Lacrimal Puncta Agenesis
Patient Information
Characteristics
Background and History
The eye requires constant moisture and irrigation for normal health and function. This is provided by the tears and blinking. When tears are produced in excess they drain into the lacrimal system which begins with openings (puncta) in the margin of the lids and ends in the nose. This is why crying, for example, is often associated with a “runny” nose.
In this rare disorder, the punctal openings do not form properly (agenesis or atresia) and this may be associated with other anatomic malformations.
Clinical Correlations
The punctal openings never form and are absent at birth. This can lead to tearing (epiphora) and may result in recurrent eye infections known as conjunctivitis or “pink eye”. Sometimes cystic structures develop in the malformed drainage system.
Vision is not affected in this condition.
Genetics
Inheritance
Several families have been reported in which sibs have had punctal atresia. In these, two copies of a mutation, one from each parent, were found in these children while only a single copy was present in other family members, including the parents, who were clinically normal. This pattern is known as autosomal recessive inheritance and such parents can expect that one in four (25%) of their children will have this condition.
Pedigree
Autosomal recessive
In order for autosomal recessive disorders to be expressed, offspring generally must inherit two mutations, one from each carrier parent. Carriers with only one mutation, such as the parents, do not have clinical disease. Note that carrier parents can expect that 1 in 4 children (25%) will inherit both mutations and have the disorder, 2 in 4 children (50%) will be carriers like their parents, while 1 in 4 children (25%) inherit neither mutation.
In order for autosomal recessive disorders to be expressed, offspring generally must inherit two mutations, one from each carrier parent. Carriers with only one mutation, such as the parents, do not have clinical disease. Note that carrier parents can expect that 1 in 4 children (25%) will inherit both mutations and have the disorder, 2 in 4 children (50%) will be carriers like their parents, while 1 in 4 children (25%) inherit neither mutation.
Diagnosis and Prognosis
The absence of punctal openings may be noted by pediatricians and other physicians but the extent of the tear drainage dysfunction would likely be determined by a medical eye doctor (ophthalmologist).
There is no impact on vision or longevity. If an eye infection develops, it can be treated with antibiotics but improvement may be only temporary. It may be necessary to surgically create an opening into the nasal cavity (dacryocystorhinostomy) to allow better tear drainage.
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