ABNORMAL PUPILLARY REACTIONS
Right physiological anisocoria
Signs ( Fig. 9.1 )
- a.
In dim light the right pupil is larger than the left.
- b.
In bright light both pupils constrict normally.
- c.
After instillation of cocaine 10% to both eyes, both pupils dilate.
Right pharmacological mydriasis
Signs ( Fig. 9.2 )
- a.
In dim light there is right mydriasis.
- b.
In bright light the right pupil does not constrict.
- c.
On accommodation the right pupil does not constrict.
- d.
After instillation of pilocarpine 1/10% to both eyes neither pupil constricts.
- e.
After instillation of pilocarpine 1% to both eyes, the right pupil does not constrict but the left does.
Right episodic mydriasis
Signs ( Fig. 9.3 )
- a.
In dim light the right pupil is larger than the left.
- b.
In bright light the right pupil does not constrict.
- c.
On accommodation the right pupil does not constrict.
- d.
After instillation of pilocarpine 1/10% to both eyes, neither pupil constricts.
- e.
After instillation of pilocarpine 1% to both eyes, both pupils constrict.
- f.
After 24 hours both pupils are of equal size.
Right tonic (Adie) pupil
Signs ( Fig. 9.4 )
- a.
In dim light there is right mydriasis.
- b.
In bright light there is right mydriasis.
- c.
On accommodation both pupils constrict although the right constricts very slowly and segmentally.
- d.
After instillation of pilocarpine 1/10% to both eyes, the right pupil constricts but not the left.
Look for
- •
Diminished or absent deep tendon reflexes (Holmes–Adie syndrome).
Right Horner syndrome
Signs ( Fig. 9.5 )
- a.
In dim light there is right miosis and mild ptosis.
- b.
In bright light both pupils constrict normally.
- c.
After instillation of cocaine 10% to both eyes, the right pupil dilates less than the left.
Look for
- •
Elevation of lower lid.
- •
Heterochromia iridis (if congenital or long-standing – see Fig. 8.96 ).
- •
Anhidrosis if the lesion is below the superior cervical ganglion.
Causes
- •
See Table 1.7 .
Right third nerve palsy
Signs ( Fig. 9.6 )
- a.
In dim light there is right mydriasis associated with ptosis and ophthalmoplegia.
- b.
In bright light the right pupil does not constrict.
- c.
On accommodation the right pupil does not constrict.
- d.
After instillation of pilocarpine 1/10% into both eyes, neither pupil constricts.
- e.
After instillation of pilocarpine 1% into both eyes, both pupils constrict.
Argyll Robertson pupils
Signs ( Fig. 9.7 )
- a.
In dim light both pupils are small.
- b.
In bright light neither pupil constricts.
- c.
On accommodation both pupils constrict (light-near dissociation – see Table 9.1 ).
Table 9.1
Causes of light-near dissociation
- 1.
Unilateral
- •
Afferent conduction defect
- •
Herpes zoster ophthalmicus
- •
Aberrant 3rd nerve regeneration
- •
- 2.
Bilateral
- •
Juvenile-onset diabetes
- •
Myotonic dystrophy
- •
Parinaud dorsal midbrain syndrome (see Table 1.6 )
- •
Argyll Robertson pupils
- •
Pituitary tumour
- •
Familial amyloidosis
- •
Encephalitis
- •
Chronic alcoholism
- •
- 1.
- d.
After instillation of pilocarpine 1/10% to both eyes, neither pupil constricts.
Tectal (dorsal midbrain) pupils
Signs ( Fig. 9.8 )
- a.
In dim light there is bilateral asymmetric mydriasis.
- b.
In bright light neither pupil constricts.
- c.
On accommodation both pupils constrict normally.
- d.
After instillation of pilocarpine 1/10% to both eyes, neither pupil constricts.
Right traumatic iridoplegia
Signs ( Fig. 9.9 )
- a.
In dim light there is right mydriasis and the pupil is irregular in shape due to segmental damage.
- b.
In bright light the right pupil does not constrict.
- c.
On accommodation the right pupil does not constrict.
- d.
After instillation of pilocarpine 1/10% to both eyes, neither pupil constricts.
- e.
After instillation of pilocarpine 1% to both eyes, the right pupil constricts partially and segmentally, and the left normally.
Look for
- •
Sphincter tears and iridodialysis (see Fig. 8.91 ).
ABNORMAL PUPIL SIZE
Small
Anterior uveitis
Signs
- •
In acute iritis miosis is caused by pupillary spasm ( Fig. 9.10 ).
Fig. 9.10
- •
In chronic iritis miosis may be caused by posterior synechiae ( Fig. 9.11 ).
Fig. 9.11
Spasm of the near reflex
Signs
- •
Transient bilateral miosis, esotropia and myopia ( Fig. 9.12 ).
Fig. 9.12
Argyll Robertson pupils
Signs
- •
Bilateral miosis and frequently irregular-shaped pupils ( Fig. 9.13 )
Fig. 9.13
- •
Light-near dissociation (see Fig. 9.7 ).
Lepromatous miosis
Signs
- •
Bilateral miosis may occur due to damage to the sympathetic innervation to the sphincter pupillae in the absence of posterior synechiae ( Fig. 9.14 ).
Fig. 9.14
Congenital microcoria
Signs
- •
Bilateral miosis and corectopia ( Fig. 9.15 ).
