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Transient internal ophthalmoplegia after inferior oblique myectomy
Transient internal ophthalmoplegia after inferior oblique myectomy John C. Bladen, BSc, MRCS,a Mariya Moosajee, MBBS, PhD,b Romesh Angunawela, MRCOphth,b and Clare Roberts, FRCOphtha,b
Internal ophthalmoplegia causing pupillary dilatation and loss of accommodation following damage to the ciliary ganglion is a rare complication of strabismus surgery. Here we report a case of parasympathetic neuropraxia resulting in transient internal ophthalmoplegia after inferior oblique myectomy in a 12-year-old girl. Short-term symptomatic relief was achieved with 1% pilocarpine. Normal visual function returned over several months.
Case Report
A
12-year-old white girl presented with a history of an intermittent exotropia from a few months of age that had become increasingly manifest over the preceding 6-month period. The patient was wearing a spectacle correction of 0.25 0.25 180 in the right eye and 0.50 0.25 180 in the left eye. On examination, bestcorrected visual acuity (measured using a LogMAR chart at 3 meters) was 0.04 (20/21 Snellen equivalent) in the right eye and 0.0 (20/20) in the left eye. Ocular motility testing was notable for a poorly controlled intermittent exotropia with bilateral inferior oblique overaction and a V-pattern. A slight left eye fixation preference was noted. The deviation measured 206 at distance and 456 at near, with convergence reduced to 25 cm. Stereopsis (by near Frisby test) was excellent at 15 arcsec as long as the eyes were aligned. Pupil reflexes were normal. Bilateral strabismus surgery was carried out under general anesthesia. Epinephrine (0.01%) eyedrops were instilled in both eyes prior to surgery to improve hemostasis. The rectus muscles were approached via limbal conjunctival incisions with blunt dissection. The right lateral rectus muscle was recessed by 4 mm using the anchored hang-back technique, and the ipsilateral medial rectus muscle was resected by 5 mm. Bilateral inferior oblique myectomies were performed—the left via a fornix incision following the technique detailed in Taylor and Hoyt’s Pediatric Ophthalmology and Strabismus.1 The right inferior oblique myectomy was performed using the same technique except that the existing limbal incision (used to
recess the lateral rectus muscle) was used. Both inferior oblique muscles were carefully identified, isolated, and checked for posterior fibers and then clamped close to the globe before disinsertion using Westcott scissors. The disinserted muscle was then reclamped 5 mm from the original clamp and myectomized with vigorous cautery to the cut end. The surgery was uneventful, with good hemostasis. At the end of surgery 0.2 mL levobupivicaine 2.5 mg/mL was infiltrated subconjunctivally at each incision site. Two hours postoperatively the eyes were comfortable with no evidence of hemorrhage or other complications. At the first postoperative visit, 2 weeks after surgery, the alignment had improved and the patient was happy with the overall outcome but complained of slightly blurred vision in the left eye since the operation. Visual acuity was 0.04 (20/21) in the right eye and 0.1 (20/25) in the left eye at distance, and N5 on the right and N6 on the left at near. Motility assessment showed a predominantly latent exodeviation, which measured 86 for distance and 146 for near. There was mild bilateral inferior oblique underaction. The left pupil was found to be dilated (anisocoria worse in the light); it did not react to light or to an accommodative target (Figure 1A). There was no relative afferent pupillary defect. Pilocarpine 0.125% caused left pupillary constriction after 30 minutes, with no change in the right pupil, suggesting left cholinergic hypersensitivity (Figure 1B). A diagnosis of left parasympathetic neuropraxia was made. The patient was treated with pilocarpine 1% drops to be instilled in the left eye as required for symptomatic relief of her blurred vision. One month after surgery, the anisocoria had begun to recover, accompanied by slight reaction to light and good reaction to accommodation. Five months postoperatively there was no anisocoria; both pupils reacted to light (the right more briskly than the left), and accommodative pupillary constriction was normal in both eyes, confirming a left transient internal ophthalmoplegia secondary to a parasympathetic neuropraxia.
Discussion Author affiliations: aChelsea and Westminster Hospital, London, United Kingdom; b Western Eye Hospital, London, United Kingdom Submitted June 21, 2009. Revision accepted September 23, 2009. Reprint requests: John Bladen BSc, MRCS, Chelsea and Westminster Hospital, London UK (email: [email protected]). J AAPOS 2009;13:596-597. Copyright Ó 2009 by the American Association for Pediatric Ophthalmology and Strabismus. 1091-8531/2009/$36.00 1 0 doi:10.1016/j.jaapos.2009.09.011
596
Internal ophthalmoplegia secondary to parasympathetic neuropraxia after inferior oblique myectomy has previously been reported.2,3 Trauma and surgery in proximity to the ciliary ganglion or short ciliary nerves can inflict an internal ophthalmoplegia, for example orbital fractures and their repair, endoscopic sinus surgery, and inferior oblique myectomy.2-5 The sequelae depend on the nature of the injury. Most clinical reports suggest near complete
Journal of AAPOS
Volume 13 Number 6 / December 2009
FIG 1. Pilocarpine test performed 2 weeks post recession-resection procedure on the right eye and bilateral inferior oblique myectomies. A, Left dilated pupil unresponsive to light or accommodation. B, Left constricted pupil, 30 minutes following instillation of pilocarpine, 0.125%. The normal right pupil has not constricted, due to insensitivity to low-dose pilocarpine.
recovery of pupil constriction and accommodation in the majority of patients, particularly where neuropraxia from perineural edema, contusion, or traction has occurred.2 More permanent damage due to transection or shearing of the nerve roots can lead to permanent anisocoria or partial reinnervation resulting in segmental, less efficient constriction and light-near dissociation. Diagnosis and investigations of parasympathetic damage depend on the clinical scenario. Reaction to light and accommodation should be performed along with slit-lamp biomicroscopy. Pharmacological testing with low-dose
Journal of AAPOS
Bladen et al
597
cholinergics (0.125% pilocarpine placed in both eyes) demonstrates hypersensitivity leading to pupil constriction after 30 minutes. Failure of the pupil to constrict in response to 1% pilocarpine, which constricts a normal iris, points to a pharmacological mydriasis. Adie’s (tonic) pupil should also be considered. Denervation hypersensitivity is not exclusive to postganglionic lesions with numerous reports on intracranial lesions demonstrating similar findings with cholinergic agents.4,6 Treatment focuses on identifying the underlying cause and providing symptomatic relief. Short-term use of 1% pilocarpine can reduce anisocoria and blurred vision. Cosmetic contact lenses can be used to reduce photophobia in a longstanding dilated pupil. The strabismus surgeon must be aware of the possibility of damaging the ciliary ganglion during surgery to the inferior oblique muscle. Internal ophthalmoplegia may be included as a potential complication when obtaining consent for inferior oblique myectomy. References 1. Morris RJ. Strabismus surgery. In: Taylor D, Hoyt CS, editors. Paediatric ophthalmology and strabismus. 3rd ed. Amsterdam: Elsevier; 2005:972. 2. Bajart AM, Robb RM. Internal ophthalmoplegia following inferior oblique myectomy: A report of three cases. Ophthalmology 1979;86: 1401-6. 3. Damanakis AG, Theodossiadis GP. Internal ophthalmoplegia caused by inferior oblique muscle myectomy. J Pediatr Ophthalmol Strabismus 1985;22:117-19. 4. Kosko JR, Pratt MF, Chames M, Letterman I. Anisocoria: A rare consequence of endoscopic sinus surgery. Otolaryngol Head Neck Surg 1998;118:242-4. 5. Bodker FS, Cytryn AS, Putterman AM, Marschall MA. Postoperative mydriasis after repair of orbital floor fracture. Am J Ophthalmol 1993;115:372-5. 6. Slamovits TL, Miller NR, Burde RM. Intracranial oculomotor nerve paresis with anisocoria and pupillary parasympathetic hypersensitivity. Am J Ophthalmol 1987;104:401-6.
Internal ophthalmoplegia causing pupillary dilatation and loss of accommodation following damage to the ciliary ganglion is a rare complication of strabismus surgery. Here we report a case of parasympathetic neuropraxia resulting in transient internal ophthalmoplegia after inferior oblique myectomy in a 12-year-old girl. Short-term symptomatic relief was achieved with 1% pilocarpine. Normal visual function returned over several months.
Case Report
A
12-year-old white girl presented with a history of an intermittent exotropia from a few months of age that had become increasingly manifest over the preceding 6-month period. The patient was wearing a spectacle correction of 0.25 0.25 180 in the right eye and 0.50 0.25 180 in the left eye. On examination, bestcorrected visual acuity (measured using a LogMAR chart at 3 meters) was 0.04 (20/21 Snellen equivalent) in the right eye and 0.0 (20/20) in the left eye. Ocular motility testing was notable for a poorly controlled intermittent exotropia with bilateral inferior oblique overaction and a V-pattern. A slight left eye fixation preference was noted. The deviation measured 206 at distance and 456 at near, with convergence reduced to 25 cm. Stereopsis (by near Frisby test) was excellent at 15 arcsec as long as the eyes were aligned. Pupil reflexes were normal. Bilateral strabismus surgery was carried out under general anesthesia. Epinephrine (0.01%) eyedrops were instilled in both eyes prior to surgery to improve hemostasis. The rectus muscles were approached via limbal conjunctival incisions with blunt dissection. The right lateral rectus muscle was recessed by 4 mm using the anchored hang-back technique, and the ipsilateral medial rectus muscle was resected by 5 mm. Bilateral inferior oblique myectomies were performed—the left via a fornix incision following the technique detailed in Taylor and Hoyt’s Pediatric Ophthalmology and Strabismus.1 The right inferior oblique myectomy was performed using the same technique except that the existing limbal incision (used to
recess the lateral rectus muscle) was used. Both inferior oblique muscles were carefully identified, isolated, and checked for posterior fibers and then clamped close to the globe before disinsertion using Westcott scissors. The disinserted muscle was then reclamped 5 mm from the original clamp and myectomized with vigorous cautery to the cut end. The surgery was uneventful, with good hemostasis. At the end of surgery 0.2 mL levobupivicaine 2.5 mg/mL was infiltrated subconjunctivally at each incision site. Two hours postoperatively the eyes were comfortable with no evidence of hemorrhage or other complications. At the first postoperative visit, 2 weeks after surgery, the alignment had improved and the patient was happy with the overall outcome but complained of slightly blurred vision in the left eye since the operation. Visual acuity was 0.04 (20/21) in the right eye and 0.1 (20/25) in the left eye at distance, and N5 on the right and N6 on the left at near. Motility assessment showed a predominantly latent exodeviation, which measured 86 for distance and 146 for near. There was mild bilateral inferior oblique underaction. The left pupil was found to be dilated (anisocoria worse in the light); it did not react to light or to an accommodative target (Figure 1A). There was no relative afferent pupillary defect. Pilocarpine 0.125% caused left pupillary constriction after 30 minutes, with no change in the right pupil, suggesting left cholinergic hypersensitivity (Figure 1B). A diagnosis of left parasympathetic neuropraxia was made. The patient was treated with pilocarpine 1% drops to be instilled in the left eye as required for symptomatic relief of her blurred vision. One month after surgery, the anisocoria had begun to recover, accompanied by slight reaction to light and good reaction to accommodation. Five months postoperatively there was no anisocoria; both pupils reacted to light (the right more briskly than the left), and accommodative pupillary constriction was normal in both eyes, confirming a left transient internal ophthalmoplegia secondary to a parasympathetic neuropraxia.
Discussion Author affiliations: aChelsea and Westminster Hospital, London, United Kingdom; b Western Eye Hospital, London, United Kingdom Submitted June 21, 2009. Revision accepted September 23, 2009. Reprint requests: John Bladen BSc, MRCS, Chelsea and Westminster Hospital, London UK (email: [email protected]). J AAPOS 2009;13:596-597. Copyright Ó 2009 by the American Association for Pediatric Ophthalmology and Strabismus. 1091-8531/2009/$36.00 1 0 doi:10.1016/j.jaapos.2009.09.011
596
Internal ophthalmoplegia secondary to parasympathetic neuropraxia after inferior oblique myectomy has previously been reported.2,3 Trauma and surgery in proximity to the ciliary ganglion or short ciliary nerves can inflict an internal ophthalmoplegia, for example orbital fractures and their repair, endoscopic sinus surgery, and inferior oblique myectomy.2-5 The sequelae depend on the nature of the injury. Most clinical reports suggest near complete
Journal of AAPOS
Volume 13 Number 6 / December 2009
FIG 1. Pilocarpine test performed 2 weeks post recession-resection procedure on the right eye and bilateral inferior oblique myectomies. A, Left dilated pupil unresponsive to light or accommodation. B, Left constricted pupil, 30 minutes following instillation of pilocarpine, 0.125%. The normal right pupil has not constricted, due to insensitivity to low-dose pilocarpine.
recovery of pupil constriction and accommodation in the majority of patients, particularly where neuropraxia from perineural edema, contusion, or traction has occurred.2 More permanent damage due to transection or shearing of the nerve roots can lead to permanent anisocoria or partial reinnervation resulting in segmental, less efficient constriction and light-near dissociation. Diagnosis and investigations of parasympathetic damage depend on the clinical scenario. Reaction to light and accommodation should be performed along with slit-lamp biomicroscopy. Pharmacological testing with low-dose
Journal of AAPOS
Bladen et al
597
cholinergics (0.125% pilocarpine placed in both eyes) demonstrates hypersensitivity leading to pupil constriction after 30 minutes. Failure of the pupil to constrict in response to 1% pilocarpine, which constricts a normal iris, points to a pharmacological mydriasis. Adie’s (tonic) pupil should also be considered. Denervation hypersensitivity is not exclusive to postganglionic lesions with numerous reports on intracranial lesions demonstrating similar findings with cholinergic agents.4,6 Treatment focuses on identifying the underlying cause and providing symptomatic relief. Short-term use of 1% pilocarpine can reduce anisocoria and blurred vision. Cosmetic contact lenses can be used to reduce photophobia in a longstanding dilated pupil. The strabismus surgeon must be aware of the possibility of damaging the ciliary ganglion during surgery to the inferior oblique muscle. Internal ophthalmoplegia may be included as a potential complication when obtaining consent for inferior oblique myectomy. References 1. Morris RJ. Strabismus surgery. In: Taylor D, Hoyt CS, editors. Paediatric ophthalmology and strabismus. 3rd ed. Amsterdam: Elsevier; 2005:972. 2. Bajart AM, Robb RM. Internal ophthalmoplegia following inferior oblique myectomy: A report of three cases. Ophthalmology 1979;86: 1401-6. 3. Damanakis AG, Theodossiadis GP. Internal ophthalmoplegia caused by inferior oblique muscle myectomy. J Pediatr Ophthalmol Strabismus 1985;22:117-19. 4. Kosko JR, Pratt MF, Chames M, Letterman I. Anisocoria: A rare consequence of endoscopic sinus surgery. Otolaryngol Head Neck Surg 1998;118:242-4. 5. Bodker FS, Cytryn AS, Putterman AM, Marschall MA. Postoperative mydriasis after repair of orbital floor fracture. Am J Ophthalmol 1993;115:372-5. 6. Slamovits TL, Miller NR, Burde RM. Intracranial oculomotor nerve paresis with anisocoria and pupillary parasympathetic hypersensitivity. Am J Ophthalmol 1987;104:401-6.