by Professor Chua Chung Nen, Dr. Ngo Chek Tung & Dr. Thomas Law
A 47 year-old man was referred to our eye department for a 20 year-history of progressive worsening bilateral ptosis and a right exo- and hypertropia (Figure 1). His Tensilon test several years ago by a neurologist was normal. He also saw a cardiologist but found to have no cardiac abnormalities including any conduction defect. He did not have muscle biopsy but based on the clinical signs and history he was diagnosed as chronic progressive external ophthalmoplegia. The ophthalmologist whom he attended regularly was unwilling to perform ptosis operation for fear of exposure keratitis as his Bell's phenomenon was poor.
On examination, the vision in each eye was normal at 6/6 with glasses. The ptosis were severe and covered the pupillary axes and he needed to elevate his head constantly to see clearly. The levator function was less than 2mm (Figure 2). The ocular movement was poor in all directions (Figure 3). The Bell's phenomenon was absent in both eyes but the corneal sensation was intact (Figure 4).
Figure 1. Severe ptosis (note the absent corneal reflexes) and right ocular deviation.
Figure 2. Poor levator function from downgaze to upgaze.
Figure 3. Poor ocular movement on attempting to look in either direction.
Figure 4. Poor Bell's phenomenon.
a. A frontalis suspension was chosen to elevate his eyelids using the techniques mention in case 34. How would the procedure in this patient differs from that of others without chronic progressive external ophthalmoplegia?
Chronic progressive external ophthalmoplegia (CPEO) is a group of disorders characterized by mitochondrial dysfunction. Clinical symptoms range from extraocular motor abnormalities to multisystem involvement. The main ocular signs are bilateral extraocular motility impairment and blepharoptosis. Onset is gradual with an slow progression to near total immobility of the eyes and levator dysfunction. Kearns and Sayre gave their names to a type of external ophthalmoplegia associated with retinitis pigmentosa and complete heart block1.
Because of inadequate Bell’s phenomenon in CPEO patient, surgery should be performed on patients who had ptosis that cover the axis of both eyes. Frontalis suspension is the treatment of choice in these patient. Levator resection is not recommended because of the progressive nature of the lesion. In addition, levator resection that is large enough to lift the eyelid off the axis carries a high incidence of exposure keratitis. The amount of elevation should be conservative so the eyelids just clear the visual axis but the eyes can still close to protect the cornea2. Liberal use of ocular lubricants is essential in these patients.
Several materials have been recommended for frontalis slings. Some authors recommend silicone tube over fascia lata because of its elasticity that allow better eye closure and the flexibility for adjusting the lid height should the frontalis muscles subsequently weaken3. We chose 2/0 prolene over the other two because it is less traumatic than harvesting the fascia lata and cheaper than silicone tube. In addition, prolene can be easily removed should the patient develops severe exposure keratitis as prolene is not integrated into the muscle.
He underwent bilateral frontalis suspension using 2/0 prolene. Post-operatively, he had reduced blinking and problems with complete eyelid closure at sleep. Despite regularly topical artificial tear and chloramphenicol ointment at night, he developed bilateral exposure keratitis 3 days post-operative with epithelial defects which was worse in the right eye than the left. He asked to have the prolene removed so that he was able to close his eyes better.
Figure 5. 5 days post-frontalis suspension. The patients developed painful eyes due to
exposure keratitis with epithelial defects.He was able to close the left eye completely but only
partially closing the right eye. His wife commented he was unable to keep both eyes closed
at sleep and the corneas were exposed.
b. What are the options for managing his corneal problems while waiting for his eye closure to improve spontaneously ?
Despite conservative elevation of the eyelids, exposure keratitis is common in the first few weeks after frontalis suspension in CPEO patients. If exposure keratitis occurs despite liberal use of lubricants, the eye should be taped at night to reduce nocturnal exposure. If these fail and the patients develop corneal epithelial defects or ulcers, tarsorrhaphy is very effective in reducing the exposure and speed up the recovery4.
Figure 5. Large right inferior corneal epithelial defect secondary to exposure keratitis. The left
picture shows the eye immediately after the application of the contact lens and the right
picture shows healing of the defect at 1 week.
Figure 6. Eyelid appearance at 2 weeks post-operative. The patient was off contact lenses.
Right corneal defect was improving and the left corneal defect had resolved completely.
1. Kearns TP, Sayre GP. Retinitis pigmentosa, external ophthalmoplegia, and complete heart block: unusual syndrome with histologic study in one of two cases. Arch Ophthalmol 1958;60:280–9.
2. Lane CM, Collin JRO. Treatment of ptosis in chronic progressive external ophthalmoplegia. Br J Ophthalmol 1987;71:290–4.
3. Wong VA,
Beckingsale PS, Oley CA, Sullivan TJ. Management of myogenic ptosis.
Ophthalmology. 2002 May;109(5):1023-31.
4. Daut PM,
Steinemann TL, Westfall CT. Chronic exposure keratopathy complicating
surgical correction of ptosis in patients with chronic progressive external
ophthalmoplegia. Am J Ophthalmol. 2000 Oct;130(4):519-21.