|Year : 1993 | Volume
| Issue : 1 | Page : 32-34
Degsagittalisation of obliques : A case report of plagiocephaly with inferior oblique overaction
Pradeep Sharma, Prem Prakash
Dr. Rajendra Prasad Centre for Ophthalmic Sciences, All-India Institute of Medical Sciences, New Delhi, India
Dr. R.P. Centre for Ophthalmic Sciences, A.I.I.M.S., New Delhi - 110 029
Source of Support: None, Conflict of Interest: None
|How to cite this article:|
Sharma P, Prakash P. Degsagittalisation of obliques : A case report of plagiocephaly with inferior oblique overaction. Indian J Ophthalmol 1993;41:32-4
Craniostenosis is a cranial deformity caused by faulty fusion of cranial sutures . The association of superior oblique underaction has been well documented with plagiocephaly ,. However, it is important to understand that this underaction is not a paresis or paralysis of the superior oblique but is primarily due to desagitallisation ,. In this case report we describe a case of plagiocephaly with superior oblique underaction and marked inferior oblique overaction and its management in order to zighlight the process of desagittallisation.
| Case Report|| |
An 11 year old girl presented to us with complaints of upward deviation of the right eye since birth. On direct questioning she reported the asymmetry of the skull since birth. On examination, head tilt to the left with secondary changes in the cervicodorsal spine and flattening of the right side of forehead was observed. [Figure - 1]
The best corrected vision was 6/12 O.D. and 6/6 O. S. There was right hypertropia (RHT) of 34 p.d. [Figure - 2] a&b However, Bielschowsky's head tilt test showed right superior oblique underaction. There was no binocularity in any gaze with or without prism neutralisation as checked by the Bagolini striated glasses. Forced duction test (FDT) revealed no restriction, while active force generation test (AFGT) showed a mild underaction of the superior oblique muscle.
Radiological examination revealed on posteroanterior view [Figure - 3] elevation of the lesser wing of sphenoid with wide and splayed appearance, asymmetrically developed (pneumatised) frontal sinuses, symmetrical maxillary sinuses and more than normal visulization of the right frontal bone. The lateral view [Figure - 4] showed clearly two-end-on projections of the greater wing of sphenoid of both the orbits instead of one view of the two superimposed. These are characteristic radiologic findings of plagiocephaly. Axial biometry showed axial length of 23.2 mm of both eyes. A final diagnosis of plagiocephaly with ocular torticollis with secondary scoliosis with predominant right inferior obliqe overaction with right amblyopia was made and the patient underwent strabismus surgery.
The surgery consisted of inferior oblique recession with antero-positioning of the insertion. The insertion was placed adjacent to the lateral border of the inferior rectus insertion. On the first post operative day the right hypertropia got relieved by 21 p.d. in the primary gaze and by 30 p.d. in the levoelevation. [Figure - 2]c&d. There was marked reduction in excyclotropia, but the torticollis persisted due to the secondary scoliosis.
Plagiocepaly involves the unilateral premature fusion of the coronal suture during the intra-uterine development. The association of the superior oblique underaction has a wide spectrum of manifestations varying from just positive Bielschowsky head tilt test to frank superior oblique underaction with head posture with secondary inferior overaction. In the present case the inferior oblique overaction overshadowed the involvement of superior oblique and inspite of maintainance of head posture with secondary scoliosis the patient had residual vertical squint which must be the cause of her suppression of right eye. The possible sequence of events could be plagiocephaly causing a retroplaced trochlea with desagitallisation of superior oblique with secondary inferior oblique overaction. In the initial phases the head posture may have helped to achieve binocularity (Vision: 6/12 O.D. 6/6 O.S.) but subsequent overaction of inferior oblique must have broken this harmony and resulted in more hypertropia with excyclotropia in the presence of a desagittalised superior_ oblique. Keeping in view this chain of events we performed a combination of anteropositioning and recession of inferior oblique.
In the presence of a desagittalised superior oblique the theoretical possibilities of surgery are : [Figure - 5]
i) Anteroplacement of the trochlea, the functional origin of superior oblique.
ii) Posterior positioning of the insertion of superior oblique
iii) Anteropositioning of the insertion of inferior oblique.
iv) Posterior placement of the origin of inferior oblique.
Since (i) and (iv) are not practical, (ii) & (iii) can be done but (ii) would be a difficult surgery to perform. In a pure case of desagittalised superior oblique one would encounter ipsilateral hypertropia and incyclophoria / tropia. But the presence of excylotropia in our case suggested inferior oblique overaction in addition to desagittalisation. This led us to a combined anteropositioning and inferior oblique recession. The results are quite satisfactory in view of a single muscle surgery in such a severe inferior oblique overaction.
This case highlights an atypical case of plagiocephaly with predominant inferior oblique overaction with gratifying results of a recession combined with anterior positioning emphasising the role of sagitallisation and its correction by anterior - positioning of the inferior oblique. The superior and inferior obliques are easily susceptible to changes in their origins or insertions. Consequently the underactions and overactions caused by sagitallisation or desagittalisation maybe more common than the paralysis and secondary overactions of these muscles. This diagnostic possibility should be considered before a definitive diagnosis of paralysis of obliques is made.
| References|| |
Archer DB, Gordon DS and Maguire CJF. Ophthalmic aspect of Craniosynostosis. Trans Ophthalmic Soc. U.K. 94: 172-196,1974.
Bagolini B, Campos E and Chiesi C. Plagiocephaly causing superior oblique deficiency and ocular torcicollis. Arch Ophthalmol. 100: 1093, 1982.
Gobin MH. Sagittalisation of the oblique muscle as AV & Phenomena. Br J Ophthalmol. 2:13, 1967.
Parks MM. The weakening surgical procedures for eliminating overaction of inferior oblique muscles. Am J Ophthalmol. 73: 107,1972.
[Figure - 1], [Figure - 2], [Figure - 3], [Figure - 4], [Figure - 5]