Pulsatile enophthalmos, severe esotropia, kinked optic nerve and visual loss in neurofibromatosis type-1.

Neurofibromatosis Type I if associated with aplasia of greater wing of sphenoid may be associated with a pulsatile exophthalmos. However, very rarely it may be associated with a pulsatile enophthalmos. This clinical image describes a rare presentation with pulsatile enophthalmos, esotropia and kinking of the optic nerve due to neurofibomatosis type I.

Introduction

Unilateral pulsatile enophthalmos may occur secondary to orbital varices,1 carotico-cavernous fistula,1 and absence of greater wing of the sphenoid.2 In addition, prolapse of the nervous tissue from the defect may cause compression of optic nerve and ocular deviation. Authors’ report in this clinical image a rare case of Neurofibromatosis Type -I with above presentation.

Case Presentation

A 64-year-old man presented to our institute with complaints of poor vision and left eye appearing small in size since childhood. He also had a history of multiple cutaneous swellings all over the body since early adulthood. His best-corrected visual acuity was 20/20 in the right eye and finger counting close to face in the left eye. External examination showed severe enophthalmos of the left eye and a large angle esotropia (>100 prism diopter by Krimsky test) with −3 limitation of abduction, elevation and depression of the left eye [Figure 1]. Faint pulsations of the enophthalmic eye were observed. The video link should work when available online [Video 1]. There was no effect of the Valsalva manoeuvre or positional change on the enophthalmos. Pupil examination showed a relative afferent pupillary defect in the left eye. Fundus examination was unremarkable in the right eye, and the optic disk was pale in the left eye. On general examination, multiple cutaneous neurofibromas [Figure 2], cafe-au-lait patches (six, most more than 15 mm in greatest diameter) over the trunk and back and hollowness of the left temporal fossa.

Figure 1

Clinical face photograph (a) and nine gaze motility picture of the patient (b) presence of neurofibromas, gross enophthalmos, large angle esotropia and limitation of abduction, elevation and depression in the left eye

Figure 2

Clinical photograph of the patient showing presence of multiple neurofibromas of the trunk and presence of cafe-au-lait spot (inset in high magnification, white arrow)

Computed tomography scan of the brain and orbits showed absence of the greater wing of the sphenoid, herniation of brain parenchyma along with cerebrospinal fluid (CSF) into the left orbit causing pulsating enophthalmos, esotropia and kinking of optic nerve [Figures 3 and 4]. Optic atrophy of the left eye was attributed to the chronic kinking of the optic nerve. A diagnosis of neurofibromatosis (NF) type I with aplasia of greater wing of sphenoid was made.

Figure 3

Axial computerised tomography scans of the orbits showing absence of the greater wing of sphenoid (white asterix), with herniation of brain parenchyma into the left orbit (long white arrow), esotropia and kinking of the left optic nerve (short white arrow)

Figure 4

Coronal computerized tomography scans (a and b) of the patient showing missing greater wing of sphenoid (white asterix) a prolapse of the temporal lobe of the brain in the left orbit (white arrows)

Discussion

Unilateral enophthalmos usually occurs as a sequeale of microphthalmos, orbital fractures, and sclerosing orbital disorders. Unilateral pulsatile eye has been reported with orbital varices,[1] carotico-cavernous fistula[2] and absence of greater wing of the sphenoid.[3]

Hypoplasia of the greater wing of the sphenoid (though mostly incomplete) is an uncommon developmental defect. It is a pathognomic features reported in about 5–10% of patients with NF-1.[4] It is usually associated with an exophthalmos, which may be pulsatile due to transmitted CSF pulsations. However, sometimes an associated enophthalmos may be seen secondary to microphthalmos or deficient lateral wall of the orbit that allows orbital contents to decompress into the temporal fossa/intracranially.[34] In our patient, the greater wing of sphenoid was almost aplastic, associated with a mild proplase of the retro-orbital fat into temporal fossa, which could have caused enophthalmos. Associated herniation of the temporal lobe into lateral orbit caused a large angle esotropia and a kinked optic nerve. This might have led to a limitation of all the movements (abduction, elevation, and depression) and compressive optic atrophy in the left eye. In our patient systemic manifestations of NF-1 (neurofibromas and café-au-lait spots) helped to make the diagnosis. Sometimes enophthalmos may be the only presenting feature of NF-1.[3] Though rare, ophthalmologists could be the first to encounter this rare presentation and should be aware of this association and possible complications accounting for visual loss.