Congenital aberrant tearing: a re-look
Marilyn T Miller1, Kerstin Strömland, Liana Ventura
1Department of Ophthalmology and Visual Sciences, University of Illinois at Chicago, Chicago, Illinois, USA.
Transactions of the American Ophthalmological Society
|March 12, 2009
Summary
Congenital aberrant tearing, including "crocodile tears" and absent emotional tearing, is rare. It is often linked to congenital conditions like Möbius sequence, Duane syndrome, and thalidomide embryopathy, suggesting an early developmental insult.
Area of Science:
- Ophthalmology
- Neurology
- Developmental Biology
Background:
- Congenital aberrant tearing presents as reflex tearing during eating (crocodile tears) or absent emotional tearing.
- It is frequently associated with Duane syndrome and has been observed in thalidomide embryopathy and Möbius sequence.
Purpose of the Study:
- To summarize existing literature on congenital aberrant lacrimation.
- To report findings from three new studies investigating this condition in individuals with Möbius sequence and thalidomide embryopathy.
Main Methods:
- Interviews regarding tearing symptoms were conducted with 28 individuals with Möbius sequence in Italy.
- 30 adults from the thalidomide series in Sweden underwent re-examination, including Schirmer testing before and after eating.
- Twenty families in Brazil with children diagnosed with Möbius sequence were surveyed about tearing symptoms and prenatal misoprostol exposure.
Main Results:
- In the Italian cohort, 7 of 28 individuals with Möbius sequence exhibited either crocodile tears or lack of emotional tearing.
- The Swedish thalidomide study found 10 of 30 patients had tearing when eating and 7 had no emotional tearing.
- Tearing abnormalities were reported in 10 of 20 Brazilian children with Möbius sequence.
Conclusions:
- Congenital anomalous lacrimation is rare and typically associated with Duane syndrome, Möbius sequence, or facial nerve palsy.
- These conditions suggest an early developmental insult occurring between 4 to 6 weeks of gestation.
- Proximity of the facial nerve, sixth nerve, and lacrimal nucleus during this embryonic period likely contributes to the observed lacrimation abnormalities.
