|Year : 1981 | Volume
| Issue : 4 | Page : 439-442
Practical approach in the diagnosis of vertical ocular palsy
Willingdon Hospital, New Delhi, India
N C Singhal
Greater Kailash, New Delhi
Source of Support: None, Conflict of Interest: None
|How to cite this article:|
Singhal N C. Practical approach in the diagnosis of vertical ocular palsy. Indian J Ophthalmol 1981;29:439-42
Vertical ocular palsy whether of congenital origin or longstanding cases of acquired palsy with little or no recovery of paralysed muscle may present a difficult diagnostic problem because of the occurrence of well recognised changes involving some of the other muscles of both eyes. The result of these changes is that besides the defective function of the primarily affected muscle, its contralateral antagonist also shows inhibitional palsy and besides the overaction of the contralateral synergist of the affected muscle, there is also an overaction of the direct antagonist in the form of contracture.
In the event of a recently palsied cyclovertical muscle, checking the eyes in the cardinal position of gaze and noticing the position of greatest vertical deviation is usually adequate in establishing a diagnosis but in course of time enough concommitance develops to reduce this simple test unreliable. To arrive at the diagnosis in such cases following practical approach is presented to find out the effected muscle in few minutes without the aid of orthoptic instruments which of course will be needed for evaluating progress and for quantitative measurement.
A patient with cyclovertical ocular palsy whether congenital or long standing acquired may present in the outpatient Deptt, with one or more of the following symptoms.
- Intermittent or constant diplopia.
- Difficulty in focussing.
- Abnormal ocular position constant or intermittent either in primary position or in various versions.
- Compensatory head posture or ocular torticollis.
- Habit of reading with one eye closed.
- No symptoms but detected in routine medical examination. Following steps are presented to arrive at a diagnosis clinically.
Step. I. We must look for any abnormal ocular posture such as hypertropia or hypotropia. If this is not obvious, alternate slow cover test should be done to determine any manifest squint. If this is negative, rapid cover test should be done to determine any latent deviation. If it is present, we must look for the extent of movement of the eye ball. The eye with the less excursion is the affected eye and hence this simple test excludes the four cyclovertical muscles of the other eye. In fully concomitant cases movement will be equal in both eyes.
Step II. Examination in lateral versions. Patient is asked to look to one side and in that position we must look for any vertical deviation between the two eyes. Similarly he should look to the other side. The side towards which the vertical deviation is seen should be noted. For example, if the vertical deviation is seen on dextroversion and the right eye is hypotropic and the left eye will obviously be hypertropic, it would mean either a palsy of right superior rectus or of left superior oblique.
If the right eye is hypertropic and the left eye is hypotropic, it would mean palsy of right inferior rectus or left inferior oblique. So we narrow down to two muscles. It may sometimes be necessary to use cover test to determine the side of vertical deviation in small degree of deviation. If the vertical deviation is present on both sides, the side towards which greater vertical deviation occurs is to be considered.
Two things need to be emphasized at this stage. (1) The two muscles under suspicion are always in different eyes, and (2) both are always either superior muscles or inferior muscles and never are superior muscle of one eye and inferior muscle of other eye implicated. Since superiors intort and inferiors extort. consequently the two accused muscles are either intorters or extorters.
Step. 3. Examination on head tilt.
The patient should fix his gaze centrally in the primary position and then tilt his head to one side without changing the fixation. We must look for the extent of deviation between the two eyes and repeat the tilt on the other side. The side towards which greater vertical deviation occurs it noted. In the case of superior muscles i.e. superior rectus of one eye and superior oblique of the other eye, the greater vertical deviation will be on the side of the affected eye. Hence if step 2 reveals right eye hypotropic, meaning thereby either a palsy of right superior rectus or left superior oblique, then vertical deviation will be more on right head tilt in right superior rectus palsy and it will be more on left head tilt in the case of left superior oblique palsy. If step 2 reveals that the inferior muscle are under suspicion, the greater vertical deviation will be on the side opposite to the head tilt. Thus on dextroversion if the right eye is hypertropic, it would mean either a palsy of right inferior rectus or left inferior oblique muscle: and if on right head tilt there is more vertical deviation on left side, it would mean left inferior oblique palsy.
Hence the rule to remember is that when the final possibility is between two superior muscle, the greater vertical deviation will be on the side of the affected muscle. If the final possibility is between two inferior muscles, the greater vertical deviation will be on the side opposite to the head tilt.
The above test is based on Bielchowsk's head tilt test traditional) applied for diagnosis of superior oblique palsy but it can be applied to diagnose other muscles also on the same principle.
The above description of step 2 and 3 is presented in the following table.
In very mild cases Maddox Rod is useful in detecting the difference in vertical deviation on right and left gaze and also it may be needed to determine whether the vertical deviation is greater on right head tilt or left head tilt. In the latter situation the Maddox Rod should be positioned so that the horizontal line is parallel to the floor even though the head is in tilted position. Having determined the paralysed muscle, Ocular movement should be performed to see the defective action of the affected muscle as a confirmatory evidence.
Rule to remember action of nuuscles.
There is no diffculty in remembering the elevation and depression action of the cyclovertical muscles but one is likely to confuse the torsional and duction action of these muscles. If we remember the word "RADSIN", there will he no confusion to remember the action of these muscles. [Table - 1]
Compensatory head posture
In palsies of superior muscles both elements of head tilt and face turn are on the same side. In the case of superior rectus they are on the side of the affected muscle and in the case of superior oblique they are on the opposite side. If the chin is elevated, it is superior rectus and if chin is depressed, it is superior oblique.
In palsies of inferior muscles, both elements of head tilt and face turn are on opposite sides. Head tilt is on the side of hypotropic eye. Chin depression will mean
Diplopia. We are sometimes at a loss to remember as to the type of diplopia in a particular muscle palsy. We all know that the commonest ocular palsy is that of lateral rectus and in that it is easy to remember that the diplopia is uncrossed, i.e., in an abductor palsy the diplopia is uncrossed. From this memory we can immediately tell the type of diplopia in any muscle palsy provided we know its duction action and that we know by the word "PADSIN". Hence vertical recti being abductors cause crossed diplopia and oblique cause uncrossed diplopia.
| Summary|| |
- Know the action of cyclovertical muscles by remembering the word "RAD SIN" i.e. recti adduct and superiors intort.
- Examination in lateral versions will give suspicion between either two superior or two inferior muscles i.e. one oblique and one rectus and belonging to two different eyes.
- Head tilt test diagnoses the particulars muscle. In the case of superior muscle greater vertical deviation will be on the side of head tilt and in the case of inferior muscle it will be on the side opposite to the head tilt.
- In the case of superior muscle palsies, both elements of compensatory head posture i.e. head tilt and face turn will be on the same side but in inferior muscle palsies they will be on opposite sides. If chin is depressed it is a depressor muscle and if elevated, it is an elevator muscle.
- Commonest ocular palsy is of 6th nerve (abductor) and diplopia is uncrossed. By remembering this fact, type of diplopia in any muscle palsy is immediately known.
- In reading a diplopia chart, if diplopia is uncrossed it is oblique muscle, and if crossed it is rectus muscle. Regarding the side, it is on the same side as the maximum separation of images in the case of rectus muscle and it is on opposite side in oblique muscle. First letters of the words 'oblique and opposite' may be remembered.
[Table - 1]