FP319 : Clinical Profile of Patients Presenting To Low Vision Clinic in a Tertiary Eye Hospital.

Dr. Raghuraman Balasubramanian, R16225, Dr. Ilango K

HOSPITAL

AIMS & OBJECTIVES 

1. To study the age distribution pattern.
2. To study the sex preponderance.
3. To study the etiology.
4. To study the Low vision aid advised.
5. To study the demographic factors.
6. To study the acceptance rate.
7. To study the quality of life of patients using LVA.

MATERIALS AND METHODS

Type of study : Hospital based prospective observational study.

Study area :Aravind Eye Hospital and Post Graduate Institute

of Ophthalmology , Madurai.

Study subjects : 1049 patients

Study period : 1st July 2013 to 30th June 2014.

INCLUSION CRITERIA:

1. Patients of both sexes and all race and age groups were includedin the study.
2. Only new patients to Low Vision clinic are included in thestudy.

EXCLUSION CRITERIA :

1. Patients with BCVA more than 6/18 in the better eye andworse than 6/18 in the other eye.
2. Patients who are already diagnosed with low vision or whoare coming for follow-up visit to Low Vision clinic.

DATA COLLECTION :

History :

At the initial visit , a detailed history was obtained from each patient. This included details of ocular complaints ( photophobia , nightblindness etc.) , duration , laterality , family history of blindness , othe rrelevant information like State of domicile , education and occupation .Information pertaining to each patient was collected and entered in aproforma specially designed for the case series , filled by examining doctor.

Ocular Examination :

A complete ocular examination was performed including

1. Best Corrected Visual Acuity ( BCVA ) on Snellen scale (LogMar scalein some) , both for distance and near.
2. Slit lamp examination of anterior and posterior segment.
3. Fixation of the eye , whether central or eccentric.
4. Direct ophthalmoscopy for fundus evaluation , supported by indirectophthalmoscopy using +20D lens.
5. Visual field examination by Confrontation method and Bjerrum’sscreenContrast sensitivity examination by PelliRobsonchart , Colour vision by Ishihara Pseudoisochromatic chart is done wherever possible.Patients with BCVA < or = 6/18 in the bettereye are considered as Lowvision and taken into the study. Those patients to low vision clinic whohad poor vision in one eye but better than 6/18 in the other eye wereexcluded from the study. The patients are given a trial with low visiondevices – both for distance and near , depending on their occupation andother needs. The improvement in vision with low vision aid is noted ,especially for near . Depending on the patient’s need and the improvementfactor , low vision aid ( optical or non optical ) was advised. For fewpatients , Rehabilitation service was recommended. The informationregarding whether the patient accepted (bought) the low vision aid or not isalso noted . If not bought ,the reason for not accepting it , is documented.The patients were advised to come for a follow up visit after 3 and 6months.

A Questionnaire on “Quality of Life” was prepared and patient’sresponse was noted before and after using Low vision aid. One score wasgiven to each category and the response was taken as Out of 9. This idone to assess whether there was any change in quality of life of patientswith low vision , after using the Low vision aid. The following parametersare taken into consideration

1. Street sign / Name board
2. Bus number / Black board DISTANCE
3. Computer work
4. Face recognition                        INTERMEDIATE
5. Reading
6. Money identification NEAR
7. Medicine identification
8. Driving                                             MOBILITY
9. Crossing streets

FOLLOW – UP :

Patients were examined by an ophthalmologist at the end of 3 and 6months. On follow up visit, details regarding the following are noted

1. Type of LVD used
2. What purpose LVD is mainly used
3. How often does the patient use it
4. Compliance to LVD
5. Any improvement in quality of life after using LVD
6. Quality of Life Questionnaire
7. BCVA

STATISTICAL METHODS:

 The data were described as Mean (SD) or frequency ( Percentage)wherever  possible. All analysis done by statistical software STATA 11.1 (Texas, USA).

RESULTS

1.Age distribution:

  12.1% of patients were of Pre school age group ( < 3 years ) , 11.8% of patients were of Primary School going children (3 – 10years ). Overall 44.6% of patients were less than 20 years of age . 25.9% of  patients were in the middle age group of 20 -40years. 18.5% of patients  were between 40 – 60 years of age and those above 60 years accounted for 11% . The Mean (SD) age of presentation was 29.2 years and  the range was from 1month to 79 years .

2.Gender distribution :

Of the total 1049 patients , 670 patients ( 63.9% ) were maleswhile the remaining 379patients ( 36.1% ) were females.

3.Demographic  distribution :

Most of the patients were from Tamilnadu state ( 49.1% ) ,which can be attributed to institutional location in Tamilnadu state.22.8% of patients were from Andhra Pradesh while 21.5% were from Kerala. Least number of  patients ( 6.6% ) were from Karnataka.

4.Residence :

Most of the patients were from rural background ( 40.3% ) .Least number of patients were from urban background ( 27.5% ) .

5.Range of  visual  acuity :

BCVA of the better eye is studied in all patients . 35.4%  ofpatients had vision in better eye between 6/18 – 6/60 . 27.4% ofpatients had vision between 6/60 – 3/60 in the better eye. 37.2%of patients had vision worse than 3/60 in the better eye , amongstwhich 2.4% of patients had no Perception of light .

6.Etiology :

38.1% of patients had Retinitis Pigmentosa , 20.7% of patienthad Amblyopia , 16.6% of patients had Age Related MacularDegeneration . 4.9% of patients had Diabetic Retinopathy while 1.6%of patients had Retinopathy of Prematurity. Patients in the Otherscategory were 4 patients with Microophthalmia , 4 patients with Macularscar , 2 patients with Congenital Glaucoma , 7 patients with Temporal pallor , 4 patients with OpticNeuropathy and 7 patients with Primary Optic Atrophy.

7.Advise :

The advise for the low patients were either non opticalmethods or counselling with trial of low vision device. Since majorityof the patients in our study were within 20 years of age , non opticalmethods of rehabilitation were  given to nearly 423 patients ( 40.3% ).These were in the form of Vision Stimulation, giving letter to schoolteacher explaining about the vision of the child and making the child sitin the front row of the class , Approach magnification , thereby  bringing the object close to the eye and visualising so that it appears enlarged .Other aspects of counselling were about the vocational rehabilitation ,Special education etc.

626 patients ( 59.7% ) were given counselling  and  also  made  to  do a trial of low vision device . The low vision device was chosen based onvarious factors like magnification , patient’s needs , cost etc. Majority(35.4% ) of the patients were advised to use Magnifiers . 32.3% ofpatients were advised to use Spectacles or Contact lens ( withmagnification ) . 21.4% of patients were advised to use Prismospherewhile Telescope was advised for only 9.4% of patients . Consideringthe cost and other factors , CCTV  was  advised  for only 1.5% of  thepatients .

8.Acceptance :

Among the 626 patients who were advised to use the Low visiondevice , only 122 patients bought the device , which shows anacceptance rate of 19.5% in total . The acceptance rate was more forMagnifiers and Prismospheres.

9.Quality of life assessment :

Out of the 122 patients who bought the low vision devices ,only 103 patients turned up for the follow-up visit . The Mean Quality ofLife assessment score ( out of 9 ) before accepting LVA was 4.11 , with astandard deviation of 1.38 . The minimum and maximum score rangingfrom 0 to 6 .The Mean Quality of Life assessment score ( out of 9 ) after usingthe LVA was 5.32 , with a standard deviation of 1.72 . The minimum andmaximum score ranging from 0 to 8.This shows that there was statistically significant improvement inthe quality of life of patients who used the Low vision devices.  

 DISCUSSION

 The estimate of people in the world with low vision is nearly246 million. It remains as one of the major global health issue ,which could be well managed by intervening at the correct time andwith correct technique to enhance their vision.Friedricket aldescribedabout the Blindness and Visual impairment as a major public healthissue both for the present and for the future.1049 patients with low vision , within our inclusion criteriawere studied in this series. The study period was from july 2013 tojune 2014 . The clinical profile of all the patients in the study wereanalysed in detail and the impact of low vision devices on thequality of life of these patients were studied.The Mean age of presentation was 29.2 years . 21.3 % ofpatients were in 11-20 years age group which was comparable to theseries of patients studied by SA Khan et al, who found that patients

in 11 – 20 years age group was 21% .The distribution of the agegroup in our study showed that 59.4 % of patients were below 30years of age and 11% of patients above 60 years . Males accounted for64% while females were 36%. SA Khan et al reported that 46% ofpatients to be within 30 years of age and 18% above 60 years of age ,with males predominating overall (72% %) . Consanguinity of parentswas present in 27% of patients.Khan et al reported that patients with visual acuity between6/18 – 6/60 were 49.3% in his study while in our study 35.4% ofpatients had BCVA of the better eye between 6/18 and 6/60 , 27.4%of patients were between 6/60 and 3/60. Rest of the patients hadBCVA worser than 3/60 with 2.4% of patients having no perceptionof light.

David et aldid study in a series of Vision disabled elderlypeople and found that majority ( 65% ) of the patients were womenand the most common cause of such visual disability being Agerelated Macular Degeneration ( 75% ) . The most common cause oflow vision in our study was Retinitis Pigmentosa ( 38.1% ) , followed by Amblyopia ( 20.7% ) and Age Related Macular Degeneration ( 16.6% ).

SA Khan et al in his study , reported the common causes beingRetinitis Pigmentosa( 19% ) , followed by Macular diseases ( 17.7% ) ,Diabetic Retinopathy ( 13% ) and Myopic degeneration ( 9% ) . Since thevast majority of the patients in our study were in the less than 30years age group , the etiology for the low vision was quite differentfrom the above two studies .

Congdonet al found that the leading cause of low visionamong whites was Age related macular degeneration while it wasglaucoma and cataract among the blacks . Also reported in this studywas above 40 years of age , nearly 1 in 28 Americans are eitherblind or with low vision .

Vijayaet al reported a positive association of blindness and lowvision with illiteracy and age. The major cause of blindness in thisstudy was Cataract ( 57.6% ) followed by Glaucoma ( 16.7% ) whilethat of low vision was Refractive error ( 68% ) followed by cataract(22% ).In the study by Silver et al, (Silver et al. 1995) which included 230children at a school for the blind, visual acuity was used to determine theneed for magnification or glasses. The majority of these children (57%)were only taught Braille and treated as totally blind, although 79% of thesechildren could benefit from near low vision devices or reading spectaclesand be enabled to read normal print. This study raises the importance ofmagnification, and the effect on the children’s academic life. This studyalso reported that stand magnifiers seem to be the easiest opticalmagnifiers for children to use.

In our study 49.1% of patients were from Tamilnadu , 22.8%of patients were from Andhra Pradesh and 21.5% of patients werefrom Kerala. Majority of the patients in our study were from a ruralbackground . The general awareness of the people about the causesof low vision and about the low vision aids is low among thesepeople and which explains the increasing number of them with lowvision. A high level of motivation is needed to educate these peopleabout the low vision devices and its importance in the life of peoplewith low vision.

According to Gompel et al, (Gompel et al. 2004) visual field defectsdo not affect children’s reading speed and comprehension. This studycompared two groups of children with low vision. The first group includedchildren with low vision who had visual field restrictions and the secondgroup were children with low vision and intact visual fields. Interestingly,no difference in reading speed and reading-comprehension skills werefound between these two groups of children with low vision. This is theonly study on the effect of visual field constrictions on reading speed ratein children with low vision. More studies need to investigate theimportance of field of view on reading speed in children with low vision.

In our study , 423 patients ( 40.3% ) were given advise on Nonoptical devices and methods , in the form of Vision stimulationexercise , Letter to school teacher , Approach magnification etc.. Letterto school teacher insists upon the visual potential of the child , thenecessity to make the child sit in the front row of the class , to payextra attention to the child , to do regular eye check up and to makeother children to understand the condition of the affected child .Approach magnification relies on bringing the book or any objectclose to the eye to see it better . These are some of the rehabilitativemeasures which would improve the residual vision of the child andhelp in doing the regular activities. Since majority of the patients inour study were children , the importance of these rehabilitativemeasures must be explained to the parents and they need to becounselled well.

626 patients ( 59.7% ) were given counselling followed by trialof low vision devices . Some of the common devices which wereadvised for trial are Magnifiers , Telescopes , Prismospheres ,Magnifying glasses , CCTV etc. 222 patients ( 35.4% ) were advised touse Magnifiers , which included 3X Pocket Magnifier , 4X DomeMagnifier , 6X Pocket Magnifier , 4X Hand Magnifier , 6X CutawayMagnifier. Spectacles or Magnifying glasses were advised for 202patients ( 32.3% ) while Prismospheres were advised for 134 patients (21.4% ) , which included 5D Prismosphere , 8D Prismosphere and 10DPrismosphere . SA Khan et al  reported in the study that majority ofthe patients were given Spectacle magnifiers , followed by glasses andtelescopes . Among the non optical devices , the most commonlyprescribed ones are reading lamps , light control devices and mobilitycanes .

Watson et al reported about the reading speed with varioustypes of spectacle magnifier. For reading Comprehension , Hybriddiffractive spectacle magnifier was effective while the print size looksbetter with aplanatic spectacle magnifier . Overall many patientspreferred using hybrid type magnifier .

Margrainet al reported that the use of suitable low visiondevice helped in improving the near visual acuity in nearly 88% ofthe patients.The acceptance rate in our study was 24.3% for the magnifiersfollowed by 20.4% for the prismospheres . The overallacceptance ratewas only 19.5% . The reason which could be attributed for such lowacceptance rate would be due to rural background of majority of thepeople , lack of awareness about the medical advances and the lowvision aids , cost factor and psychological factors .Binnset al reported inthe study that the rehabilitative services providing low vision deviceshelped in improving the reading ability of the patients and also muchpreferred by the users.

The Quality of Life questionnaire score in our study showed asignificant increase in those using low vision aids . It showed a meanincrease from 4.11 to 5.22 which is statistically significant .Theimprovement was mainly due to the enhancement of near vision .

Robert et al interpreted the low vision rehabilitation outcome measuresusing questionnaires with rating scale. Tiffany et alcompared theprobability of low vision rehabilitation’s success by comparing theclinician’s predictions with the patient’s outcomes and concluded thatthe clinician’s predictions doesn’t agree with the changes observedin functional ability from the patient’s perspective.In the educational setting , questions arise regarding thecapabilities of the student , as well as needs for glasses or lowvision devices. How the glasses or low vision devices should be used ,instructional tips in using the devices , and suggestions forpreferential seating or modifications in the environment are some ofthe important that should be included. These reports tend to be moredetailed and should be written in lay terms , as they will be used byparents , teachers , therapists and other s who may not beknowledgeable about medical or ocular terminology. A statementregarding the size of print as well as the distance the material isheld is much more helpful. Issues such as efficiency , practicality andstudent’s acceptance of low vision device are all important pieces ofinformation that may play a role in the student’s educational setting.

LIMITATIONS

 Though we elaborately studied the demographic features , variouslow vision devices advised , rehabilitative measures , acceptance rateand the change in quality of life of patients , still some lacuna existsin this study . –

1.The parental consanguinity is not being taken into account inthe study.

2.As this hospital ( Aravind Eye Hospital ) is a tertiary carehospital all difficult end stage cases are only referred to thishospital and hence the actual number of patients with lowvision would be much more in the community . – Referral Bias.

3.We followed up all the patients for a maximum of 6 months.A longer follow up might give better evaluation of theeffectiveness of low vision devices and quality of life ofpatients.

SUMMARY 

• Children less than 10 years were the most commonly affected.
• Males were more affected.
• More patients of rural background
• Low acceptance rate of low vision devices .
• Significant improvement in quality of life of patients whoaccepted the assistance with Low vision devices .

CONCLUSION 

Low vision remains a global health issue and India aloneaccounts for a major portion of it . It can occur from as early assoon after birth to old age , which necessitates the importance ofregular eye check up since childhood , in order to avoid major eyeillness in the future. Few school teachers must be trained under theSchool screening programme , to pick up the eye disorder of the childata earlier stage . In the old age , strict control of diabetes andhypertension is needed . The increased number of patients withbilateral low vision also depicts the problem load.

The people of the rural background are not much educated aboutthe health problem and its consequences . Awareness must be createdamong those people about the health problems , eye related disorders ,low vision devices. This would help in increasing the acceptance rateand improving their quality of life.

• In case of pre – school children and infants , early identificationand rehabilitation is needed.

• For school going children , Proper guidance , co-operation withschool teacher in proper identification and management.

• Special trainingabout early identification for selected teachers inall schools.

• To incorporate an Integrated education in schools.
• To include in Primary eye care programs about the effectivemeasures to make and early identification and referral ofpatients who would benefit from the rehabilitation services.

• Educate people about services and rehabilitative measuresavailable for the low vision people .

• To promote self and family motivation and confidence.
• To promote Community based rehabilitation.
• To study in detail about the cost effectiveness of the low vision

devices .

With early recognition , effective and appropriate rehabilitation , regular follow up , the burden of low vision could be well tackled .

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