Clinical Problems
Question #1
A 5 years old boy was taken to an ophthalmologist because his right eye turned
inward when he was tired and excited. And especially when he was looking at an object
intently. On physical examination it was noted that he had a convergent strain of the right
eye. On questioning the child. The doctor ascertained that he did not have double vision.
Examination of the fundus showed it to be normal in both the right and left eyes. Covering
the nonstalrabismus eye showed that the child had severe impairment of vision in the
strabismic eye. Can strabismus be a congenital anomaly? Is this condition hereditary? Does
this condition cure itself spontaneously?
Answer:
This child had a congenital convergent strabismus of the right eye(esotropia),
resulting from an imbalance of extraocular muscles. Although abnormalities of the central
nervous system can cause strabismus in many cases the condition results from a simple
congenital muscle imbalance, and about half the incidence is familial. The condition never
cures itself spontaneously. In this case the deviating right eye, which was not being used for
seeing, failed to develop good central vision, and the child actually suppressed the image.
Covering the normal undeviated eye immediately revealed the impaired vision in the
deviating eye.
Question #2
A 2 month old boy was taken to an ophthalmologist because the child’s mother had
noticed an opacity of his left eye since birth. The mother gave a history of rubella infection
during the first trimester of the pregnancy. On physical examination a pearly nuclear cataract
of the left eye was found. The child also had impaired hearing in the right ear and evidence
of a ventricular septal defect. Is there any connection between rubella infection of the mother
and the congenital defects noted in the child?
U
Answer:
Yes, there is a connection between rubella infection of the mother and the congenital
defects in the child. The rubella virus is a potent teratogenic agent. The virus is transmitted
to the fetus via the placenta, and the effects on the fetus usually are multiple. If the mother is
infected with rubella before the seventh week of pregnancy, a time when the lens is actively
developing, the child may have congenital cataract. In a similar manner, the organ cortical of
the ear may undergo viral destruction. The most common heart anomalies caused by rubella
are pulmonary stenosis, patent ductus arteriosus, and ventricular septal defects. Remember
that a child born of a mother infected by rubella will have the virus within his tissues for many
months after birth.
Question #3
A 5 year old boy undergoing routine examination by an ophthalmologist was found to
have a small notch on the inferior nasal section of his left iris. The notch measured about 0.5
mm long and involved the pupillary margins. The boy’s mother stated that he had had the
notch once before birth. What is your diagnosis? How would you explain this connection?
How would you explain this condition embryologically?
Question #1
A 5 years old boy was taken to an ophthalmologist because his right eye turned
inward when he was tired and excited. And especially when he was looking at an object
intently. On physical examination it was noted that he had a convergent strain of the right
eye. On questioning the child. The doctor ascertained that he did not have double vision.
Examination of the fundus showed it to be normal in both the right and left eyes. Covering
the nonstalrabismus eye showed that the child had severe impairment of vision in the
strabismic eye. Can strabismus be a congenital anomaly? Is this condition hereditary? Does
this condition cure itself spontaneously?
Answer:
This child had a congenital convergent strabismus of the right eye(esotropia),
resulting from an imbalance of extraocular muscles. Although abnormalities of the central
nervous system can cause strabismus in many cases the condition results from a simple
congenital muscle imbalance, and about half the incidence is familial. The condition never
cures itself spontaneously. In this case the deviating right eye, which was not being used for
seeing, failed to develop good central vision, and the child actually suppressed the image.
Covering the normal undeviated eye immediately revealed the impaired vision in the
deviating eye.
Question #2
A 2 month old boy was taken to an ophthalmologist because the child’s mother had
noticed an opacity of his left eye since birth. The mother gave a history of rubella infection
during the first trimester of the pregnancy. On physical examination a pearly nuclear cataract
of the left eye was found. The child also had impaired hearing in the right ear and evidence
of a ventricular septal defect. Is there any connection between rubella infection of the mother
and the congenital defects noted in the child?
U
Answer:
Yes, there is a connection between rubella infection of the mother and the congenital
defects in the child. The rubella virus is a potent teratogenic agent. The virus is transmitted
to the fetus via the placenta, and the effects on the fetus usually are multiple. If the mother is
infected with rubella before the seventh week of pregnancy, a time when the lens is actively
developing, the child may have congenital cataract. In a similar manner, the organ cortical of
the ear may undergo viral destruction. The most common heart anomalies caused by rubella
are pulmonary stenosis, patent ductus arteriosus, and ventricular septal defects. Remember
that a child born of a mother infected by rubella will have the virus within his tissues for many
months after birth.
Question #3
A 5 year old boy undergoing routine examination by an ophthalmologist was found to
have a small notch on the inferior nasal section of his left iris. The notch measured about 0.5
mm long and involved the pupillary margins. The boy’s mother stated that he had had the
notch once before birth. What is your diagnosis? How would you explain this connection?
How would you explain this condition embryologically?
