Research Article
Open Access
Effect of Visual Acuity in Different Amount of
Deviation of Exotropia
Partha HC1*, Brinda HS2
1M.Optom, Department of Optometry, Shree Satchandi Jankalyan Samiti Netra Prasikshan Sansthan, Pauri, Affliated to
Uttarakhand State Medical Faculty, Dehradun, India
2B.Optom, Department of Optometry, Gujarat University, Gujarat, India
2B.Optom, Department of Optometry, Gujarat University, Gujarat, India
*Corresponding author: Partha HC, M.Optom, Department of Optometry, Shree Satchandi Jankalyan Samiti Netra Prasikshan Sansthan, Pauri, Affliated
to Uttarakhand State Medical Faculty, Dehradun, India, E-mail:
@
Received: 14 March, 2018; Accepted: 25 April, 2018; Published: 03 May, 2018
Citation: Partha HC, Brinda HS (2018) Effect of Visual Acuity in Different Amount of Deviation of Exotropia. Int J Open Access Ophthal 3(1):1-2. DOI: 10.15226/2474-9249/3/1/00131
Abstract
Purpose: The aim of the present study is to compare the effect of
visual acuity in different amount of deviations in Exotropia.
Methods: A pilot, cross sectional, observational study was performed at tertiary eye care centers. Subjects with Ocular deviation between 10 to 40 prism diopters, Corrected distance Visual Acuity should be greater than 6/18 and Age should be between 10 to 40 years of age were included in the study. Visual Acuity was assessed with Log Mar chart.
Results: 30 subjects were included in the study. Out of that, 16 subjects were in the age group of 11-20 years, 12 subjects were in the age group of 21-30 years and 2 subjects were in the age group of 31-40 years. 60% subjects were Female and 40% subjects were Male. The mean visual acuity was considered in each amount of deviation. It shows that visual acuity will be deteriorated more as ocular deviation increases in cases of Exotropia.
Conclusions: In ocular deviation of Exotropia, as amount of deviation increases, visual acuity decreases gradually.
Keywords: Exotropia; Amount of Deviation; Visual Acuity;
Methods: A pilot, cross sectional, observational study was performed at tertiary eye care centers. Subjects with Ocular deviation between 10 to 40 prism diopters, Corrected distance Visual Acuity should be greater than 6/18 and Age should be between 10 to 40 years of age were included in the study. Visual Acuity was assessed with Log Mar chart.
Results: 30 subjects were included in the study. Out of that, 16 subjects were in the age group of 11-20 years, 12 subjects were in the age group of 21-30 years and 2 subjects were in the age group of 31-40 years. 60% subjects were Female and 40% subjects were Male. The mean visual acuity was considered in each amount of deviation. It shows that visual acuity will be deteriorated more as ocular deviation increases in cases of Exotropia.
Conclusions: In ocular deviation of Exotropia, as amount of deviation increases, visual acuity decreases gradually.
Keywords: Exotropia; Amount of Deviation; Visual Acuity;
Introduction
In case of Exodeviation images of an object fall on the
Para foveal region and deteriorate the visual performance.
Esodeviation is more harmful as compared to Exodeviation,
because intermittent timings are very less in Esodeviation as
compared to Exodeviation. Because in the foveal region the cone
cell density is much more compare to para foveal region. That’s
why in case of Exodeviation the images of an object is shifted
to the temporal para foveal region and this image shifted is
completely depends on the ocular deviation. In case of high ocular
deviation the image shift will be high. Image will shift towards the
temporal region and due to decrease in cone cell number, visual
performance is deteriorated. Due to less intermittent stages in
Exodeviation compare to Esodeviation there may be less chance
to become Amblyopia in Exodeviation. That’s why there may be
strong correlation with the ocular deviation with Visual Acuity
due to anatomical anomalies of the photo receptor cells.
Methodology
A pilot, cross sectional, observational study was performed at
tertiary eye care centers. Subjects with Ocular deviation between
10 to 40 prism diopters, Corrected distance Visual Acuity should
be greater than 6/18 and Age should be between 10 to 40 years
of age were included in the study. Individuals with any other
systemic disease (specially which can affect study), Individuals
with any other Ocular Pathology, with any active ocular infection,
any ocular anomalies like Corneal Scar etc ,ocular deviation if
less than 10 degree and Significant amount of amblyopic patient
were excluded from the study. Full refractive correction along
with detailed fund us evaluation was performed in each and
every patient. Visual acuity was assessed with Log Mar chart in
different amounts of deviation in Exotropia. Data was analyzed
using SPSS software version 20.
Results
30 subjects were included in the study. (Graph 1) shows
distribution of subjects in various age groups.16 subjects were in
the age group of 11-20 years, 12 subjects were in the age group
of 21-30 years and 2 subjects were in the age group of 31-40
years. (Graph 2) shows gender wise distribution of the subjects.
60% subjects were Female and 40% subjects were Male. (Graph
3) shows comparison of Visual Acuity for different amount of
Graph 1: Shows Age Wise Distribution of the Subject
Graph 2: Shows Gender Wise Distribution of the Subjects
Graph 3: Shows comparison of Visual Acuity for different amount of
deviation for Exotropia
deviation for Exotropia. The mean visual acuity was considered
in each amount of deviation. It shows that visual acuity will be
deteriorated more as ocular deviation increases in cases of
Exotropia.
Discussion
Visual acuity of a normal person is 0.00 log units. In this study,
according to statistical analysis it shows that visual acuity was
deteriorated to 0.13 log units in the ocular deviaition of 11-20
prism diopters, 0.2 log units in 21-30 prism diopters and 0.27 log
units in 31-40 prism diopters . It shows that as there in increase
in the amount of ocular deviation, visual acuity with decrease
gradually. In case of ocular deviation images of an object are
falling on para foveal region and due to inequality of the number
of the cone cells in the macular region there may be chances of
the vision deterioration with increasing ocular deviation. In case
of Exodeviation the images of an object is placed at the temporal
retinal side and due to its intermittent stages is very high compare
to Esodeviation, there have less chances to become Amblyopia.
Thus statistically it has been proved that with increasing ocular
deviation visual Acuity has been deteriorated proportionately
but compare to Esodeviation with same amount of deviation
Visual Acuity is more deteriorated in Esodeviation compare to
exodeviation.
Conclusion
In ocular deviation of Exotropia, as amount of deviation
increases, visual acuity decreases gradually.
Consent
Oral/ written consent was obtained from patient as well as
from tertiary eye care centers.
Ethical Approval
It is not applicable.
Competing Interests
Authors have declared that no competing interests exist.
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