Clinical Pearl of the Month - Ptosis Ptroubles?
Ptosis is an abnormally low position of the upper eyelid. It can be congenital or acquired, but is more common in elderly patients due to a gradual loss of muscle function. It typically impacts vision as it reduces the amount of light entering the eye.
However we can’t blame everything on “age” or “you were just born this way” … there are other sinister causes of ptosis and it is important to rule them out or identify them in order to manage your patient appropriately.
PEARL 1: IDENTIFY THE PTYPE OF PTOSIS
Ptosis can be classified broadly based on their cause.
- Myogenic ptosis
- Poor levator (muscle) function, more commonly congenital and present at birth. Acquired myogenic ptosis may be seen with muscular dystrophy and CPEO.
- Aponeuotic ptosis
- Good levator function however it is stretched out or dehiscence, which could be due to normal aging, repetitive eye rubbing, RGPs, or previous intraocular surgery
- Neurogenic ptosis
- Nerve problem which is responsible for controlling the eyelid function
- CNIII (congenital, compressive, vasculopathic), Horner syndrome,Myasthenia Gravis , Marcus Gunn Jaw-Winking syndrome, Multiple sclerosis,
- Mechanic ptosis
- Something physically pushing or weighing down the lid
- Upper eyelid inflammation E.g. Chalazion, Foreign body in upper fornix, Neoplasm
- Traumatic ptosis
- Previous trauma causing it E.g. eyelid laceration, contusion injury to levator, orbital roof fracture
- When the lids itself aren’t dropping but appears that way due to another anatomical anomaly E.g. the other eyelid is contracted so in comparison it may look lower.
PEARL 2: RULE OUT OR REFER
Ensure you have a mental check list of ruling out all sinister causes of a ptosis and refer appropriately if necessary.
- CNIII Palsy
- Check: the affected eye is DOWN and OUT, pupil dilated
- Questions to ask: Sudden onset? Experiencing double vision? Any systemic diseases (E.g. Diabetes, hypertension)
- Horner Syndrome
- Check: Anisocoria that is greater in dim illumination, smaller pupil which lags to dilate and occurs on the same side as a mild ptosis
- Questions to ask: Change in sweat patterns? Any neck or head trauma? Any surgery to neck, thyroid or heart?
- Myasthenia Gravis
- Check: Weak eyelid muscles that get tired very quickly
- Questions to ask: Is the drooping worse towards end of the day?
- Check: Pupil involvement, exophthalmos
- Questions to ask: Sudden onset?
- Chronic progressive external ophthalmoplegia
- Check: Limitation to ocular motilities, usually bilateral, pupils normal
- Questions to ask: rate of onset? (Usually slowly progressive)
PEARL 3: PTYPES OF PTESTS
- Pupil assessment
- Assess reaction, RAPD, lag, anisocoria, light vs dark conditions
- Cover Test
- Marginal reflex distance
- Compare reflex from upper lid (typically 4-5mm) vs lower lid (typically 5mm)
- Levator function
- Assess to see how far the upper lid can be raised starting from downgaze, with your thumb over their eyebrow to prevent the frontalis muscle from assisting
- Repeat with ice test for comparison if suspecting myasthenia gravis
- Lid crease height
- Compare the distance between upper lid margin to crease between the eyes on downgaze
- Obtain patient’s previous photos for comparison
- Determine if it was present before and if so, how long? Compare to see if it has worsened or improved
PEARL 4: PROPER RECORDING IS KEY
Ensure you record in detail the responses to the questions you have asked (both yes and no), results of tests you have conducted (positive and negative), and state that you have explained to the patient the situation, reason for referral (if necessary), and the importance of further testing/imaging.