Test 14

1. In the measurement of the palpebral fissure: a. in patients with malposition of the lower lid, MRD     (margin-reflex distance) gives a more accurate measurement     of ptosis than the interpalpebral fissure b. MRD is the distance between the upper eyelid margin and the      corneal light reflex in the primary gaze c. ptosis is present if the MRD is less than 2 mm d. the MRD is increased in facial nerve palsy e. in normal persons, the upper lid is at the level of the limbus   answera.T   b.T   c.T   d.T   e.F In facial nerve palsy, the upper lid is elevated  due to the unopposed action of the orbicularis. In normal persons, the upper lid is 1 mm below the limbus.     2. In levator disinsertion, the following features are seen: a. high skin crease b. levator function less than 10 mm c. frontalis over action d. failure of the upper lid to relax on down-gaze e. decreased ptosis on up-gaze answera.T   b.F   c.T   d.F   e.F In levator disinsertion such as involutional ptosis,  the levator function is normal and typically is 12 mm or more. d and e are features of congenital ptosis.   3. Features of congenital ptosis include: a. absent or poor skin crease b. lid lag on down-gaze c. increased ptosis on up-gaze d. limitation of up-gaze e. reduced levator function. answera.T   b.T   c.F   d.T   e.T In congenital ptosis, the ptosis is usually reduced on up-gaze. Up-gaze is often reduced in congenital  ptosis possibly because of abnormal  development of the superior rectus.      4. Pseudoptosis occurs in: a. hypotropia. b. unilateral thyroid eye disease c. unilateral high myopia. d. myotonic dystrophy e. myasthenia gravis answera.T   b.T   c.T  d.F   e.F True ptosis occurs in myotonic dystrophy. The ptosis in myasthenia gravis may be intermittent.   5. The following are true about the eyelids: a. the lower eyelid is normally 1 mm below the limbus b. the lower eyelid is retracted in Horner's syndrome c. basal cell carcinoma affects the lower lids more commonly     than the upper lid d. the upper lid is more important than the lower lid in maintaining       the integrity of the cornea e. the skin crease of the upper lid represents the insertion of the      levator muscle. answera.F   b.F   c.T   d.T   e.T The lower eyelid is normally at the level of the inferior limbus. The lower eyelid is updrawn in Horner's syndrome.   Return to the main page