Abstract
Purpose: :
The development of the human eye as well as prenatal variations can be studied in fetal eyes. In some syndromes ocular involvement of the adult eye is well known but the presence and extent of prenatal changes remain unclear. In addition, artifacts due to iatrogenic trauma or autolysis can make an exact interpretation difficult. In this study, we examined the possibility of detecting prenatal specific ocular features associated with general disease, thus evaluating the importance and relevance of an ophthalmopathologic investigation of fetal eyes.
Methods: :
Since March 2008 a cohort of 149 eyes from 81 fetuses was collected from the Dept. of Pathology/Paidopathology. The age range was 9 to 37 weeks of gestation with a median of 21 weeks. The fetuses were divided into the following subgroups: no evidence of any syndrome (n=25), trisomy 21 (n=6), Turner's syndrome (n=4), trisomy 13 (n=3), miscell. syndromes (n=3), spina bifida (n=7), fetuses with syndromes/malformations that were not expected to reveal ocular abnormalities (n=17), unfinished cases (n=16). The eyes were removed and fixed in formalin. After macroscopic inspection they were opened horizontally, examined with the dissecting microscope and embedded in paraffin. Step sections were stained with H&E and PAS, and if appropriate, immunohistochemistry was performed.
Results: :
In most specimens, artifacts such as pigment spillage (mostly in the ciliary body region) and traumatic changes of the lens were noted. These were prominent in older eyes, probably due to a longer "delivery time" and, therefore, delayed fixation. Haemorrhages had to be evaluated regarding the actual trauma (pre-termination versus abortion). Structural changes were seen in some of the syndrome cases as previously documented but findings were also unexpectedly different from what has been described in literature so far, e.g. in Goldenhar's syndrome and trisomy 13.
Conclusions: :
Morphologic changes in eyes from fetuses removed during abortion have to be classified in artifacts caused by the inducing toxin during abortion, mechanical effects due to the procedure itself, delayed fixation with autolysis, and genuine structural abnormalities in the context of ocular or systemic disease. This classification can be fairly difficult, and considerable experience is required to determine the presence not only of subtle but also of more advanced prenatal ocular abnormalities. However, there might be an interesting additional spectrum of ocular involvement in various syndromes hitherto not seen in postnatal examinations.
Keywords: pathology: human • development • microscopy: light/fluorescence/immunohistochemistry