Malay Glaucoma Eye Study II Navigation, Mobility and Reading Ability in Primary Glaucoma
Malay Glaucoma Eye Study II Navigation, Mobility and Reading Ability in Primary Glaucoma
With the improvement of health system, the life span of Asians has increased tremendously
 especially in Malaysia. As an early preparation to be an 'aging country' in 2023, Malaysia
 needs to prepare infrastructure and policy to improve quality of life (QoL) in older adults.
 Glaucoma is an aging related chronic disease that cause progressive optic neuropathy and
 visual field defect1. The main aim of glaucoma treatment is to slow down disease progression
 and preserve patient's QoL2. Modification of intraocular (IOP) is believed to be the mainstay
 of treatment but may not prevent progression of the disease. Modification of lifestyle has
 been found to change the prognosis of many chronic diseases such as diabetes mellitus.
 However, there is minimal evidence on the effect of lifestyle modification on glaucoma.
 Although constricted visual field almost asymptomatic especially in primary open angle
 glaucoma but many domestic injuries such as fall has been reported. Glaucoma patients
 reported greatest restriction with mobility especially driving compared to the other
 domains3,4. Reduction of walking and moderate-to-vigorous physical activity was also found in
 those with bilateral visual field loss5. Progressive constriction of visual field has been
 found to increase dependency, reduce mobility, pleasure of reading and QoL of glaucoma
 patients6. This will lead to psychological and emotional disturbance, in certain cases even
 resulted in depression. On the other hand, being physically active is found to have some
 protective effect against development and severity of glaucoma8,9. Thus, identifying problems
 related to physical activities in constricted visual field is important for improvement of
 rehabilitation and exercise regime for glaucoma patients. An exercise regime must be
 effective without causing major changes to IOP, safe in patients with constricted visual
 field and sensitive to social culture of Malaysians. Addressing these issues will lessen
 dependency and promotes healthy living among older adults. Improvement in navigation perhaps
 may increase the physical activities in glaucoma. Reading is another important pleasure in
 life. Visual field defect in glaucoma patients has been reported to associate with slower
 reading speed, saccade rate and visual span10,11. Identification of factors associated with
 difficulty in reading among glaucoma patients and development of rehabilitation regime in
 reading may improve the happiness index in literate patients. Nevertheless, there is no
 specific rehabilitation program to improve reading abilities among glaucoma patients. A
 combination of visual rehabilitation of low vision therapy and occupational therapy is ideal.
 Although, there is improvement in reading ability and mobility post low visual aid
 rehabilitation but there is no evidence on glaucoma patients specifically12. Improvement in
 daily living and dependency may improve their QoL. Happiness perhaps may improve the balance
 between oxidative stress damage and antioxidant level. Many previous studies discovered that
 various biomarkers of oxidative stress are elevated in people with depression, and anxiety
 disorders13. Similarly, oxidative stress has been implicated in pathogenesis of glaucoma and
 accelerates retinal ganglion cell damage in glaucoma14. Indirectly, improvement of QoL will
 help in halting the progression of visual field defect. Based on the previous research
 project on Malays in Malaysia, navigation and mobility has been identified to be mostly
 affect in primary glaucoma patients based on QoL questionnaires. Physical activities have
 potential protective effect against progression and severity of glaucoma9. Improvement in
 navigation, physical activities and reading ability, perhaps may improve their QoL. The main
 problem is how do we improve their navigation, physical activities and reading ability
 despite their constricted visual field. The most important step is to understand the problem
 and issues pertaining to the navigation, physical activities and reading faced by patients
 with glaucoma.
Objectives General objective: to develop, validate and evaluate the effectiveness of
 navigation, physical activities and reading abilities (the new rehabilitation protocols) in
 Malay adults with primary glaucoma.

 Specific objectives:

 1. To identify problems with navigation, physical activities and reading in Malay adults
 with primary glaucoma

 2. To develop and validate the new rehabilitation protocols for patients with primary
 glaucoma

 3. To evaluate the effectiveness of the new rehabilitation protocols in improving the
 quality of life of primary glaucoma patients

 4. To evaluate the mean changes of total antioxidant level pre- and post-intervention with
 the new rehabilitation protocols in primary glaucoma patients

 5. To evaluate the changes of ocular parameters pre- and post-intervention with the new
 rehabilitation protocols in primary glaucoma patients Research design

 This research project will be divided into 3 phases with different research designs:

 Phase 1: case control study on factors affecting navigation, physical activities and reading
 between primary glaucoma patients and age matched controls.

 Phase 2: development and validation study on new rehabilitation program for navigation,
 physical activities and reading.

 Phase 3: randomized control trial study to evaluate the effectiveness of rehabilitation
 program and exercise on clinical parameters, quality of life and oxidative stress of primary
 glaucoma patients.

 Study area

 A. Glaucoma clinic for patient recruitment, assessment and follow up in:

 Hospital Universiti Sains Malaysia (HUSM), Kota Bharu, Kelantan, Malaysia Hospital Raja
 Perempuan Zainab II (HRPZII), Kota Bharu, Kelantan, Malaysia Hospital Sultanah Bahiyah (HSB),
 Alor Setar, Kedah, Malaysia Hospital Melaka, Melaka, Malaysia

 B. Occupational rehabilitation, Rehabilitation Unit for visual rehabilitation program in:

 Hospital Universiti Sains Malaysia (HUSM) Kota Bharu, Kelantan, Malaysia Hospital Raja
 Perempuan Zainab II, Kota Bharu, Kelantan, Malaysia Hospital Sultanah Bahiyah, Alor Setar,
 Kedah, Malaysia Hospital Melaka, Melaka, Malaysia Study population Reference population:
 Primary glaucoma patients-primary open angle glaucoma (POAG) and primary angle closure
 glaucoma (PACG) Target population: Primary glaucoma patients (POAG and PACG) who attended
 glaucoma clinic in HUSM, HRPZII, HSB and Hospital Melaka Source population: Patients aged 40
 to 70 years old diagnosed with POAG or PACG who are attending the glaucoma clinic, HUSM,
 HRPZII, HSB and Hospital Melaka from June 2020 until February 2020.

 Sampling frame: Glaucoma database in eye clinic of HUSM, HRPZII, HSB and Hospital Melaka
 Sampling method and subject recruitment The sampling method is based on the specific
 objective and phases of the study For objective 1: a simple random sampling will be used. For
 objective 2: convenience sampling.

 For objective 3, 4 and 5: randomized Controlled Trial will be conducted. Using block
 randomization method with sequentially numbered in opaque sealed envelopes (SNOSE), the
 eligible patients will be randomized into:

 Group A: Intervention group Group B: Non-intervention group Primary investigators
 (Postgraduate students) will be blinded.

 Operational definition Primary Open Angle Glaucoma (POAG): A chronic, progressive optic
 neuropathies that characterised by structural changes in the optic nerve head and/ or with
 visual field defect without identifiable causes (Asia Pacific Glaucoma guidelines, 2008).

 Primary Angle Closure Glaucoma (PACG): An eye with an occludable drainage angle and features
 indicating that trabecular obstruction by the peripheral iris has occurred, such as
 peripheral anterior synechiae, elevated intraocular pressure and optic neuropathy (Foster et
 al., 2002).

 Target Intraocular pressure: Target intraocular pressure throughout this study is dependent
 on severity of the disease based on threshold IOP (Sihota et al., 2018). In this study,
 target intraocular pressure will be personalized accordingly.

 Lens status: Phakic is defined as patients with an intact natural lens without visually
 significant cataract. A person with visually significant cataract was defined by having, in
 either eye: any LOCS II grading of ≥2, best-corrected visual acuity of <6/12 in the
 cataractous eye, cataract as primary cause of vision impairment in that eye, and patient
 report that general vision was fair, poor, very poor, or blind (Ritcher et al, 2009).
 Pseudophakic refers to patients who have underwent lens extraction procedure with
 implantation of artificial intraocular lens for more than 3 months prior to recruitment.

 Compliance to treatment: Patients who adhere and persistent to instillation of topical
 intraocular pressure lowering medications as recommended by their physician throughout follow
 up (Robin et al, 2011). Adherence is defined as less than 3 times missed their medication in
 a week. Persistence is defined as continuously on prescribed medication for more than 3
 months.

 Visual rehabilitation: The process of treatment and education that helps individuals who are
 visually disabled to attain maximum function, a sense of wellbeing, a personally satisfying
 level of independence, and optimum quality of life (American Optometric Association, 2004).

 Reading speed: rate at which a person reads written text (printed or electronic) in a
 specific unit of time (Muñoz B et al, 2000).

 In this study, the definition of reading speed will differ according to the task of reading
 and the reading material.

 1. Reading speed in reading the Bahasa Malaysia reading chart: number of words read per
 minute

 2. Reading the newspaper print and pharmacy label print: time taken to finish a reading
 task in minute

 3. Reading book: number of pages read per hour/day Eye movement during reading: movement of
 the eye between the start of first saccade and the end of final saccade during the
 reading (Muñoz B et al, 2000).

 Head movement during reading: all head movement during reading including of
 modulatory-velocity component with eye saccades and constant-velocity component independent
 of eye saccades (Muñoz B et al, 2000).

 Quality of life: The term "quality of life (QoL)" is defined by the World Health Organization
 as individuals' perception of their position in life in the context of culture and value
 systems in which they live in relation to their goals, expectations, standards and concerns
 (World Health Group, 1995). Total scoring and each domain score of Bahasa Malaysia version
 GlauQoL -36 questionnaires will be used to determine the QoL. It has been translated and
 validated and piloted in 96 samples. All 36 translated questions were retained as the
 Cronbach alpha was found to be 0.85 (Chandramohan et al, 2015).

 Depression: a feeling of depressed mood or loss of interest with at least five out of nine
 symptoms present for a diagnosis of major depression. The mGDS 14 questionnaire was used in
 this study to assess depression among primary glaucoma patients.

 Bump: body contact above the knee, excluding the hands-on adjacent objects. Stumble: a change
 in posture or gait due to contact with an object below the knee.

 Data collection method

 This study will be divided into three phases:

 1. Phase 1: identification factor affecting navigation, physical activities & reading

 2. Phase 2: development and validation of rehabilitation for navigation, physical
 activities & reading

 3. Phase 3: evaluation of the effectiveness of rehabilitation on clinical parameters,
 quality of life and oxidative stress Phase 1 A case control study will be conducted
 involving POAG and PACG patients with different severity according to Esterman binocular
 visual field. An age-matched control subjects will also be recruited. We estimated a
 sample size of 40 glaucoma subjects and 40 age-matched controls. Selected patients must
 be physical and mentally fit. Simple random sampling will be applied to patients who
 attend ophthalmology clinic for other ophthalmological conditions except for glaucoma
 especially those who were on follow-up for dry eye, non-visually significant cataract,
 pseudophakic patients. Patients that fulfil the inclusion and exclusion criteria will be
 selected during their follow up. These patients will be grouped as controls.

 Ocular examination: Baseline examination will be conducted in all subjects including visual
 acuity assessment, contrast sensitivity, stereoacuity and Esterman binocular visual field.

 Navigation & physical activities: A stimulated area will be created using the existing
 facility in occupation rehabilitation unit, HUSM. Similar set up will be conducted in HRPZII,
 Hospital Sultanah Bahiyah and Hospital Melaka. Glaucoma patients and age-matched control
 subjects will be asked to navigate in the stimulated area and several areas will be equipped
 with closed circuit television (CCTV).

 A predefined obstacle course navigation will be used to measure mobility performance among
 glaucoma and control groups. Subjects will be instructed to walk through the course as
 quickly and safely as possible while avoiding all obstacles in their path. The course will be
 constructed in a maze form, 30m length in total and seeded with obstacles made with styrofoam
 that represent objects in a patient's home environment. The illumination along the path range
 from 100 to 300 lux. Before walking through the course, participants will be given
 instructions and directions to ensure that they understood the path.

 Mobility performance will be assessed by the time required to complete the obstacle course
 and the number of mobility incidents, which included bumps, stumbles, and orientation
 problems. A bump will be defined as a body contact above the knee, excluding the hands. A
 stumble will be defined as a change in posture or gait due to contact with an object below
 the knee. An orientation problem will be defined as a change in direction that was not
 consistent with the instructions. A trained observer will be following the participants
 closely behind to record time and bumps. Surveillance system comprising video camera to
 record the activities will be implemented as well. Errors are quantified on a 3 point scale,
 where errors were scored as 1 point if the subject made contact with an obstacle but was able
 to correct in ≤ 5 sec, 2 points if the subject took 5-15 sec to correct errors, and 3 points
 if the subject took > 15 sec to self-correct or required the assistance of one of the
 research assistants to correct the error. Travel time will be converted into walking speed
 (meters per second) by dividing the distance of established travel path by the time to
 complete the course. The converted measure permits a direct comparison of mobility
 performance across other routes and studies.

 Special exercise: A special exercise will be designed that is safe for person with
 constricted visual field; combination of isometric and aerobic exercise. IOP will be taken at
 baseline and at certain phases of the exercise. If there is an increase of more than 20% from
 baseline IOP at certain phase of the exercise, that phase will be excluded or replaced
 accordingly.

 Reading: Subject will be asked to read at 40cm (reading distance) with the reading material
 on a special pedestal. Reading materials include:

 1. Universiti Teknologi Mara -Malay related words (UiTM-MrW)

 2. Universiti Teknologi Mara- Malay unrelated words (UiTM-MuW)

 3. Different sizes of text of common reading materials (Bahasa Malaysia):

 -  Pharmacy label print (0.131° print)

 -  Newspaper print size (0.26° print)

 -  Small newspaper headline/heading size (0.525° print)

 -  Large newspaper headline size (1.71° print)

 4. A book in Bahasa Malaysia will be selected Reading speed will be assessed using Matlab
 version 8.3 programme. Eye and head trackers will be used (Polhemus Visiontrak Desktop
 300) to document the head and eye movement. Reading will be done in a fix light
 intensity (500-600lux). A rehabilitation reading regime with or without low vision aid
 will be designed.

 Phase 2

 From phase 1 findings, a special rehabilitation device and programme will be designed for:

 1. Navigation and mobility

 2. Exercise

 3. Reading A user friendly and inexpensive device and program with minimal usage of low
 vision aid will be designed and piloted for 30 glaucoma patients and 30 controls. Simple
 random sampling will be applied on the patients and control subjects recruited for phase
 1 study. An advertisement is also attached here(phase 2).

 Devices will include wearable body sensor vibrator and special smartphone apps for
 recognition of objects. The control subject will be using the special glasses (available in
 the department) that simulated constricted visual field. For the pilot study, the
 effectiveness will be considered based on the evaluation conducted for phase 1. The recruited
 subjects will be asked to practice according to the rehabilitation protocol for 2 weeks.
 Improvement will be made based on the outcome of the pilot study.

 Validation process:

 After development or modification of the program, the recruited subjects will be trained and
 asked to perform it at home for two weeks. They will be provided with a dairy (to ensure that
 they have conducted it daily). They will be seen after two weeks and the rehabilitation
 method will be assessed using specific questionnaire. Tentative questionnaire is attached
 here.

 Navigation and physical activities- Any step of the program will be eliminated from the
 program if it is deemed dangerous (20% of the subjects reported bumping, stumbling, fall or
 near fall), difficult to manoeuvre (20% of the subjects have difficulty or expressed
 difficulty in performing the step) and impractical (20% of the subjects expressed infrequent
 of performing the step at home). Assessment will be made based on simple questionnaire, which
 will be made once the rehabilitation program has been developed.

 Exercise - IOP will be obtained from the patients before and 10min after performing each
 important step of the exercise using tonometer. If any step of the exercise cause elevation
 of IOP of more than 2mmHg from the baseline IOP will be eliminated and replaced (if deem
 necessary). Patients will also be asked on the feasibility and practicality using the
 questionnaire.

 Reading- if the reading material (book) is found to difficult, the material will be replaced.
 Any new movement of the eye or head that is scored difficult to manoeuvre or impractical will
 be removed. A questionnaire with Likert score scoring will be developed after completion of
 phase 1.

 Definition of acceptable rehabilitation regime are as below:

 Navigation and physical activities- reduction of at least 40% of bumping or stumbling to
 objects or fall in simulated area. An increase of 40% of total step per day based on
 accelerometer.

 Exercise - An increase of 30% of based on accelerometer. Reading -An increase of 20% of
 reading task and reading speed.

 Phase 3

 A randomized single blinded control trial study will be conducted using the newly developed
 rehabilitation programme from phase 2. A known case of POAG and PACG patients who are
 compliance to treatment and follow up will be selected. Patients involved in phase 1 will not
 be recruited into this study. A total of 300 patients will be involved (100-navigation and
 mobility, 100- exercise and 100-reading). Based on the most recent reliable Humphrey visual
 field, only those who has more than 10 degree from fixation using Estermann binocular
 analysis will be selected. Other selection includes best corrected visual acuity of 6/60 on
 the better seeing eye, pseudophakic or phakic (without visually significant cataract) and
 without history of surgical intervention 3 months prior to recruitment. Those with severe
 hearing impairment, physical disabilities such as stroke, limbs amputation, macular and
 retinal pathology, and on low vision aids will be excluded. Using block randomization method
 with sequentially numbered in opaque sealed envelopes (SNOSE), the eligible patients will be
 randomized into:

 Group A: Intervention group Group B: Non-intervention group In both groups, their usual
 topical treatment will be continued. They will be advised to be compliance to the existing
 treatment. This study will take 6 months to complete.

 Baseline assessment An introductory session will be conducted to all selected subjects. The
 purpose of the study will be explained, and compliance will be emphasized. Venesection will
 be conducted and 3cc of blood will be obtained. The blood will be kept in the plain bottles
 and analysed for the level of total anti-oxidant capacity (TAC).

 Patients (in group A & B) will be given the GlauQol-36 and mGDS-14 questionnaire in Bahasa
 Malaysia (Appendix A & B) and be given adequate time to read and answer the questionnaire. If
 the patient does not understand the questionnaire, they can obtain clarification from the
 primary investigators (SMCM & NS). The GlauQoL-36 questionnaire consists of 36 questions
 grouped into 7 domains (daily life, driving, psychological well-being, self-image, anxiety,
 burden of treatment and confidence in healthcare). Each question was given 4- and 5- point on
 the Likert scale. The total score from each domain was summed and the score calculated. The
 mGDS-14 questionnaire consists of 14 questions. It has a yes/no answer and is scored 1 or 0
 for each question. Patients with the score of 8 and above are considered depressed.

 Accelerometer will be given to the patients with the instruction to wear it all day long
 except for sleeping and bathing. A baseline reading speed, visual span, eye and head movement
 will be obtained in those involved in reading rehabilitation program using the reading
 charts, newspaper and pharmacy label print. These assessments will be conducted twice; before
 the rehabilitation program and after 6 months of the program. Reading materials in Bahasa
 Malaysia (a book to read) will also be given. Clinical parameters including IOP and ONH
 imaging to assess the RNFL thickness and ONH parameters will also be conducted.

 Rehabilitation regime

 A.Navigation & mobility:

 The rehabilitation sessions will be conducted in the Rehabilitation Medicine Unit of HUSM,
 HRPZII and Hospital Melaka provided by the Occupational Therapy division. The patient is
 expected and encouraged to come with a carer (who live together with the patient) during the
 early part of the sessions. After randomization, patients in the group A will be assessed
 using modified Barthell index, the patient's limitations in daily activities with special
 attention to the components related to restricted visual field. An introductory session will
 be conducted by the occupational rehabilitation therapist (baseline), patients will be asked
 to practice it at home.

 Depending on the respective limitations the patient will be taught of ways to get around the
 problems, emphasizing on the Visual Perception and Sensory Motor Ability as outlined by the
 Chessington Occupational Therapy Neurological Assessment Battery to maximize function, health
 and wellbeing. A set of realistic goals will be established together with the patient whether
 using the restorative or compensatory methods to promote motivation and enhance confidence.
 Restorative method includes restorative visual field training, optokinetic training and and
 search task training focussed at improving the loss in visual field or disability arises from
 the loss of patient's eye field. Interventions involve compensation which are strategies to
 minimize mismatch in the patient's ability with task difficulty; and substitution which can
 include environmental modifications to enhance vision such as adjustment of lighting.
 Subsequent sessions will involve consolidation of the concepts with supervised practices
 comprising indoor and outdoor activities to enhance patients' understanding and confidence
 and encourage participation.

 Rehabilitation education and activities include:

 1. Dressing Light closet to improve acuity. Hang matching clothes together. Pin socks
 together when placing them in the washer so they will stay matched.

 2. Feeding Provide high contrast. Ensure that plates contrast with table surface. Avoid
 patterned table clothes. Arrange food on the plate in a clockwise fashion and orient the
 person to the arrangement.

 3. Personal hygiene and grooming activities Reduce clutter in bathroom and kitchen
 cabinets. Use high contrast bathmat and minified mirrors

 4. Communication and environmental hardware adaptations Use talking watches or clocks to
 tell time and high contrast doorknobs.

 5. Functional mobility Mobility is eased with the clearing of pathways and the minimizing
 of clutter and furniture. Lighting in hallways and entryways is also needed. The person
 with constricted visual field needs to optimize visual scanning abilities by learning to
 turn and position the head frequently when mobile or participating in an activity.

 6. Scanning activity or search task While focusing on a point central to the visual axis,
 the patient is asked to arrange wooden cubes forming vertical and horizontal lines one
 at a time. The instruction will be given to arrange from left to right, then right to
 left, top to bottom and lastly bottom to the top. Patient's visual field is estimated
 and described to the patient. Patient is advised on the 'danger area' outside the visual
 field that can pose various risks to the patient.

 7. Room orientation and memory This is applied to a small area such as a bedroom or a
 toilet. The patient is asked to stand inside a simulated room in the Rehabilitation Unit
 and describe the names of the objects that he/she can see. Emphasizing on the location
 of the objects and their directions from the patient (right, left, in front, behind),
 patient is trained to systematically orientate himself in the room relative to those
 objects. Certain objects are highlighted to the patient as a precaution to avoid
 stumbles and falls. For safety, cleaning supplies should be placed separately from food
 supplies.

 8. Orientation and mobility This activity covers a larger area that the patient will be in
 which is the patient's home. Patient will be instructed regarding room familiarisation
 according to the house's structure as described by patient's carer with the help of a
 drawing. For example, the patient is taught to memorize the number of steps needed to be
 made to get to the toilet from his room, and in what direction.

 9. Reading (this is not part of the reading rehabilitation) Patient will be taught to label
 the things that are of importance to them at home to aid recognition, for example
 bottles of spice. The letters should be of appropriate size deemed legible by the
 patient according to the patient's field of view, and of high contrast. For patients on
 medications, they are advised to use medication organizer to get them organized.

 10. Eye-hand coordination To enhance hand-eye coordination, a pegboard is used as a form of
 exercise for the patient. Patient is asked to match coloured pegs into its corresponding
 holes according to a reference template. This training also allows the patient to get
 used to the extent of field of view that he possesses.

 11. Optokinetic training programme This programme is built based on the knowledge that eye
 and body movements are coordinated by the same parts of the brain, which is important in
 maintaining stability and balance. Repeated training helps to re-teach the body of its
 responsible actions, by the means of precise eye movements. This is done via optokinetic
 eye programme to accelerate physical and mental fitness. Fortunately, the high
 functional adaptability of the brain permits positive training and learning as the
 person ages.

 Occupational therapist will conduct a home visit if necessary. A diary will be given to
 assess their compliance. Reassessment will be done for every 2 weeks for 2 months and every
 month for the next 2 months. Another home visit will be conducted if the patients show poor
 understanding or compliance during the re-assessment evaluation.

 Patients in group B will also be given a diary to record their activities. In both groups,
 their usual topical treatment will be continued. They will be advised to be compliance to the
 existing treatment.

 B. Special exercise:

 An instruction course will be conducted and a CD (with step by step exercise demonstration)
 will be given to the patients in group A. They will be asked to come for another session in 2
 weeks. Then they will be asked to conduct the exercise for at least three times a week.
 Exercise diary and accelerometer will also be given to patients of both groups.

 C. Reading regime:

 A briefing will be given to all the patients involved in this regime. Patients in both groups
 will be asked to complete a reading task (reading the given book) a day; number of pages
 completed in an hour per day, and time taken to complete a page in the given book. They will
 be asked to record the time they have completed the task in their reading diary. Any extra
 reading task will also be recorded this include reading Quran and newspaper.

 Final assessment At 6 months post recruitment, patients in group A and B will be asked to
 complete the Malay version of Glau-QOL 36 and MGD14. Accelerometer reading will also be
 documented. The number of pages read for the given task will be compiled. The reading diary
 will be evaluated. Reading speed will be calculated daily and the mean reading speed will be
 used for analysis. Another venesection will be conducted to examine the level of TAC.
 Clinical assessment including IOP, RNFL thickness and ONH parameters will be conducted.

 Serum TAC analysis Level of TAC analysis will be conducted using using QuantiChromTM
 Antioxidant Assay Kit (DTAC-100). It will be centrifuged 10 min at 14000 rpm, the plasma will
 be used as sample for calculation of total antioxidant capacity (TAC). Plasma can be stored
 in a freeze at -80°C in the laboratory (stable for 1 month) for future analysis if required.
 After preparing the reagent provided from the test kit (DTAC-100), patient plasma will be
 mixed with the diluted reagent in a plate which will be read at optical density of 570nm. The
 result obtained will be plotted against the standard concentration and a standard curve is
 obtained. By using the graph plotted and a formula provided in the test kit, the serum TAC
 will be calculated. Serum total antioxidant capacity will be calculated at baseline and at
 six months post recruitment.

 Data Entry and Statistical Analysis The data entry and analysis will be performed by using
 Statistical Package for the Social Sciences (SPSS) version 22 licensed to USM. For numerical
 data, paired t-test will be used to compare the changes at baseline and 6 months post
 intervention. Multivariate analysis will also be conducted
Inclusion Criteria:

 1. Known cases of POAG and PACG who are compliance to treatment and follow up

 2. Those who have more than 10 degree from fixation (based on Humphrey visual field)

 3. Best corrected visual acuity of 6/60 on the better seeing eye

 4. Pseudophakic or phakic (without visually significant cataract)

 Exclusion Criteria:

 1. History of surgical intervention 3 months prior to recruitment

 2. Physical disabilities such as stroke, limbs amputation

 3. Severe hearing impairment

 4. Those with macular and retinal pathology

 5. Those already on low vision aids