Patient Evaluationchapter 1

MRD 1—margin reflex distance 1 → distance between upper lid margin and corneal reflection of a pen torch (patient looking directly at it) Normal = 4–4.5 mm

MRD 2—margin reflex distance 2 → distance between lower lid margin and corneal reflection of a pen torch

VFH—vertical fissure height → MRD 1 + MRD 2; Normal: 8–12 mm; Measure in upgaze/ downgaze/primary gaze

MCD—margin crease distance—distance between upper lid margin and lid crease in downgaze; Normal in female = 10 mm; male = 8 mm

MLD—margin limbal distance—distance between upper lid margin and lower limbus in upgaze

LPS function—place a thumb firmly against patient's brow to negate the action of the frontalis; then patient looks up as far as possible; measure the excursion of the lid

Bell's phenomenon—present if upward and outward rotation of the globe occurs on forceful closure of the lids; if absent—patient may develop post-operative exposure keratopathy

Herring reflex → in unilateral ptosis, manually elevate the ptotic lid and look for drooping of the fellow upper lid (it may show a subtle bilateral ptosis in which case surgery may induce ptosis in the fellow eye)

Marcus Gunn jaw winking phenomenon—when patient makes chewing movements with his jaw, the lid intermittently droops and elevates

Tests for ocular myasthenia (mentioned under neuro-ophthalmology)