Ptosis
Congenital ptosis is often myogenic in origin and can be distinguished from other types of ptosis by a lid crease that is subtle or absent. Congenital ptosis is usually not concerning unless it is so severe it obstructs the visual axis, potentially leading to amblyopia (Figure 3).
Figure 3. Partial left eyelid ptosis. The lid is partially occluding the pupil and is probably restricting the patient's superior visual field. This patient may be at risk of developing deprivational amblyopia, depending on the duration of the ptosis. Courtesy of National Institutes of Health.
If the ptosis is long-standing, it can affect the shape of the cornea and induce astigmatism, but this is readily corrected with spectacles. Patients with congenital ptosis may also develop a chin-up posture that can lead to other musculoskeletal conditions.
Acute onset of ptosis may be secondary to Horner syndrome or an oculomotor nerve palsy; in these patients, it is critical to assess the pupils. If Horner syndrome is confirmed by the presence of a miotic pupil, a diagnosis of neuroblastoma must be excluded, because this is a potentially life-threatening condition. If the pupil on the affected side is dilated, emergency referral is warranted. Ptosis may mask the perception of diplopia in young patients with oculomotor nerve palsies, so it is important to lift the lid to examine both the pupil and the extraocular motility of the affected eye (Figure 4). Horner syndrome should not cause diplopia unless it coexists with another condition.
Figure 4. Subtle ptosis in the right eye of a patient with a history of an oculomotor nerve palsy secondary to a ruptured arteriovenous malformation. The patient originally had a large exotropia in the right eye due to the oculomotor nerve palsy, but the strabismus was surgically repaired. This patient also had a substantial amount of astigmatism in the right eye, possibly secondary to the ptosis. Image courtesy of Christina Esposito, OD.
Another distinguishing factor between ptosis caused by Horner syndrome and an oculomotor nerve palsy is the severity of the ptosis. The ptosis is mild in Horner syndrome because only the Mueller muscle is affected, but is often severe in an oculomotor nerve palsy because the levator is affected.
Pediatric myasthenia gravis is a rare cause of ptosis and is characterized by variable ptosis that tends to worsen with fatigue.
Pseudoptosis may be caused by contralateral proptosis, so it is important to evaluate both eyes to determine which one is actually abnormal. Lid edema from a chalazion or hordeolum may also cause the appearance of ptosis.
Key Factors
Concerning diagnoses:
Acute: neuroblastoma, oculomotor nerve palsy, myasthenia gravis
Congenital, if severe: amblyopia
History: Onset (age and nature), variability of ptosis
Examination: Evaluation of upper lid crease, pupillary assessment, extraocular motility testing
Management: Work-up for neuroblastoma (new onset of Horner syndrome); neuroimaging studies if oculomotor nerve palsy
The Bottom Line
Acute onset of any of these ocular signs deserves consideration and additional testing. In the pediatric population, the integrity of the visual system must be maintained for optimal visual function over the lifetime, so even small reductions in visual acuity or subtle ocular misalignment should be taken seriously.
The correct identification and evaluation of the four ocular signs described above helps safeguard the visual system and ensures that potentially devastating diagnoses are detected early.
Medscape Ophthalmology © 2019 WebMD, LLC
Any views expressed above are the author's own and do not necessarily reflect the views of WebMD or Medscape.
Cite this: Four Ocular Abnormalities Not to Overlook in Children - Medscape - Jan 17, 2019.
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