the SHP is
the referral centre (in most rural areas) for the volunteer cadres such as Traditional Birth
Attendants (TBAs; total no = 15000+) and female Community Health Volunteers (FHCV;
total no = 48,000) who are active in rural village communities.
III. Current Health Scenario
The overall morbidity in Nepal is dominated by infectious disease, nutritional disorders,
and maternal and perinatal diseases. Half of all the deaths and two thirds of all Disability
Adjusted Life Years (DALYs) are caused by them. However non- communicable diseases
are beginning to increase in relative importance, though not to the same extent as they have
been in many low-income countries.2 The top five leading causes of mortality among in-
patients by Central Hospitals, as per reports in 20095 are shown in the table 1.

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General IntroductionGeneral Introduction
11
Table 1. Causes of death as per reports in 2009 (5)
Cause of Death Percentage of all deaths
Chronic Obstructive Lung Disease65
Cerebrovascular attack 44
Alcoholic Liver Disease43
Head Injuries39
Diabetes19
As per the latest government report on the current national health data in the year 2009,
the top 5 conditions diagnosed among patients attending outpatients clinic throughout the
government run health care institutions are presented in table 2.
Table 2. Most common conditions among patients attending outpatients’ clinic in government run health care institutions.
Diseases / Conditions Prevalence/Burden
Intestinal worms3.76 %
Lower respiratory tract infections3.68 %
Fever3.39 %
Gastritis 3.39 %
Headache3.26 %
Fever2.50 %
Health expenditure is very low in Nepal in spite of some real increase over recent years.
Currently the total expenditure is about $10.50 per capita with $7.40 being private-the
majority of which is out of the pocket expenditure. Transport costs are a significant deterrent
to the poor accessing heath care in remote areas and the largest equity discrepancies relate
to the area of residence.
The challenged faced by the health sector in Nepal are similar to those facing other
low income countries-namely an unregulated private sector and a rapid expanding and
unregulated private sector. While the government needs to focus on ensuring access by
the poor and vulnerable to essential health care service (EHCS), this will only succeed if it
ensures that systems- both financial and regulatory-are in place to meet the expectations if
the population who wish to access services outside the EHCS.2

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Chapter 1 Chapter 1
12
Infrastructure of Eye Health Care in Nepal
The Nepal Prevention Blindness Program was jointly established by the Ministry of Health
and WHO in 1979 with the objective to provide eye care services to Nepal. The project was
launched with the following objectives:
• National Blindness Survey
• Establishment of eye care services
• Development of human resources
• Integration of primary eye care into the primary health care
Nepal Blindness Survey 1981
The Nepal Blindness Survey (NBS) was a multipurpose, interdisciplinary study directed
toward improving the knowledge about the amount and location of blindness in Nepal.
Since the primary objective of the Nepal Prevention Blindness Program was to reduce levels
of avoidable blindness by 90 percent, only certain cause specific blindness were of interest
to the program and hence the survey. These include blinding diseases of conditions that
could be eliminated through treatment. The focus of the program and of the survey thus
was narrowed to examine the nature of the diseases such as cataract, trachoma, vitamin A
deficiency, and eye injury or trauma.
The Nepal Blindness Survey was designed during a two- year period between the early
1979 until the end of 1980. A large national sample of 105 sites comprising of households and
their residents was designed and selected. Principles of probably sampling were used.6
Summary of the NBS 1981: Of the 39,887 people examined, The NBS found 335 blind,
using the WHO criterion on visual acuity less than 3/60 in the better eye. It is estimated that
there are 117,623 blind in Nepal (0.84%); 259,888 with low vision (1.85%); and 233,612
blind in one eye (1.66%).

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General Introduction General Introduction
13
The following tables (Table 3-8 summarises the results of the NBS of 1981)
Table 3. Visual impairment by WHO categories
Visual Acuity Sample NPopulation Estimates Percentage in population
Not impaired 38,47823,680,14297.31%
Low Vision738
259,8881.85
Blind335117,6230.84
Table 4. Distribution, estimated number of cases and prevalence of unilateral and bilateral blindness
Sample NEstimated Number of casesPercentage of Nepal’s Total
Sighted both eyes38,54713,703,50097.5%
Blind in one eye661233,6121.7
Blind in both eyes335117,623 0.8
Subtotal39,54314,054,735100.0
Missing344118,346NA
Total39,88714,137,081 100.0
Table 5. Distribution of blindness by age and sex
Sample N
Estimated Number of
Cases
Prevalence
(Per100)
Percentage of
Nepal’s Total
Male
0-96,0997260.040.7%
10-194,388 1,8600.121.6
20-292,6051,9120.19 1.6
30-392,1352,9250.372.5
40-491,6673,6340.593.1
50-591,2779,3962.068.0
60-6978313,6124.9011.6
70+41513,0259.11 11.1
Total Male19,37947,1260.6841.2
Female
0-9 60401,3100.061.1
10-1940442,3480.162.0
20-2932132,0360.171.7
30-3923923,1460.36 2.7
40-4919445,1030.744.4
50-59126410,3232.388.8

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Chapter 1Chapter 1
14
60-69865 22,5637.7919.3
70+38023,256 17.2519.8
Total Female 20142 70,0850.9859.8
Sub Total 395211,17,2110.83100.0
Missing3660NA NA
Total398871,17,2210.83100.0
Table 6. Distribution, estimated number of cases and prevalence of blindness by urban/rural residence
Urban/rural
Sample
N
37,561
Estimated number
of cases
107,834
Prevalence
(Per 100)
0.8
Percentage of
Nepal’s Total
91.7%Urban
Rural 1,9909,789 1.08.3
Subtotal39,551117,6230.8100.0
Missing 336NANANA
Total 39,887117,623 0.8100.0
Table 7. Distribution, estimated, number of cases and prevalence of blindness by terrain
Terrain
Sample
N
17135
Estimated number
of cases
61379
Prevalence
(Per 100)
1.01(1.06)
Percentage of
Nepal’s Total
52.2% Terai (Plains)
Hills18885476190.71(0.66)40.5
Mountains156237780.67(0.59)3.2
Valley 19614846 0.63(0.67)4.1
Subtotal395431176230.84100.0
Missing 3440 NANA
Total398871176230.84100.0
Table 8. Distribution, estimated number of cases and prevalence of blindness by region
Urban/rural
Sample
N
9819
Estimated number
of cases
29785
Prevalence
(Per 100)
0.86(0.89)
Percentage of
Nepal’s Total
25.3%Eastern
Central1234737591 0.82(0.77)32.0
Western7548181270.69(0.60)15.4
Far West A5665178110.92(1.06)15.1
Far West B4172143090.97(0.95)12.2
Subtotal395511176230.84100.0
Missing 336 NA NANA
Total398871176230.84100.0

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General IntroductionGeneral Introduction
15
Causes of Blindness NBS 1981
The major cause of blindness has been presented in table 9. Cataract is the leading cause of
blindness in Nepal. It accounts for more than two-thirds of all blindness and more than four-
fifths of all avoidable blindness. Of the 39,887 people examined during the survey, 1137
(2.8%) were found to have some degree of lenticular opacity or evidence of prior cataract
surgery. Approximately 20% of those with cataracts are blind. Over half of these cataract
blind live in the Terai regions and one third of them live in the hills and the mountains.
Trachoma is the most widespread condition leading to blindness. Out of the 39,887 people
examined, 2770 had Trachoma (6.9%). Despite its prevalence, trachoma causes only 2.4%
of the blindness in Nepal. Trachoma is clustered in certain geographic areas and among
certain population groups. Most notably, Trachoma is prevalent in the Western terai and
affects females more than males.
Table 9. The causes of blindness NBS 1981
Cause of blindnessSample
Estimated number of
cases
Percentage
1Cataract81 28,43060.3
2Cataract sequelae103,6937.8
3Retinal Disease62,0944.4
4Trauma 5 1,799 3.8
5Amblyopia31,134 2.4
6Glaucoma3 1,128 2.4
7Other infections31,101 2.3
8Small pox2 713 1.5
9 Nutritional aetiology1 3720.8
10Trachoma0--
Other unknown causes134,818 10.2
Undetermined62,152 1.8
Total33511,7623100.0