|Year : 1991 | Volume
| Issue : 3 | Page : 112-114
Study of primary convergence insufficiency
Shreerang B Deshpande, RK Ghosh
Department of Ophthalmology, Bombay Hospital, Mumbai, India
Shreerang B Deshpande
Department of Ophthalmology, Bombay Hospital, Mumbai
Source of Support: None, Conflict of Interest: None
The present study was done to find out the incidence of primary insufficiency of involuntary convergence and evaluate the relative efficacy of synoptophore treatment against home exercise in its management. During the period of study, 2162 cases in the age group 15 to 35 years were studied for convergence in detail. It was found out that the incidence of primary convergence insufficiency is quite high (7.7% of total orthoptic clinic attendance). It commonly affects those who are constantly engaged in near work. Response to synoptophore exercises and home exercises is comparably equal. Recurrence of the ailment after stopping the exercises is not uncommon.
|How to cite this article:|
Deshpande SB, Ghosh R K. Study of primary convergence insufficiency. Indian J Ophthalmol 1991;39:112-4
| Introduction|| |
It is very common indeed to have young patients in the age group of 15 to 35 years coming to the out patient departments with persistent headache, eyestrain (particularly for near work) and other vague complaints. Such patients are examined to rule out the probable ophthalmic causes of headache and eyestrain. However a large number of them remain unsatisfied and the symptoms persist. On being examined by other related specialists who are also unable to point out the cause of headache, these cases are then often labelled as cases of "functional headache". We have found out that one often fails to look for convergence in such patients. Many of them are in fact cases of insufficiency of involuntary convergence.
The aims of the present study were:
To bring out the incidence of primary insufficiency of involuntary convergence in patients belonging to the age group of 15 to 35 years.
To test such cases of convergence insufficiency and to evaluate the therapeutic efficiency of synoptophore exercises against home exercises.
To find out the possible causes of insufficiency of convergence.
| Material and methods|| |
We have studied the convergence in all cases in the age group of 15 to 35 years complaining of headache, and eyestrain particularly for near work during the period August 1986 to December 1987.
Routine clinical examination with fundoscopy and refraction under tropicamide, test for binocularity of vision, Maddox rod tests, near point of convergence and near point of accommodation on the Livingston gauge and adduction abduction on synoptophore were carried out.
Cases of convergence insufficiency were divided into two groups. One group was given orthoptic treatment on the synoptophore and the other was prescribed home exercises for a definite period.
These cases were followed up for a period varying between 6 months to one year.
| Observations|| |
During the period of study 2162 consecutive cases attended our orthoptic clinic, out of which 168 were cases of primary insufficiency of involuntary convergence, We have excluded those associated with refractive errors, phorias and muscular weakness.
Thus the incidence of primary insufficiency of involuntary convergence is 7.7% of the total attendance of the orthoptic clinic.
This table shows that maximum number of patients were in the age group of 15 to 19 years. The incidence was slightly higher in males than females.
It is seen that the maximum number of cases were from the group which had to do more near work.
Maximum adduction in these cases was 18, while the minimum was 8. Abduction in all cases was normal. In all cases the near point of accommodation was normal. There was no refraction error, phorias, muscular weakness, neurological deficit etc.
Out of 168 cases only 81 reported back for treatment. 56 patients were given synoptophore exercises in 10 sittings and 25 patients were prescribed home exercises for about 3 weeks.
Synoptophore exercise consisted of increasing the power of stereopsis by the study of stereo grams of increasing difficulty to build up an adequate fusional reserve. Home exercises consisted of approximating the near point of convergence by fixing on an object as it approaches his eyes until it appears double.
After home exercise, 15 out of 25 cases improved.
So we can estimate that the cure rate with synoptophore exercises is 80.2% where as with home exercises it is 60%. The overall cure rate turns out to be 74%.
| Discussion and conclusion|| |
Convergence insufficiency is a common condition. Convergence is indispensable for the maintenance of single binocular vision for all distances nearer to infinity and therefore its failure is of great clinical significance, its clinical importance has been recognized from the time of von Graefe(1862) sub . In spite of this, we often tend to overlook the faculty of convergence during routine clinical examination. In our series, the incidence of primary insufficiency of involuntary convergence turns out to be 7.7% of the total attendance of the orthoptic clinic ,.The basis of the anomaly is the delayed development of lately acquired function 
Improvement on synoptophore exercises with the possibility of failure again, sometimes after the break in the exercise would support the above mentioned hypothesis.
The weakness of convergence is quite common in those who are constantly engaged in near work like students, clerks and house wives who do a lot of stitching and embroidery work. Fatigue of the power. of convergence might be the factor. General disease or debility due to illness as well as mental and physical stress are the contributing factors. In this series seven cases had recurrence about 4 to 6 months after stopping the exercises, however they improved rapidly after resuming the exercises.
The cases of convergence insufficiency show remarkable improvement after exercises. The cure rate given by several authors is as follows: Mann(1960) 67%, Mayou(1946) 72%, Davies(1946) 70%, Cashmann and Barri(1941) 64%, Mellick(1950) 67%, Passmon(1957) 89.3%, Khosla(1960) 69%, Norn(1968) 70 to 80% God at al(1971) 89.3% .
The overall cure rate of 67.2% in our series is quite encouraging. The psychological set up and motivation of the patient are two very important factors which contribute to the speedy recovery of the patient. Those cases which failed to improve can be attributed to multiple factors like psychosomatic disorders, nutritional imbalance, physical and mental stress and strain.
The synoptophore exercises are the mainstay of the treatment, of convergence insufficiency, however, they are not indispensable. Simpler home exercises like recognition of physiological diplopia are also helpful. Home exercises required a lot of co-operation from the patients. The patient must be intelligent enough to recognise the physiological diplopia. They have to be sincere enough to carry out the exercises regularly and he must be determined to get rid of the ailment.
| Summary|| |
We fail to realise that primary insufficiency of involuntary convergence is a common condition and it carries a great nuisance value. It commonly effects those who are consistently engaged in near work. It responds well to synoptophore exercises and fairly well to home exercises. Psychological set up of the patient is an important factor.
Synoptophore is not indispensable, the condition can be treated by home exercises particularly when the patient is co-operative or synoptophore facilities are not available.
| References|| |
Ahluwalia. Chandran, Gupta,: East Arch. Ophth. 1974-2 (148-151)
Duke Elder's Practice of Refraction (91-109)
Goel.!Gogi, Oriental Arch. Ophth. 1971,.9 : (308-311).
[Table - 1], [Table - 2], [Table - 3], [Table - 4], [Table - 5]