Indian Journal of Ophthalmology

: 1992  |  Volume : 40  |  Issue : 1  |  Page : 18--19

Cyclic vertical squint

Prem Prakash, V Menon, KK Gupta, Surinder Kumar 
 Dr. Rajendra Prasad Centre for Ophthalmic Sciences, A.I.I.M.S., New Delhi- 110 029, India

Correspondence Address:
Prem Prakash
Dr. Rajendra Prasad Centre for Ophthalmic Sciences, A.I.I.M.S., New Delhi- 110 029


A rare case of cyclic vertical squint which developed after surgery on medial rectus muscle and its subsequent management by the Faden operation is described.

How to cite this article:
Prakash P, Menon V, Gupta K K, Kumar S. Cyclic vertical squint.Indian J Ophthalmol 1992;40:18-19

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Prakash P, Menon V, Gupta K K, Kumar S. Cyclic vertical squint. Indian J Ophthalmol [serial online] 1992 [cited 2021 Apr 21 ];40:18-19
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A 25 year old female was first seen in February 1985 when she complained of constant squint with vertical diplopia of 2 years duration. There was a past history of trauma to the left eye with a broomstick resulting in cataract. In 1971, she was operated for cataract and regained good vision with the use of a contact lens. In 1982, she was operated upon for squint on the left eye.

In February, 1985, when she first reported to us the refractive correction was +2.00 dioptre spherical OD and + 10.0 dioptre spherical OS. Visual acuity was 6/6 OD and 6/6 OS with contact lens. The patient had an exodeviation of 14 prism dioptres (PD.) with 20 PD. left hypotropia and limitation of sursumduction in the left eye. Under local anaesthesia, the forced duction test revealed restriction in upward direction in the left eye. Adjustable suture surgery was un­dertaken with conjunctival recession on the left inferior rectus muscle. After 24 hours, proper vertical align­ment was achieved by tightening the sutures.

During the follow up the patient complained of in­termittent diplopia. In September 1985, an esodevia­tion of 14 PD. was detected with right medial rectus overaction but no significant vertical deviation was observed. She underwent right medial rectus reces­sion of 3 mm and post operatively the alignment was satisfactory but she complained of definite upward deviation of the left eye with vertical diplopia occurring every 24 hours in a cyclic manner.

On repeated examination, the cyclic nature of the deviation was confirmed. On squinting days, left hypertropia of 26 PD. with exodeviation of 6 - 8 PD. was present. Movement of the left eye was limited in downgaze on the squinting days when she had large vertical squint [Figure 1]. Lees chart on squinting days revealed double depressor palsy in the left eye with corresponding overaction of the inferior rectus and superior oblique in the right eye [Figure 2]. Forced duction test showed no restriction

In January 1986, a posterior fixation suture was applied to the left superior rectus muscle 14 mm, behind its insertion. Postoperatively she had good alignment in the primary position and movements were mildly restricted in downgaze and upgaze [Figure 3]. Lees chart showed underaction of left elevators and depressors [Figure 4]. This underaction was seen on all days but the cyclic vertical deviation did not manifest in 6 months of follow up after surgery.


Incidence of cyclic heterotropia is believed to be 1 in 3000 to 5000 [4] t is presumed that the incidence is much more and that most cases escape detec­tion [4],[10],[5] In most of the reports, which could be reviewed, the cyclic nature of the squint was noted by the parents or the patient [6],[7],[10],[11],[12]. In the present case also the true nature of the deviation escaped detection till the patient reported that the deviation was present on alternate days. It would therefore be worthwhile examining all cases of so called intermittent deviation on 3 to 4 consecutive days to exclude the possibility of cyclic heterotropia.

Previously reported cases of cyclic vertical heterotropia had cyclic superior oblique paresis. One of them had cyclic esotropia with cyclic vertical squint [6], while the other one developed following trauma in the superonasal aspect of the upper lid [7]. The present case is to the best of our knowledge is the third reported case of cyclic vertical heterotropia. Overaction of the inferior oblique muscle, only on squinting days has been noted [4]. Many authors have reported limitation of duction movements in incomitant cyclic heterotropia [4],[5] cases on squinting days but they have not mentioned the status of duction movements on the non squinting days [6],[7],[8],[10],[11]. The present case had full duction movements on the nonsquinting days. Diplopia as seen in the present case on squinting days is rare in cyclic heterotropia [4],[5] but has been reported in cases which developed cyclic heterotropia following trauma [7],[8],[9], surgery [6],[10],[11] or at a relatively later age [1],[2]

The cause of cyclic heterotropia is presumptive. It is said to be related to the biological clock mechanism [3], alternation of cerebral dominance [4] or believed to resemble the decompensated accommodative esotropia [13]. Ritcher [3] thought that the manifes­tation of the cyclic nature depends on a combination of abnormal conditions in the clock, the oculomotor nucleus or even in the superior colliculi, though it is not related to abnormality of the pituitary hypothalamic axis. The effectiveness of posterior fixation suture 'on superior rectus in eliminating the cyclic vertical squint points towards cyclic increased innervation to the superior rectus muscle of the left eye. However why such a cyclic innervation should occur remains a mystery.


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