Ocular motility findings in chronic progressive external ophthalmoplegia

Abstract

Aims To characterise the ocular motility features of chronic progressive external ophthalmoplegia by quantitative and semiquantitative means.To assess the prevalence of diplopia and the binocular adaptations to nonaligned visual axes. Method We studied 25 patients with chronic progressive external ophthalmoplegia. In each case muscle biopsies were consistent with mitochondrial myopathy. All patients underwent cover test in the primary position, assessment of binocular status, and measurement of uniocular fields of fixation using the Goldmann perimeter. Results A total of 23 (92%) patients had an exo-deviation, with six (26%) of those having an associated vertical deviation: 12 patients were binocular. Of the 13 patients with a manifest deviation seven had diplopia and six had suppression. Of all paired extra-ocular muscles (EOM), 68% had symmetry of movement within 51 of each other. Conclusion Almost all patients had an exodeviation. Diplopia was more common than expected. The majority of patients had symmetry of EOM limitation.

Dynamic properties of eye movements in mitochondrial chronic progressive external ophthalmoplegia

“…Extraocular movements were very limited, especially in the horizontal plane. Attempts were made to estimate his range of eye movements using a Goldmann perimeter; 8 his right eye appeared to have 281 horizontal and over 501vertical movement whereas his left eye appeared to have 221horizontal and 271 vertical movement. However, the patient had difficulty in distinguishing when the visual stimulus was in his central or peripheral vision, making this approach unreliable (see measurements of eye movements in next section).…”

“…7 Acquired disorders, especially myasthenia gravis, sometimes mimic CPEO in patients who present to physicians after the disease has been evolving for some time. 1 Although the clinical features of CPEO are well described, including detailed examinations of visual function and eye movements, 8,9 there are few reports of the dynamic properties of eye movements in CPEO using reliable recording techniques. We studied a patient with longstanding CPEO with the goal of defining the dynamic properties of his residual eye movements and relating them to his lack of diplopia and oscillopsia (illusory motion of the visual world) while at rest or during activities such as walking.…”

Assessment of visual function in chronic progressive external ophthalmoplegia

“…12,13 This test uses the Goldmann perimeter to measure movement in the main field of muscle action. One eye is occluded and the patient is asked to follow the smallest dimmest light target possible and indicate when it disappears.…”

“…Since the ophthalmoplegia in CPEO is relatively symmetrical 13 and diplopia is said to be uncommon, there is a perception that patients with CPEO are not greatly visually handicapped. However, recent work has shown that diplopia in CPEO is more common than previously thought.…”

“…However, recent work has shown that diplopia in CPEO is more common than previously thought. 13 Furthermore, the associated ptosis in CPEO patients may further increase their levels of visual impairment. A rating scale of visual function is thus required as visual acuity alone may not reflect levels of visual handicap.…”