EXAMINATION PARAMETERS

Question 1

MRD1

Answer 1

Upper eyelid margin to reflex distance
Corneal light reflex → upper lid margin
4 – 5.5mm

Question 2

MRD2

Answer 2

Lower eyelid margin to reflex distance
Corneal light reflex → lower lid margin
4.5 – 6.5mm

Question 3

PFH

Answer 3

Palpebral fissure height
Upper lid margin → lower lid margin
MRD1 + MRD2 = PFH
M: 8 – 12mm
F: 7 – 10mm

Question 4

LF

Answer 4

Levator excursion or levator function
Distance upper lid elevates from
1) downgaze with hand on patient’s forehead followed by
2) upgaze without change in head position
patient’s forehead followed by 2) upgaze without change in head position
Good: 12 +
Fair: 5 – 11mm
Poor: ≤4mm

Question 5

Upper lid crease

Answer 5

Upper lid margin → upper lid crease in downgaze

M: 10mm
F: 8mm

Question 6

Hertel exophthalmometry

Answer 6

This is used to quantify axial globe position (the amount of proptosis or enophthalmos present).
Proptosis of ≥ 22 mm or a difference of ≥ 2mm between eyes may need more evaluation.

Question 7

Phenylephrine testing

Answer 7

Instilling phenylephrine in patients with ptosis informs whether they would benefit from surgical excision of the Muller’s muscle (Muller’s muscle-conjunctival resection [CMMR]). Phenylephrine is an alpha-adrenergic agonist and stimulates the sympathetically innervated Muller’s muscle. Significant improvement in ptosis after instilling phenylephrine indicates the patient may be a good candidate for CMMR.

Phenylephrine 2.5% instilled in the inferior fornix of the more ptotic eye → positive test if MRD1 increases >1.5mm in 3-5 minutes

Question 8

Forced duction testing

Answer 8

This may be used to evaluate for restrictive strabismus as well as muscle entrapment in the setting of orbital fracture. You will probably do this a lot on call! (anytime there is trauma to the orbital area)