ORIGINAL ARTICLE

Clinical Characteristics of Patients Presenting with

Headache at Binocular Vision Clinic: A Hospital

Based Study

Saif Hassan Al-Rasheed¹

¹Department of Optometry, Qasim University, Saudi Arabia and Department of Binocular vision, Al- Neelain

University, Khartoum, Sudan

ABSTRACT

Purpose: To assess the clinical characteristics of patients presenting with headache at binocular vision clinic.

Place and Duration of Study: Al-Neelain eye hospital, Khartoum, Sudan, from February to October 2018.

Study Design: Descriptive cross-sectional study.

Material and Methods: One hundred fifty patients with history of headache were included in study. Detailed

ocular examination was performed. Dissociated heterophoria was measured using Maddox Wing and Maddox

Rod. Associated heterophoria was assessed by the Mallett unit fixation disparity and fusional vergence was

measured using a prism bar. Data was analyzed using SPSS, version 25. The relationship between measures

was determined using the chi-squared analysis. For all statistical determinations, significance levels were set at p

< 0.05.

Results: Mean age was 25 ± 3.5 years. 86.7% patients with headache had visual acuity of 6/6. Females

constituted 78% and headache was significantly associated with females (P < 0.0001). Majority of patients (82%)

presented with exophoria (mean = 4.74 ± 0.75 Δ Base-In) at near fixation, 10.7% were orthophoric and

7.34percentage were esophoric (mean = 3.24 ± 0.5 Δ Base-Out). The association between near heterophoria and

headache was statically significant (χ²= 7.426; p = 0.001). Association between distance heterophoria and

headache was not statistically significant (χ²= 22.172; p = 0.265). The association between headache and

positive fusional vergence at near fixation was statically significant (p = 0.03). Leading cause of headache was

convergence weakness exophoria (39.3%; p = 0.001), followed by convergence insufficiency (24%; p = 0.02).

Conclusion: Headache was more common in females and was associated with exophoria, convergence

insufficiency and inadequate positive fusional vergence at near fixation.

Key Words: Headache, binocular vision, exophoria, convergence insufficiency.

How to Cite this Article: Al-Rasheed SH. Clinical Characteristics of Patients Presenting with Headache at

Binocular Vision Clinic: A Hospital Based Study. Pak J Ophthalmol. 2020; 36 (3): 247-252.

Doi: 10.36351/pjo.v36i3.1046

has significant effect on work productivity and quality

INTRODUCTION

Headache is one of the commonest health complaints

of life¹.

The problem may arise from conditions that range

from benign to catastrophic. Quick and accurate

diagnosis is an important step for successful

management of headache^2,3. A review of studies

conducted globally, estimated the prevalence of

headache as 58.4% among school-going children and

46% in adult population^2,3,4. It is commonly believed

and it affect approximately half of world population. It

Correspondence to: Saif Hassan Al-Rasheed

College of Applied Medical Sciences, Qasim University,

Saudi Arabia, Email: saif.alrasheed@yahoo.com

Received: April 18, 2020

Accepted: May 4, 2020

Revised: May 4, 2020

Pakistan Journal of Ophthalmology, 2020, Vol. 36 (3): 247-252

247

Saif Hassan Al-Rasheed, et al

that refractive errors and binocular vision anomalies

can lead to headache among young individual⁴. Eye

care professional reported that headache is a common

patient complaint^5,6,7. International headache society

reported that the diagnostic criteria of headache

associated with refractive errors is as follows: a)

Uncorrected refractive errors such as hypermetropia,

astigmatism, presbyopia, or wearing incorrect glasses,

b) Mild headaches in the frontal region and in the eyes,

c) pain absent on awakening and worse by prolonged

visual tasks at distance or near⁸.

excluded from the study. All selected patients

underwent detailed ocular examinations by trained

ophthalmologists. The patients were then referred to

the orthoptic clinic for binocular vision assessment.

Optometry graduate research assistants with

experience in clinical optometry assisted with data

collection. The data collectors underwent training in

the study protocol procedures. Ethical approval for

study was obtained from Al-Neelain University. To

facilitate a better understanding of the procedures and

conditions of involvement in the study, an information

document detailing the nature of the study was

provided to all the patients. Participation in the study

was voluntary and patients were informed that they

could withdraw from the study at any time without

giving any reason. All forms and data sheets were

shredded as soon as it is entered into database system

for analysis.

In a masked case control study, to assess the

relation between headache and binocular vision

anomalies it was concluded that people suffering from

headache had higher prevalence of heterophoria,

associated phoria and reduced stereopsis compared

with controls. The study found that there was strong

association between exophoria and complaint of

headache⁹. Another study have indicated that the

positive fusional reserve should be at least twice the

magnitude of an exophoria to be compensated (without

symptoms)¹⁰.

The demographic information was collected from

all the participants followed by measurement of visual

acuity at distance using Snellen tumbling E-chart.

Amplitude of accommodation and near point of

convergence were measured using RAF Rule. Cover

test was conducted at 33 cm for near and 6-meter for

distance with the patients fixating on one line above

the best visual acuity of the poor eye. The subjects

underwent motility tests to assess the integrity of the

eye muscles. Objective refraction was assessed using

retinoscopy (NeitzRX, Japan) while dissociated

heterophoria was measured using Maddox Wing and

Maddox Rod at near and distance fixation,

respectively. Associated heterophoria was assessed by

the Mallett unit fixation disparity while the positive

and negative fusional vergence were measured using a

prism bar at 33 cm and 6 meter for near and distance

respectively.

Binocular visual dysfunctions such as convergence

insufficiency (CI) affects young people and is

characterised by the inability to accurately converge,

or sustain accurate convergence when focusing at near

targets. It is associated with symptoms such as

headache, blurry vision, eyestrain, and double vision¹⁰.

Headache may also be due to different ocular diseases

such as acute glaucoma, optic neuritis, uveitis, and

visual anomalies such as uncorrected refractive errors,

accommodative and vergence dysfunctions. The most

common eye condition leading to headache after

refractive errors is binocular vision anomalies¹¹.

There is a general increase in the number of

people suffering from headaches. In addition,

headaches have a significant negative impact on the

quality of life and productivity. Therefore, the current

study was conducted to assess the clinical

characteristics of patients suffering from headaches

who attended the binocular vision clinic at Al-Neelain

eye hospital Khartoum, Sudan.

The data was entered in Microsoft Excel

spreadsheet and analyzed using SPSS software,

version 25 (SPSS, Inc., Chicago, IL). The data were

analysed descriptively using standard deviations and

percentages. The relationship between measures was

determined using the chi-square analysis. Significance

levels were set at p < 0.05.

MATERIAL AND METHODS

RESULTS

One hundred and fifty patients suffering from

headache and referred by ophthalmologists to the

binocular vision clinic were selected by convenient

sampling technique, from February to October 2018.

Patients with other ocular or systemic diseases were

A total of 150 patients who attended Al-Neelain eye

hospital complaining of headaches were included in

this study. The age of the participants ranged between

10 and 35 years with a mean age of 25.0 ± 3.5 years.

248

Pakistan Journal of Ophthalmology, 2020, Vol. 36 (3): 247-252

Clinical Characteristics of Patients Presenting with Headache at Binocular Vision Clinic: A Hospital Based Study

Table 1:Visual acuity (VA) among patients complaining of headache (χ²

4.082 p = 0.850).

Seventy-one percent were between

15-20 years, followed by age groups

(21–25) representing 57 (38%). One

hundred and seventeen (78%)

patients who complained of

headache were females. Association

of headache with females was

statistically significant (χ²= 149.18,

p < 0.0001).

VA of Participants

6/6 n % 6/9 n % ≤ 6/12 n %

Age of Participants

Mean SD (25.0 ±3.5 Years)

Total n (%)

10 – 14

15 – 20

21 – 25

26 – 30

31 – 35

Total

11 (7.3)

61 (40.7) 5 (3.3)

48 (32.0) 3 (2.0)

8 (5.3)

2 (1.3)

130 (86.7) 9 (6.0)

0 (0.0)

5 (3.3)

6 (4.0)

0 (0.0)

11 (7.3)

71 (47.3)

57 (38.0)

9 (6.0)

2 (1.3)

150 (100)

1 (4.6)

0 (0.0)

Association of decreased vision

with headache was not statistically

significant (χ²= 4.082, p = 0.850),

as shown in table 1.

Table 2: Distribution of refractive error among participants.

Refractive error of participants

Emmetropia Hypermetropia Myopia Astigmatism

Age of Participants

Mean SD

(25.0 ±3.5 Years)

10 – 14

Total

n (%)

8 (5.3)

n (%)

0 (0.0)

1 (0.6)

0 (0.0)

1 (0.6)

1 (0.0)

3 (2.0)

n (%)

1 (0.6)

6 (4.0)

1 (0.6)

0 (0.0)

9 (6.0)

n (%)

2(1.3)

4(2.7)

1(0.6)

0(0.0)

9(6.0)

The

headache and types of refractive

errors was not statistically

association

between

11 (7.3)

71 (47.3)

57 (38.0)

9 (6.0)

2 (1.3)

150 (100)

15 – 20

21 – 25

26 – 30

62 (41.3)

52 (34.7)

6 (4.0)

significant (χ2 = 2.05; p = 0.562) as

illustrated in table 2.

31 – 35

1 (0.6)

Total

129 (86.0)

Majority of the patients (82%)

presented with exophoria (mean =

4.74 ± 0.75Δ Base-In) at near. The

(χ²= 2.05; p = 0.562)

Table 3: Near and distance dissociated heterophoria among the participants.

association

between

near

heterophoria and headache was

statistically significant (χ²= 7.426; p

= 0.001) as shown in table 3.

Gender of Participants

Male n (%) Female n (%)

Heterophoria

Orthophoria

Dissociated Exophoria

phoria Esophoria

Distance Orthophoria

Dissociated Exophoria

Total n (%) P-value

Near

5 (3.3)

25 (16.7)

3 (2.0)

11 (7.3)

98 (65.3)

8 (5.3)

16 (10.7)

123 (82)

11 (7.3)

110 (73.3)

34 (22.7)

6 (4.0)

0.001

0.265

The

association

between

21 (14.0)

9 (6.0)

3 (2.0)

89 (59.3)

25 (16.7)

3 (2.0)

distance heterophoria and headache

was not statistically significant (χ²=

22.172; p = 0.265) as shown in table

Phoria

Esophoria

Total

33 (22.0)

117 (78.0)

150 (100)

Association between near point

of convergence and headache was

not statistically significant (χ2 =

3.04; p = 0.836). Table 3. 72.7%

patients presented without an

Table 4: Distribution of associated phoria among the participants.

Gender of Participants

Male n (%) Female n (%)

Associated Phoria

Total n (%) P-value

Near

Orthophoria

19 (12.7)

14 (9.3)

0 (0.0)

90 (60.0)

17 (11.3)

10 (5.3)

109 (72.7)

31 (20.7)

11 (6.6)

Associated Base-in

Phoria

0.001

associated

phoria.

Association

Base-out

between headache and associated

phoria was statistically significant.

(χ²= 13.837; p = 0.001) as shown in

table 4.

Total

33 (22.0)

117 (78.0)

150 (100)

(χ²= 13.837; p = 0.001)

Table 5: Fusional vergence among participants suffering from headache.

Gender of Participants

Male n (%) Female n (%)

Fusional Vergence

Total n (%) P-value

59.3% patients presented with

weak positive fusional vergence at

near fixation (2 – 14Δ Base-Out).

Weak (2 – 14

Positive

Fusional

Vergence

19 (12.7)

14 (9.4)

8 (5.3)

70 (46.6)

47 (31.3)

16 (10.7)

89 (59.3)

Base-out Δ)

Strong (16 – 35

Base-out Δ)

Weak (2 – 4

Base-in Δ)

Strong (6 – 15

Base-in Δ)

Total

61 (40.7)

24 (16.0)

0.03

The

association

between

headache and weak positive fusional

vergence at near fixation was

statistically significant χ²= 10.726;

p = 0.03) as illustrated in table 5.

Negative

Fusional

Vergence

25 (16.7)

101 (67.3)

126 (84.0)

0.534

33 (22.0)

117 (78.0)

150 (100)

Pakistan Journal of Ophthalmology, 2020, Vol. 36 (3): 247-252

249

Saif Hassan Al-Rasheed, et al

With respects to negative

fusional vergence, most of the

patients (84%) had strong negative

fusional vergence at near fixation (6

– 15Δ Base-in). The association

between headache and weak

negative fusional vergence at near

fixation was not statistically

significant (χ²= 2.139; p = 0.534) as

shown in table 5.

Table 6: Binocular vision anomalies among patients complaining from

headache.

Gender of Participants

Male n (%) Female n (%)

Binocular Vision Anomalies

Total n (%) P-value

Convergence Weakness

Exophoria

10 (6.7)

49 (32.6)

59 (39.3)

0.001

Convergence Insufficiency

Weak Fusional Vergence

Divergence Excess Exophoria

Convergence Excess

Esophoria

8 (5.3)

4 (2.7)

5 (3.3)

28 (18.7)

15 (10.0)

13 (8.7)

36 (24)

19 (12.7)

18 (12.0)

0.02

0.124

0.131

4 (2.7)

7 (4.6)

11 (7.3)

0.423

0.658

Divergence weakness

esophoria

2 (1.3)

5 (3.4)

7 (4.7)

Binocular vision anomalies

among patients complaining of

headache is shown in table 6. The

association between headache and

Total

33 (22.0)

117 (78.0)

150 (100)

convergence weakness exophoria was statistically

significant p = 0.001. The association between

headache and convergence insufficiency was also

statistically significant P=0.02.

significant (χ²= 12.726; p = 0.001). This is in

agreement with Harle et al⁹, who reported that there

was a strong association between exophoria and

headache. Evans¹⁶reported that symptoms of

exophoria were likely to include headache, which was

associated with prolonged use of eyes in near task.

This may be due to inadequate positive fusional

vergence to compensate the degree of exophoria at

near fixation. Another study suggested that the

positive relative convergence (positive fusional

reserve) should be at least twice the magnitude of an

exophoria to be compensated¹⁷. This is supported by

the result of the present study where the majority of

patients suffering from headaches presented with weak

positive fusional vergence at near fixation. The

association between headache and weak positive

fusional vergence at near fixation was statistically

significant (χ²= 4.584; p = 0.03). Gargetal¹¹reported

that the insufficient positive fusional vergence was

more common among patients suffering from

headaches. However, in this study there were only

7.3% esophoric patients who complained of

headaches. Rabbetts reported that the symptoms of

esophoric patients were frontal headaches, which

might occur after prolonged use of eyes¹⁸. The

association between near heterophoria and headache

was also statistically significant (χ²= 7.426; p =

0.001). However, the association between distance

heterophoria and headache was not statistically

significant (χ²= 22.172; p = 0.265). This could be due

to the fact that, at distance fixation, visual axis need

less convergence effort, resulting in less ocular

deviation compared to near fixation tasks such as

reading and chatting on the smart phone.

DISCUSSION

Headache is a common health complaint and is

considered a public health problem. It has signiﬁcant

effect on public health as well as personal health.

However, diagnosis of headache and its management

is not always easy because the list of differential

diagnosis of headache is one of longest in all of the

diseases. Majority of the patients complaining of

headache are referred to eye care professionals,

ophthalmologist or optometrist for further diagnosis

and management. When headache is a sign of a central

nervous system disease, an ophthalmologist can offer

valuable information about the nature and localization

of the lesion to the neurologists¹². In the current study,

percentage of females presenting with headache was

more than males. This was in accordance with a study

in which it was reported that headache was three times

more prevalent in females than males particularly

during the reproductive age⁵. Similar results were

published in other studies^13,14,15. The commonest age

group suffering from headaches was 15 – 20 years,

representing 47.3%. The reason behind this could be

more near tasks like reading and writing, in this age

group. Jain et al¹²also reported that headache was

more prevalent among young age group and the

authors concluded that it could be due to psychological

stress caused by educational pressures, emotional

factors, and family conflicts.

Almost 27.4% of patients suffering from headache

presented with associated heterophoria (aligning

The current study revealed that the association

between headache and near exophoria was statistically

250

Pakistan Journal of Ophthalmology, 2020, Vol. 36 (3): 247-252

Clinical Characteristics of Patients Presenting with Headache at Binocular Vision Clinic: A Hospital Based Study

prism). Several authors^19-23reported that patients with

a fixation disparity (associated heterophoria) on the

near Mallett Unit were likely to have symptoms such

as headache and eye strain.

Conflict of Interest

Authors declared no conflict of interest.

Author’s Designation and Contribution

With regards to final diagnosis the leading cause

of headache among the patients referred to the

binocular vision clinic was convergence weakness

exophoria which was statistically significant (χ²=

13.426; p = 0.001). It was followed by convergence

insufficiency (χ²= 6.483; p = 0.02). Rouse et al²⁴

defined convergence insufficiency as a syndrome

based on near exophoria, low positive fusional

reserves (e.g. failing Sheard’s criterion) and near point

of convergence more remote than 7.5 cm. In a study to

assess the association between binocular vision

anomalies and headache, it was revealed that the

common binocular vision anomaly found in patients

with headache was convergence insufficiency

39.19%.¹¹This was supported by the fact that majority

of patients in this study had near exophoria and weak

positive fusional vergence.

Saif Hassan Alrasheed; Optometrist: Study design,

data collection, and manuscript writing.

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^.…^….

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