Specular Microscopy In Clinical Practice - Is It Always Reliable?

To assess the reproducibility and reliability of specular microscopy before and one month after an uneventful phacoemulsification surgery in patients with pseudoexfoliation syndrome and senile cataract.

Specular microscopy is a non-invasive diagnostic method to image the corneal endothelium. Common indications are endotheliopathies like cornea guttata, Fuchs endothelial corneal dystrophy, congenital hereditary endothelial dystrophy, endothelial changes after surgery, pseudoexfoliation induced endotheliopathy and others. In our clinical practice it is regularly used before and after cataract surgery.

In this prospective controlled clinical study, 6 patients with pseudoexfoliation syndrome and 6 control patients with senile cataracts only were studied. All patients were operated with standardized phacoemulsification done by the same surgeon. Non-contact specular microscopy was performed 1 day preoperatively and postoperatively at 1 month.

The preoperative cell density in the group with pseudoefxoliation syndrome arithmetic mean was 2619 cells/mm²(min 2460 up to max 2741). One month later the endothelial cell loss was between 41-210 cells/mm². But peculiar results came out in two patients - 4 weeks after cataract surgery, we not only managed not to lose endothelial cells, but also “won” some. The patients had between 169-254 more endothelial cells afterwards. The results are identical in our control group with only senile cataract with cell loss up to 206. And also with two patients who appeared with gain of up to 60 cells/mm².

Specular microscopy helps in the diagnosis and management of several endothelial pathologies. It is a valuable tool in clinical practice to examine the health of corneal endothelium before planning surgery in compromised endothelial cases and patients counseling. However, results obtained by a specular microscopy sometimes may have limited reliability and reproducibility, depending on multiple factors.