Ditropan-associated Esotropia

1
Ditropan-associated Esotropia

• Dr. Elaine Wong
• Dr. Lionel Kowal
• Ocular motility clinic, RVEEH
• CERA, Uni Melb, RVEEH

2
Ditropan-associated ET

• 5 yo girl
• PMHx
• Hypothyroidism on oroxine
• Enuresis
• HOPC
• Recent onset intermittent ET
• Closing L eye when drawing or reading
• Recently started on Ditropan (Oxybutynin) for
  enuresis

3
Examination _at_ presentation

• VAR 6/8 VAL 6/8
• Near VAR 6/9 VAL 6/8
• Stereopsis Titmus fly 100
• CT D) RET 15? N) RET 35?
• OM normal
• Polarised 4 dot test R suppression
• Cycloplegic refraction
• R 3.25 L 2.75

4
Ditropan-associated ET

• After cessation of Oxybutynin
• VAR 6/8 VAL 6/8
• Near VAR 6/6 VAL6/8
• CT D) orthophoria
• N) orthophoria
• ELAINE CHECK THE DATA ON THIS SLIDE PLS
• Polarised 4 dot test Fusion
• Stereopsis Titmus fly 100

5
Discussion - Oxybutynin

• Muscarinic receptor antagonist often used for
  overactive bladder
• COMMONLY PRESCRIBED
• Anticholinergic systemic SE
• Ocular effects
• Ciliary ganglion accomodation
• Pterygopalatine ganglion lacrimation

6
Ocular side-effects of tolterodine and
oxybutynin, a single-blind prospective randomized
trial

• Altan-Yaycioglu et al. Br J Clin Pharmacol 955,
  588-592
• 52 patients, 104 eyes
• Randomised into
• Tolterodine 2mg bd 28 pts
• Oxybutynin 5 mg tds 24 pts
• All examined by ophthalmologists
• Schirmers
• Accomodative amplitude
• Pupillary diameter PD

7
Discussion

• Tolterodine Oxybutynin
• Accom amp (DS) 2.06 to 1.65 2.18 to 1.80
• (p 0.07) (p 0.003)
• Schirmers (mm) 12.82 to 12.32 12.21 to 14.83
• (p 0.698) (p 0.342)
• PD bright (mm) 1.94 to 2.02 2.07 to 2.08
• (p 0.174) ( p 0.953)

8
Discussion

• In this case Oxybutynin
• Impairs accommodation
• Pre-existing moderate uncorrected
• To accommodate sufficiently to see, the pt
  converges, and the CA/C ratio then generates
  accommodation
• hence ESOTROPIA!!!
• ? Is Tolterodine (Detrusitol) safer

9
Ditropan

• Frequently prescribed
• Has never been described as cause of ET!
• Likely to cause ?accommodation and ? convergence
• Dit hyperopia likely to cause ET
• Almost certainly underrecognised