Presentation
Routine antenatal ultrasound in third trimester for the first time
Patient Data
Single intrauterine fetus was seen.
Polyhydramnios.
A single midline orbit and an overlying process was seen (proboscis).
Fetal head size was small for gestation age & holoprosencephaly was seen.
Nasal bones were absent. Fetal lips were normal.
Case Discussion
Cyclopia is an extremely rare type of congenital malformation & is part of a spectrum of anomalies occurring in holoprosencephaly.
This group of congenital anomalies occurs due to to abnormal differentiation & cleavage of the prosencephalon. There is anomalous formation of the central cavity of the orbit, with absence of the nasal cavity. A rudimentary bony process is formed over the orbital cavity called proboscis.
True cyclopia is an extreme form, where only a single orbit is present. But two globes may be found in different degrees of fusion, called synopthalmos.
Associated mid line facial deformities like midfacial clefts, primitive nasal structures & hypotelorism, may be there.